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Smallman TR, Perlaza-Jiménez L, Wang X, Korman TM, Kotsanas D, Gibson JS, Turni C, Harper M, Boyce JD. Pathogenomic analysis and characterization of Pasteurella multocida strains recovered from human infections. Microbiol Spectr 2024; 12:e0380523. [PMID: 38426766 DOI: 10.1128/spectrum.03805-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 02/03/2024] [Indexed: 03/02/2024] Open
Abstract
Pasteurella multocida is an upper respiratory tract commensal in several mammal and bird species but can also cause severe disease in humans and in production animals such as poultry, cattle, and pigs. In this study, we performed whole-genome sequencing of P. multocida isolates recovered from a range of human infections, from the mouths of cats, and from wounds on dogs. Together with publicly available P. multocida genome sequences, we performed phylogenetic and comparative genomic analyses. While isolates from cats and dogs were spread across the phylogenetic tree, human infections were caused almost exclusively by subsp. septica strains. Most of the human isolates were capsule type A and LPS type L1 and L3; however, some strains lacked a capsule biosynthesis locus, and some strains contained a novel LPS outer-core locus, distinct from the eight LPS loci that can currently be identified using an LPS multiplex PCR. In addition, the P. multocida strains isolated from human infections contained novel mobile genetic elements. We compiled a curated database of known P. multocida virulence factor and antibiotic resistance genes (PastyVRDB) allowing for detailed characterization of isolates. The majority of human P. multocida isolates encoded a reduced range of iron receptors and contained only one filamentous hemagglutinin gene. Finally, gene-trait analysis identified a putative L-fucose uptake and utilization pathway that was over-represented in subsp. septica strains and may represent a novel host predilection mechanism in this subspecies. Together, these analyses have identified pathogenic mechanisms likely important for P. multocida zoonotic infections.IMPORTANCEPasteurella multocida can cause serious infections in humans, including skin and wound infections, pneumonia, peritonitis, meningitis, and bacteraemia. Cats and dogs are known vectors of human pasteurellosis, transmitting P. multocida via bite wounds or contact with animal saliva. The mechanisms that underpin P. multocida human predilection and pathogenesis are poorly understood. With increasing identification of antibiotic-resistant P. multocida strains, understanding these mechanisms is vital for developing novel treatments and control strategies to combat P. multocida human infection. Here, we show that a narrow range of P. multocida strains cause disease in humans, while cats and dogs, common vectors for zoonotic infections, can harbor a wide range of P. multocida strains. We also present a curated P. multocida-specific database, allowing quick and detailed characterization of newly sequenced P. multocida isolates.
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Affiliation(s)
- Thomas R Smallman
- Department of Microbiology, Infection Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Laura Perlaza-Jiménez
- Monash Bioinformatics Platform, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Xiaochu Wang
- Department of Microbiology, Infection Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Tony M Korman
- Monash University and Monash Health, Clayton, Victoria, Australia
| | - Despina Kotsanas
- Monash University and Monash Health, Clayton, Victoria, Australia
| | - Justine S Gibson
- School of Veterinary Science, University of Queensland, Gatton, Queensland, Australia
| | - Conny Turni
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, St Lucia, Queensland, Australia
| | - Marina Harper
- Department of Microbiology, Infection Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - John D Boyce
- Department of Microbiology, Infection Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
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Breen SKJ, Harper M, López-Causapé C, Rogers KE, Tait JR, Smallman TR, Lang Y, Lee WL, Zhou J, Zhang Y, Bulitta JB, Nation RL, Oliver A, Boyce JD, Landersdorfer CB. Synergistic effects of inhaled aztreonam plus tobramycin on hypermutable cystic fibrosis Pseudomonas aeruginosa isolates in a dynamic biofilm model evaluated by mechanism-based modelling and whole genome sequencing. Int J Antimicrob Agents 2024; 63:107161. [PMID: 38561094 DOI: 10.1016/j.ijantimicag.2024.107161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 03/19/2024] [Accepted: 03/22/2024] [Indexed: 04/04/2024]
Abstract
OBJECTIVE Hypermutable Pseudomonas aeruginosa strains are highly prevalent in chronic lung infections of patients with cystic fibrosis (CF). Acute exacerbations of these infections have limited treatment options. This study aimed to investigate inhaled aztreonam and tobramycin against clinical hypermutable P. aeruginosa strains using the CDC dynamic in vitro biofilm reactor (CBR), mechanism-based mathematical modelling (MBM) and genomic studies. METHODS Two CF multidrug-resistant strains were investigated in a 168 h CBR (n = 2 biological replicates). Regimens were inhaled aztreonam (75 mg 8-hourly) and tobramycin (300 mg 12-hourly) in monotherapies and combination. The simulated pharmacokinetic profiles of aztreonam and tobramycin (t1/2 = 3 h) were based on published lung fluid concentrations in patients with CF. Total viable and resistant counts were determined for planktonic and biofilm bacteria. MBM of total and resistant bacterial counts and whole genome sequencing were completed. RESULTS Both isolates showed reproducible bacterial regrowth and resistance amplification for the monotherapies by 168 h. The combination performed synergistically, with minimal resistant subpopulations compared to the respective monotherapies at 168 h. Mechanistic synergy appropriately described the antibacterial effects of the combination regimen in the MBM. Genomic analysis of colonies recovered from monotherapy regimens indicated noncanonical resistance mechanisms were likely responsible for treatment failure. CONCLUSION The combination of aztreonam and tobramycin was required to suppress the regrowth and resistance of planktonic and biofilm bacteria in all biological replicates of both hypermutable multidrug-resistant P. aeruginosa CF isolates. The developed MBM could be utilised for future investigations of this promising inhaled combination.
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Affiliation(s)
- Siobhonne K J Breen
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Marina Harper
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Carla López-Causapé
- Servicio de Microbiología, Hospital Universitario Son Espases-IdISBa, Palma de Mallorca, Spain; CIBER Enfermedades Infecciosas (CIBERINFEC), Madrid, Spain
| | - Kate E Rogers
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Jessica R Tait
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Thomas R Smallman
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Yinzhi Lang
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
| | - Wee L Lee
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Jieqiang Zhou
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
| | - Yongzhen Zhang
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
| | - Jurgen B Bulitta
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
| | - Roger L Nation
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Antonio Oliver
- Servicio de Microbiología, Hospital Universitario Son Espases-IdISBa, Palma de Mallorca, Spain; CIBER Enfermedades Infecciosas (CIBERINFEC), Madrid, Spain
| | - John D Boyce
- Department of Microbiology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Cornelia B Landersdorfer
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia.
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Agyeman AA, López-Causapé C, Rogers KE, Lucas DD, Cortés-Lara S, Gomis-Font MA, Fraile-Ribot P, Figuerola J, Lang Y, Franklyn ERT, Lee WL, Zhou J, Zhang Y, Bulitta JB, Boyce JD, Nation RL, Oliver A, Landersdorfer CB. Ceftolozane/tazobactam plus tobramycin against free-floating and biofilm bacteria of hypermutable Pseudomonas aeruginosa epidemic strains: Resistance mechanisms and synergistic activity. Int J Antimicrob Agents 2023; 62:106887. [PMID: 37315906 DOI: 10.1016/j.ijantimicag.2023.106887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 05/26/2023] [Accepted: 06/07/2023] [Indexed: 06/16/2023]
Abstract
OBJECTIVE Acute exacerbations of biofilm-associated Pseudomonas aeruginosa infections in cystic fibrosis (CF) have limited treatment options. Ceftolozane/tazobactam (alone and with a second antibiotic) has not yet been investigated against hypermutable clinical P. aeruginosa isolates in biofilm growth. This study aimed to evaluate, using an in vitro dynamic biofilm model, ceftolozane/tazobactam alone and in combination with tobramycin at simulated representative lung fluid pharmacokinetics against free-floating (planktonic) and biofilm states of two hypermutable P. aeruginosa epidemic strains (LES-1 and CC274) from adolescents with CF. METHODS Regimens were intravenous ceftolozane/tazobactam 4.5 g/day continuous infusion, inhaled tobramycin 300 mg 12-hourly, intravenous tobramycin 10 mg/kg 24-hourly, and both ceftolozane/tazobactam-tobramycin combinations. The isolates were susceptible to both antibiotics. Total and less-susceptible free-floating and biofilm bacteria were quantified over 120-168 h. Ceftolozane/tazobactam resistance mechanisms were investigated by whole-genome sequencing. Mechanism-based modelling of bacterial viable counts was performed. RESULTS Monotherapies of ceftolozane/tazobactam and tobramycin did not sufficiently suppress emergence of less-susceptible subpopulations, although inhaled tobramycin was more effective than intravenous tobramycin. Ceftolozane/tazobactam resistance development was associated with classical (AmpC overexpression plus structural modification) and novel (CpxR mutations) mechanisms depending on the strain. Against both isolates, combination regimens demonstrated synergy and completely suppressed the emergence of ceftolozane/tazobactam and tobramycin less-susceptible free-floating and biofilm bacterial subpopulations. CONCLUSION Mechanism-based modelling incorporating subpopulation and mechanistic synergy well described the antibacterial effects of all regimens against free-floating and biofilm bacterial states. These findings support further investigation of ceftolozane/tazobactam in combination with tobramycin against biofilm-associated P. aeruginosa infections in adolescents with CF.
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Affiliation(s)
- Akosua A Agyeman
- Centre for Medicine Use and Safety, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Carla López-Causapé
- Servicio de Microbiología, Hospital Universitario Son Espases-IdISBa, Palma de Mallorca, Spain; CIBER Enfermedades Infecciosas (CIBERINFEC), Madrid, Spain
| | - Kate E Rogers
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Deanna Deveson Lucas
- Monash Bioinformatics Platform, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Sara Cortés-Lara
- Servicio de Microbiología, Hospital Universitario Son Espases-IdISBa, Palma de Mallorca, Spain; CIBER Enfermedades Infecciosas (CIBERINFEC), Madrid, Spain
| | - Maria A Gomis-Font
- Servicio de Microbiología, Hospital Universitario Son Espases-IdISBa, Palma de Mallorca, Spain; CIBER Enfermedades Infecciosas (CIBERINFEC), Madrid, Spain
| | - Pablo Fraile-Ribot
- Servicio de Microbiología, Hospital Universitario Son Espases-IdISBa, Palma de Mallorca, Spain; CIBER Enfermedades Infecciosas (CIBERINFEC), Madrid, Spain
| | - Joan Figuerola
- Servicio de Pediatría, Hospital Universitario Son Espases-IdISBa, Palma de Mallorca, Spain
| | - Yinzhi Lang
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
| | - Eva R T Franklyn
- Centre for Medicine Use and Safety, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Wee Leng Lee
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Jieqiang Zhou
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
| | - Yongzhen Zhang
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
| | - Jurgen B Bulitta
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
| | - John D Boyce
- Biomedicine Discovery Institute, Department of Microbiology, Monash University, Melbourne, Victoria, Australia
| | - Roger L Nation
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Antonio Oliver
- Servicio de Microbiología, Hospital Universitario Son Espases-IdISBa, Palma de Mallorca, Spain; CIBER Enfermedades Infecciosas (CIBERINFEC), Madrid, Spain.
| | - Cornelia B Landersdorfer
- Centre for Medicine Use and Safety, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia; Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia.
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Tait JR, Harper M, Cortés-Lara S, Rogers KE, López-Causapé C, Smallman TR, Lang Y, Lee WL, Zhou J, Bulitta JB, Nation RL, Boyce JD, Oliver A, Landersdorfer CB. Ceftolozane-Tazobactam against Pseudomonas aeruginosa Cystic Fibrosis Clinical Isolates in the Hollow-Fiber Infection Model: Challenges Imposed by Hypermutability and Heteroresistance. Antimicrob Agents Chemother 2023; 67:e0041423. [PMID: 37428034 PMCID: PMC10433881 DOI: 10.1128/aac.00414-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 05/20/2023] [Indexed: 07/11/2023] Open
Abstract
Pseudomonas aeruginosa remains a challenge in chronic respiratory infections in cystic fibrosis (CF). Ceftolozane-tazobactam has not yet been evaluated against multidrug-resistant hypermutable P. aeruginosa isolates in the hollow-fiber infection model (HFIM). Isolates CW41, CW35, and CW44 (ceftolozane-tazobactam MICs of 4, 4, and 2 mg/L, respectively) from adults with CF were exposed to simulated representative epithelial lining fluid pharmacokinetics of ceftolozane-tazobactam in the HFIM. Regimens were continuous infusion (CI; 4.5 g/day to 9 g/day, all isolates) and 1-h infusions (1.5 g every 8 hours and 3 g every 8 hours, CW41). Whole-genome sequencing and mechanism-based modeling were performed for CW41. CW41 (in four of five biological replicates) and CW44 harbored preexisting resistant subpopulations; CW35 did not. For replicates 1 to 4 of CW41 and CW44, 9 g/day CI decreased bacterial counts to <3 log10 CFU/mL for 24 to 48 h, followed by regrowth and resistance amplification. Replicate 5 of CW41 had no preexisting subpopulations and was suppressed below ~3 log10 CFU/mL for 120 h by 9 g/day CI, followed by resistant regrowth. Both CI regimens reduced CW35 bacterial counts to <1 log10 CFU/mL by 120 h without regrowth. These results corresponded with the presence or absence of preexisting resistant subpopulations and resistance-associated mutations at baseline. Mutations in ampC, algO, and mexY were identified following CW41 exposure to ceftolozane-tazobactam at 167 to 215 h. Mechanism-based modeling well described total and resistant bacterial counts. The findings highlight the impact of heteroresistance and baseline mutations on the effect of ceftolozane-tazobactam and limitations of MIC to predict bacterial outcomes. The resistance amplification in two of three isolates supports current guidelines that ceftolozane-tazobactam should be utilized together with another antibiotic against P. aeruginosa in CF.
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Affiliation(s)
- Jessica R. Tait
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Marina Harper
- Biomedicine Discovery Institute, Department of Microbiology, Monash University, Melbourne, Victoria, Australia
| | - Sara Cortés-Lara
- Servicio de Microbiología, Hospital Universitario Son Espases-IdISBa, Palma de Mallorca, Spain
- CIBER Enfermedades Infecciosas (CIBERINFEC), Madrid, Spain
| | - Kate E. Rogers
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Carla López-Causapé
- Servicio de Microbiología, Hospital Universitario Son Espases-IdISBa, Palma de Mallorca, Spain
- CIBER Enfermedades Infecciosas (CIBERINFEC), Madrid, Spain
| | - Thomas R. Smallman
- Biomedicine Discovery Institute, Department of Microbiology, Monash University, Melbourne, Victoria, Australia
| | - Yinzhi Lang
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
| | - Wee Leng Lee
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Jieqiang Zhou
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
| | - Jürgen B. Bulitta
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
| | - Roger L. Nation
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - John D. Boyce
- Biomedicine Discovery Institute, Department of Microbiology, Monash University, Melbourne, Victoria, Australia
| | - Antonio Oliver
- Servicio de Microbiología, Hospital Universitario Son Espases-IdISBa, Palma de Mallorca, Spain
- CIBER Enfermedades Infecciosas (CIBERINFEC), Madrid, Spain
| | - Cornelia B. Landersdorfer
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
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Massier S, Robin B, Mégroz M, Wright A, Harper M, Hayes B, Cosette P, Broutin I, Boyce JD, Dé E, Hardouin J. Phosphorylation of Extracellular Proteins in Acinetobacter baumannii in Sessile Mode of Growth. Front Microbiol 2021; 12:738780. [PMID: 34659171 PMCID: PMC8517400 DOI: 10.3389/fmicb.2021.738780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 08/30/2021] [Indexed: 11/21/2022] Open
Abstract
Acinetobacter baumannii is a problematic nosocomial pathogen owing to its increasing resistance to antibiotics and its great ability to survive in the hospital environment, which is linked to its capacity to form biofilms. Structural and functional investigations of post-translational modifications, such as phosphorylations, may lead to identification of candidates for therapeutic targets against this pathogen. Here, we present the first S/T/Y phosphosecretome of two A. baumannii strains, the reference strain ATCC 17978 and the virulent multi-drug resistant strain AB0057, cultured in two modes of growth (planktonic and biofilm) using TiO2 chromatography followed by high resolution mass spectrometry. In ATCC 17978, we detected a total of 137 (97 phosphoproteins) and 52 (33 phosphoproteins) phosphosites in biofilm and planktonic modes of growth, respectively. Similarly, in AB0057, 155 (119 phosphoproteins) and 102 (74 phosphoproteins) phosphosites in biofilm and planktonic modes of growth were identified, respectively. Both strains in the biofilm mode of growth showed a higher number of phosphosites and phosphoproteins compared to planktonic growth. Several phosphorylated sites are localized in key regions of proteins involved in either drug resistance (β-lactamases), adhesion to host tissues (pilins), or protein secretion (Hcp). Site-directed mutagenesis of the Hcp protein, essential for type VI secretion system-mediated interbacterial competition, showed that four of the modified residues are essential for type VI secretion system activity.
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Affiliation(s)
- Sébastien Massier
- Normandie Univ., UNIROUEN, INSA Rouen, CNRS, Polymers, Biopolymers, Surfaces Laboratory, Rouen, France
- PISSARO Proteomic Facility, IRIB, Mont-Saint-Aignan, France
| | - Brandon Robin
- Normandie Univ., UNIROUEN, INSA Rouen, CNRS, Polymers, Biopolymers, Surfaces Laboratory, Rouen, France
| | - Marianne Mégroz
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
| | - Amy Wright
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
| | - Marina Harper
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
| | - Brooke Hayes
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
| | - Pascal Cosette
- Normandie Univ., UNIROUEN, INSA Rouen, CNRS, Polymers, Biopolymers, Surfaces Laboratory, Rouen, France
- PISSARO Proteomic Facility, IRIB, Mont-Saint-Aignan, France
| | | | - John D. Boyce
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia
| | - Emmanuelle Dé
- Normandie Univ., UNIROUEN, INSA Rouen, CNRS, Polymers, Biopolymers, Surfaces Laboratory, Rouen, France
| | - Julie Hardouin
- Normandie Univ., UNIROUEN, INSA Rouen, CNRS, Polymers, Biopolymers, Surfaces Laboratory, Rouen, France
- PISSARO Proteomic Facility, IRIB, Mont-Saint-Aignan, France
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Abdul Rahim N, Zhu Y, Cheah SE, Johnson MD, Yu HH, Sidjabat HE, Butler MS, Cooper MA, Fu J, Paterson DL, Nation RL, Boyce JD, Creek DJ, Bergen PJ, Velkov T, Li J. Synergy of the Polymyxin-Chloramphenicol Combination against New Delhi Metallo-β-Lactamase-Producing Klebsiella pneumoniae Is Predominately Driven by Chloramphenicol. ACS Infect Dis 2021; 7:1584-1595. [PMID: 33834753 DOI: 10.1021/acsinfecdis.0c00661] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Carbapenem-resistant Klebsiella pneumoniae has been classified as an Urgent Threat by the Centers for Disease Control and Prevention (CDC). The combination of two "old" antibiotics, polymyxin and chloramphenicol, displays synergistic killing against New Delhi metallo-β-lactamase (NDM)-producing K. pneumoniae. However, the mechanism(s) underpinning their synergistic killing are not well studied. We employed an in vitro pharmacokinetic/pharmacodynamic model to mimic the pharmacokinetics of the antibiotics in patients and examined bacterial killing against NDM-producing K. pneumoniae using a metabolomic approach. Metabolomic analysis was integrated with an isolate-specific genome-scale metabolic network (GSMN). Our results show that metabolic responses to polymyxin B and/or chloramphenicol against NDM-producing K. pneumoniae involved the inhibition of cell envelope biogenesis, metabolism of arginine and nucleotides, glycolysis, and pentose phosphate pathways. Our metabolomic and GSMN modeling results highlight the novel mechanisms of a synergistic antibiotic combination at the network level and may have a significant potential in developing precision antimicrobial chemotherapy in patients.
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Affiliation(s)
- Nusaibah Abdul Rahim
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
- Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Yan Zhu
- Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Soon-Ee Cheah
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Matthew D. Johnson
- Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Heidi H. Yu
- Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Hanna E. Sidjabat
- University of Queensland Centre for Clinical Research, Herston, Queensland 4029, Australia
| | - Mark S. Butler
- Institute for Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Matthew A. Cooper
- Institute for Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Jing Fu
- Department of Mechanical and Aerospace Engineering, Faculty of Engineering, Monash University, Clayton, Victoria 3800, Australia
| | - David L. Paterson
- University of Queensland Centre for Clinical Research, Herston, Queensland 4029, Australia
- Pathology Queensland, Royal Brisbane and Women’s Hospital Campus, Herston, Queensland 4029, Australia
| | - Roger L. Nation
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - John D. Boyce
- Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Darren J. Creek
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
| | - Phillip J. Bergen
- Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
- Centre for Medicine Use and Safety, Monash University, Parkville, Victoria 3052, Australia
| | - Tony Velkov
- Department of Pharmacology & Therapeutics, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Jian Li
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria 3052, Australia
- Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
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Tait JR, Bilal H, Kim TH, Oh A, Peleg AY, Boyce JD, Oliver A, Bergen PJ, Nation RL, Landersdorfer CB. Pharmacodynamics of ceftazidime plus tobramycin combination dosage regimens against hypermutable Pseudomonas aeruginosa isolates at simulated epithelial lining fluid concentrations in a dynamic in vitro infection model. J Glob Antimicrob Resist 2021; 26:55-63. [PMID: 34023531 DOI: 10.1016/j.jgar.2021.04.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 03/12/2021] [Accepted: 04/16/2021] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVES Hypermutable Pseudomonas aeruginosa strains are a major challenge in cystic fibrosis. We investigated bacterial killing and resistance emergence for approved ceftazidime and tobramycin regimens, alone and in combination. METHODS Pseudomonas aeruginosa PAOΔmutS and six hypermutable clinical isolates were examined using 48-h static concentration time-kill (SCTK) studies (inoculum ~107.5 CFU/mL); four strains were also studied in a dynamic in vitro model (IVM) (inoculum ~108 CFU/mL). The IVM simulated concentration-time profiles in epithelial lining fluid following intravenous administration of ceftazidime (3 g/day and 9 g/day continuous infusion), tobramycin (5 mg/kg and 10 mg/kg via 30-min infusion 24-hourly; half-life 3.5 h), and their combinations. Time courses of total and less-susceptible populations were determined. RESULTS Ceftazidime plus tobramycin demonstrated synergistic killing in SCTK studies for all strains, although to a lesser extent for ceftazidime-resistant strains. In the IVM, ceftazidime and tobramycin monotherapies provided ≤5.4 and ≤3.4 log10 initial killing, respectively; however, re-growth with resistance occurred by 72 h. Against strains susceptible to one or both antibiotics, high-dose combination regimens provided >6 log10 initial killing, which was generally synergistic from 8-24 h, and marked suppression of re-growth and resistance at 72 h. The time course of bacterial density in the IVM was well described by mechanism-based models, enabling Monte Carlo simulations (MCSs) to predict likely effectiveness of the combination in patients. CONCLUSION Results of the IVM and MCS suggested antibacterial effect depends both on the strain's susceptibility and hypermutability. Further investigation of the combination against hypermutable P. aeruginosa strains is warranted.
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Affiliation(s)
- Jessica R Tait
- Centre for Medicine Use and Safety, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia; Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | - Hajira Bilal
- Centre for Medicine Use and Safety, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | - Tae Hwan Kim
- College of Pharmacy, Daegu Catholic University, Daegu, South Korea
| | - Abigail Oh
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | - Anton Y Peleg
- Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, VIC, Australia; Biomedicine Discovery Institute, Department of Microbiology, Monash University, Melbourne, VIC, Australia
| | - John D Boyce
- Biomedicine Discovery Institute, Department of Microbiology, Monash University, Melbourne, VIC, Australia
| | - Antonio Oliver
- Servicio de Microbiología, Hospital Universitario Son Espases, Instituto de Investigación Sanitaria de Palma, Palma de Mallorca, Spain
| | - Phillip J Bergen
- Centre for Medicine Use and Safety, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | - Roger L Nation
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | - Cornelia B Landersdorfer
- Centre for Medicine Use and Safety, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia.
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8
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Lang Y, Shah NR, Tao X, Reeve SM, Zhou J, Moya B, Sayed ARM, Dharuman S, Oyer JL, Copik AJ, Fleischer BA, Shin E, Werkman C, Basso KB, Lucas DD, Sutaria DS, Mégroz M, Kim TH, Loudon-Hossler V, Wright A, Jimenez-Nieves RH, Wallace MJ, Cadet KC, Jiao Y, Boyce JD, LoVullo ED, Schweizer HP, Bonomo RA, Bharatham N, Tsuji BT, Landersdorfer CB, Norris MH, Shin BS, Louie A, Balasubramanian V, Lee RE, Drusano GL, Bulitta JB. Combating Multidrug-Resistant Bacteria by Integrating a Novel Target Site Penetration and Receptor Binding Assay Platform Into Translational Modeling. Clin Pharmacol Ther 2021; 109:1000-1020. [PMID: 33576025 PMCID: PMC10662281 DOI: 10.1002/cpt.2205] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 02/08/2021] [Accepted: 02/08/2021] [Indexed: 12/26/2022]
Abstract
Multidrug-resistant bacteria are causing a serious global health crisis. A dramatic decline in antibiotic discovery and development investment by pharmaceutical industry over the last decades has slowed the adoption of new technologies. It is imperative that we create new mechanistic insights based on latest technologies, and use translational strategies to optimize patient therapy. Although drug development has relied on minimal inhibitory concentration testing and established in vitro and mouse infection models, the limited understanding of outer membrane permeability in Gram-negative bacteria presents major challenges. Our team has developed a platform using the latest technologies to characterize target site penetration and receptor binding in intact bacteria that inform translational modeling and guide new discovery. Enhanced assays can quantify the outer membrane permeability of β-lactam antibiotics and β-lactamase inhibitors using multiplex liquid chromatography tandem mass spectrometry. While β-lactam antibiotics are known to bind to multiple different penicillin-binding proteins (PBPs), their binding profiles are almost always studied in lysed bacteria. Novel assays for PBP binding in the periplasm of intact bacteria were developed and proteins identified via proteomics. To characterize bacterial morphology changes in response to PBP binding, high-throughput flow cytometry and time-lapse confocal microscopy with fluorescent probes provide unprecedented mechanistic insights. Moreover, novel assays to quantify cytosolic receptor binding and intracellular drug concentrations inform target site occupancy. These mechanistic data are integrated by quantitative and systems pharmacology modeling to maximize bacterial killing and minimize resistance in in vitro and mouse infection models. This translational approach holds promise to identify antibiotic combination dosing strategies for patients with serious infections.
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Affiliation(s)
- Yinzhi Lang
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
| | - Nirav R. Shah
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
- Present address: Jansen R&D, Johnson & Johnson, Spring House, Pennsylvania, USA
| | - Xun Tao
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
- Present address: Genentech USA,Inc., South San Francisco, California, USA
| | - Stephanie M. Reeve
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
| | - Jieqiang Zhou
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
| | - Bartolome Moya
- Servicio de Microbiología and Unidad de Investigación, Hospital Universitario Son Espases, Instituto de Investigación Sanitaria Illes Balears (IdISBa), Palma de Mallorca, Spain
| | - Alaa R. M. Sayed
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
- Department of Chemistry, Faculty of Science, Fayoum University, Fayoum, Egypt
| | - Suresh Dharuman
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
| | - Jeremiah L. Oyer
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Alicja J. Copik
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Brett A. Fleischer
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
| | - Eunjeong Shin
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
| | - Carolin Werkman
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
| | - Kari B. Basso
- Department of Chemistry, University of Florida, Gainesville, Florida, USA
| | - Deanna Deveson Lucas
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Dhruvitkumar S. Sutaria
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
- Present address: Genentech USA,Inc., South San Francisco, California, USA
| | - Marianne Mégroz
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Tae Hwan Kim
- College of Pharmacy, Catholic University of Daegu, Gyeongsan, Gyeongbuk, Korea
| | - Victoria Loudon-Hossler
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
| | - Amy Wright
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Rossie H. Jimenez-Nieves
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
| | - Miranda J. Wallace
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
| | - Keisha C. Cadet
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
| | - Yuanyuan Jiao
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
| | - John D. Boyce
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia
| | - Eric D. LoVullo
- Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, USA
| | - Herbert P. Schweizer
- Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, USA
| | - Robert A. Bonomo
- Research Service and GRECC, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio, USA
- Department of Medicine, Pharmacology, Molecular Biology and Microbiology, Biochemistry and Proteomics and Bioinformatics, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
- CWRU-Cleveland VAMC Center for Antimicrobial Resistance and Epidemiology (Case VA CARES), Cleveland, Ohio, USA
| | - Nagakumar Bharatham
- BUGWORKS Research India Pvt. Ltd., Centre for Cellular & Molecular Platforms, National Centre for Biological Sciences, Bengaluru, Karnataka, India
| | - Brian T. Tsuji
- Laboratory for Antimicrobial Pharmacodynamics, University at Buffalo, Buffalo, New York, USA
| | - Cornelia B. Landersdorfer
- Drug Delivery, Disposition, and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Victoria, Australia
- Centre for Medicine Use and Safety, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Victoria, Australia
| | - Michael H. Norris
- Spatial Epidemiology and Ecology Research Laboratory, Department of Geography and the Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA
| | - Beom Soo Shin
- School of Pharmacy, Sungkyunkwan University, Suwon, Gyeonggi-do, Korea
| | - Arnold Louie
- Institute for Therapeutic Innovation, College of Medicine, University of Florida, Orlando, Florida, USA
| | - Venkataraman Balasubramanian
- BUGWORKS Research India Pvt. Ltd., Centre for Cellular & Molecular Platforms, National Centre for Biological Sciences, Bengaluru, Karnataka, India
| | - Richard E. Lee
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, Tennessee, USA
| | - George L. Drusano
- Institute for Therapeutic Innovation, College of Medicine, University of Florida, Orlando, Florida, USA
| | - Jürgen B. Bulitta
- Department of Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
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9
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Zhu Y, Lu J, Han M, Jiang X, Azad MAK, Patil NA, Lin Y, Zhao J, Hu Y, Yu HH, Chen K, Boyce JD, Dunstan RA, Lithgow T, Barlow CK, Li W, Schneider‐Futschik EK, Wang J, Gong B, Sommer B, Creek DJ, Fu J, Wang L, Schreiber F, Velkov T, Li J. Polymyxins Bind to the Cell Surface of Unculturable Acinetobacter baumannii and Cause Unique Dependent Resistance. Adv Sci (Weinh) 2020; 7:2000704. [PMID: 32775156 PMCID: PMC7403960 DOI: 10.1002/advs.202000704] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/28/2020] [Indexed: 05/13/2023]
Abstract
Multidrug-resistant Acinetobacter baumannii is a top-priority pathogen globally and polymyxins are a last-line therapy. Polymyxin dependence in A. baumannii (i.e., nonculturable on agar without polymyxins) is a unique and highly-resistant phenotype with a significant potential to cause treatment failure in patients. The present study discovers that a polymyxin-dependent A. baumannii strain possesses mutations in both lpxC (lipopolysaccharide biosynthesis) and katG (reactive oxygen species scavenging) genes. Correlative multiomics analyses show a significantly remodeled cell envelope and remarkably abundant phosphatidylglycerol in the outer membrane (OM). Molecular dynamics simulations and quantitative membrane lipidomics reveal that polymyxin-dependent growth emerges only when the lipopolysaccharide-deficient OM distinctively remodels with ≥ 35% phosphatidylglycerol, and with "patch" binding on the OM by the rigid polymyxin molecules containing strong intramolecular hydrogen bonding. Rather than damaging the OM, polymyxins bind to the phosphatidylglycerol-rich OM and strengthen the membrane integrity, thereby protecting bacteria from external reactive oxygen species. Dependent growth is observed exclusively with polymyxin analogues, indicating a critical role of the specific amino acid sequence of polymyxins in forming unique structures for patch-binding to bacterial OM. Polymyxin dependence is a novel antibiotic resistance mechanism and the current findings highlight the risk of 'invisible' polymyxin-dependent isolates in the evolution of resistance.
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Affiliation(s)
- Yan Zhu
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | - Jing Lu
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | - Mei‐Ling Han
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | - Xukai Jiang
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | - Mohammad A. K. Azad
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | - Nitin A. Patil
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | - Yu‐Wei Lin
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | - Jinxin Zhao
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | - Yang Hu
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | - Heidi H. Yu
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | - Ke Chen
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | - John D. Boyce
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | - Rhys A. Dunstan
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | - Trevor Lithgow
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | | | - Weifeng Li
- School of Physics and State Key Laboratory of Crystal MaterialsShandong UniversityJinan250100China
| | | | - Jiping Wang
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
| | - Bin Gong
- School of Computer Science and TechnologyShandong UniversityJinan250100China
| | - Bjorn Sommer
- Department of Computer and Information ScienceUniversity of KonstanzKonstanz78457Germany
| | - Darren J. Creek
- Drug Delivery, Disposition and DynamicsMonash Institute of Pharmaceutical SciencesMonash UniversityMelbourne3052Australia
| | - Jing Fu
- Department of Mechanical and Aerospace EngineeringMonash UniversityMelbourne3800Australia
| | - Lushan Wang
- State Key Laboratory of Microbial TechnologyShandong UniversityQingdao CampusQingdao266237China
| | - Falk Schreiber
- Department of Computer and Information ScienceUniversity of KonstanzKonstanz78457Germany
| | - Tony Velkov
- Department of Pharmacology and TherapeuticsUniversity of MelbourneMelbourne3010Australia
| | - Jian Li
- Infection & Immunity ProgramBiomedicine Discovery Institute and Department of MicrobiologyMonash UniversityMelbourne3800Australia
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10
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Michael FS, Cairns CM, Fleming P, Vinogradov EV, Boyce JD, Harper M, Cox AD. The capsular polysaccharides of Pasteurella multocida serotypes B and E: Structural, genetic and serological comparisons. Glycobiology 2020; 31:307-314. [PMID: 32839812 DOI: 10.1093/glycob/cwaa069] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/06/2020] [Accepted: 07/20/2020] [Indexed: 01/28/2023] Open
Abstract
We describe the structural characterization of the capsular polysaccharides (CPSs) of Pasteurella multocida serotypes B and E. CPS was isolated following organic solvent precipitation of the supernatant from flask grown cells. Structural analysis utilizing nuclear magnetic resonance spectroscopy enabled the determination of the CPS structures and revealed significant structural similarities between the two serotypes, but also provided an explanation for the serological distinction. This observation was extended by the development of polyclonal sera to the glycoconjugate of serotype B CPS that corroborated the structural likenesses and differences. Finally, identification of these structures enabled a more comprehensive interrogation of the genetic loci and prediction of roles for some of the encoded proteins in repeat unit biosynthesis.
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Affiliation(s)
- Frank St Michael
- Vaccine and Emerging Infections Research, Human Health Therapeutics Research Centre, National Research Council, 1200 Montreal Road, Ottawa K1A 0R6, Canada
| | - Chantelle M Cairns
- Vaccine and Emerging Infections Research, Human Health Therapeutics Research Centre, National Research Council, 1200 Montreal Road, Ottawa K1A 0R6, Canada
| | - Perry Fleming
- Vaccine and Emerging Infections Research, Human Health Therapeutics Research Centre, National Research Council, 1200 Montreal Road, Ottawa K1A 0R6, Canada
| | - Evgeny V Vinogradov
- Vaccine and Emerging Infections Research, Human Health Therapeutics Research Centre, National Research Council, 1200 Montreal Road, Ottawa K1A 0R6, Canada
| | - John D Boyce
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Wellington Rd, Melbourne 3800, Australia
| | - Marina Harper
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Wellington Rd, Melbourne 3800, Australia
| | - Andrew D Cox
- Vaccine and Emerging Infections Research, Human Health Therapeutics Research Centre, National Research Council, 1200 Montreal Road, Ottawa K1A 0R6, Canada
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11
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Li M, Aye SM, Ahmed MU, Han ML, Li C, Song J, Boyce JD, Powell DR, Azad MAK, Velkov T, Zhu Y, Li J. Pan-transcriptomic analysis identified common differentially expressed genes of Acinetobacter baumannii in response to polymyxin treatments. Mol Omics 2020; 16:327-338. [PMID: 32469363 DOI: 10.1039/d0mo00015a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Multidrug-resistant Acinetobacter baumannii is a top-priority Gram-negative pathogen and polymyxins are a last-line therapeutic option. Previous systems pharmacological studies examining polymyxin killing and resistance usually focused on individual strains, and the derived knowledge could be limited by strain-specific genomic context. In this study, we examined the gene expression of five A. baumannii strains (34654, 1207552, 1428368, 1457504 and ATCC 19606) to determine the common differentially expressed genes in response to polymyxin treatments. A pan-genome containing 6061 genes was identified for 89 A. baumannii genomes from RefSeq database which included the five strains examined in this study; 2822 of the 6061 genes constituted the core genome. After 2 mg L-1 or 0.75 × MIC polymyxin treatments for 15 min, 41 genes were commonly up-regulated, including those involved in membrane biogenesis and homeostasis, lipoprotein and phospholipid trafficking, efflux pump and poly-N-acetylglucosamine biosynthesis; six genes were commonly down-regulated, three of which were related to fatty acid biosynthesis. Additionally, comparison of the gene expression at 15 and 60 min in ATCC 19606 revealed that polymyxin treatment resulted in a rapid change in amino acid metabolism at 15 min and perturbations on envelope biogenesis at both time points. This is the first pan-transcriptomic study for polymyxin-treated A. baumannii and our results identified that the remodelled outer membrane, up-regulated efflux pumps and down-regulated fatty acid biosynthesis might be essential for early responses to polymyxins in A. baumannii. Our findings provide important mechanistic insights into bacterial responses to polymyxin killing and may facilitate the optimisation of polymyxin therapy against this problematic 'superbug'.
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Affiliation(s)
- Mengyao Li
- Biomedicine Discovery Institute, Infection & Immunity Program and Department of Microbiology, Monash University, 19 Innovation Walk, Melbourne 3800, Australia.
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12
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Alwis PA, Treerat P, Gong L, Deveson Lucas D, Allwood EM, Prescott M, Devenish RJ, Adler B, Boyce JD. Disruption of the Burkholderia pseudomallei two-component signal transduction system BbeR-BbeS leads to increased extracellular DNA secretion and altered biofilm formation. Vet Microbiol 2020; 242:108603. [PMID: 32122607 DOI: 10.1016/j.vetmic.2020.108603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Accepted: 02/03/2020] [Indexed: 10/25/2022]
Abstract
Two-component signal transduction systems (TCSTS) are abundant among prokaryotes and regulate important functions, including drug resistance and virulence. The Gram-negative bacterium Burkholderia pseudomallei, which causes the severe infectious disease melioidosis, encodes 136 putative TCSTS components. In silico analyses of these TCSTS indicated that the predicted BbeR-BbeS system (BPSL1036-BPSL1037) displayed significant amino acid sequence similarity to the Shigella flexneri virulence-associated OmpR-EnvZ osmoregulator. To assess the function of the B. pseudomallei BbeR-BbeS system, we constructed by allelic exchange a ΔbbeRS double mutant strain lacking both genes, and single ΔbbeR and ΔbbeS mutants. All three mutant strains caused disease in the BALB/c acute melioidosis model at the same rate as the wild-type strain, displayed unchanged swarming motility on semi-solid medium, and were unaffected for viability on high-osmolarity media. However, when cultured at 37 °C for at least 14 days, ΔbbeS and ΔbbeR colonies developed a distinct, hypermucoid morphology absent in similarly-cultured wild-type colonies. At both 30 °C and 37 °C, these hypermucoid strains produced wild-type levels of type I capsule but released increased quantities of extracellular DNA (eDNA). Upon static growth in liquid medium, all B. pseudomallei strains produced pellicle biofilms that contained DNA in close association with bacterial cells; however, the ΔbbeS and ΔbbeR strains produced increased biofilms with altered microscopic architecture compared to the wild-type. Unusually, while the ΔbbeS and ΔbbeR single-deletion mutants displayed clear phenotypes, the ΔbbeRS double-deletion mutant was indistinguishable from the wild-type strain. We propose that BbeR-BbeS indirectly affects eDNA secretion and biofilm formation through cross-talk with one or more other TCSTS.
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Affiliation(s)
- Priyangi A Alwis
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia; Department of Microbiology, Monash University, Melbourne, Victoria, Australia
| | - Puthayalai Treerat
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia; Department of Microbiology, Monash University, Melbourne, Victoria, Australia
| | - Lan Gong
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia; Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria, Australia
| | - Deanna Deveson Lucas
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia; Department of Microbiology, Monash University, Melbourne, Victoria, Australia
| | - Elizabeth M Allwood
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia; Department of Microbiology, Monash University, Melbourne, Victoria, Australia
| | - Mark Prescott
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia; Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria, Australia
| | - Rodney J Devenish
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia; Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria, Australia
| | - Ben Adler
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia; Department of Microbiology, Monash University, Melbourne, Victoria, Australia
| | - John D Boyce
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria, Australia; Department of Microbiology, Monash University, Melbourne, Victoria, Australia.
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13
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Kim TH, Tao X, Moya B, Jiao Y, Basso KB, Zhou J, Lang Y, Sutaria DS, Zavascki AP, Barth AL, Reeve SM, Schweizer HP, Deveson Lucas D, Boyce JD, Bonomo RA, Lee RE, Shin BS, Louie A, Drusano GL, Bulitta JB. Novel Cassette Assay To Quantify the Outer Membrane Permeability of Five β-Lactams Simultaneously in Carbapenem-Resistant Klebsiella pneumoniae and Enterobacter cloacae. mBio 2020; 11:e03189-19. [PMID: 32047131 PMCID: PMC7018653 DOI: 10.1128/mbio.03189-19] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 12/23/2019] [Indexed: 02/05/2023] Open
Abstract
Poor penetration through the outer membrane (OM) of Gram-negative bacteria is a major barrier of antibiotic development. While β-lactam antibiotics are commonly used against Klebsiella pneumoniae and Enterobacter cloacae, there are limited data on OM permeability especially in K. pneumoniae Here, we developed a novel cassette assay, which can simultaneously quantify the OM permeability to five β-lactams in carbapenem-resistant K. pneumoniae and E. cloacae Both clinical isolates harbored a blaKPC-2 and several other β-lactamases. The OM permeability of each antibiotic was studied separately ("discrete assay") and simultaneously ("cassette assay") by determining the degradation of extracellular β-lactam concentrations via multiplex liquid chromatography-tandem mass spectrometry analyses. Our K. pneumoniae isolate was polymyxin resistant, whereas the E. cloacae was polymyxin susceptible. Imipenem penetrated the OM at least 7-fold faster than meropenem for both isolates. Imipenem penetrated E. cloacae at least 258-fold faster and K. pneumoniae 150-fold faster compared to aztreonam, cefepime, and ceftazidime. For our β-lactams, OM permeability was substantially higher in the E. cloacae compared to the K. pneumoniae isolate (except for aztreonam). This correlated with a higher OmpC porin production in E. cloacae, as determined by proteomics. The cassette and discrete assays showed comparable results, suggesting limited or no competition during influx through OM porins. This cassette assay allowed us, for the first time, to efficiently quantify the OM permeability of multiple β-lactams in carbapenem-resistant K. pneumoniae and E. cloacae Characterizing the OM permeability presents a critical contribution to combating the antimicrobial resistance crisis and enables us to rationally optimize the use of β-lactam antibiotics.IMPORTANCE Antimicrobial resistance is causing a global human health crisis and is affecting all antibiotic classes. While β-lactams have been commonly used against susceptible isolates of Klebsiella pneumoniae and Enterobacter cloacae, carbapenem-resistant isolates are spreading worldwide and pose substantial clinical challenges. Rapid penetration of β-lactams leads to high drug concentrations at their periplasmic target sites, allowing β-lactams to more completely inactivate their target receptors. Despite this, there are limited tangible data on the permeability of β-lactams through the outer membranes of many Gram-negative pathogens. This study presents a novel, cassette assay, which can simultaneously characterize the permeability of five β-lactams in multidrug-resistant clinical isolates. We show that carbapenems, and especially imipenem, penetrate the outer membrane of K. pneumoniae and E. cloacae substantially faster than noncarbapenem β-lactams. The ability to efficiently characterize the outer membrane permeability is critical to optimize the use of β-lactams and combat carbapenem-resistant isolates.
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Affiliation(s)
- Tae Hwan Kim
- Departments of Pharmaceutics and Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
| | - Xun Tao
- Departments of Pharmaceutics and Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
| | - Bartolome Moya
- Departments of Pharmaceutics and Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
| | - Yuanyuan Jiao
- Departments of Pharmaceutics and Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
| | - Kari B Basso
- Department of Chemistry, University of Florida, Gainesville, Florida, USA
| | - Jieqiang Zhou
- Departments of Pharmaceutics and Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
| | - Yinzhi Lang
- Departments of Pharmaceutics and Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
| | - Dhruvitkumar S Sutaria
- Departments of Pharmaceutics and Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
| | | | - Afonso L Barth
- Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
- Laboratório de Pesquisa em Resistência Bacteriana, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil
| | - Stephanie M Reeve
- Department of Chemical Biology and Therapeutics, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Herbert P Schweizer
- Department of Molecular Genetics and Microbiology, Emerging Pathogens Institute, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Deanna Deveson Lucas
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Victoria, Australia
| | - John D Boyce
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Victoria, Australia
| | - Robert A Bonomo
- Medical Service and GRECC, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio, USA
- Departments of Medicine, Pharmacology, Molecular Biology and Microbiology, Biochemistry, and Proteomics and Bioinformatics, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
- CWRU-Cleveland VAMC Center for Antimicrobial Resistance and Epidemiology (Case VA CARES), Cleveland, Ohio, USA
| | - Richard E Lee
- Department of Chemical Biology and Therapeutics, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - Beom Soo Shin
- School of Pharmacy, Sungkyunkwan University, Suwon, Gyeonggi-do, South Korea
| | - Arnold Louie
- Institute for Therapeutic Innovation, College of Medicine, University of Florida, Orlando, Florida, USA
| | - George L Drusano
- Institute for Therapeutic Innovation, College of Medicine, University of Florida, Orlando, Florida, USA
| | - Jürgen B Bulitta
- Departments of Pharmaceutics and Pharmacotherapy and Translational Research, College of Pharmacy, University of Florida, Orlando, Florida, USA
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14
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Lewis JM, Deveson Lucas D, Harper M, Boyce JD. Systematic Identification and Analysis of Acinetobacter baumannii Type VI Secretion System Effector and Immunity Components. Front Microbiol 2019; 10:2440. [PMID: 31736890 PMCID: PMC6833914 DOI: 10.3389/fmicb.2019.02440] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 10/10/2019] [Indexed: 12/17/2022] Open
Abstract
Many Gram-negative bacteria use a type VI secretion system (T6SS) for microbial warfare and/or host manipulation. Acinetobacter baumannii is an important nosocomial pathogen and many A. baumannii strains utilize a T6SS to deliver toxic effector proteins to surrounding bacterial cells. These toxic effectors are usually delivered together with VgrG proteins, which form part of the T6SS tip complex. All previously identified A. baumannii T6SS effectors are encoded within a three- or four-gene locus that also encodes a cognate VgrG and immunity protein, and sometimes a chaperone. In order to characterize the diversity and distribution of T6SS effectors and immunity proteins in this species, we first identified all vgrG genes in 97 A. baumannii strains via the presence of the highly conserved VgrG domain. Most strains encoded between two and four different VgrG proteins. We then analyzed the regions downstream of the identified vgrG genes and identified more than 240 putative effectors. The presence of conserved domains in these effectors suggested a range of functions, including peptidoglycan hydrolases, lipases, nucleases, and nucleic acid deaminases. However, 10 of the effector groups had no functionally characterized domains. Phylogenetic analysis of these putative effectors revealed that they clustered into 32 distinct groups that appear to have been acquired from a diverse set of ancestors. Corresponding immunity proteins were identified for all but two of the effector groups. Effectors from eight of the 32 groups contained N-terminal rearrangement hotspot (RHS) domains. The C-terminal regions of these RHS proteins, which are predicted to confer the toxic effector function, were very diverse, but the N-terminal RHS domains clustered into just two groups. While the majority of A. baumannii strains contained an RHS type effector, no strains encoded two RHS effectors with similar N-terminal sequences, suggesting that the presence of similar N-terminal RHS domains leads to competitive exclusion. Together, these analyses define the extreme diversity of T6SS effectors within A. baumannii and, as many have unknown functions, future detailed characterization of these effectors may lead to the identification of proteins with novel antibacterial properties.
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Affiliation(s)
- Jessica M Lewis
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Deanna Deveson Lucas
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Marina Harper
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - John D Boyce
- Infection and Immunity Program, Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
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15
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Abstract
Polymyxin antibiotics are increasingly being used as last-line therapeutic options against a number of multidrug resistant bacteria. These antibiotics show strong bactericidal activity against a range of Gram-negative bacteria, but with the increased use of these antibiotics resistant strains are emerging at an alarming rate. Furthermore, some Gram-negative species, such as Neisseria meningitidis, Proteus mirabilis and Burkholderia spp., are intrinsically resistant to the action of polymyxins. Most identified polymyxin resistance mechanisms in Gram-negative bacteria involve changes to the lipopolysaccharide (LPS) structure, as polymyxins initially interact with the negatively charged lipid A component of LPS. The controlled addition of positively charged residues such as 4-amino-L-arabinose, phosphoethanolamine and/or galactosamine to LPS results in a reduced negative charge on the bacterial surface and therefore reduced interaction between the polymyxin and the LPS. Polymyxin resistant species produce LPS that intrinsically contains one or more of these additions. While the genes necessary for most of these additions are chromosomally encoded, plasmid-borne phosphoethanolamine transferases (mcr-1 to mcr-8) have recently been identified and these plasmids threaten to increase the rate of dissemination of clinically relevant colistin resistance. Uniquely, Acinetobacter baumannii can also become highly resistant to polymyxins via spontaneous mutations in the lipid A biosynthesis genes lpxA, lpxC or lpxD such that they produce no LPS or lipid A. A range of other non-LPS-dependent polymyxin resistance mechanisms has also been identified in bacteria, but these generally result in only low levels of resistance. These include increased anionic capsular polysaccharide production in Klebsiella pneumoniae, expression of efflux systems such as MtrCDE in N. meningitidis, and altered expression of outer membrane proteins in a small number of species.
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Affiliation(s)
- Jennifer H Moffatt
- Biomedicine Discovery Institute, Infection and Immunity Program and Department of Microbiology, Monash University, Clayton, Australia
| | - Marina Harper
- Biomedicine Discovery Institute, Infection and Immunity Program and Department of Microbiology, Monash University, Clayton, Australia.,Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Clayton, Australia
| | - John D Boyce
- Biomedicine Discovery Institute, Infection and Immunity Program and Department of Microbiology, Monash University, Clayton, Australia. .,Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Clayton, Australia.
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16
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Gulliver EL, Wright A, Lucas DD, Mégroz M, Kleifeld O, Schittenhelm RB, Powell DR, Seemann T, Bulitta JB, Harper M, Boyce JD. Determination of the small RNA GcvB regulon in the Gram-negative bacterial pathogen Pasteurella multocida and identification of the GcvB seed binding region. RNA 2018; 24:704-720. [PMID: 29440476 PMCID: PMC5900567 DOI: 10.1261/rna.063248.117] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 02/01/2018] [Indexed: 05/12/2023]
Abstract
Pasteurella multocida is a Gram-negative bacterium responsible for many important animal diseases. While a number of P. multocida virulence factors have been identified, very little is known about how gene expression and protein production is regulated in this organism. Small RNA (sRNA) molecules are critical regulators that act by binding to specific mRNA targets, often in association with the RNA chaperone protein Hfq. In this study, transcriptomic analysis of the P. multocida strain VP161 revealed a putative sRNA with high identity to GcvB from Escherichia coli and Salmonella enterica serovar Typhimurium. High-throughput quantitative liquid proteomics was used to compare the proteomes of the P. multocida VP161 wild-type strain, a gcvB mutant, and a GcvB overexpression strain. These analyses identified 46 proteins that displayed significant differential production after inactivation of gcvB, 36 of which showed increased production. Of the 36 proteins that were repressed by GcvB, 27 were predicted to be involved in amino acid biosynthesis or transport. Bioinformatic analyses of putative P. multocida GcvB target mRNAs identified a strongly conserved 10 nucleotide consensus sequence, 5'-AACACAACAT-3', with the central eight nucleotides identical to the seed binding region present within GcvB mRNA targets in E. coli and S. Typhimurium. Using a defined set of seed region mutants, together with a two-plasmid reporter system that allowed for quantification of sRNA-mRNA interactions, this sequence was confirmed to be critical for the binding of the P. multocida GcvB to the target mRNA, gltA.
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Affiliation(s)
- Emily L Gulliver
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Amy Wright
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Deanna Deveson Lucas
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Marianne Mégroz
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Oded Kleifeld
- Monash Biomedical Proteomics Facility, Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Ralf B Schittenhelm
- Monash Biomedical Proteomics Facility, Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
| | - David R Powell
- Monash Bioinformatics Platform, Monash University, Clayton, Victoria 3800, Australia
| | - Torsten Seemann
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
- Victorian Life Sciences Computation Initiative, The University of Melbourne, Parkville, Victoria 3052, Australia
| | - Jürgen B Bulitta
- Department of Pharmaceutics, College of Pharmacy, University of Florida, Orlando, Florida 32827, USA
| | - Marina Harper
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - John D Boyce
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
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17
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Harper M, Wright A, St Michael F, Li J, Deveson Lucas D, Ford M, Adler B, Cox AD, Boyce JD. Characterization of Two Novel Lipopolysaccharide Phosphoethanolamine Transferases in Pasteurella multocida and Their Role in Resistance to Cathelicidin-2. Infect Immun 2017; 85:e00557-17. [PMID: 28874446 PMCID: PMC5649011 DOI: 10.1128/iai.00557-17] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 08/29/2017] [Indexed: 12/16/2022] Open
Abstract
The lipopolysaccharide (LPS) produced by the Gram-negative bacterial pathogen Pasteurella multocida has phosphoethanolamine (PEtn) residues attached to lipid A, 3-deoxy-d-manno-octulosonic acid (Kdo), heptose, and galactose. In this report, we show that PEtn is transferred to lipid A by the P. multocida EptA homologue, PetL, and is transferred to galactose by a novel PEtn transferase that is unique to P. multocida called PetG. Transcriptomic analyses indicated that petL expression was positively regulated by the global regulator Fis and negatively regulated by an Hfq-dependent small RNA. Importantly, we have identified a novel PEtn transferase called PetK that is responsible for PEtn addition to the single Kdo molecule (Kdo1), directly linked to lipid A in the P. multocida glycoform A LPS. In vitro assays showed that the presence of a functional petL and petK, and therefore the presence of PEtn on lipid A and Kdo1, was essential for resistance to the cationic, antimicrobial peptide cathelicidin-2. The importance of PEtn on Kdo1 and the identification of the transferase responsible for this addition have not previously been shown. Phylogenetic analysis revealed that PetK is the first representative of a new family of predicted PEtn transferases. The PetK family consists of uncharacterized proteins from a range of Gram-negative bacteria that produce LPS glycoforms with only one Kdo molecule, including pathogenic species within the genera Vibrio, Bordetella, and Haemophilus We predict that many of these bacteria will require the addition of PEtn to Kdo for maximum protection against host antimicrobial peptides.
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Affiliation(s)
- Marina Harper
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, VIC, Australia
| | - Amy Wright
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, VIC, Australia
| | - Frank St Michael
- Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, ON, Canada
| | - Jianjun Li
- Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, ON, Canada
| | - Deanna Deveson Lucas
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, VIC, Australia
| | - Mark Ford
- CSIRO Australian Animal Health Laboratory, Geelong, VIC, Australia
| | - Ben Adler
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, VIC, Australia
| | - Andrew D Cox
- Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, ON, Canada
| | - John D Boyce
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, VIC, Australia
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18
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Murray GL, Tsyganov K, Kostoulias XP, Bulach DM, Powell D, Creek DJ, Boyce JD, Paulsen IT, Peleg AY. Global Gene Expression Profile of Acinetobacter baumannii During Bacteremia. J Infect Dis 2017; 215:S52-S57. [PMID: 28375520 DOI: 10.1093/infdis/jiw529] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Background Acinetobacter baumannii is a pathogen of major importance in intensive care units worldwide, with the potential to cause problematic outbreaks and acquire high-level resistance to antibiotics. There is an urgent need to understand the mechanisms of A. baumannii pathogenesis for the future development of novel targeted therapies. In this study we performed an in vivo transcriptomic analysis of A. baumannii isolated from a mammalian host with bacteremia. Methods Mice were infected with A. baumannii American Type Culture Collection 17978 using an intraperitoneal injection, and blood was extracted at 8 hours to purify bacterial RNA for RNA-Seq with an Illumina platform. Results Approximately one-quarter of A. baumannii protein coding genes were differentially expressed in vivo compared with in vitro (false discovery rate, ≤0.001; 2-fold change) with 557 showing decreased and 329 showing increased expression. Gene groups with functions relating to translation and RNA processing were overrepresented in genes with increased expression, and those relating to chaperone and protein turnover were overrepresented in the genes with decreased expression. The most strongly up-regulated genes corresponded to the 3 recognized siderophore iron uptake clusters, reflecting the iron-restrictive environment in vivo. Metabolic changes in vivo included reduced expression of genes involved in amino acid and fatty acid transport and catabolism, indicating metabolic adaptation to a different nutritional environment. Genes encoding types I and IV pili, quorum sensing components, and proteins involved in biofilm formation all showed reduced expression. Many genes that have been reported as essential for virulence showed reduced or unchanged expression in vivo. Conclusion This study provides the first insight into A. baumannii gene expression profiles during a life-threatening mammalian infection. Analysis of differentially regulated genes highlights numerous potential targets for the design of novel therapeutics.
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Affiliation(s)
- Gerald L Murray
- Royal Women's Hospital.,Murdoch Childrens Research Institute, Parkville, Victoria.,Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology
| | | | - Xenia P Kostoulias
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology
| | | | - David Powell
- Monash Bioinformatics Platform, Monash University, Clayton
| | - Darren J Creek
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville
| | - John D Boyce
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology
| | - Ian T Paulsen
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Anton Y Peleg
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology.,Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, and
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19
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Low LY, Harrison PF, Lin YH, Boyce JD, Rood JI, Cheung JK. RNA-seq analysis of virR and revR mutants of Clostridium perfringens. BMC Genomics 2016; 17:391. [PMID: 27216822 PMCID: PMC4877802 DOI: 10.1186/s12864-016-2706-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 05/05/2016] [Indexed: 12/15/2022] Open
Abstract
Background Clostridium perfringens causes toxin-mediated diseases, including gas gangrene (clostridial myonecrosis) and food poisoning in humans. The production of the toxins implicated in gas gangrene, α-toxin and perfringolysin O, is regulated by the VirSR two-component regulatory system. In addition, RevR, an orphan response regulator, has been shown to affect virulence in the mouse myonecrosis model. RevR positively regulates the expression of genes that encode hydrolytic enzymes, including hyaluronidases and sialidases. Results To further characterize the VirSR and RevR regulatory networks, comparative transcriptomic analysis was carried out with strand-specific RNA-seq on C. perfringens strain JIR325 and its isogenic virR and revR regulatory mutants. Using the edgeR analysis package, 206 genes in the virR mutant and 67 genes in the revR mutant were found to be differentially expressed. Comparative analysis revealed that VirR acts as a global negative regulator, whilst RevR acts as a global positive regulator. Therefore, about 95 % of the differentially expressed genes were up-regulated in the virR mutant, whereas 81 % of the differentially expressed genes were down-regulated in the revR mutant. Importantly, we identified 23 genes that were regulated by both VirR and RevR, 18 of these genes, which included the sporulation-specific spoIVA, sigG and sigF genes, were regulated positively and negatively by RevR and VirR, respectively. Furthermore, analysis of the mapped RNA-seq reads visualized as depth of coverage plots showed that there were 93 previously unannotated transcripts in intergenic regions. These transcripts potentially encode small RNA molecules. Conclusion In conclusion, using strand-specific RNA-seq analysis, this study has identified differentially expressed chromosomal and pCP13 native plasmid-encoded genes, antisense transcripts, and transcripts within intergenic regions that are controlled by the VirSR or RevR regulatory systems. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2706-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lee-Yean Low
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, 3800, Australia
| | - Paul F Harrison
- Monash Bioinformatics Platform, Monash University, Clayton, 3800, Australia
| | - Ya-Hsun Lin
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, 3800, Australia
| | - John D Boyce
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, 3800, Australia
| | - Julian I Rood
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, 3800, Australia
| | - Jackie K Cheung
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, 3800, Australia.
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20
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Cheah SE, Johnson MD, Zhu Y, Tsuji BT, Forrest A, Bulitta JB, Boyce JD, Nation RL, Li J. Polymyxin Resistance in Acinetobacter baumannii: Genetic Mutations and Transcriptomic Changes in Response to Clinically Relevant Dosage Regimens. Sci Rep 2016; 6:26233. [PMID: 27195897 PMCID: PMC4872528 DOI: 10.1038/srep26233] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 04/29/2016] [Indexed: 12/11/2022] Open
Abstract
Polymyxins are often last-line therapeutic agents used to treat infections caused by multidrug-resistant A. baumannii. Recent reports of polymyxin-resistant A. baumannii highlight the urgent need for research into mechanisms of polymyxin resistance. This study employed genomic and transcriptomic analyses to investigate the mechanisms of polymyxin resistance in A. baumannii AB307-0294 using an in vitro dynamic model to mimic four different clinically relevant dosage regimens of polymyxin B and colistin over 96 h. Polymyxin B dosage regimens that achieved peak concentrations above 1 mg/L within 1 h caused significant bacterial killing (~5 log10CFU/mL), while the gradual accumulation of colistin resulted in no bacterial killing. Polymyxin resistance was observed across all dosage regimens; partial reversion to susceptibility was observed in 6 of 8 bacterial samples during drug-free passaging. Stable polymyxin-resistant samples contained a mutation in pmrB. The transcriptomes of stable and non-stable polymyxin-resistant samples were not substantially different and featured altered expression of genes associated with outer membrane structure and biogenesis. These findings were further supported via integrated analysis of previously published transcriptomics data from strain ATCC19606. Our results provide a foundation for understanding the mechanisms of polymyxin resistance following exposure to polymyxins and the need to explore effective combination therapies.
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Affiliation(s)
- Soon-Ee Cheah
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville campus), 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Matthew D Johnson
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville campus), 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Yan Zhu
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville campus), 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Brian T Tsuji
- Laboratory for Antimicrobial Pharmacodynamics, Department of Pharmacy Practice, University of Buffalo, Kapoor Hall, Buffalo, NY 14214-8033, USA
| | - Alan Forrest
- Laboratory for Antimicrobial Pharmacodynamics, Department of Pharmacy Practice, University of Buffalo, Kapoor Hall, Buffalo, NY 14214-8033, USA.,Division of Pharmacotherapy and Experimental Therapeutics, University of North Carolina Eshelman School of Pharmacy, Genetic Medicine Building, 120 Mason Farm Road, Chapel Hill NC 27599, USA
| | - Jurgen B Bulitta
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville campus), 381 Royal Parade, Parkville, Victoria 3052, Australia.,Center for Pharmacometrics and Systems Pharmacology, Department of Pharmaceutics, College of Pharmacy, University of Florida, 6550 Sanger Road, Orloando FL 32827, USA
| | - John D Boyce
- Biomedicine Discovery Institute and Department of Microbiology, School of Biomedical Sciences, Monash University (Clayton campus), Wellington Road, Clayton, Victoria 3800, Australia
| | - Roger L Nation
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville campus), 381 Royal Parade, Parkville, Victoria 3052, Australia
| | - Jian Li
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville campus), 381 Royal Parade, Parkville, Victoria 3052, Australia
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21
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Lazar Adler NR, Allwood EM, Deveson Lucas D, Harrison P, Watts S, Dimitropoulos A, Treerat P, Alwis P, Devenish RJ, Prescott M, Govan B, Adler B, Harper M, Boyce JD. Perturbation of the two-component signal transduction system, BprRS, results in attenuated virulence and motility defects in Burkholderia pseudomallei. BMC Genomics 2016; 17:331. [PMID: 27147217 PMCID: PMC4855414 DOI: 10.1186/s12864-016-2668-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 04/26/2016] [Indexed: 02/08/2023] Open
Abstract
Background Burkholderia pseudomallei is the causative agent of melioidosis, a severe invasive disease of humans and animals. Initial screening of a B. pseudomallei signature-tagged mutagenesis library identified an attenuated mutant with a transposon insertion in a gene encoding the sensor component of an uncharacterised two-component signal transduction system (TCSTS), which we designated BprRS. Results Single gene inactivation of either the response regulator gene (bprR) or the sensor histidine kinase gene (bprS) resulted in mutants with reduced swarming motility and reduced virulence in mice. However, a bprRS double mutant was not attenuated for virulence and displayed wild-type levels of motility. The transcriptomes of the bprS, bprR and bprRS mutants were compared with the transcriptome of the parent strain K96243. Inactivation of the entire BprRS TCSTS (bprRS double mutant) resulted in altered expression of only nine genes, including both bprR and bprS, five phage-related genes and bpss0686, encoding a putative 5, 10-methylene tetrahydromethanopterin reductase involved in one carbon metabolism. In contrast, the transcriptomes of each of the bprR and bprS single gene mutants revealed more than 70 differentially expressed genes common to both mutants, including regulatory genes and those required for flagella assembly and for the biosynthesis of the cytotoxic polyketide, malleilactone. Conclusions Inactivation of the entire BprRS TCSTS did not alter virulence or motility and very few genes were differentially expressed indicating that the definitive BprRS regulon is relatively small. However, loss of a single component, either the sensor histidine kinase BprS or its cognate response regulator BprR, resulted in significant transcriptomic and phenotypic differences from the wild-type strain. We hypothesize that the dramatically altered phenotypes of these single mutants are the result of cross-regulation with one or more other TCSTSs and concomitant dysregulation of other key regulatory genes.
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Affiliation(s)
- Natalie R Lazar Adler
- Department of Microbiology, Monash University, 19 Innovation Walk, Clayton, Victoria, 3800, Australia.,Core Biotechnology Services, University of Leicester, Leicester, LE1 9HN, UK
| | - Elizabeth M Allwood
- Department of Microbiology, Monash University, 19 Innovation Walk, Clayton, Victoria, 3800, Australia
| | - Deanna Deveson Lucas
- Department of Microbiology, Monash University, 19 Innovation Walk, Clayton, Victoria, 3800, Australia.,Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Victoria, Australia
| | - Paul Harrison
- Victorian Bioinformatics Platform, Monash University, Victoria, Australia
| | - Stephen Watts
- Department of Microbiology, Monash University, 19 Innovation Walk, Clayton, Victoria, 3800, Australia
| | - Alexandra Dimitropoulos
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Victoria, Australia.,Department of Biochemistry and Molecular Biology, Monash University, Victoria, Australia
| | - Puthayalai Treerat
- Department of Microbiology, Monash University, 19 Innovation Walk, Clayton, Victoria, 3800, Australia.,Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Priyangi Alwis
- Department of Microbiology, Monash University, 19 Innovation Walk, Clayton, Victoria, 3800, Australia.,Faculty of Dentistry, National University of Singapore, Singapore, Singapore
| | - Rodney J Devenish
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Victoria, Australia.,Department of Biochemistry and Molecular Biology, Monash University, Victoria, Australia
| | - Mark Prescott
- Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Victoria, Australia.,Department of Biochemistry and Molecular Biology, Monash University, Victoria, Australia
| | - Brenda Govan
- Department of Microbiology and Immunology, James Cook University, Townsville, Queensland, Australia
| | - Ben Adler
- Department of Microbiology, Monash University, 19 Innovation Walk, Clayton, Victoria, 3800, Australia.,Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Victoria, Australia
| | - Marina Harper
- Department of Microbiology, Monash University, 19 Innovation Walk, Clayton, Victoria, 3800, Australia.,Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Victoria, Australia
| | - John D Boyce
- Department of Microbiology, Monash University, 19 Innovation Walk, Clayton, Victoria, 3800, Australia. .,Infection and Immunity Program, Monash Biomedicine Discovery Institute, Monash University, Victoria, Australia.
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22
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Maifiah MHM, Cheah SE, Johnson MD, Han ML, Boyce JD, Thamlikitkul V, Forrest A, Kaye KS, Hertzog P, Purcell AW, Song J, Velkov T, Creek DJ, Li J. Global metabolic analyses identify key differences in metabolite levels between polymyxin-susceptible and polymyxin-resistant Acinetobacter baumannii. Sci Rep 2016; 6:22287. [PMID: 26924392 PMCID: PMC4770286 DOI: 10.1038/srep22287] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 02/11/2016] [Indexed: 02/07/2023] Open
Abstract
Multidrug-resistant Acinetobacter baumannii presents a global medical crisis and polymyxins are used as the last-line therapy. This study aimed to identify metabolic differences between polymyxin-susceptible and polymyxin-resistant A. baumannii using untargeted metabolomics. The metabolome of each A. baumannii strain was measured using liquid chromatography-mass spectrometry. Multivariate and univariate statistics and pathway analyses were employed to elucidate metabolic differences between the polymyxin-susceptible and -resistant A. baumannii strains. Significant differences were identified between the metabolic profiles of the polymyxin-susceptible and -resistant A. baumannii strains. The lipopolysaccharide (LPS) deficient, polymyxin-resistant 19606R showed perturbation in specific amino acid and carbohydrate metabolites, particularly pentose phosphate pathway (PPP) and tricarboxylic acid (TCA) cycle intermediates. Levels of nucleotides were lower in the LPS-deficient 19606R. Furthermore, 19606R exhibited a shift in its glycerophospholipid profile towards increased abundance of short-chain lipids compared to the parent polymyxin-susceptible ATCC 19606. In contrast, in a pair of clinical isolates 03-149.1 (polymyxin-susceptible) and 03-149.2 (polymyxin-resistant, due to modification of lipid A), minor metabolic differences were identified. Notably, peptidoglycan biosynthesis metabolites were significantly depleted in both of the aforementioned polymyxin-resistant strains. This is the first comparative untargeted metabolomics study to show substantial differences in the metabolic profiles of the polymyxin-susceptible and -resistant A. baumannii.
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Affiliation(s)
- Mohd Hafidz Mahamad Maifiah
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Soon-Ee Cheah
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Matthew D Johnson
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Mei-Ling Han
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - John D Boyce
- Department of Microbiology, Faculty of Medicine, Nursing &Health Sciences, Monash University, Clayton, VIC, 3800, Australia
| | - Visanu Thamlikitkul
- Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, 10700, Thailand
| | - Alan Forrest
- UNC Eshelman School of Pharmacy, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-7569, USA
| | - Keith S Kaye
- Detroit Medical Centre and Wayne State University, University Health Centre, Detroit, MI, 48201, USA
| | - Paul Hertzog
- Hudson Institute of Medical Research, Clayton, VIC, 3168, Australia.,Faculty of Medicine, Nursing &Health Sciences, Monash University, Clayton, VIC, 3800, Australia
| | - Anthony W Purcell
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Nursing &Health Sciences, Monash University, Clayton, VIC, 3800, Australia
| | - Jiangning Song
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Nursing &Health Sciences, Monash University, Clayton, VIC, 3800, Australia
| | - Tony Velkov
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Darren J Creek
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
| | - Jian Li
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, 3052, Australia
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23
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Harper M, John M, Edmunds M, Wright A, Ford M, Turni C, Blackall PJ, Cox A, Adler B, Boyce JD. Protective efficacy afforded by live Pasteurella multocida vaccines in chickens is independent of lipopolysaccharide outer core structure. Vaccine 2016; 34:1696-703. [PMID: 26892738 DOI: 10.1016/j.vaccine.2016.02.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 02/01/2016] [Accepted: 02/03/2016] [Indexed: 11/30/2022]
Abstract
Pasteurella multocida is a major animal pathogen that causes a range of diseases including fowl cholera. P. multocida infections result in considerable losses to layer and breeder flocks in poultry industries worldwide. Both killed whole-cell and live-attenuated vaccines are available; these vaccines vary in their protective efficacy, particularly against heterologous strains. Moreover, until recently there was no knowledge of P. multocida LPS genetics and structure to determine precisely how LPS structure affects the protective capacity of these vaccines. In this study we show that defined lipopolysaccharide (LPS) mutants presented as killed whole-cell vaccines elicited solid protective immunity only against P. multocida challenge strains expressing highly similar or identical LPS structures. This finding indicates that vaccination of commercial flocks with P. multocida killed cell formulations will not protect against strains producing an LPS structure different to that produced by strains included in the vaccine formulation. Conversely, protective immunity conferred by vaccination with live P. multocida strains was found to be largely independent of LPS structure. Birds vaccinated with a range of live mutants belonging to the L1 and L3 LPS genotypes, each expressing a specific truncated LPS structure, were protected against challenge with the parent strain. Moreover, birds vaccinated with any of the five LPS mutants belonging to the L1 LPS genotype were also protected against challenge with an unrelated strain and two of the five groups vaccinated with live LPS mutants belonging to the L3 genotype were protected against challenge with an unrelated strain. In summary, vaccination with live P. multocida aroA mutants producing full-length L1 or L3 LPS or vaccination with live strains producing shortened L1 LPS elicited strong protective immunity against both homologous and heterologous challenge.
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Affiliation(s)
- Marina Harper
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne 3800, VIC, Australia.
| | - Marietta John
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne 3800, VIC, Australia
| | - Mark Edmunds
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne 3800, VIC, Australia; Poultry CRC, University of New England, Armidale 2351, NSW, Australia
| | - Amy Wright
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne 3800, VIC, Australia
| | - Mark Ford
- CSIRO Livestock Industries, Australian Animal Health Laboratory, Geelong 3220, VIC, Australia
| | - Conny Turni
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane 4072, QLD, Australia
| | - P J Blackall
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane 4072, QLD, Australia
| | - Andrew Cox
- Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, ON, Canada K1A 0R6
| | - Ben Adler
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne 3800, VIC, Australia
| | - John D Boyce
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne 3800, VIC, Australia
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Moustafa AM, Seemann T, Gladman S, Adler B, Harper M, Boyce JD, Bennett MD. Comparative Genomic Analysis of Asian Haemorrhagic Septicaemia-Associated Strains of Pasteurella multocida Identifies More than 90 Haemorrhagic Septicaemia-Specific Genes. PLoS One 2015; 10:e0130296. [PMID: 26151935 PMCID: PMC4495038 DOI: 10.1371/journal.pone.0130296] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Accepted: 05/19/2015] [Indexed: 12/16/2022] Open
Abstract
Pasteurella multocida is the primary causative agent of a range of economically important diseases in animals, including haemorrhagic septicaemia (HS), a rapidly fatal disease of ungulates. There is limited information available on the diversity of P. multocida strains that cause HS. Therefore, we determined draft genome sequences of ten disease-causing isolates and two vaccine strains and compared these genomes using a range of bioinformatic analyses. The draft genomes of the 12 HS strains were between 2,298,035 and 2,410,300 bp in length. Comparison of these genomes with the North American HS strain, M1404, and other available P. multocida genomes (Pm70, 3480, 36950 and HN06) identified a core set of 1,824 genes. A set of 96 genes was present in all HS isolates and vaccine strains examined in this study, but absent from Pm70, 3480, 36950 and HN06. Moreover, 59 genes were shared only by the Asian B:2 strains. In two Pakistani isolates, genes with high similarity to genes in the integrative and conjugative element, ICEPmu1 from strain 36950 were identified along with a range of other antimicrobial resistance genes. Phylogenetic analysis indicated that the HS strains formed clades based on their country of isolation. Future analysis of the 96 genes unique to the HS isolates will aid the identification of HS-specific virulence attributes and facilitate the development of disease-specific diagnostic tests.
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Affiliation(s)
- Ahmed M. Moustafa
- School of Veterinary and Life Sciences, Murdoch University, South Street, Perth, Western Australia, Australia
| | - Torsten Seemann
- Victorian Bioinformatics Consortium, Monash University, Wellington Road, Clayton, Melbourne, Victoria, Australia
- Victorian Life Sciences Computation Initiative, Grattan Street, Carlton, Melbourne, Victoria, Australia
| | - Simon Gladman
- Victorian Bioinformatics Consortium, Monash University, Wellington Road, Clayton, Melbourne, Victoria, Australia
- Victorian Life Sciences Computation Initiative, Grattan Street, Carlton, Melbourne, Victoria, Australia
| | - Ben Adler
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Wellington Road, Clayton, Melbourne, Victoria, Australia
- Department of Microbiology, Monash University, Wellington Road, Clayton, Melbourne, Victoria, Australia
| | - Marina Harper
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Wellington Road, Clayton, Melbourne, Victoria, Australia
- Department of Microbiology, Monash University, Wellington Road, Clayton, Melbourne, Victoria, Australia
| | - John D. Boyce
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Wellington Road, Clayton, Melbourne, Victoria, Australia
- Department of Microbiology, Monash University, Wellington Road, Clayton, Melbourne, Victoria, Australia
- * E-mail:
| | - Mark D. Bennett
- School of Veterinary and Life Sciences, Murdoch University, South Street, Perth, Western Australia, Australia
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25
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Gong L, Lai SC, Treerat P, Prescott M, Adler B, Boyce JD, Devenish RJ. Burkholderia pseudomallei type III secretion system cluster 3 ATPase BsaS, a chemotherapeutic target for small-molecule ATPase inhibitors. Infect Immun 2015; 83:1276-85. [PMID: 25605762 PMCID: PMC4363454 DOI: 10.1128/iai.03070-14] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 01/05/2015] [Indexed: 12/18/2022] Open
Abstract
Melioidosis is an infectious disease of high mortality for humans and other animal species; it is prevalent in tropical regions worldwide. The pathogenesis of melioidosis depends on the ability of its causative agent, the Gram-negative bacterium Burkholderia pseudomallei, to enter and survive in host cells. B. pseudomallei can escape from the phagosome into the cytosol of phagocytic cells where it replicates and acquires actin-mediated motility, avoiding killing by the autophagy-dependent process, LC3 (microtubule-associated protein light chain 3)-associated phagocytosis (LAP). The type III secretion system cluster 3 (TTSS3) facilitates bacterial escape from phagosomes, although the mechanism has not been fully elucidated. Given the recent identification of small-molecule inhibitors of the TTSS ATPase, we sought to determine the potential of the predicted TTSS3 ATPase, encoded by bsaS, as a target for chemotherapeutic treatment of infection. A B. pseudomallei bsaS deletion mutant was generated and used as a control against which to assess the effect of inhibitor treatment. Infection of RAW 264.7 cells with wild-type bacteria and subsequent treatment with the ATPase inhibitor compound 939 resulted in reduced intracellular bacterial survival, reduced escape from phagosomes, and increased colocalization with both LC3 and the lysosomal marker LAMP1 (lysosome-associated membrane protein 1). These changes were similar to those observed for infection of RAW 264.7 cells with the bsaS deletion mutant. We propose that treatment with the ATPase inhibitor compound 939 decreased intracellular bacterial survival through a reduced ability of bacteria to escape from phagosomes and increased killing via LAP. Therefore, small-molecule inhibitors of the TTSS3 ATPase have potential as therapeutic treatments against melioidosis.
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Affiliation(s)
- Lan Gong
- Department of Biochemistry and Molecular Biology, Monash University, Victoria, Clayton, Australia Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Victoria, Clayton, Australia
| | - Shu-Chin Lai
- Department of Biochemistry and Molecular Biology, Monash University, Victoria, Clayton, Australia
| | - Puthayalai Treerat
- Department of Microbiology, Monash University, Victoria, Clayton, Australia Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Victoria, Clayton, Australia
| | - Mark Prescott
- Department of Biochemistry and Molecular Biology, Monash University, Victoria, Clayton, Australia
| | - Ben Adler
- Department of Microbiology, Monash University, Victoria, Clayton, Australia Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Victoria, Clayton, Australia
| | - John D Boyce
- Department of Microbiology, Monash University, Victoria, Clayton, Australia Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Victoria, Clayton, Australia
| | - Rodney J Devenish
- Department of Biochemistry and Molecular Biology, Monash University, Victoria, Clayton, Australia Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Victoria, Clayton, Australia
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26
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Henry R, Crane B, Powell D, Deveson Lucas D, Li Z, Aranda J, Harrison P, Nation RL, Adler B, Harper M, Boyce JD, Li J. The transcriptomic response of Acinetobacter baumannii to colistin and doripenem alone and in combination in an in vitro pharmacokinetics/pharmacodynamics model. J Antimicrob Chemother 2015; 70:1303-13. [PMID: 25587995 DOI: 10.1093/jac/dku536] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 12/01/2014] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVES Colistin remains a last-line treatment for MDR Acinetobacter baumannii and combined use of colistin and carbapenems has shown synergistic effects against MDR strains. In order to understand the bacterial responses to these antibiotics, we analysed the transcriptome of A. baumannii following exposure to each. METHODS RNA sequencing was employed to determine changes in the transcriptome following treatment with colistin and doripenem, both alone and in combination, using an in vitro pharmacokinetics (PK)/pharmacodynamics model to mimic the PK of both antibiotics in patients. RESULTS After treatment with colistin (continuous infusion at 2 mg/L), >400 differentially regulated genes were identified, including many associated with outer membrane biogenesis, fatty acid metabolism and phospholipid trafficking. No genes were differentially expressed following treatment with doripenem (Cmax 25 mg/L, t1/2 1.5 h) for 15 min, but 45 genes were identified as differentially expressed after 1 h of growth under this condition. Treatment of A. baumannii with both colistin and doripenem together for 1 h resulted in >450 genes being identified as differentially expressed. More than 70% of these gene expression changes were also observed following colistin treatment alone. CONCLUSIONS These data suggest that colistin causes gross damage to the outer membrane, facilitates lipid exchange between the inner and outer membrane and alters the normal asymmetric outer membrane composition. The transcriptional response to colistin was highly similar to that observed for an LPS-deficient strain, indicating that many of the observed changes are responses to outer membrane instability resulting from LPS loss.
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Affiliation(s)
- Rebekah Henry
- Department of Microbiology, Monash University, Clayton, Australia
| | - Bethany Crane
- Department of Microbiology, Monash University, Clayton, Australia
| | - David Powell
- Victorian Bioinformatics Consortium, Monash University, Clayton, Australia
| | | | - Zhifeng Li
- Department of Microbiology, Monash University, Clayton, Australia State Key Laboratory of Microbial Technology, School of Life Science, Shandong University, Jinan, 250100, Shandong, P. R. China
| | - Jesús Aranda
- Department of Microbiology, Monash University, Clayton, Australia
| | - Paul Harrison
- Victorian Bioinformatics Consortium, Monash University, Clayton, Australia
| | - Roger L Nation
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
| | - Ben Adler
- Department of Microbiology, Monash University, Clayton, Australia Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Clayton, Australia
| | - Marina Harper
- Department of Microbiology, Monash University, Clayton, Australia Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Clayton, Australia
| | - John D Boyce
- Department of Microbiology, Monash University, Clayton, Australia
| | - Jian Li
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
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27
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Cullinane M, Gong L, Li X, Adler NL, Tra T, Wolvetang E, Prescott M, Boyce JD, Devenish RJ, Adler B. Stimulation of autophagy suppresses the intracellular survival ofBurkholderia pseudomalleiin mammalian cell lines. Autophagy 2014; 4:744-53. [DOI: 10.4161/auto.6246] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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28
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Harper M, St Michael F, Steen JA, John M, Wright A, van Dorsten L, Vinogradov E, Adler B, Cox AD, Boyce JD. Characterization of the lipopolysaccharide produced by Pasteurella multocida serovars 6, 7 and 16: Identification of lipopolysaccharide genotypes L4 and L8. Glycobiology 2014; 25:294-302. [DOI: 10.1093/glycob/cwu110] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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29
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Bager RJ, Kudirkiene E, da Piedade I, Seemann T, Nielsen TK, Pors SE, Mattsson AH, Boyce JD, Adler B, Bojesen AM. In silico prediction of Gallibacterium anatis pan-immunogens. Vet Res 2014; 45:80. [PMID: 25223320 PMCID: PMC4423631 DOI: 10.1186/s13567-014-0080-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 07/21/2014] [Indexed: 12/22/2022] Open
Abstract
The Gram-negative bacterium Gallibacterium anatis is a major cause of salpingitis and peritonitis in commercial egg-layers, leading to reduced egg production and increased mortality. Unfortunately, widespread multidrug resistance and antigenic diversity makes it difficult to control infections and novel prevention strategies are urgently needed. In this study, a pan-genomic reverse vaccinology (RV) approach was used to identify potential vaccine candidates. Firstly, the genomes of 10 selected Gallibacterium strains were analyzed and proteins selected on the following criteria; predicted surface-exposure or secretion, none or one transmembrane helix (TMH), and presence in six or more of the 10 genomes. In total, 42 proteins were selected. The genes encoding 27 of these proteins were successfully cloned in Escherichia coli and the proteins expressed and purified. To reduce the number of vaccine candidates for in vivo testing, each of the purified recombinant proteins was screened by ELISA for their ability to elicit a significant serological response with serum from chickens that had been infected with G. anatis. Additionally, an in silico prediction of the protective potential was carried out based on a protein property prediction method. Of the 27 proteins, two novel putative immunogens were identified; Gab_1309 and Gab_2312. Moreover, three previously characterized virulence factors; GtxA, FlfA and Gab_2156, were identified. Thus, by combining the pan-genomic RV approach with subsequent in vitro and in silico screening, we have narrowed down the pan-proteome of G. anatis to five vaccine candidates. Importantly, preliminary immunization trials indicated an in vivo protective potential of GtxA-N, FlfA and Gab_1309.
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Affiliation(s)
- Ragnhild J Bager
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, 1870, Frederiksberg C, Denmark.
| | - Egle Kudirkiene
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, 1870, Frederiksberg C, Denmark.
| | - Isabelle da Piedade
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, 1870, Frederiksberg C, Denmark.
| | - Torsten Seemann
- Victorian Bioinformatics Consortium, Monash University, 3800, Clayton, Melbourne, Australia.
| | - Tine K Nielsen
- The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, 2200, Copenhagen N, Denmark.
| | - Susanne E Pors
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, 1870, Frederiksberg C, Denmark.
| | - Andreas H Mattsson
- Center for Biological Sequence Analysis, Technical University of Denmark, 2800, Lyngby, Denmark. .,Evaxion Biotech North America LLC, Wilmington, USA.
| | - John D Boyce
- Department of Microbiology, Monash University, 3800, Clayton, Melbourne, Australia.
| | - Ben Adler
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Department of Microbiology, Monash University, 3800, Clayton, Melbourne, Australia.
| | - Anders M Bojesen
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, 1870, Frederiksberg C, Denmark.
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30
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Harper M, St Michael F, John M, Steen J, van Dorsten L, Parnas H, Vinogradov E, Adler B, Cox AD, Boyce JD. Structural analysis of lipopolysaccharide produced by Heddleston serovars 10, 11, 12 and 15 and the identification of a new Pasteurella multocida lipopolysaccharide outer core biosynthesis locus, L6. Glycobiology 2014; 24:649-59. [PMID: 24740556 DOI: 10.1093/glycob/cwu030] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Pasteurella multocida is a Gram-negative bacterial pathogen classified into 16 serovars based on lipopolysaccharide (LPS) antigens. Previously, we have characterized the LPS outer core biosynthesis loci L1, L2, L3, L5 and L7, and have elucidated the full range of LPS structures associated with each. In this study, we have determined the LPS structures produced by the type strains representing the serovars 10, 11, 12 and 15 and characterized a new LPS outer core biosynthesis locus, L6, common to all. The L6 outer core biosynthesis locus shares significant synteny with the L3 locus but due to nucleotide divergence, gene duplication and gene redundancy, the L6 and L3 LPS outer cores are structurally distinct. Using LPS structural and genetic differences identified in each L6 strain, we have predicted a role for most of the L6 glycosyltransferases in LPS assembly. Importantly, we have identified two glycosyltransferases, GctD and GatB, that differ by one amino acid, A162T, but use different donor sugars [uridine diphosphate (UDP)-Glc and UDP-Gal, respectively]. The longest outer core oligosaccharide, produced by the serovar 12 type strain, contained a terminal region consisting of β-Gal-(1,4)-β-GlcNAc-(1,3)-β-Gal-(1,4)-β-Glc that was identical in structure to the vertebrate glycosphingolipid, paragloboside. Mimicry of host glycosphingolipids has been observed previously in P. multocida strains belonging to L3 LPS genotype, which produce LPS similar in structure to the globo-series of glycosphingolipids. The expression of a paragloboside-like oligosaccharide on the LPS produced by the serovar 12 type strain indicates that strains belonging to the L6 LPS genotype may also engage in molecular mimicry.
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Affiliation(s)
- Marina Harper
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, VIC 3800, Australia
| | - Frank St Michael
- Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, ON, Canada K1A 0R6
| | - Marietta John
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, VIC 3800, Australia
| | - Jason Steen
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, VIC 3800, Australia
| | - Lieke van Dorsten
- Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, ON, Canada K1A 0R6
| | - Henrietta Parnas
- Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, ON, Canada K1A 0R6
| | - Evgeny Vinogradov
- Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, ON, Canada K1A 0R6
| | - Ben Adler
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, VIC 3800, Australia
| | - Andrew D Cox
- Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, ON, Canada K1A 0R6
| | - John D Boyce
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, VIC 3800, Australia Department of Microbiology, Monash University, Clayton, VIC 3800, Australia
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31
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Bager RJ, Kudirkiene E, da Piedade I, Seemann T, Nielsen TK, Pors SE, Mattsson AH, Boyce JD, Adler B, Bojesen AM. In silico prediction of. Vet Res 2014. [DOI: 10.1186/preaccept-1710723955128849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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32
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Harper M, St. Michael F, John M, Vinogradov E, Steen JA, van Dorsten L, Steen JA, Turni C, Blackall PJ, Adler B, Cox AD, Boyce JD. Pasteurella multocida Heddleston serovar 3 and 4 strains share a common lipopolysaccharide biosynthesis locus but display both inter- and intrastrain lipopolysaccharide heterogeneity. J Bacteriol 2013; 195:4854-64. [PMID: 23974032 PMCID: PMC3807493 DOI: 10.1128/jb.00779-13] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Accepted: 08/16/2013] [Indexed: 11/20/2022] Open
Abstract
Pasteurella multocida is a Gram-negative multispecies pathogen and the causative agent of fowl cholera, a serious disease of poultry which can present in both acute and chronic forms. The major outer membrane component lipopolysaccharide (LPS) is both an important virulence factor and a major immunogen. Our previous studies determined the LPS structures expressed by different P. multocida strains and revealed that a number of strains belonging to different serovars contain the same LPS biosynthesis locus but express different LPS structures due to mutations within glycosyltransferase genes. In this study, we report the full LPS structure of the serovar 4 type strain, P1662, and reveal that it shares the same LPS outer core biosynthesis locus, L3, with the serovar 3 strains P1059 and Pm70. Using directed mutagenesis, the role of each glycosyltransferase gene in LPS outer core assembly was determined. LPS structural analysis of 23 Australian field isolates that contain the L3 locus revealed that at least six different LPS outer core structures can be produced as a result of mutations within the LPS glycosyltransferase genes. Moreover, some field isolates produce multiple but related LPS glycoforms simultaneously, and three LPS outer core structures are remarkably similar to the globo series of vertebrate glycosphingolipids. Our in-depth analysis showing the genetics and full range of P. multocida lipopolysaccharide structures will facilitate the improvement of typing systems and the prediction of the protective efficacy of vaccines.
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Affiliation(s)
- Marina Harper
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Department of Microbiology, Monash University, Melbourne, Australia
| | - Frank St. Michael
- Institute for Biological Sciences, National Research Council, Ottawa, Ontario, Canada
| | - Marietta John
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Department of Microbiology, Monash University, Melbourne, Australia
| | - Evgeny Vinogradov
- Institute for Biological Sciences, National Research Council, Ottawa, Ontario, Canada
| | - Jennifer A. Steen
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Department of Microbiology, Monash University, Melbourne, Australia
| | - Lieke van Dorsten
- Institute for Biological Sciences, National Research Council, Ottawa, Ontario, Canada
| | - Jason A. Steen
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Department of Microbiology, Monash University, Melbourne, Australia
| | - Conny Turni
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Dutton Park, Brisbane, Australia
| | - Patrick J. Blackall
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Dutton Park, Brisbane, Australia
| | - Ben Adler
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Department of Microbiology, Monash University, Melbourne, Australia
| | - Andrew D. Cox
- Institute for Biological Sciences, National Research Council, Ottawa, Ontario, Canada
| | - John D. Boyce
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Department of Microbiology, Monash University, Melbourne, Australia
- Department of Microbiology, Monash University, Melbourne, Australia
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Soon RL, Li J, Boyce JD, Harper M, Adler B, Larson I, Nation RL. Cell surface hydrophobicity of colistin-susceptible vs resistant Acinetobacter baumannii determined by contact angles: methodological considerations and implications. J Appl Microbiol 2013; 113:940-51. [PMID: 22574702 DOI: 10.1111/j.1365-2672.2012.05337.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Contact angle analysis of cell surface hydrophobicity (CSH) describes the tendency of a water droplet to spread across a lawn of filtered bacterial cells. Colistin-induced disruption of the Gram-negative outer membrane necessitates hydrophobic contacts with lipopolysaccharide (LPS). We aimed to characterize the CSH of Acinetobacter baumannii using contact angles, to provide insight into the mechanism of colistin resistance. Contact angles were analysed for five paired colistin-susceptible and resistant Ac. baumannii strains. Drainage of the water droplet through bacterial layers was demonstrated to influence results. Consequently, measurements were performed 0·66s after droplet deposition. Colistin-resistant cells exhibited lower contact angles (38·8±2·8-46·8±1·3°) compared with their paired colistin-susceptible strains (40·7±3·0-48·0±1·4°; anova; P<0·05). Contact angles increased at stationary phase (50·3±2·9-61·5±2·5° and 47·4±2·0-50·8±3·2°, susceptible and resistant, respectively, anova; P<0·05) and in response to colistin 32mgl(-1) exposure (44·5±1·5-50·6±2·8° and 43·5±2·2-48·0±2·2°, susceptible and resistant, respectively; anova; P<0·05). Analysis of complemented strains constructed with an intact lpxA gene, or empty vector, highlighted the contribution of LPS to CSH. Compositional outer-membrane variations likely account for CSH differences between Ac. baumannii phenotypes, which influence the hydrophobic colistin-bacterium interaction. Important insight into the mechanism of colistin resistance has been provided. Greater consideration of contact angle methodology is necessary to ensure accurate analyses are performed.
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Affiliation(s)
- R L Soon
- Facility for Anti-infective Drug Development and Innovation, Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Vic., Australia
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Hatfaludi T, Al-Hasani K, Gong L, Boyce JD, Ford M, Wilkie IW, Quinsey N, Dunstone MA, Hoke DE, Adler B. Screening of 71 P. multocida proteins for protective efficacy in a fowl cholera infection model and characterization of the protective antigen PlpE. PLoS One 2012; 7:e39973. [PMID: 22792202 PMCID: PMC3390355 DOI: 10.1371/journal.pone.0039973] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Accepted: 06/05/2012] [Indexed: 12/26/2022] Open
Abstract
Background There is a strong need for a recombinant subunit vaccine against fowl cholera. We used a reverse vaccinology approach to identify putative secreted or cell surface associated P. multocida proteins that may represent potential vaccine candidate antigens. Principal Findings A high-throughput cloning and expression protocol was used to express and purify 71 recombinant proteins for vaccine trials. Of the 71 proteins tested, only one, PlpE in denatured insoluble form, protected chickens against fowl cholera challenge. PlpE also elicited comparable levels of protection in mice. PlpE was localized by immunofluorescence to the bacterial cell surface, consistent with its ability to elicit a protective immune response. To explore the role of PlpE during infection and immunity, a plpE mutant was generated. The plpE mutant strain retained full virulence for mice. Conclusion These studies show that PlpE is a surface exposed protein and was the only protein of 71 tested that was able to elicit a protective immune response. However, PlpE is not an essential virulence factor. This is the first report of a denatured recombinant protein stimulating protection against fowl cholera.
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Affiliation(s)
- Tamás Hatfaludi
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia.
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Abstract
Pasteurella multocida is an enigmatic pathogen. It is remarkable both for the number and range of specific disease syndromes with which it is associated, and the wide range of host species affected. The pathogenic mechanisms involved in causing the different syndromes are, for the most part, poorly understood or completely unknown. The biochemical and serological properties of some organisms responsible for quite different syndromes appear to be similar. Thus, the molecular basis for host predilection remains unknown. The recent development of genetic manipulation systems together with the availability of multiple genome sequences should help to explain the association of particular pathological conditions with particular hosts as well as helping to elucidate pathogenic mechanisms.
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Affiliation(s)
- I W Wilkie
- Department of Microbiology, Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Clayton, VIC 3800, Australia
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Abstract
The capsule and lipopolysaccharide (LPS) of Pasteurella multocida constitute the major components of the bacterial cell surface. As well as forming the basis for the most widely used classification systems, they play key roles in a range of interactions between the bacteria and the hosts they colonize or infect. Both polysaccharides are involved in the avoidance of host innate immune mechanisms, such as resistance to phagocytosis, complement-mediated killing, and the bactericidal activity of antimicrobial peptides; they are therefore essential for virulence. In addition, LPS is a major antigen in the stimulation of adaptive immune responses to infection.
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Affiliation(s)
- Marina Harper
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
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Harper M, Cox AD, Adler B, Boyce JD. Pasteurella multocida lipopolysaccharide: The long and the short of it. Vet Microbiol 2011; 153:109-15. [DOI: 10.1016/j.vetmic.2011.05.022] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Revised: 04/27/2011] [Accepted: 05/10/2011] [Indexed: 11/25/2022]
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Harper M, St Michael F, Vinogradov E, John M, Boyce JD, Adler B, Cox AD. Characterization of the lipopolysaccharide from Pasteurella multocida Heddleston serovar 9: identification of a proposed bi-functional dTDP-3-acetamido-3,6-dideoxy-α-D-glucose biosynthesis enzyme. Glycobiology 2011; 22:332-44. [PMID: 22002973 DOI: 10.1093/glycob/cwr147] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Pasteurella multocida strains are classified into 16 different lipopolysaccharide (LPS) serovars using the Heddleston serotyping scheme. Ongoing studies in our laboratories on the LPS aim to determine the core oligosaccharide (OS) structures expressed by each of the Heddleston type strains and identify the genes and transferases required for the biosynthesis of the serovar-specific OSs. In this study, we have determined the core OS of the LPS expressed by the Heddleston serovar 9 type strain, P2095. Structural information was established by a combination of monosaccharide and methylation analyses, nuclear magnetic resonance spectroscopy and mass spectrometry revealing the following structure: . The serovar 9 OS contains an inner core that is conserved among P. multocida strains with an elaborate outer core extension containing rhamnose (Rha), a D-glycero-D-manno isomer of heptose, and the unusual deoxyamino sugar, 3-acetamido-3,6-dideoxy-α-D-glucose (Qui3NAc). Genetic analyses of the LPS outer core biosynthesis locus revealed that in addition to the glycosyltransferases predicted to transfer the sugars to the nascent LPS molecule, the locus also contained the complete set of genes required for the biosynthesis of the nucleotide sugar donors dTDP-Rha and dTDP-Qui3NAc. One of the genes identified as part of the dTDP-Qui3NAc biosynthesis pathway, qdtD, encodes a proposed bi-functional enzyme with N-terminal amino acid identity to dTDP-4-oxo-6-deoxy-D-glucose-3,4-oxoisomerase and C-terminal amino acid identity to dTDP-3-oxo-6-deoxy-α-D-glucose transacetylase.
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Affiliation(s)
- Marina Harper
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Department of Microbiology, Monash University, Melbourne 3800, Australia
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Soon RL, Nation RL, Harper M, Adler B, Boyce JD, Tan CH, Li J, Larson I. Effect of colistin exposure and growth phase on the surface properties of live Acinetobacter baumannii cells examined by atomic force microscopy. Int J Antimicrob Agents 2011; 38:493-501. [PMID: 21925844 DOI: 10.1016/j.ijantimicag.2011.07.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 07/20/2011] [Accepted: 07/26/2011] [Indexed: 11/17/2022]
Abstract
The diminishing antimicrobial development pipeline has forced the revival of colistin as a last line of defence against infections caused by multidrug-resistant Gram-negative 'superbugs' such as Acinetobacter baumannii. The complete loss of lipopolysaccharide (LPS) mediates colistin resistance in some A. baumannii strains. Atomic force microscopy was used to examine the surface properties of colistin-susceptible and -resistant A. baumannii strains at mid-logarithmic and stationary growth phases in liquid and in response to colistin treatment. The contribution of LPS to surface properties was investigated using A. baumannii strains constructed with and without the lpxA gene. Bacterial spring constant measurements revealed that colistin-susceptible cells were significantly stiffer than colistin-resistant cells at both growth phases (P<0.01), whilst colistin treatment at high concentrations (32 mg/L) resulted in more rigid surfaces for both phenotypes. Multiple, large adhesive peaks frequently noted in force curves captured on colistin-susceptible cells were not evident for colistin-resistant cells. Adhesion events were markedly reduced following colistin exposure. The cell membranes of strains of both phenotypes remained intact following colistin treatment, although fine topographical details were illustrated. These studies, conducted for the first time on live A. baumannii cells in liquid, have contributed to our understanding of the action of colistin in this problematic pathogen.
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Affiliation(s)
- Rachel L Soon
- Facility for Anti-infective Drug Development and Innovation, Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
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Allwood EM, Devenish RJ, Prescott M, Adler B, Boyce JD. Strategies for Intracellular Survival of Burkholderia pseudomallei. Front Microbiol 2011; 2:170. [PMID: 22007185 PMCID: PMC3159172 DOI: 10.3389/fmicb.2011.00170] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Accepted: 07/26/2011] [Indexed: 11/13/2022] Open
Abstract
Burkholderia pseudomallei is the causative agent of melioidosis, a disease with high mortality that is prevalent in tropical regions of the world. A key component of the pathogenesis of melioidosis is the ability of B. pseudomallei to enter, survive, and replicate within mammalian host cells. For non-phagocytic cells, bacterial adhesins have been identified both on the bacterial surface and associated with Type 4 pili. Cell invasion involves components of one or more of the three Type 3 Secretion System clusters, which also mediate, at least in part, the escape of bacteria from the endosome into the cytoplasm, where bacteria move by actin-based motility. The mechanism of actin-based motility is not clearly understood, but appears to differ from characterized mechanisms in other bacterial species. A small proportion of intracellular bacteria is targeted by host cell autophagy, involving direct recruitment of LC3 to endosomes rather than through uptake by canonical autophagosomes. However, the majority of bacterial cells are able to circumvent autophagy and other intracellular defense mechanisms such as the induction of inducible nitric oxide synthase, and then replicate in the cytoplasm and spread to adjacent cells via membrane fusion, resulting in the formation of multi-nucleated giant cells. A potential role for host cell ubiquitin in the autophagic response to bacterial infection has recently been proposed.
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Gong L, Cullinane M, Treerat P, Ramm G, Prescott M, Adler B, Boyce JD, Devenish RJ. The Burkholderia pseudomallei type III secretion system and BopA are required for evasion of LC3-associated phagocytosis. PLoS One 2011; 6:e17852. [PMID: 21412437 PMCID: PMC3055895 DOI: 10.1371/journal.pone.0017852] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Accepted: 02/10/2011] [Indexed: 01/19/2023] Open
Abstract
Burkholderia pseudomallei is the causative agent of melioidosis, a fatal infectious disease endemic in tropical regions worldwide, and especially prevalent in southeast Asia and northern Australia. This intracellular pathogen can escape from phagosomes into the host cytoplasm, where it replicates and infects adjacent cells. We previously demonstrated that, in response to B. pseudomallei infection of macrophage cell line RAW 264.7, a subset of bacteria co-localized with the autophagy marker protein, microtubule-associated protein light chain 3 (LC3), implicating autophagy in host cell defence against infection. Recent reports have suggested that LC3 can be recruited to both phagosomes and autophagosomes, thereby raising questions regarding the identity of the LC3-positive compartments in which invading bacteria reside and the mechanism of the autophagic response to B. pseudomallei infection. Electron microscopy analysis of infected cells demonstrated that the invading bacteria were either free in the cytosol, or sequestered in single-membrane phagosomes rather than double-membrane autophagosomes, suggesting that LC3 is recruited to B. pseudomallei-containing phagosomes. Partial or complete loss of function of type III secretion system cluster 3 (TTSS3) in mutants lacking the BopA (effector) or BipD (translocator) proteins respectively, resulted in delayed or no escape from phagosomes. Consistent with these observations, bopA and bipD mutants both showed a higher level of co-localization with LC3 and the lysosomal marker LAMP1, and impaired survival in RAW264.7 cells, suggesting enhanced killing in phagolysosomes. We conclude that LC3 recruitment to phagosomes stimulates killing of B. pseudomallei trapped in phagosomes. Furthermore, BopA plays an important role in efficient escape of B. pseudomallei from phagosomes.
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Affiliation(s)
- Lan Gong
- Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria, Australia
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Melbourne, Victoria, Australia
| | - Meabh Cullinane
- Department of Microbiology, Monash University, Melbourne, Victoria, Australia
| | - Puthayalai Treerat
- Department of Microbiology, Monash University, Melbourne, Victoria, Australia
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Melbourne, Victoria, Australia
| | - Georg Ramm
- Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria, Australia
| | - Mark Prescott
- Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria, Australia
| | - Ben Adler
- Department of Microbiology, Monash University, Melbourne, Victoria, Australia
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Melbourne, Victoria, Australia
| | - John D. Boyce
- Department of Microbiology, Monash University, Melbourne, Victoria, Australia
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Melbourne, Victoria, Australia
| | - Rodney J. Devenish
- Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria, Australia
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Melbourne, Victoria, Australia
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Soon RL, Nation RL, Cockram S, Moffatt JH, Harper M, Adler B, Boyce JD, Larson I, Li J. Different surface charge of colistin-susceptible and -resistant Acinetobacter baumannii cells measured with zeta potential as a function of growth phase and colistin treatment. J Antimicrob Chemother 2011; 66:126-33. [PMID: 21081544 PMCID: PMC3001852 DOI: 10.1093/jac/dkq422] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Revised: 10/06/2010] [Accepted: 10/12/2010] [Indexed: 01/28/2023] Open
Abstract
OBJECTIVES electrostatic forces mediate the initial interaction between cationic colistin and Gram-negative bacterial cells. Lipopolysaccharide (LPS) loss mediates colistin resistance in some A. baumannii strains. Our aim was to determine the surface charge of colistin-susceptible and -resistant A. baumannii as a function of growth phase and in response to polymyxin treatment. METHODS the zeta potential of A. baumannii ATCC 19606 and 10 clinical multidrug-resistant strains (MICs 0.5-2 mg/L) was assessed. Colistin-resistant derivatives (MIC >128 mg/L) of wild-type strains were selected in the presence of 10 mg/L colistin, including the LPS-deficient lpxA mutant, ATCC 19606R. To determine the contribution of LPS to surface charge, two complemented ATCC 19606R derivatives were examined, namely ATCC 19606R + lpxA (containing an intact lpxA gene) and ATCC 19606R + V (containing empty vector). Investigations were conducted as a function of growth phase and polymyxin treatment (1, 4 and 8 mg/L). RESULTS wild-type cells exhibited a greater negative charge (-60.5 ± 2.36 to -26.2 ± 2.56 mV) thancolistin-resistant cells (-49.2 ± 3.09 to -19.1 ± 2.80 mV) at mid-log phase (ANOVA, P < 0.05). Opposing growth-phase trends were observed for both phenotypes: wild-type cells displayed reduced negative charge and colistin-resistant cells displayed increased negative charge at stationary compared with mid-logarithmic phase. Polymyxin exposure resulted in a concentration-dependent increase in zeta potential. Examination of ATCC 19606R and complemented strains supported the importance of LPS in determining surface charge, suggesting a potential mechanism of colistin resistance. CONCLUSIONS zeta potential differences between A. baumannii phenotypes probably reflect compositional outer-membrane variations that impact the electrostatic component of colistin activity.
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Affiliation(s)
- Rachel L. Soon
- Facility for Anti-infective Drug Development and Innovation, Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria, Australia
| | - Roger L. Nation
- Facility for Anti-infective Drug Development and Innovation, Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria, Australia
| | - Stewart Cockram
- Facility for Anti-infective Drug Development and Innovation, Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria, Australia
| | | | - Marina Harper
- Department of Microbiology, Monash University, Victoria, Australia
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Victoria, Australia
| | - Ben Adler
- Department of Microbiology, Monash University, Victoria, Australia
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Victoria, Australia
| | - John D. Boyce
- Department of Microbiology, Monash University, Victoria, Australia
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Victoria, Australia
| | - Ian Larson
- Facility for Anti-infective Drug Development and Innovation, Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria, Australia
| | - Jian Li
- Facility for Anti-infective Drug Development and Innovation, Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria, Australia
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Lazar Adler NR, Govan B, Cullinane M, Harper M, Adler B, Boyce JD. The molecular and cellular basis of pathogenesis in melioidosis: how does Burkholderia pseudomallei cause disease? FEMS Microbiol Rev 2009; 33:1079-99. [PMID: 19732156 DOI: 10.1111/j.1574-6976.2009.00189.x] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Melioidosis, a febrile illness with disease states ranging from acute pneumonia or septicaemia to chronic abscesses, was first documented by Whitmore & Krishnaswami (1912). The causative agent, Burkholderia pseudomallei, was subsequently identified as a motile, gram-negative bacillus, which is principally an environmental saprophyte. Melioidosis has become an increasingly important disease in endemic areas such as northern Thailand and Australia (Currie et al., 2000). This health burden, plus the classification of B. pseudomallei as a category B biological agent (Rotz et al., 2002), has resulted in an escalation of research interest. This review focuses on the molecular and cellular basis of pathogenesis in melioidosis, with a comprehensive overview of the current knowledge on how B. pseudomallei can cause disease. The process of B. pseudomallei movement from the environmental reservoir to attachment and invasion of epithelial and macrophage cells and the subsequent intracellular survival and spread is outlined. Furthermore, the diverse assortment of virulence factors that allow B. pseudomallei to become an effective opportunistic pathogen, as well as to avoid or subvert the host immune response, is discussed. With the recent increase in genomic and molecular studies, the current understanding of the infection process of melioidosis has increased substantially, yet, much still remains to be elucidated.
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Lo AW, Seers CA, Boyce JD, Dashper SG, Slakeski N, Lissel JP, Reynolds EC. Comparative transcriptomic analysis of Porphyromonas gingivalis biofilm and planktonic cells. BMC Microbiol 2009; 9:18. [PMID: 19175941 PMCID: PMC2637884 DOI: 10.1186/1471-2180-9-18] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2008] [Accepted: 01/29/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Porphyromonas gingivalis in subgingival dental plaque, as part of a mature biofilm, has been strongly implicated in the onset and progression of chronic periodontitis. In this study using DNA microarray we compared the global gene expression of a P. gingivalis biofilm with that of its planktonic counterpart grown in the same continuous culture. RESULTS Approximately 18% (377 genes, at 1.5 fold or more, P-value < 0.01) of the P. gingivalis genome was differentially expressed when the bacterium was grown as a biofilm. Genes that were down-regulated in biofilm cells, relative to planktonic cells, included those involved in cell envelope biogenesis, DNA replication, energy production and biosynthesis of cofactors, prosthetic groups and carriers. A number of genes encoding transport and binding proteins were up-regulated in P. gingivalis biofilm cells. Several genes predicted to encode proteins involved in signal transduction and transcriptional regulation were differentially regulated and may be important in the regulation of biofilm growth. CONCLUSION This study analyzing global gene expression provides insight into the adaptive response of P. gingivalis to biofilm growth, in particular showing a down regulation of genes involved in growth and metabolic activity.
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Affiliation(s)
- Alvin W Lo
- Cooperative Research Centre for Oral Health Science, Melbourne Dental School and the Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Melbourne, Victoria, Australia.
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Keyburn AL, Boyce JD, Vaz P, Bannam TL, Ford ME, Parker D, Di Rubbo A, Rood JI, Moore RJ. NetB, a new toxin that is associated with avian necrotic enteritis caused by Clostridium perfringens. PLoS Pathog 2008; 4:e26. [PMID: 18266469 PMCID: PMC2233674 DOI: 10.1371/journal.ppat.0040026] [Citation(s) in RCA: 420] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2007] [Accepted: 12/22/2007] [Indexed: 11/18/2022] Open
Abstract
For over 30 years a phospholipase C enzyme called alpha-toxin was thought to be the key virulence factor in necrotic enteritis caused by Clostridium perfringens. However, using a gene knockout mutant we have recently shown that alpha-toxin is not essential for pathogenesis. We have now discovered a key virulence determinant. A novel toxin (NetB) was identified in a C. perfringens strain isolated from a chicken suffering from necrotic enteritis (NE). The toxin displayed limited amino acid sequence similarity to several pore forming toxins including beta-toxin from C. perfringens (38% identity) and alpha-toxin from Staphylococcus aureus (31% identity). NetB was only identified in C. perfringens type A strains isolated from chickens suffering NE. Both purified native NetB and recombinant NetB displayed cytotoxic activity against the chicken leghorn male hepatoma cell line LMH; inducing cell rounding and lysis. To determine the role of NetB in NE a netB mutant of a virulent C. perfringens chicken isolate was constructed by homologous recombination, and its virulence assessed in a chicken disease model. The netB mutant was unable to cause disease whereas the wild-type parent strain and the netB mutant complemented with a wild-type netB gene caused significant levels of NE. These data show unequivocally that in this isolate a functional NetB toxin is critical for the ability of C. perfringens to cause NE in chickens. This novel toxin is the first definitive virulence factor to be identified in avian C. perfringens strains capable of causing NE. Furthermore, the netB mutant is the first rationally attenuated strain obtained in an NE-causing isolate of C. perfringens; as such it has considerable vaccine potential. Clostridium perfringens can cause gas gangrene and food poisoning in humans and causes several enterotoxemic diseases in animals including avian necrotic enteritis. This disease affects all chicken producing countries worldwide and is a considerable burden on the commercial chicken production industry. Until recently alpha-toxin was thought to be the major virulence factor involved in necrotic enteritis. However, by using an alpha-toxin null mutant it has been demonstrated that this toxin is not essential for disease. This paper details the identification and characterisation of a novel toxin, NetB, and provides evidence that the protein is an essential factor in causing necrotic enteritis in chickens. NetB has limited protein sequence identity to the beta-toxin of C. perfringens, which causes mucosal necrosis of the small intestine in humans and animals. We demonstrate that NetB null mutants can no longer cause disease in chickens, whereas both the wild-type and mutant complemented with a wild-type netB gene caused significant levels of necrotic enteritis. The identification of this important toxin advances our understanding of the pathogenesis of the disease and opens significant opportunities for the development of novel vaccines against necrotic enteritis in poultry.
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Affiliation(s)
- Anthony L Keyburn
- CSIRO Livestock Industries, Australian Animal Health Laboratory, Geelong, Victoria, Australia
- Department of Microbiology, ARC Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Clayton, Victoria, Australia
- Australian Poultry Cooperative Research Centre, Armidale, New South Wales, Australia
| | - John D Boyce
- Department of Microbiology, ARC Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Clayton, Victoria, Australia
| | - Paola Vaz
- Department of Microbiology, ARC Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Clayton, Victoria, Australia
| | - Trudi L Bannam
- Department of Microbiology, ARC Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Clayton, Victoria, Australia
| | - Mark E Ford
- CSIRO Livestock Industries, Australian Animal Health Laboratory, Geelong, Victoria, Australia
| | - Dane Parker
- Department of Microbiology, ARC Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Clayton, Victoria, Australia
| | - Antonio Di Rubbo
- CSIRO Livestock Industries, Australian Animal Health Laboratory, Geelong, Victoria, Australia
| | - Julian I Rood
- Department of Microbiology, ARC Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Clayton, Victoria, Australia
- Australian Poultry Cooperative Research Centre, Armidale, New South Wales, Australia
| | - Robert J Moore
- CSIRO Livestock Industries, Australian Animal Health Laboratory, Geelong, Victoria, Australia
- Department of Microbiology, ARC Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Clayton, Victoria, Australia
- Australian Poultry Cooperative Research Centre, Armidale, New South Wales, Australia
- * To whom correspondence should be addressed. E-mail:
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Harper M, Cox A, St Michael F, Parnas H, Wilkie I, Blackall PJ, Adler B, Boyce JD. Decoration of Pasteurella multocida lipopolysaccharide with phosphocholine is important for virulence. J Bacteriol 2007; 189:7384-91. [PMID: 17704225 PMCID: PMC2168462 DOI: 10.1128/jb.00948-07] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Phosphocholine (PCho) is an important substituent of surface structures expressed by a number of bacterial pathogens. Its role in virulence has been investigated in several species, in which it has been shown to play a role in bacterial adhesion to mucosal surfaces, in resistance to antimicrobial peptides, or in sensitivity to complement-mediated killing. The lipopolysaccharide (LPS) structure of Pasteurella multocida strain Pm70, whose genome sequence is known, has recently been determined and does not contain PCho. However, LPS structures from the closely related, virulent P. multocida strains VP161 and X-73 were shown to contain PCho on their terminal galactose sugar residues. To determine if PCho was involved in the virulence of P. multocida, we used subtractive hybridization of the VP161 genome against the Pm70 genome to identify a four-gene locus (designated pcgDABC) which we show is required for the addition of the PCho residues to LPS. The proteins predicted to be encoded by pcgABC showed identity to proteins involved in choline uptake, phosphorylation, and nucleotide sugar activation of PCho. We constructed a P. multocida VP161 pcgC mutant and demonstrated that this strain produces LPS that lacks PCho on the terminal galactose residues. This pcgC mutant displayed reduced in vivo growth in a chicken infection model and was more sensitive to the chicken antimicrobial peptide fowlicidin-1 than the wild-type P. multocida strain.
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Affiliation(s)
- Marina Harper
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, VIC, Australia
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47
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Harper M, Boyce JD, Cox AD, St Michael F, Wilkie IW, Blackall PJ, Adler B. Pasteurella multocida expresses two lipopolysaccharide glycoforms simultaneously, but only a single form is required for virulence: identification of two acceptor-specific heptosyl I transferases. Infect Immun 2007; 75:3885-93. [PMID: 17517879 PMCID: PMC1952014 DOI: 10.1128/iai.00212-07] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lipopolysaccharide (LPS) is a critical virulence determinant in Pasteurella multocida and a major antigen responsible for host protective immunity. In other mucosal pathogens, variation in LPS or lipooligosaccharide structure typically occurs in the outer core oligosaccharide regions due to phase variation. P. multocida elaborates a conserved oligosaccharide extension attached to two different, simultaneously expressed inner core structures, one containing a single phosphorylated 3-deoxy-D-manno-octulosonic acid (Kdo) residue and the other containing two Kdo residues. We demonstrate that two heptosyltransferases, HptA and HptB, add the first heptose molecule to the Kdo(1) residue and that each exclusively recognizes different acceptor molecules. HptA is specific for the glycoform containing a single, phosphorylated Kdo residue (glycoform A), while HptB is specific for the glycoform containing two Kdo residues (glycoform B). In addition, KdkA was identified as a Kdo kinase, required for phosphorylation of the first Kdo molecule. Importantly, virulence data obtained from infected chickens showed that while wild-type P. multocida expresses both LPS glycoforms in vivo, bacterial mutants that produced only glycoform B were fully virulent, demonstrating for the first time that expression of a single LPS form is sufficient for P. multocida survival in vivo. We conclude that the ability of P. multocida to elaborate alternative inner core LPS structures is due to the simultaneous expression of two different heptosyltransferases that add the first heptose residue to the nascent LPS molecule and to the expression of both a bifunctional Kdo transferase and a Kdo kinase, which results in the initial assembly of two inner core structures.
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Affiliation(s)
- Marina Harper
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Victoria 3800, Australia
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48
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Myers GSA, Parker D, Al-Hasani K, Kennan RM, Seemann T, Ren Q, Badger JH, Selengut JD, Deboy RT, Tettelin H, Boyce JD, McCarl VP, Han X, Nelson WC, Madupu R, Mohamoud Y, Holley T, Fedorova N, Khouri H, Bottomley SP, Whittington RJ, Adler B, Songer JG, Rood JI, Paulsen IT. Genome sequence and identification of candidate vaccine antigens from the animal pathogen Dichelobacter nodosus. Nat Biotechnol 2007; 25:569-75. [PMID: 17468768 DOI: 10.1038/nbt1302] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2006] [Accepted: 04/04/2007] [Indexed: 11/09/2022]
Abstract
Dichelobacter nodosus causes ovine footrot, a disease that leads to severe economic losses in the wool and meat industries. We sequenced its 1.4-Mb genome, the smallest known genome of an anaerobe. It differs markedly from small genomes of intracellular bacteria, retaining greater biosynthetic capabilities and lacking any evidence of extensive ongoing genome reduction. Comparative genomic microarray studies and bioinformatic analysis suggested that, despite its small size, almost 20% of the genome is derived from lateral gene transfer. Most of these regions seem to be associated with virulence. Metabolic reconstruction indicated unsuspected capabilities, including carbohydrate utilization, electron transfer and several aerobic pathways. Global transcriptional profiling and bioinformatic analysis enabled the prediction of virulence factors and cell surface proteins. Screening of these proteins against ovine antisera identified eight immunogenic proteins that are candidate antigens for a cross-protective vaccine.
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Affiliation(s)
- Garry S A Myers
- The Institute for Genomic Research, 9712 Medical Center Drive, Rockville, Maryland 20850, USA
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Abstract
Pasteurella multocida was first shown to be the causative agent of fowl cholera by Louis Pasteur in 1881. Since then, this Gram-negative bacterium has been identified as the causative agent of many other economically important diseases in a wide range of hosts. The mechanisms by which these bacteria can invade the mucosa, evade innate immunity and cause systemic disease are slowly being elucidated. Key virulence factors identified to date include capsule and lipopolysaccharide. The capsule is clearly involved in bacterial avoidance of phagocytosis and resistance to complement, while complete lipopolysaccharide is critical for bacterial survival in the host. A number of other virulence factors have been identified by both directed and random mutagenesis, including Pasteurella multocida toxin (PMT), putative surface adhesins and iron acquisition proteins. However, it is likely that many key virulence factors are yet to be identified, including those required for initial attachment and invasion of host cells and for persistence in a relatively nutrient poor and hostile environment.
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Affiliation(s)
- Marina Harper
- Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Department of Microbiology, Monash University, Melbourne, Australia
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50
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Boyce JD, Cullen PA, Nguyen V, Wilkie I, Adler B. Analysis of thePasteurella multocida outer membrane sub-proteome and its response to thein vivo environment of the natural host. Proteomics 2006; 6:870-80. [PMID: 16372271 DOI: 10.1002/pmic.200401342] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This study describes the identification of outer membrane proteins (OMPs) of the bacterial pathogen Pasteurella multocida and an analysis of how the expression of these proteins changes during infection of the natural host. We analysed the sarcosine-insoluble membrane fractions, which are highly enriched for OMPs, from bacteria grown under a range of conditions. Initially, the OMP-containing fractions were resolved by 2-DE and the proteins identified by MALDI-TOF MS. In addition, the OMP-containing fractions were separated by 1-D SDS-PAGE and protein identifications were made using nano LC MS/MS. Using these two methods a total of 35 proteins was identified from samples obtained from organisms grown in rich culture medium. Six of the proteins were identified only by 2-DE MALDI-TOF MS, whilst 17 proteins were identified only by 1-D LC MS/MS. We then analysed the OMPs from P. multocida which had been isolated from the bloodstream of infected chickens (a natural host) or grown in iron-depleted medium. Three proteins were found to be significantly up-regulated during growth in vivo and one of these (Pm0803) was also up-regulated during growth in iron-depleted medium. After bioinformatic analysis of the protein matches, it was predicted that over one third of the combined OMPs predicted by the bioinformatics sub-cellular localisation tools PSORTB and Proteome Analyst, had been identified during this study. This is the first comprehensive proteomic analysis of the P. multocida outer membrane and the first proteomic analysis of how a bacterial pathogen modifies its outer membrane proteome during infection.
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Affiliation(s)
- John D Boyce
- Australian Research Council Centre for Structural and Functional Microbial Genomics, Monash University, Victoria, Australia.
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