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Hajdú G, Szathmári C, Sőti C. Modeling Host-Pathogen Interactions in C. elegans: Lessons Learned from Pseudomonas aeruginosa Infection. Int J Mol Sci 2024; 25:7034. [PMID: 39000143 PMCID: PMC11241598 DOI: 10.3390/ijms25137034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2024] [Revised: 06/17/2024] [Accepted: 06/22/2024] [Indexed: 07/16/2024] Open
Abstract
Infections, such as that by the multiresistant opportunistic bacterial pathogen Pseudomonas aeruginosa, may pose a serious health risk, especially on vulnerable patient populations. The nematode Caenorhabditis elegans provides a simple organismal model to investigate both pathogenic mechanisms and the emerging role of innate immunity in host protection. Here, we review the virulence and infection strategies of P. aeruginosa and host defenses of C. elegans. We summarize the recognition mechanisms of patterns of pathogenesis, including novel pathogen-associated molecular patterns and surveillance immunity of translation, mitochondria, and lysosome-related organelles. We also review the regulation of antimicrobial and behavioral defenses by the worm's neuroendocrine system. We focus on how discoveries in this rich field align with well-characterized evolutionary conserved protective pathways, as well as on potential crossovers to human pathogenesis and innate immune responses.
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Affiliation(s)
- Gábor Hajdú
- Department of Molecular Biology, Semmelweis University, 1094 Budapest, Hungary
| | - Csenge Szathmári
- Department of Molecular Biology, Semmelweis University, 1094 Budapest, Hungary
| | - Csaba Sőti
- Department of Molecular Biology, Semmelweis University, 1094 Budapest, Hungary
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2
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Srivastava V, Bandhu S, Mishra S, Chaudhuri TK. Calcium-induced structural transitions are central to the folding, function, and processing of serratiopeptidase zymogen into mature form. FEBS J 2024; 291:1958-1973. [PMID: 38700222 DOI: 10.1111/febs.17090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 01/05/2024] [Accepted: 02/01/2024] [Indexed: 05/05/2024]
Abstract
Serratia marcescens is an emerging health-threatening, gram-negative opportunistic pathogen associated with a wide variety of localized and life-threatening systemic infections. One of the most crucial virulence factors produced by S. marcescens is serratiopeptidase, a 50.2-kDa repeats-in-toxin (RTX) family broad-specificity zinc metalloprotease. RTX family proteins are functionally diverse exoproteins of gram-negative bacteria that exhibit calcium-dependent structural dynamicity and are secreted through a common type-1 secretion system (T1SS) machinery. To evaluate the impact of various divalent ligands on the folding and maturation of serratiopeptidase zymogen, the protein was purified and a series of structural and functional investigations were undertaken. The results indicate that calcium binding to the C-terminal RTX domain acts as a folding switch, triggering a disordered-to-ordered transition in the enzyme's conformation. Further, the auto-processing of the 16-amino acid N-terminal pro-peptide results in the maturation of the enzyme. The binding of calcium ions to serratiopeptidase causes a highly cooperative conformational transition in its structure, which is essential for the enzyme's activation and maturation. This conformational change is accompanied by an increase in solubility and enzymatic activity. For efficient secretion and to minimize intracellular toxicity, the enzyme needs to be in an unfolded extended form. The calcium-rich extracellular environment favors the folding and processing of zymogen into mature serratiopeptidase, i.e., the holo-form required by S. marcescens to establish infections and survive in different environmental niches.
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Affiliation(s)
- Vishal Srivastava
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, India
| | - Sheetal Bandhu
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, India
| | - Shivam Mishra
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, India
| | - Tapan K Chaudhuri
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, India
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3
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Aguilera-Toro M, Kragh ML, Thomasen AV, Piccini V, Rauh V, Xiao Y, Wiking L, Poulsen NA, Hansen LT, Larsen LB. Proteolytic activity and heat resistance of the protease AprX from Pseudomonas in relation to genotypic characteristics. Int J Food Microbiol 2023; 391-393:110147. [PMID: 36848797 DOI: 10.1016/j.ijfoodmicro.2023.110147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 02/15/2023] [Accepted: 02/17/2023] [Indexed: 02/24/2023]
Abstract
AprX is an alkaline metalloprotease produced by Pseudomonas spp. and encoded by its initial gene of the aprX-lipA operon. The intrinsic diversity among Pseudomonas spp. regarding their proteolytic activity is the main challenge for the development of accurate methods for spoilage prediction of ultra-high temperature (UHT) treated milk in the dairy industry. In the present study, 56 Pseudomonas strains were characterized by assessing their proteolytic activity in milk before and after lab-scale UHT treatment. From these, 24 strains were selected based on their proteolytic activity for whole genome sequencing (WGS) to identify common genotypic characteristics that correlated with the observed variations in proteolytic activity. Four groups (A1, A2, B and N) were determined based on operon aprX-lipA sequence similarities. These alignment groups were observed to significantly influence the proteolytic activity of the strains, with an average proteolytic activity of A1 > A2 > B > N. The lab-scale UHT treatment did not significantly influence their proteolytic activity, indicating a high thermal stability of proteases among strains. Amino acid sequence variation of biologically-relevant motifs in the AprX sequence, namely the Zn2+-binding motif at the catalytic domain and the C-terminal type I secretion signaling mechanism, were found to be highly conserved within alignment groups. These motifs could serve as future potential genetic biomarkers for determination of alignment groups and thereby strain spoilage potential.
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Affiliation(s)
| | - Martin Laage Kragh
- Technical University of Denmark, Food Microbiology and Hygiene Research Group, Denmark
| | | | | | | | - Yinghua Xiao
- Arla Innovation Center, Arla Foods Amba, Denmark
| | - Lars Wiking
- Department of Food Science, Aarhus University, Denmark
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4
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Liao C, Huang X, Wang Q, Yao D, Lu W. Virulence Factors of Pseudomonas Aeruginosa and Antivirulence Strategies to Combat Its Drug Resistance. Front Cell Infect Microbiol 2022; 12:926758. [PMID: 35873152 PMCID: PMC9299443 DOI: 10.3389/fcimb.2022.926758] [Citation(s) in RCA: 85] [Impact Index Per Article: 42.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Accepted: 06/09/2022] [Indexed: 11/24/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen causing nosocomial infections in severely ill and immunocompromised patients. Ubiquitously disseminated in the environment, especially in hospitals, it has become a major threat to human health due to the constant emergence of drug-resistant strains. Multiple resistance mechanisms are exploited by P. aeruginosa, which usually result in chronic infections difficult to eradicate. Diverse virulence factors responsible for bacterial adhesion and colonization, host immune suppression, and immune escape, play important roles in the pathogenic process of P. aeruginosa. As such, antivirulence treatment that aims at reducing virulence while sparing the bacterium for its eventual elimination by the immune system, or combination therapies, has significant advantages over traditional antibiotic therapy, as the former imposes minimal selective pressure on P. aeruginosa, thus less likely to induce drug resistance. In this review, we will discuss the virulence factors of P. aeruginosa, their pathogenic roles, and recent advances in antivirulence drug discovery for the treatment of P. aeruginosa infections.
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Affiliation(s)
- Chongbing Liao
- Key Laboratory of Medical Molecular Virology (Ministry of Education (MOE)/National Health Commission (NHC)/Chinese Academy of Medical Sciences (CAMS)), School of Basic Medical Science, Fudan University, Shanghai, China
| | - Xin Huang
- Key Laboratory of Medical Molecular Virology (Ministry of Education (MOE)/National Health Commission (NHC)/Chinese Academy of Medical Sciences (CAMS)), School of Basic Medical Science, Fudan University, Shanghai, China
| | - Qingxia Wang
- Key Laboratory of Medical Molecular Virology (Ministry of Education (MOE)/National Health Commission (NHC)/Chinese Academy of Medical Sciences (CAMS)), School of Basic Medical Science, Fudan University, Shanghai, China
| | - Dan Yao
- Key Laboratory of Medical Molecular Virology (Ministry of Education (MOE)/National Health Commission (NHC)/Chinese Academy of Medical Sciences (CAMS)), School of Basic Medical Science, Fudan University, Shanghai, China
| | - Wuyuan Lu
- Key Laboratory of Medical Molecular Virology (Ministry of Education (MOE)/National Health Commission (NHC)/Chinese Academy of Medical Sciences (CAMS)), School of Basic Medical Science, Fudan University, Shanghai, China.,Shanghai Institute of Infectious Disease and Biosecurity, School of Public Health, Fudan University, Shanghai, China
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5
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Wu Y, Ma F, Pang X, Chen Y, Niu A, Tan S, Chen X, Qiu W, Wang G. Involvement of AprD in regulating biofilm structure, matrix secretion, and cell metabolism of meat-borne Pseudomonas fragi during chilled storage. Food Res Int 2022; 157:111400. [PMID: 35761654 DOI: 10.1016/j.foodres.2022.111400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 05/18/2022] [Accepted: 05/20/2022] [Indexed: 11/04/2022]
Abstract
Pseudomonas fragi is by far one of the most threatening species in the spoilage of chilled meat that is stored under aerobic conditions. The membrane protein AprD is a well-established regulator controlling protease secretion in Pseudomonas spp. However, its exact roles in modulating metabolic pathways and spoilage potential of P. fragi at the molecular level remain undefined. Here, an in-frame deletion mutation of aprD was used to explore the impacts on their biofilm structure, matrix secretion, and cell metabolism. The results showed that ΔaprD formed relatively disorganized loose aggregation in biofilm, resulting in a thinner structure and more dead cells. Meanwhile, marked changes in the content of extracellular carbohydrates and proteins were observed. Furthermore, intracellular metabolomic profiling revealed the involvement of aprD in several cellular metabolic pathways, mostly including the carbohydrate pathway, amino acid pathway, and nucleotide pathway, while the characterization of extracellular metabolism clarified the variations in the spoilage-related metabolites (e.g., creatine, IMP, spermine, fatty acids, amino acids, and oligopeptides) could be highly correlated with aprD deletion. In this finding, we indicated that aprD could be responsible for cell reproduction and in situ spoilage potential of P. fragi NMC25 during chilled storage by controlling related metabolism and nutrients utilization. Thus, our results will contribute to an improved understanding of the regulatory mechanism of aprD gene in meat spoilage contaminated with P. fragi, which can be valuable to ensure the quality and safety of meat.
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Affiliation(s)
- Yajie Wu
- College of Food Science and Engineering/Collaborative Innovation Center for Modern Grain Circulation and Safety/Key Laboratory of Grains and Oils Quality Control and Processing, Nanjing University of Finance and Economics, Nanjing 210023, China
| | - Fang Ma
- Institute of Veterinary Immunology & Engineering, National Research Center of Engineering and Technology for Veterinary Biologicals, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Xinyi Pang
- College of Food Science and Engineering/Collaborative Innovation Center for Modern Grain Circulation and Safety/Key Laboratory of Grains and Oils Quality Control and Processing, Nanjing University of Finance and Economics, Nanjing 210023, China
| | - Yuping Chen
- College of Food Science and Engineering/Collaborative Innovation Center for Modern Grain Circulation and Safety/Key Laboratory of Grains and Oils Quality Control and Processing, Nanjing University of Finance and Economics, Nanjing 210023, China
| | - Ajuan Niu
- College of Food Science and Engineering/Collaborative Innovation Center for Modern Grain Circulation and Safety/Key Laboratory of Grains and Oils Quality Control and Processing, Nanjing University of Finance and Economics, Nanjing 210023, China
| | - Song Tan
- College of Food Science and Engineering/Collaborative Innovation Center for Modern Grain Circulation and Safety/Key Laboratory of Grains and Oils Quality Control and Processing, Nanjing University of Finance and Economics, Nanjing 210023, China
| | - Xing Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Weifen Qiu
- College of Food Science and Engineering/Collaborative Innovation Center for Modern Grain Circulation and Safety/Key Laboratory of Grains and Oils Quality Control and Processing, Nanjing University of Finance and Economics, Nanjing 210023, China
| | - Guangyu Wang
- College of Food Science and Engineering/Collaborative Innovation Center for Modern Grain Circulation and Safety/Key Laboratory of Grains and Oils Quality Control and Processing, Nanjing University of Finance and Economics, Nanjing 210023, China.
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Molecular Investigation of Outer Membrane Channel Genes Among Multidrug Resistance Clinical Pseudomonas Aeruginosa Isolates. Rep Biochem Mol Biol 2022; 11:102-110. [PMID: 35765529 PMCID: PMC9208561 DOI: 10.52547/rbmb.11.1.102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 09/19/2021] [Indexed: 01/11/2023]
Abstract
Background Multidrug resistance Pseudomonas aeruginosa (MDRPA) is most important issue in healthcare setting. It can secrete many virulence effector proteins via its secretion system type (T1SS-T6SS). They are using them as conductor for delivering the effector proteins outside to begins harmful effect on host cell increasing pathogenicity, competition against other microorganism and nutrient acquisition. Methods The study include investigation of 50 isolates of MDRPA for transport secretion system and resistance for antibiotics. Molecular diagnosis using P. aeruginosa specific primer pairs, investigation of AprF, HasF, XcpQ, HxcQ, PscC, CdrB, CupB3, and Hcp using specific primer pairs by PCR were also performed. Results The results revealed high resistance to beta lactam antibiotics (78% for ceftazidime, 78% for cefepime and 46% for piperacillin) can indicate possessing of isolates for beta lactamases and this confirmed by dropping resistance to piperacillin to 16% when combined with tazobactam. Also, the results shown the ability of MDRPA for pyocyanin biosynthesis using the system of genes. Conclusion The current study conclude that all isolates of P. aeruginosa were highly virulent due to their possessing of all transport secretion system to deliver different effector proteins with possible harmful effects of these proteins.
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Turco S, Drais MI, Rossini L, Chaboteaux E, Rahi YJ, Balestra GM, Iacobellis NS, Mazzaglia A. Complete genome assembly of the levan-positive strain PVFi1 of Pseudomonas savastanoi pv. savastanoi isolated from olive knots in Central Italy. ENVIRONMENTAL MICROBIOLOGY REPORTS 2022; 14:274-285. [PMID: 35107220 PMCID: PMC9302664 DOI: 10.1111/1758-2229.13048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 01/23/2022] [Indexed: 05/08/2023]
Abstract
Pseudomonas savastanoi pv. savastanoi, the causal agent of olive knot disease, is a fluorescent Gram-negative bacterium classified, according to the specific LOPAT profile, as Ib. However, during the 90s, a number of atypical non-fluorescent levan-positive strains of Pseudomonas savastanoi pv. savastanoi have been unexpectedly isolated from olive knots in Central Italy. Since its first report, several studies were conducted on this species variant, but its genome sequence has never been reported. The complete genome sequence and two additional plasmids of PVFi1, a representative strain, were here obtained using a hybrid sequencing approach with both Oxford Nanopore Technology and Illumina sequencing. A thorough genomic analysis unravelled several genetic features of this peculiar strain, showing a transposase insertion downstream a fragmented copy of the levansucrase gene. The same features were previously reported on levan-negative Pseudomonas savastanoi pv. savastanoi strains. In addition, a second copy of the levansucrase gene fully equipped for a gene expression and comparable to the levan-positive Pseudomonas savastanoi pv. glycinea, may explain the levan-positive test. This result provides a solid genetic demonstration that the bacterial species Pseudomonas savastanoi contains either levan-positive or levan-negative strains, providing insights for an update of the related LOPAT classification.
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Affiliation(s)
- Silvia Turco
- Dipartimento di Scienze Agrarie e Forestali, Università degli Studi della Tuscia, Via S. Camillo de Lellis sncViterbo01100Italy
| | - Mounira Inas Drais
- Dipartimento di Scienze Agrarie e Forestali, Università degli Studi della Tuscia, Via S. Camillo de Lellis sncViterbo01100Italy
| | - Luca Rossini
- Dipartimento di Scienze Agrarie e Forestali, Università degli Studi della Tuscia, Via S. Camillo de Lellis sncViterbo01100Italy
| | - Elena Chaboteaux
- Dipartimento di Scienze Agrarie e Forestali, Università degli Studi della Tuscia, Via S. Camillo de Lellis sncViterbo01100Italy
| | - Yaseen Jundi Rahi
- Dipartimento di Scienze Agrarie e Forestali, Università degli Studi della Tuscia, Via S. Camillo de Lellis sncViterbo01100Italy
- CIHEAM‐Mediterranean Agronomic Institute of Bari, Via Ceglie 9Valenzano70010Italy
| | - Giorgio Mariano Balestra
- Dipartimento di Scienze Agrarie e Forestali, Università degli Studi della Tuscia, Via S. Camillo de Lellis sncViterbo01100Italy
| | | | - Angelo Mazzaglia
- Dipartimento di Scienze Agrarie e Forestali, Università degli Studi della Tuscia, Via S. Camillo de Lellis sncViterbo01100Italy
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8
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Wang G, Qing li, Tang W, Ma F, Wang H, Xu X, Qiu W. AprD is important for extracellular proteolytic activity, physicochemical properties and spoilage potential in meat-borne Pseudomonas fragi. Food Control 2021. [DOI: 10.1016/j.foodcont.2021.107868] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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9
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Maier C, Hofmann K, Huptas C, Scherer S, Wenning M, Lücking G. Simultaneous quantification of the most common and proteolytic Pseudomonas species in raw milk by multiplex qPCR. Appl Microbiol Biotechnol 2021; 105:1693-1708. [PMID: 33527148 PMCID: PMC7880948 DOI: 10.1007/s00253-021-11109-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 12/17/2020] [Accepted: 01/11/2021] [Indexed: 12/26/2022]
Abstract
Abstract The heat-stable peptidase AprX, secreted by psychrotolerant Pseudomonas species in raw milk, is a major cause of destabilization and premature spoilage of ultra-high temperature (UHT) milk and milk products. To enable rapid detection and quantification of seven frequent and proteolytic Pseudomonas species (P. proteolytica, P. gessardii, P. lactis, P. fluorescens, P. protegens, P. lundensis, and P. fragi) in raw milk, we developed two triplex qPCR assays taking into account species-dependent differences in AprX activity. Besides five species-specific hydrolysis probes, targeting the aprX gene, a universal rpoB probe was included in the assay to determine the total Pseudomonas counts. For all six probes, linear regression lines between Cq value and target DNA concentration were obtained in singleplex as well as in multiplex approaches, yielding R2 values of > 0.975 and amplification efficiencies of 85–97%. Moreover, high specificity was determined using genomic DNA of 75 Pseudomonas strains, assigned to 57 species, and 40 other bacterial species as templates in the qPCR. Quantification of the target species and total Pseudomonas counts resulted in linear detection ranges of approx. 103–107 cfu/ml, which correspond well to common Pseudomonas counts in raw milk. Application of the assay using 60 raw milk samples from different dairies showed good agreement of total Pseudomonas counts calculated by qPCR with cell counts derived from cultivation. Furthermore, a remarkably high variability regarding the species composition was observed for each milk sample, whereby P. lundensis and P. proteolytica/P. gessardii were the predominant species detected. Key points • Multiplex qPCR for quantification of seven proteolytic Pseudomonas species and total Pseudomonas counts in raw milk • High specificity and sensitivity via hydrolysis probes against aprX and rpoB • Rapid method to determine Pseudomonas contamination in raw milk and predict spoilage potential Supplementary Information The online version contains supplementary material available at 10.1007/s00253-021-11109-0.
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Affiliation(s)
- Christopher Maier
- ZIEL Institute for Food and Health, Wissenschaftszentrum Weihenstephan, Technische Universität München, Weihenstephaner Berg 1, 85354, Freising, Germany
| | - Katharina Hofmann
- ZIEL Institute for Food and Health, Wissenschaftszentrum Weihenstephan, Technische Universität München, Weihenstephaner Berg 1, 85354, Freising, Germany
| | - Christopher Huptas
- Lehrstuhl für Mikrobielle Ökologie, Wissenschaftszentrum Weihenstephan, Technische Universität München, Weihenstephaner Berg 3, 85354, Freising, Germany
| | - Siegfried Scherer
- ZIEL Institute for Food and Health, Wissenschaftszentrum Weihenstephan, Technische Universität München, Weihenstephaner Berg 1, 85354, Freising, Germany.,Lehrstuhl für Mikrobielle Ökologie, Wissenschaftszentrum Weihenstephan, Technische Universität München, Weihenstephaner Berg 3, 85354, Freising, Germany
| | - Mareike Wenning
- Bavarian Health and Food Safety Authority (LGL), Veterinärstr. 2, 85764, Oberschleißheim, Germany
| | - Genia Lücking
- ZIEL Institute for Food and Health, Wissenschaftszentrum Weihenstephan, Technische Universität München, Weihenstephaner Berg 1, 85354, Freising, Germany.
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Phenotypic Adaptation of Pseudomonas aeruginosa in the Presence of Siderophore-Antibiotic Conjugates during Epithelial Cell Infection. Microorganisms 2020; 8:microorganisms8111820. [PMID: 33218210 PMCID: PMC7699141 DOI: 10.3390/microorganisms8111820] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 11/12/2020] [Accepted: 11/15/2020] [Indexed: 12/14/2022] Open
Abstract
Iron acquisition pathways have often been considered to be gateways for the uptake of antibiotics into bacteria. Bacteria excrete chelators, called siderophores, to access iron. Antibiotic molecules can be covalently attached to siderophores for their transport into pathogens during the iron-uptake process. P. aeruginosa produces two siderophores and is also able to use many siderophores produced by other bacteria. We investigated the phenotypic plasticity of iron-uptake pathway expression in an epithelial cell infection assay in the presence of two different siderophore-antibiotic conjugates, one with a hydroxamate siderophore and the second with a tris-catechol. Proteomic and RT-qPCR approaches showed that P. aeruginosa was able to sense the presence of both compounds in its environment and adapt the expression of its iron uptake pathways to access iron via them. Moreover, the catechol-type siderophore-antibiotic was clearly more efficient in inducing the expression of its corresponding transporter than the hydroxamate compound when both were simultaneously present. In parallel, the expression of the proteins of the two iron uptake pathways using siderophores produced by P. aeruginosa was significantly repressed in the presence of both conjugates. Altogether, the data indicate that catechol-type siderophores are more promising vectors for antibiotic vectorization using a Trojan-horse strategy.
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11
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Varadarajan AR, Allan RN, Valentin JDP, Castañeda Ocampo OE, Somerville V, Pietsch F, Buhmann MT, West J, Skipp PJ, van der Mei HC, Ren Q, Schreiber F, Webb JS, Ahrens CH. An integrated model system to gain mechanistic insights into biofilm-associated antimicrobial resistance in Pseudomonas aeruginosa MPAO1. NPJ Biofilms Microbiomes 2020; 6:46. [PMID: 33127897 PMCID: PMC7603352 DOI: 10.1038/s41522-020-00154-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 10/07/2020] [Indexed: 12/11/2022] Open
Abstract
Pseudomonas aeruginosa MPAO1 is the parental strain of the widely utilized transposon mutant collection for this important clinical pathogen. Here, we validate a model system to identify genes involved in biofilm growth and biofilm-associated antibiotic resistance. Our model employs a genomics-driven workflow to assemble the complete MPAO1 genome, identify unique and conserved genes by comparative genomics with the PAO1 reference strain and genes missed within existing assemblies by proteogenomics. Among over 200 unique MPAO1 genes, we identified six general essential genes that were overlooked when mapping public Tn-seq data sets against PAO1, including an antitoxin. Genomic data were integrated with phenotypic data from an experimental workflow using a user-friendly, soft lithography-based microfluidic flow chamber for biofilm growth and a screen with the Tn-mutant library in microtiter plates. The screen identified hitherto unknown genes involved in biofilm growth and antibiotic resistance. Experiments conducted with the flow chamber across three laboratories delivered reproducible data on P. aeruginosa biofilms and validated the function of both known genes and genes identified in the Tn-mutant screens. Differential protein abundance data from planktonic cells versus biofilm confirmed the upregulation of candidates known to affect biofilm formation, of structural and secreted proteins of type VI secretion systems, and provided proteogenomic evidence for some missed MPAO1 genes. This integrated, broadly applicable model promises to improve the mechanistic understanding of biofilm formation, antimicrobial tolerance, and resistance evolution in biofilms.
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Affiliation(s)
- Adithi R Varadarajan
- Research Group Molecular Diagnostics Genomics & Bioinformatics, Agroscope and SIB Swiss Institute of Bioinformatics, Wädenswil, Switzerland.
| | - Raymond N Allan
- School of Biological Sciences and Institute for Life Sciences, University of Southampton, Southampton, SO17 1BJ, UK
- National Biofilms Innovation Centre, University of Southampton, Southampton, SO17 1BJ, UK
- School of Pharmacy, Faculty of Health and Life Sciences, De Montfort University, Leicester, LE1 9BH, UK
| | - Jules D P Valentin
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen, Switzerland
- Department of BioMedical Engineering, University of Groningen and University Medical Center Groningen, Groningen, Netherlands
| | - Olga E Castañeda Ocampo
- Department of BioMedical Engineering, University of Groningen and University Medical Center Groningen, Groningen, Netherlands
| | - Vincent Somerville
- Research Group Molecular Diagnostics Genomics & Bioinformatics, Agroscope and SIB Swiss Institute of Bioinformatics, Wädenswil, Switzerland
| | - Franziska Pietsch
- Division of Biodeterioration and Reference Organisms, Federal Institute for Materials Research and Testing (BAM), Berlin, Germany
| | - Matthias T Buhmann
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen, Switzerland
| | - Jonathan West
- Faculty of Medicine, University of Southampton, Southampton, SO17 1BJ, UK
- Centre for Hybrid Biodevices, University of Southampton, Southampton, SO17 1BJ, UK
| | - Paul J Skipp
- Centre for Proteomics Research, University of Southampton, Southampton, SO17 1BJ, UK
| | - Henny C van der Mei
- Department of BioMedical Engineering, University of Groningen and University Medical Center Groningen, Groningen, Netherlands
| | - Qun Ren
- Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, St. Gallen, Switzerland
| | - Frank Schreiber
- Division of Biodeterioration and Reference Organisms, Federal Institute for Materials Research and Testing (BAM), Berlin, Germany
| | - Jeremy S Webb
- School of Biological Sciences and Institute for Life Sciences, University of Southampton, Southampton, SO17 1BJ, UK
- National Biofilms Innovation Centre, University of Southampton, Southampton, SO17 1BJ, UK
| | - Christian H Ahrens
- Research Group Molecular Diagnostics Genomics & Bioinformatics, Agroscope and SIB Swiss Institute of Bioinformatics, Wädenswil, Switzerland.
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12
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Quantification of Extracellular Proteases and Chitinases from Marine Bacteria. Curr Microbiol 2020; 77:3927-3936. [PMID: 32986181 DOI: 10.1007/s00284-020-02216-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 09/17/2020] [Indexed: 01/23/2023]
Abstract
A total of 92 marine bacteria belonging to Pseudomonas, Pseudoalteromonas, Psychrobacter, and Shewanella were first screened for their proteolytic activity. In total, four Pseudomonas strains belonging to Ps. fluorescens, Ps. fragi, Ps. gessardii, and Ps. marginalis; 14 Pseudoalteromonas strains belonging to Psa. arctica, Psa. carrageenovora, Psa. elyakovii, Psa. issachenkonii, Psa. rubra, Psa. translucida, and Psa. tunicata; and two Shewanella strains belonging to S. baltica and S. putrefaciens were identified to have a weak to high proteolytic activity (from 478 to 4445 mU/mg trypsin equivalent) against skim milk casein as protein source. Further chitinolytic activity screening based on these 20 proteolytic strains using colloidal chitin yielded five positive strains which were tested against three different chitin substrates in order to determine the various types of chitinases. Among the strains that can produce both proteases and chitinases, Psa. rubra DSM 6842T expressed not only the highest proteolytic activity (2558 mU/mg trypsin equivalent) but also the highest activity of exochitinases, specifically, β-N-acetylglucosaminidase (6.33 mU/107 cfu) as well. We anticipate that this strain can be innovatively applied to the valorization of marine crustaceans side streams.
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Identification of Pseudomonas jessenii and Pseudomonas gessardii as the most proteolytic Pseudomonas isolates in Iranian raw milk and their impact on stability of sterilized milk during storage. J DAIRY RES 2020; 87:368-374. [PMID: 32893770 DOI: 10.1017/s0022029920000709] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Identification of the most proteolytic Pseudomonas strains that can produce heat-resistant proteases and contribute to the Ultra High Temperature (UHT) milk destabilization is of great interest. In the present study, among the 146 Pseudomonas isolates that encoded the aprX gene, five isolates with the highest proteolytic activity were selected and identified based on 16S rRNA, rpoD and gyrB gene sequences data. The identification results were confirmed by phylogenetic analysis based on multilocus sequence analysis and identified the representative isolates as P. jessenii (two isolates) and P. gessardii (three isolates). Casein zymography demonstrated the ability of these species to produce heat-resistant enzymes, AprX, with molecular mass of about 48 kDa during storage at 7° C for 72 h. In sterilized milk samples, the residual activity of AprX caused a considerable enhancement in the degree of protein hydrolysis, non-protein nitrogen and non-casein nitrogen contents of the samples during a two-month storage. This enhancement was slightly higher in samples containing enzyme produced by P. jessenii compared to P. gessardii ones, resulting in earlier onset of sterilized milk destabilization. Hence, this study revealed that P. jessenii and P. gessardii can play a considerable role in deterioration of Iranian commercial long-life milk.
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Maier C, Huptas C, von Neubeck M, Scherer S, Wenning M, Lücking G. Genetic Organization of the aprX-lipA2 Operon Affects the Proteolytic Potential of Pseudomonas Species in Milk. Front Microbiol 2020; 11:1190. [PMID: 32587583 PMCID: PMC7298200 DOI: 10.3389/fmicb.2020.01190] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 05/11/2020] [Indexed: 11/30/2022] Open
Abstract
Psychrotolerant Pseudomonas species are a main cause of proteolytic spoilage of ultra-high temperature (UHT) milk products due to the secretion of the heat-resistant metallopeptidase AprX, which is encoded by the first gene of the aprX-lipA2 operon. While the proteolytic property has been characterized for many different Pseudomonas isolates, the underlying aprX-lipA2 gene organization was only described for a few strains so far. In this study, the phylogenomic analysis of 185 Pseudomonas type strains revealed that the presence of aprX is strongly associated to a monophylum composed of 81 species, of which 83% carried the aprX locus. Furthermore, almost all type strains of known milk-relevant species were shown to be members of the three monophyletic groups P. fluorescens, P. gessardii, and P. fragi. In total, 22 different types of aprX-lipA2 genetic organizations were identified in the genus, whereby 31% of the species tested carried the type 1 operon structure consisting of eight genes (aprXIDEF prtAB lipA2). Other genetic structures differed from type 1 mainly in the presence and location of genes coding for two lipases (lipA1 and lipA2) and putative autotransporters (prtA and prtB). The peptidase activity of 129 strains, as determined on skim milk agar and in UHT-milk, correlated largely with different aprX-lipA2 gene compositions. Particularly, isolates harboring the type 1 operon were highly proteolytic, while strains with other operon types, especially ones lacking prtA and prtB, exhibited significantly lower peptidase activities. In conclusion, the phylogenomic position and the aprX-lipA2 gene organization specify the proteolytic potential of Pseudomonas isolates. In addition, however, an interplay of several environmental factors and intrinsic traits influences production and activity of AprX, leading to strain-specific proteolytic phenotypes.
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Affiliation(s)
- Christopher Maier
- ZIEL Institute for Food and Health, Wissenschaftszentrum Weihenstephan, Technische Universität München, Freising, Germany
| | - Christopher Huptas
- Lehrstuhl für Mikrobielle Ökologie, Wissenschaftszentrum Weihenstephan, Technische Universität München, Freising, Germany
| | - Mario von Neubeck
- ZIEL Institute for Food and Health, Wissenschaftszentrum Weihenstephan, Technische Universität München, Freising, Germany
| | - Siegfried Scherer
- ZIEL Institute for Food and Health, Wissenschaftszentrum Weihenstephan, Technische Universität München, Freising, Germany
- Lehrstuhl für Mikrobielle Ökologie, Wissenschaftszentrum Weihenstephan, Technische Universität München, Freising, Germany
| | - Mareike Wenning
- Bavarian Health and Food Safety Authority (LGL), Oberschleißheim, Germany
| | - Genia Lücking
- ZIEL Institute for Food and Health, Wissenschaftszentrum Weihenstephan, Technische Universität München, Freising, Germany
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Lucas R, Hadizamani Y, Gonzales J, Gorshkov B, Bodmer T, Berthiaume Y, Moehrlen U, Lode H, Huwer H, Hudel M, Mraheil MA, Toque HAF, Chakraborty T, Hamacher J. Impact of Bacterial Toxins in the Lungs. Toxins (Basel) 2020; 12:toxins12040223. [PMID: 32252376 PMCID: PMC7232160 DOI: 10.3390/toxins12040223] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 03/30/2020] [Accepted: 03/31/2020] [Indexed: 12/13/2022] Open
Abstract
Bacterial toxins play a key role in the pathogenesis of lung disease. Based on their structural and functional properties, they employ various strategies to modulate lung barrier function and to impair host defense in order to promote infection. Although in general, these toxins target common cellular signaling pathways and host compartments, toxin- and cell-specific effects have also been reported. Toxins can affect resident pulmonary cells involved in alveolar fluid clearance (AFC) and barrier function through impairing vectorial Na+ transport and through cytoskeletal collapse, as such, destroying cell-cell adhesions. The resulting loss of alveolar-capillary barrier integrity and fluid clearance capacity will induce capillary leak and foster edema formation, which will in turn impair gas exchange and endanger the survival of the host. Toxins modulate or neutralize protective host cell mechanisms of both the innate and adaptive immunity response during chronic infection. In particular, toxins can either recruit or kill central players of the lung's innate immune responses to pathogenic attacks, i.e., alveolar macrophages (AMs) and neutrophils. Pulmonary disorders resulting from these toxin actions include, e.g., acute lung injury (ALI), the acute respiratory syndrome (ARDS), and severe pneumonia. When acute infection converts to persistence, i.e., colonization and chronic infection, lung diseases, such as bronchitis, chronic obstructive pulmonary disease (COPD), and cystic fibrosis (CF) can arise. The aim of this review is to discuss the impact of bacterial toxins in the lungs and the resulting outcomes for pathogenesis, their roles in promoting bacterial dissemination, and bacterial survival in disease progression.
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Affiliation(s)
- Rudolf Lucas
- Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Department of Medicine and Division of Pulmonary Critical Care Medicine, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Correspondence: (R.L.); (J.H.); Tel.: +41-31-300-35-00 (J.H.)
| | - Yalda Hadizamani
- Lungen-und Atmungsstiftung, Bern, 3012 Bern, Switzerland;
- Pneumology, Clinic for General Internal Medicine, Lindenhofspital Bern, 3012 Bern, Switzerland
| | - Joyce Gonzales
- Department of Medicine and Division of Pulmonary Critical Care Medicine, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
| | - Boris Gorshkov
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
| | - Thomas Bodmer
- Labormedizinisches Zentrum Dr. Risch, Waldeggstr. 37 CH-3097 Liebefeld, Switzerland;
| | - Yves Berthiaume
- Department of Medicine, Faculty of Medicine, Université de Montréal, Montréal, QC H3T 1J4, Canada;
| | - Ueli Moehrlen
- Pediatric Surgery, University Children’s Hospital, Zürich, Steinwiesstrasse 75, CH-8032 Zürch, Switzerland;
| | - Hartmut Lode
- Insitut für klinische Pharmakologie, Charité, Universitätsklinikum Berlin, Reichsstrasse 2, D-14052 Berlin, Germany;
| | - Hanno Huwer
- Department of Cardiothoracic Surgery, Voelklingen Heart Center, 66333 Voelklingen/Saar, Germany;
| | - Martina Hudel
- Justus-Liebig-University, Biomedical Research Centre Seltersberg, Schubertstr. 81, 35392 Giessen, Germany; (M.H.); (M.A.M.); (T.C.)
| | - Mobarak Abu Mraheil
- Justus-Liebig-University, Biomedical Research Centre Seltersberg, Schubertstr. 81, 35392 Giessen, Germany; (M.H.); (M.A.M.); (T.C.)
| | - Haroldo Alfredo Flores Toque
- Pharmacology and Toxicology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA;
| | - Trinad Chakraborty
- Justus-Liebig-University, Biomedical Research Centre Seltersberg, Schubertstr. 81, 35392 Giessen, Germany; (M.H.); (M.A.M.); (T.C.)
| | - Jürg Hamacher
- Lungen-und Atmungsstiftung, Bern, 3012 Bern, Switzerland;
- Pneumology, Clinic for General Internal Medicine, Lindenhofspital Bern, 3012 Bern, Switzerland
- Medical Clinic V-Pneumology, Allergology, Intensive Care Medicine and Environmental Medicine, Faculty of Medicine, Saarland University, University Medical Centre of the Saarland, D-66421 Homburg, Germany
- Institute for Clinical & Experimental Surgery, Faculty of Medicine, Saarland University, D-66421 Homburg, Germany
- Correspondence: (R.L.); (J.H.); Tel.: +41-31-300-35-00 (J.H.)
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16
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Mesquita CS, Soares-Castro P, Faustino A, Santos HM, Capelo JL, Santos P. Identification of genomic loci associated with genotypic and phenotypic variation among Pseudomonas aeruginosa clinical isolates from pneumonia. Microb Pathog 2019; 136:103702. [PMID: 31472259 DOI: 10.1016/j.micpath.2019.103702] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 08/27/2019] [Accepted: 08/28/2019] [Indexed: 11/19/2022]
Abstract
In this work, a genotype-phenotype survey of a highly diversified Pseudomonas aeruginosa collection was conducted, aiming to detail pathogen-associated scenarios that clinicians face nowadays. Genetic relation based on RAPD-PCR of 705 isolates, retrieved from 424 patients and several clinical contexts, reported an almost isolate-specific molecular-pattern. Pneumonia-associated isolates HB13 and HB15, clustered in the same RAPD-PCR group, were selected to evaluate the genomic background underlying their contrasting antibiotic resistance and virulence. The HB13 genome harbors antibiotic-inactivating enzymes-coding genes (e.g. aac(3)-Ia, arr, blaVIM-2) and single-nucleotide variations (SNVs) in antibiotic targets, likely accounting for its pan-resistance, whereas HB15 susceptibility correlated to predicted dysfunctional alleles. Isolate HB13 showed the unprecedented rhl-cluster absence and variations in other pathogen competitiveness contributors. Conversely, HB15 genome comprises exoenzyme-coding genes and SNVs linked to increased virulence. Secretome analysis identified signatures features with unknown function as potential novel pathogenic (e.g. a MATE-protein in HB13, a protease in HB15) and antibiotic resistance (a HlyD-like secretion protein in HB13) determinants. Detection of active prophages, proteases (including protease IV and alkaline metalloproteinase), a porin and a peptidase in HB15 highlights the secreted arsenal likely essential for its virulent behavior. The presented phenotype-genome association will contribute to the current knowledge on Pseudomonas aeruginosa pathogenomics.
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Affiliation(s)
- Cristina S Mesquita
- CBMA - Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Pedro Soares-Castro
- CBMA - Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal
| | - Alberta Faustino
- Clinical Pathology Service, Hospital de Braga, 4710-243, Braga, Portugal
| | - Hugo M Santos
- UCIBIO, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal; PROTEOMASS Scientific Society, Madan Park, Rua dos Inventores, 2825-152, Caparica, Portugal
| | - José L Capelo
- UCIBIO, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal; PROTEOMASS Scientific Society, Madan Park, Rua dos Inventores, 2825-152, Caparica, Portugal
| | - Pedro Santos
- CBMA - Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal.
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Zhang C, Bijl E, Svensson B, Hettinga K. The Extracellular Protease AprX fromPseudomonasand its Spoilage Potential for UHT Milk: A Review. Compr Rev Food Sci Food Saf 2019; 18:834-852. [DOI: 10.1111/1541-4337.12452] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 03/06/2019] [Accepted: 03/10/2019] [Indexed: 01/10/2023]
Affiliation(s)
- Chunyue Zhang
- Dairy Science and Technology, Food Quality and Design GroupWageningen Univ. and Research P.O. Box 17 6700 AA Wageningen the Netherlands
| | - Etske Bijl
- Dairy Science and Technology, Food Quality and Design GroupWageningen Univ. and Research P.O. Box 17 6700 AA Wageningen the Netherlands
| | - Birgitta Svensson
- Tetra Pak Processing Systems ABRuben Rausings gata 221 86 Lund Sweden
| | - Kasper Hettinga
- Dairy Science and Technology, Food Quality and Design GroupWageningen Univ. and Research P.O. Box 17 6700 AA Wageningen the Netherlands
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18
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TesG is a type I secretion effector of Pseudomonas aeruginosa that suppresses the host immune response during chronic infection. Nat Microbiol 2019; 4:459-469. [PMID: 30617346 DOI: 10.1038/s41564-018-0322-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 11/16/2018] [Indexed: 02/05/2023]
Abstract
Pseudomonas aeruginosa is a versatile Gram-negative pathogen with intricate intracellular regulatory networks that enable it to adapt to and flourish in a variety of biotic and abiotic habitats. However, the mechanism permitting the persistent survival of P. aeruginosa within host tissues and causing chronic symptoms still remains largely elusive. By using in situ RNA sequencing, here we show that P. aeruginosa adopts different metabolic pathways and virulence repertoires to dominate the progression of acute and chronic lung infections. Notably, a virulence factor named TesG, which is controlled by the vital quorum-sensing system and secreted by the downstream type I secretion system, can suppress the host inflammatory response and facilitate the development of chronic lung infection. Mechanically, TesG can enter the intracellular compartment of macrophages through clathrin-mediated endocytosis, competitively inhibit the activity of eukaryotic small GTPase and thus suppress subsequent neutrophil influx, cell cytoskeletal rearrangement of macrophages and the secretion of cytokines and chemokines. Therefore, the identification of TesG in this study reveals a type I secretion apparatus of P. aeruginosa that functions during the host-pathogen interaction, and may open an avenue for the further mechanistic study of chronic respiratory diseases and the development of antibacterial therapy.
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19
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Gonzalez MR, Ducret V, Leoni S, Fleuchot B, Jafari P, Raffoul W, Applegate LA, Que YA, Perron K. Transcriptome Analysis of Pseudomonas aeruginosa Cultured in Human Burn Wound Exudates. Front Cell Infect Microbiol 2018. [PMID: 29535973 PMCID: PMC5835353 DOI: 10.3389/fcimb.2018.00039] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Pseudomonas aeruginosa is a severe opportunistic pathogen and is one of the major causes of hard to treat burn wound infections. Herein we have used an RNA-seq transcriptomic approach to study the behavior of P. aeruginosa PAO1 growing directly on human burn wound exudate. A chemical analysis of compounds used by this bacterium, coupled with kinetics expression of central genes has allowed us to obtain a global view of P. aeruginosa physiological and metabolic changes occurring while growing on human burn wound exudate. In addition to the numerous virulence factors and their secretion systems, we have found that all iron acquisition mechanisms were overexpressed. Deletion and complementation with pyoverdine demonstrated that iron availability was a major limiting factor in burn wound exudate. The quorum sensing systems, known to be important for the virulence of P. aeruginosa, although moderately induced, were activated even at low cell density. Analysis of bacterial metabolism emphasized importance of lactate, lipid and collagen degradation pathways. Overall, this work allowed to designate, for the first time, a global view of P. aeruginosa characteristics while growing in human burn wound exudate and highlight the possible therapeutic approaches to combat P. aeruginosa burn wound infections.
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Affiliation(s)
- Manuel R Gonzalez
- Microbiology Unit, Department of Botany and Plant Biology, Sciences III, University of Geneva, Geneva, Switzerland
| | - Verena Ducret
- Microbiology Unit, Department of Botany and Plant Biology, Sciences III, University of Geneva, Geneva, Switzerland
| | - Sara Leoni
- Microbiology Unit, Department of Botany and Plant Biology, Sciences III, University of Geneva, Geneva, Switzerland
| | - Betty Fleuchot
- Microbiology Unit, Department of Botany and Plant Biology, Sciences III, University of Geneva, Geneva, Switzerland
| | - Paris Jafari
- Plastic, Reconstructive and Hand Surgery, Unit of Regenerative Therapy, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Wassim Raffoul
- Plastic, Reconstructive and Hand Surgery, Unit of Regenerative Therapy, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Lee A Applegate
- Plastic, Reconstructive and Hand Surgery, Unit of Regenerative Therapy, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Yok-Ai Que
- Department of Intensive Care Medicine, Bern University Hospital, Bern, Switzerland
| | - Karl Perron
- Microbiology Unit, Department of Botany and Plant Biology, Sciences III, University of Geneva, Geneva, Switzerland.,School of Pharmaceutical Sciences, University of Geneva and Centre Hospitalier Universitaire Vaudois, Geneva, Switzerland
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20
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Grady SL, Malfatti SA, Gunasekera TS, Dalley BK, Lyman MG, Striebich RC, Mayhew MB, Zhou CL, Ruiz ON, Dugan LC. A comprehensive multi-omics approach uncovers adaptations for growth and survival of Pseudomonas aeruginosa on n-alkanes. BMC Genomics 2017; 18:334. [PMID: 28454561 PMCID: PMC5410065 DOI: 10.1186/s12864-017-3708-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 04/17/2017] [Indexed: 11/20/2022] Open
Abstract
Background Examination of complex biological systems has long been achieved through methodical investigation of the system’s individual components. While informative, this strategy often leads to inappropriate conclusions about the system as a whole. With the advent of high-throughput “omic” technologies, however, researchers can now simultaneously analyze an entire system at the level of molecule (DNA, RNA, protein, metabolite) and process (transcription, translation, enzyme catalysis). This strategy reduces the likelihood of improper conclusions, provides a framework for elucidation of genotype-phenotype relationships, and brings finer resolution to comparative genomic experiments. Here, we apply a multi-omic approach to analyze the gene expression profiles of two closely related Pseudomonas aeruginosa strains grown in n-alkanes or glycerol. Results The environmental P. aeruginosa isolate ATCC 33988 consumed medium-length (C10–C16) n-alkanes more rapidly than the laboratory strain PAO1, despite high genome sequence identity (average nucleotide identity >99%). Our data shows that ATCC 33988 induces a characteristic set of genes at the transcriptional, translational and post-translational levels during growth on alkanes, many of which differ from those expressed by PAO1. Of particular interest was the lack of expression from the rhl operon of the quorum sensing (QS) system, resulting in no measurable rhamnolipid production by ATCC 33988. Further examination showed that ATCC 33988 lacked the entire lasI/lasR arm of the QS response. Instead of promoting expression of QS genes, ATCC 33988 up-regulates a small subset of its genome, including operons responsible for specific alkaline proteases and sphingosine metabolism. Conclusion This work represents the first time results from RNA-seq, microarray, ribosome footprinting, proteomics, and small molecule LC-MS experiments have been integrated to compare gene expression in bacteria. Together, these data provide insights as to why strain ATCC 33988 is better adapted for growth and survival on n-alkanes. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3708-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sarah L Grady
- Biosciences and Biotechnology Division, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA.
| | - Stephanie A Malfatti
- Biosciences and Biotechnology Division, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Thusitha S Gunasekera
- Environmental Microbiology Group, University of Dayton Research Institute, University of Dayton, Dayton, OH, 45469, USA
| | - Brian K Dalley
- Huntsman Cancer Institute, University of Utah School of Medicine, Salt Lake City, UT, 84112, USA
| | - Matt G Lyman
- Biosciences and Biotechnology Division, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Richard C Striebich
- Environmental Microbiology Group, University of Dayton Research Institute, University of Dayton, Dayton, OH, 45469, USA
| | - Michael B Mayhew
- Computational Engineering Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Carol L Zhou
- Computing Applications and Research Department, Global Security Computing and Applications Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Oscar N Ruiz
- Fuels and Energy Branch, Aerospace Systems Directorate, Air Force Research Laboratory, Wright-Patterson AFB, OH, 45433, USA
| | - Larry C Dugan
- Biosciences and Biotechnology Division, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
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21
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Depluverez S, Devos S, Devreese B. The Role of Bacterial Secretion Systems in the Virulence of Gram-Negative Airway Pathogens Associated with Cystic Fibrosis. Front Microbiol 2016; 7:1336. [PMID: 27625638 PMCID: PMC5003817 DOI: 10.3389/fmicb.2016.01336] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 08/12/2016] [Indexed: 11/16/2022] Open
Abstract
Cystic fibrosis (CF) is the most common lethal inherited disorder in Caucasians. It is caused by mutation of the CF transmembrane conductance regulator (CFTR) gene. A defect in the CFTR ion channel causes a dramatic change in the composition of the airway surface fluid, leading to a highly viscous mucus layer. In healthy individuals, the majority of bacteria trapped in the mucus layer are removed and destroyed by mucociliary clearance. However, in the lungs of patients with CF, the mucociliary clearance is impaired due to dehydration of the airway surface fluid. As a consequence, patients with CF are highly susceptible to chronic or intermittent pulmonary infections, often causing extensive lung inflammation and damage, accompanied by a decreased life expectancy. This mini review will focus on the different secretion mechanisms used by the major bacterial CF pathogens to release virulence factors, their role in resistance and discusses the potential for therapeutically targeting secretion systems.
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Affiliation(s)
- Sofie Depluverez
- Laboratory for Protein Biochemistry and Biomolecular Engineering, Department of Biochemistry and Microbiology, Ghent University Ghent, Belgium
| | - Simon Devos
- Laboratory for Protein Biochemistry and Biomolecular Engineering, Department of Biochemistry and Microbiology, Ghent University Ghent, Belgium
| | - Bart Devreese
- Laboratory for Protein Biochemistry and Biomolecular Engineering, Department of Biochemistry and Microbiology, Ghent University Ghent, Belgium
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22
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Caldera L, Franzetti L, Van Coillie E, De Vos P, Stragier P, De Block J, Heyndrickx M. Identification, enzymatic spoilage characterization and proteolytic activity quantification of Pseudomonas spp. isolated from different foods. Food Microbiol 2016. [DOI: 10.1016/j.fm.2015.10.004] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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23
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Wagner S, Sommer R, Hinsberger S, Lu C, Hartmann RW, Empting M, Titz A. Novel Strategies for the Treatment of Pseudomonas aeruginosa Infections. J Med Chem 2016; 59:5929-69. [DOI: 10.1021/acs.jmedchem.5b01698] [Citation(s) in RCA: 176] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Stefanie Wagner
- Chemical
Biology of Carbohydrates, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany
- Deutsches Zentrum für Infektionsforschung (DZIF), 30625 Standort Hannover-Braunschweig, Germany
| | - Roman Sommer
- Chemical
Biology of Carbohydrates, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany
- Deutsches Zentrum für Infektionsforschung (DZIF), 30625 Standort Hannover-Braunschweig, Germany
| | - Stefan Hinsberger
- Deutsches Zentrum für Infektionsforschung (DZIF), 30625 Standort Hannover-Braunschweig, Germany
- Drug
Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany
| | - Cenbin Lu
- Deutsches Zentrum für Infektionsforschung (DZIF), 30625 Standort Hannover-Braunschweig, Germany
- Drug
Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany
| | - Rolf W. Hartmann
- Deutsches Zentrum für Infektionsforschung (DZIF), 30625 Standort Hannover-Braunschweig, Germany
- Drug
Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany
| | - Martin Empting
- Deutsches Zentrum für Infektionsforschung (DZIF), 30625 Standort Hannover-Braunschweig, Germany
- Drug
Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany
| | - Alexander Titz
- Chemical
Biology of Carbohydrates, Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), D-66123 Saarbrücken, Germany
- Deutsches Zentrum für Infektionsforschung (DZIF), 30625 Standort Hannover-Braunschweig, Germany
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Zrieq R, Sana TG, Vergin S, Garvis S, Volfson I, Bleves S, Voulhoux R, Hegemann JH. Genome-wide Screen of Pseudomonas aeruginosa in Saccharomyces cerevisiae Identifies New Virulence Factors. Front Cell Infect Microbiol 2015; 5:81. [PMID: 26636043 PMCID: PMC4644809 DOI: 10.3389/fcimb.2015.00081] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 10/31/2015] [Indexed: 01/12/2023] Open
Abstract
Pseudomonas aeruginosa is a human opportunistic pathogen that causes mortality in cystic fibrosis and immunocompromised patients. While many virulence factors of this pathogen have already been identified, several remain to be discovered. In this respect we set an unprecedented genome-wide screen of a P. aeruginosa expression library based on a yeast growth phenotype. Fifty-one candidates were selected in athree-round screening process. The robustness of the screen was validated by the selection of three well known secreted proteins including one demonstrated virulence factor, the protease LepA. Further in silico sorting of the 51 candidates highlighted three potential new Pseudomonas effector candidates (Pec). By testing the cytotoxicity of wild type P. aeruginosa vs. pec mutants toward macrophages and the virulence in the Caenorhabditis elegans model, we demonstrated that the three selected Pecs are novel virulence factors of P. aeruginosa. Additional cellular localization experiments in the host revealed specific localization for Pec1 and Pec2 that could inform about their respective functions.
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Affiliation(s)
- Rafat Zrieq
- Institut für Funktionelle Genomforschung der Mikroorganismen, Heinrich-Heine-Universität Düsseldorf Düsseldorf, Germany
| | - Thibault G Sana
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires (UMR7255), Institut de Microbiologie de la Méditerranée, Centre National de la Recherche Scientifique, Aix-Marseille Université Marseille, France
| | - Sandra Vergin
- Institut für Funktionelle Genomforschung der Mikroorganismen, Heinrich-Heine-Universität Düsseldorf Düsseldorf, Germany
| | - Steve Garvis
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires (UMR7255), Institut de Microbiologie de la Méditerranée, Centre National de la Recherche Scientifique, Aix-Marseille Université Marseille, France
| | - Irina Volfson
- Institut für Funktionelle Genomforschung der Mikroorganismen, Heinrich-Heine-Universität Düsseldorf Düsseldorf, Germany
| | - Sophie Bleves
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires (UMR7255), Institut de Microbiologie de la Méditerranée, Centre National de la Recherche Scientifique, Aix-Marseille Université Marseille, France
| | - Romé Voulhoux
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires (UMR7255), Institut de Microbiologie de la Méditerranée, Centre National de la Recherche Scientifique, Aix-Marseille Université Marseille, France
| | - Johannes H Hegemann
- Institut für Funktionelle Genomforschung der Mikroorganismen, Heinrich-Heine-Universität Düsseldorf Düsseldorf, Germany
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25
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Smith KP, Voogt RD, Ruiz T, Mintz KP. The conserved carboxyl domain of MorC, an inner membrane protein of Aggregatibacter actinomycetemcomitans, is essential for membrane function. Mol Oral Microbiol 2015. [PMID: 26205976 DOI: 10.1111/omi.12120] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Morphogenesis protein C (MorC) of Aggregatibacter actinomycetemcomitans is important for maintaining the membrane morphology and integrity of the cell envelope of this oral pathogen. The MorC sequence and operon organization were found to be conserved in Gammaproteobacteria, based on a bioinformatic analysis of 435 sequences from representative organisms. Functional conservation of MorC was investigated using an A. actinomycetemcomitans morC mutant as a model system to express MorC homologs from four phylogenetically diverse representatives of the Gammaproteobacteria: Haemophilus influenzae, Escherichia coli, Pseudomonas aeruginosa, and Moraxella catarrhalis. The A. actinomycetemcomitans strains expressing the homologous proteins were assessed for sensitivity to bile salts, leukotoxin secretion, autoaggregation and membrane morphology. MorC from the most closely related organism (H. influenzae) was functionally identical to MorC from A. actinomycetemcomitans. However, the genes from more distantly related organisms restored some but not all A. actinomycetemcomitans mutant phenotypes. In addition, deletion mutagenesis indicated that the most conserved portion of the protein, the C-terminus DUF490 domain, was necessary to maintain the integrity of the membrane. Deletion of the last 10 amino acids of this domain of the A. actinomycetemcomitans MorC protein was sufficient to disrupt membrane stability and leukotoxin secretion. The data suggest that the MorC sequence is functionally conserved across Gammaproteobacteria and the C-terminus of the protein is essential for maintaining membrane physiology.
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Affiliation(s)
- K P Smith
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT, USA
| | - R D Voogt
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT, USA
| | - T Ruiz
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT, USA
| | - K P Mintz
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT, USA
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26
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Pouring salt on a wound: Pseudomonas aeruginosa virulence factors alter Na+ and Cl- flux in the lung. J Bacteriol 2013; 195:4013-9. [PMID: 23836869 DOI: 10.1128/jb.00339-13] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Pseudomonas aeruginosa is a ubiquitous opportunistic pathogen with multiple niches in the human body, including the lung. P. aeruginosa infections are particularly damaging or fatal for patients with ventilator-associated pneumonia, chronic obstructive pulmonary disease, and cystic fibrosis (CF). To establish an infection, P. aeruginosa relies on a suite of virulence factors, including lipopolysaccharide, phospholipases, exoproteases, phenazines, outer membrane vesicles, type III secreted effectors, flagella, and pili. These factors not only damage the epithelial cell lining but also induce changes in cell physiology and function such as cell shape, membrane permeability, and protein synthesis. While such virulence factors are important in initial infection, many become dysregulated or nonfunctional during the course of chronic infection. Recent work on the virulence factors alkaline protease (AprA) and CF transmembrane conductance regulator inhibitory factor (Cif) show that P. aeruginosa also perturbs epithelial ion transport and osmosis, which may be important for the long-term survival of this microbe in the lung. Here we discuss the literature regarding host physiology-altering virulence factors with a focus on Cif and AprA and their potential roles in chronic infection and immune evasion.
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27
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Zhang L, Conway JF, Thibodeau PH. Calcium-induced folding and stabilization of the Pseudomonas aeruginosa alkaline protease. J Biol Chem 2011; 287:4311-22. [PMID: 22170064 DOI: 10.1074/jbc.m111.310300] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that contributes to the mortality of immunocompromised individuals and patients with cystic fibrosis. Pseudomonas infection presents clinical challenges due to its ability to form biofilms and modulate host-pathogen interactions through the secretion of virulence factors. The calcium-regulated alkaline protease (AP), a member of the repeats in toxin (RTX) family of proteins, is implicated in multiple modes of infection. A series of full-length and truncation mutants were purified for structural and functional studies to evaluate the role of Ca(2+) in AP folding and activation. We find that Ca(2+) binding induces RTX folding, which serves to chaperone the folding of the protease domain. Subsequent association of the RTX domain with an N-terminal α-helix stabilizes AP. These results provide a basis for the Ca(2+)-mediated regulation of AP and suggest mechanisms by which Ca(2+) regulates the RTX family of virulence factors.
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Affiliation(s)
- Liang Zhang
- Department of Cell Biology and Physiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA
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29
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Filloux A. Protein Secretion Systems in Pseudomonas aeruginosa: An Essay on Diversity, Evolution, and Function. Front Microbiol 2011; 2:155. [PMID: 21811488 PMCID: PMC3140646 DOI: 10.3389/fmicb.2011.00155] [Citation(s) in RCA: 122] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Accepted: 07/01/2011] [Indexed: 12/25/2022] Open
Abstract
Protein secretion systems are molecular nanomachines used by Gram-negative bacteria to thrive within their environment. They are used to release enzymes that hydrolyze complex carbon sources into usable compounds, or to release proteins that capture essential ions such as iron. They are also used to colonize and survive within eukaryotic hosts, causing acute or chronic infections, subverting the host cell response and escaping the immune system. In this article, the opportunistic human pathogen Pseudomonas aeruginosa is used as a model to review the diversity of secretion systems that bacteria have evolved to achieve these goals. This diversity may result from a progressive transformation of cell envelope complexes that initially may not have been dedicated to secretion. The striking similarities between secretion systems and type IV pili, flagella, bacteriophage tail, or efflux pumps is a nice illustration of this evolution. Differences are also needed since various secretion configurations call for diversity. For example, some proteins are released in the extracellular medium while others are directly injected into the cytosol of eukaryotic cells. Some proteins are folded before being released and transit into the periplasm. Other proteins cross the whole cell envelope at once in an unfolded state. However, the secretion system requires conserved basic elements or features. For example, there is a need for an energy source or for an outer membrane channel. The structure of this review is thus quite unconventional. Instead of listing secretion types one after each other, it presents a melting pot of concepts indicating that secretion types are in constant evolution and use basic principles. In other words, emergence of new secretion systems could be predicted the way Mendeleïev had anticipated characteristics of yet unknown elements.
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Affiliation(s)
- Alain Filloux
- Division of Cell and Molecular Biology, Centre for Molecular Microbiology and Infection, Imperial College London London, UK
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30
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Contribution of an arsenal of virulence factors to pathogenesis of Pseudomonas aeruginosa infections. ANN MICROBIOL 2011. [DOI: 10.1007/s13213-011-0273-y] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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31
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Seet Q, Zhang LH. Anti-activator QslA defines the quorum sensing threshold and response in Pseudomonas aeruginosa. Mol Microbiol 2011; 80:951-65. [PMID: 21392132 DOI: 10.1111/j.1365-2958.2011.07622.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Quorum sensing (QS) in a bacterial population is activated when extracellular concentration of QS signal reaches a threshold, but how this threshold is determined remains largely unknown. In this study, we report the identification and characterization of a novel anti-activator encoded by qslA in Pseudomonas aeruginosa. The null mutation of qslA elevated AHL-dependent QS and PQS signalling, increased the expression of QS-dependent genes, and enhanced the virulence factor production and pathogenicity. We further present evidence that modulation of QS by QslA is due to protein-protein interaction with LasR, which prevents LasR from binding to its target promoter. QslA also influences the threshold concentration of QS signal needed for QS activation; in the absence of qslA, QS is activated by nine times less N-3-oxo-dodecanoyl-homoserine lactone (3-oxo-C12-HSL) than that in wild type. The findings from this study depict a new mechanism that governs the QS threshold in P. aeruginosa.
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Affiliation(s)
- Qihui Seet
- Institute of Molecular and Cell Biology, 61 Biopolis Drive, Proteos, Singapore
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32
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Rampioni G, Pustelny C, Fletcher MP, Wright VJ, Bruce M, Rumbaugh KP, Heeb S, Cámara M, Williams P. Transcriptomic analysis reveals a global alkyl-quinolone-independent regulatory role for PqsE in facilitating the environmental adaptation of Pseudomonas aeruginosa to plant and animal hosts. Environ Microbiol 2010; 12:1659-73. [PMID: 20406282 PMCID: PMC2901523 DOI: 10.1111/j.1462-2920.2010.02214.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The quorum sensing (QS) system of Pseudomonas aeruginosa constitutes a sophisticated genome-wide gene regulatory network employing both N-acylhomoserine lactone and 2-alkyl-4-quinolone (AQ) signal molecules. AQ signalling utilizes 2-heptyl-3-hydroxy-4-quinolone (PQS) and its immediate precursor, 2-heptyl-4-quinolone (HHQ). AQ biosynthesis requires the first four genes of the pqsABCDE operon and while the biochemical function of pqsE is not known, it is required for the production of secondary metabolites such as pyocyanin. To gain insights into the relationship between the AQ stimulon, the PqsE stimulon and the regulatory function of PqsE, we constructed a pqsE inducible mutant (pqsEind) and compared the transcriptomes of the induced and uninduced states with a pqsA mutant. Of 158 genes exhibiting altered expression in the pqsA mutant, 51% were also affected in the pqsE mutant. Following induction of pqsE, 237 genes were differentially expressed compared with the wild-type strain. In the pqsEind strain, pqsA was highly expressed but following induction both pqsA expression and AQ biosynthesis were repressed, revealing a negative autoregulatory role for PqsE. Furthermore, pqsE was required for swarming motility and virulence in plant and animal infection models in the absence of AQs, while mature biofilm development required both pqsA and pqsE. Taken together these data reveal that PqsE is a key regulator within the QS circuitry facilitating the environmental adaptation of P. aeruginosa.
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Affiliation(s)
- Giordano Rampioni
- School of Molecular Medical Sciences, Centre for Biomolecular Sciences, University Park, University of Nottingham, Nottingham NG7 2RD, UK
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Rodríguez-Palenzuela P, Matas IM, Murillo J, López-Solanilla E, Bardaji L, Pérez-Martínez I, Rodríguez-Moskera ME, Penyalver R, López MM, Quesada JM, Biehl BS, Perna NT, Glasner JD, Cabot EL, Neeno-Eckwall E, Ramos C. Annotation and overview of thePseudomonas savastanoipv. savastanoi NCPPB 3335 draft genome reveals the virulence gene complement of a tumour-inducing pathogen of woody hosts. Environ Microbiol 2010; 12:1604-20. [DOI: 10.1111/j.1462-2920.2010.02207.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Rhizobium sp. strain NGR234 possesses a remarkable number of secretion systems. Appl Environ Microbiol 2009; 75:4035-45. [PMID: 19376903 DOI: 10.1128/aem.00515-09] [Citation(s) in RCA: 134] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Rhizobium sp. strain NGR234 is a unique alphaproteobacterium (order Rhizobiales) that forms nitrogen-fixing nodules with more legumes than any other microsymbiont. We report here that the 3.93-Mbp chromosome (cNGR234) encodes most functions required for cellular growth. Few essential functions are encoded on the 2.43-Mbp megaplasmid (pNGR234b), and none are present on the second 0.54-Mbp symbiotic plasmid (pNGR234a). Among many striking features, the 6.9-Mbp genome encodes more different secretion systems than any other known rhizobia and probably most known bacteria. Altogether, 132 genes and proteins are linked to secretory processes. Secretion systems identified include general and export pathways, a twin arginine translocase secretion system, six type I transporter genes, one functional and one putative type III system, three type IV attachment systems, and two putative type IV conjugation pili. Type V and VI transporters were not identified, however. NGR234 also carries genes and regulatory networks linked to the metabolism of a wide range of aromatic and nonaromatic compounds. In this way, NGR234 can quickly adapt to changing environmental stimuli in soils, rhizospheres, and plants. Finally, NGR234 carries at least six loci linked to the quenching of quorum-sensing signals, as well as one gene (ngrI) that possibly encodes a novel type of autoinducer I molecule.
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35
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Wolf P, Elsässer-Beile U. Pseudomonas exotoxin A: from virulence factor to anti-cancer agent. Int J Med Microbiol 2009; 299:161-76. [PMID: 18948059 DOI: 10.1016/j.ijmm.2008.08.003] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2008] [Revised: 07/07/2008] [Accepted: 08/13/2008] [Indexed: 11/24/2022] Open
Abstract
The pathogenic bacterium Pseudomonas aeruginosa has the ability to cause severe acute and chronic infections in humans. Pseudomonas exotoxin A (PE) is the most toxic virulence factor of this bacterium. It has ADP-ribosylation activity and decisively affects the protein synthesis of the host cells. The cytotoxic pathways of PE have been elucidated, and it could be shown that PE uses several molecular strategies developed under evolutionary pressure for effective killing. Interestingly, a medical benefit from this molecule has also been ascertained in recent years and several PE-based immunotoxins have been constructed and tested in preclinical and clinical trials against different cancers. In these molecules, the enzymatic active domain of PE is specifically targeted to tumor-related antigens. This review describes the current knowledge about the cytotoxic pathways of PE. Additionally, it summarizes preclinical and clinical trials of PE-based immunotoxins and furthermore discusses current problems and answers with these agents.
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Affiliation(s)
- Philipp Wolf
- Department of Urology, University of Freiburg, Germany.
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36
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Joardar V, Lindeberg M, Jackson RW, Selengut J, Dodson R, Brinkac LM, Daugherty SC, Deboy R, Durkin AS, Giglio MG, Madupu R, Nelson WC, Rosovitz MJ, Sullivan S, Crabtree J, Creasy T, Davidsen T, Haft DH, Zafar N, Zhou L, Halpin R, Holley T, Khouri H, Feldblyum T, White O, Fraser CM, Chatterjee AK, Cartinhour S, Schneider DJ, Mansfield J, Collmer A, Buell CR. Whole-genome sequence analysis of Pseudomonas syringae pv. phaseolicola 1448A reveals divergence among pathovars in genes involved in virulence and transposition. J Bacteriol 2005; 187:6488-98. [PMID: 16159782 PMCID: PMC1236638 DOI: 10.1128/jb.187.18.6488-6498.2005] [Citation(s) in RCA: 241] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Pseudomonas syringae pv. phaseolicola, a gram-negative bacterial plant pathogen, is the causal agent of halo blight of bean. In this study, we report on the genome sequence of P. syringae pv. phaseolicola isolate 1448A, which encodes 5,353 open reading frames (ORFs) on one circular chromosome (5,928,787 bp) and two plasmids (131,950 bp and 51,711 bp). Comparative analyses with a phylogenetically divergent pathovar, P. syringae pv. tomato DC3000, revealed a strong degree of conservation at the gene and genome levels. In total, 4,133 ORFs were identified as putative orthologs in these two pathovars using a reciprocal best-hit method, with 3,941 ORFs present in conserved, syntenic blocks. Although these two pathovars are highly similar at the physiological level, they have distinct host ranges; 1448A causes disease in beans, and DC3000 is pathogenic on tomato and Arabidopsis. Examination of the complement of ORFs encoding virulence, fitness, and survival factors revealed a substantial, but not complete, overlap between these two pathovars. Another distinguishing feature between the two pathovars is their distinctive sets of transposable elements. With access to a fifth complete pseudomonad genome sequence, we were able to identify 3,567 ORFs that likely comprise the core Pseudomonas genome and 365 ORFs that are P. syringae specific.
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Affiliation(s)
- Vinita Joardar
- The Institute for Genomic Research, 9712 Medical Center Dr., Rockville, MD 20850, USA
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37
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Toporowski MC, Nomellini JF, Awram P, Levi A, Smit J. Transcriptional regulation of the S-layer protein type I secretion system inCaulobacter crescentus. FEMS Microbiol Lett 2005; 251:29-36. [PMID: 16111836 DOI: 10.1016/j.femsle.2005.07.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2005] [Revised: 07/18/2005] [Accepted: 07/19/2005] [Indexed: 10/25/2022] Open
Abstract
The Gram-negative Caulobacter crescentus exports RsaA, the crystalline S-layer subunit protein using a dedicated type I secretion system. The protein and two transporter genes (rsaADE) are located together, comparable to the Escherichia coli type I hemolysin hlyCABD operon, where read through of a stem loop following hlyCA results in reduced transcription of the hlyBD. Using two genetic approaches and a direct assessment of transcription from regions 5' to the genes we learned that rsaD and rsaE were transcribed together as a separate transcript from rsaA. These results are contrary to previous assumptions about the rsaADE type I secretion gene control and add another theme to the area of type I secretion transcription regulation. It may be that to accommodate the high levels of RsaA secretion, the type I transporters must be transcribed independently from rsaA.
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Affiliation(s)
- Michael C Toporowski
- University of British Columbia, Department of Microbiology and Immunology, Vancouver, B.C. Canada V6T 1Z3
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38
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Toporowski MC, Nomellini JF, Awram P, Smit J. Two outer membrane proteins are required for maximal type I secretion of the Caulobacter crescentus S-layer protein. J Bacteriol 2004; 186:8000-9. [PMID: 15547272 PMCID: PMC529074 DOI: 10.1128/jb.186.23.8000-8009.2004] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Transport of RsaA, the crystalline S-layer subunit protein of Caulobacter crescentus, is mediated by a type I secretion mechanism. Two proteins have been identified that play the role of the outer membrane protein (OMP) component in the RsaA secretion machinery. The genes rsaF(a) and rsaF(b) were identified by similarity to the Escherichia coli hemolysin secretion OMP TolC by using the C. crescentus genome sequence. The rsaF(a) gene is located several kilobases downstream of the other transporter genes, while rsaF(b) is completely unlinked. An rsaF(a) knockout had approximately 56% secretion compared to wild-type levels, while the rsaF(b) knockout reduced secretion levels to approximately 79%. When expression of both proteins was eliminated, there was no RsaA secretion, but a residual level of approximately 9% remained inside the cell, suggesting posttranslational autoregulation. Complementation with either of the individual rsaF genes by use of a multicopy vector, which resulted in 8- to 10-fold overexpression of the proteins, did not restore RsaA secretion to wild-type levels, indicating that both rsaF genes were required for full-level secretion. However, overexpression of rsaF(a) (with normal rsaF(b) levels) in concert with overexpression of rsaA resulted in a 28% increase in RsaA secretion, indicating a potential for significantly increasing expression levels of an already highly expressing type I secretion system. This is the only known example of type I secretion requiring two OMPs to assemble a fully functional system.
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Affiliation(s)
- Michael C Toporowski
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
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39
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Wehmhöner D, Häussler S, Tümmler B, Jänsch L, Bredenbruch F, Wehland J, Steinmetz I. Inter- and intraclonal diversity of the Pseudomonas aeruginosa proteome manifests within the secretome. J Bacteriol 2003; 185:5807-14. [PMID: 13129952 PMCID: PMC193958 DOI: 10.1128/jb.185.19.5807-5814.2003] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The proteomes of cultured Pseudomonas aeruginosa isolates from chronically infected cystic fibrosis (CF) lungs were compared by using genetically divergent clones and isogenic morphotypes of one strain. Cellular extracts gave very similar protein patterns in two-dimensional gels, suggesting that the conserved species-specific core genome encodes proteins that are expressed under standard culture conditions in vitro. In contrast, the protein profiles of extracts of culture supernatants were dependent on the growth phase, and there were significant differences between clones. The profiles also varied within clonally related morphotypes from one CF patient, including a hyperpiliated small-colony variant. Mass spectrometry revealed that this variant overexpressed proteins secreted by the type I secretion system (including proteins involved in iron acquisition) and by the type III secretion system. Furthermore, the proteins in the supernatant extracts from the small-colony variant which were recognized by sera from different CF patients varied greatly. We concluded that the secretome expression is a sensitive measure of P. aeruginosa strain variation.
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Affiliation(s)
- Dirk Wehmhöner
- Institute of Medical Microbiology, Hannover Medical School, 30265 Hannover, Germany
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40
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Abstract
Metalloendopeptidases are present across all kingdoms of living organisms; they are ubiquitous and widely involved in metabolism regulation through their ability either to extensively degrade proteins or to selectively hydrolyze specific peptide bonds. They must be subjected to exquisite spatial and temporal control to prevent this vast potential from becoming destructive. These enzymes are mostly zinc-dependent and the majority of them, named zincins, possess a short consensus sequence, HEXXH, with the two histidines acting as ligands of the catalytic zinc and the glutamate as the general base. A subclass of the zincins is characterized by a C-terminally elongated motif, HEXXHXXGXXH/D, with an additional strictly conserved glycine and a third zinc-binding histidine or aspartate. Currently, representative three-dimensional structures of six different proteinase families bearing this motif show, despite low sequence similarity, comparable overall topology. This includes a substrate-binding crevice, which subdivides the enzyme moiety into an upper and a lower subdomain. A common five-stranded beta-sheet and two alpha-helices are always found in the upper subdomain. The second of these helices encompasses the first half of the elongated consensus sequence and is therefore termed the active-site helix. Other shared characteristics are an invariant methionine-containing Met-turn beneath the catalytic metal and a further C-terminal helix in the lower subdomain. All these structural features identify the metzincin clan of metalloendopeptidases. This clan is reviewed from a structural point of view, based on the reported structures of representative members of the astacins, adamalysins, serralysins, matrixins, snapalysins, and leishmanolysins, and of inhibited forms, either by specific endogenous protein inhibitors or by zymogenic pro-domains. Moreover, newly available genomic sequences have unveiled novel putative metzincin families and new hypothetical members of existing ones.
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Affiliation(s)
- F Xavier Gomis-Rüth
- Institut de Biologia Molecular de Barcelona, CID-CSICC/ Jordi Girona, 18-26; 08034 Barcelona, Spain.
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Bitter W. Secretins of Pseudomonas aeruginosa: large holes in the outer membrane. Arch Microbiol 2003; 179:307-14. [PMID: 12664194 DOI: 10.1007/s00203-003-0541-8] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2003] [Revised: 02/24/2003] [Accepted: 02/24/2003] [Indexed: 10/20/2022]
Abstract
Pseudomonas aeruginosa produces a large number of exoproteins, ranging from the ADP-ribosyltransferases exotoxin A and ExoS to degradative enzymes, such as elastase and chitinase. As it is a gram-negative bacterium, P. aeruginosa must be able to transport these exoproteins across both membranes of the cell envelope. In addition, also proteins that are part of cellular appendages, such as type IV pili and flagella, have to cross the cell envelope. Whereas the majority of the proteins transported across the inner membrane are dependent on the Sec channel, the systems for translocation across the outer membrane seem to be more diverse. Gram-negative bacteria have invented a number of different strategies during the course of evolution to achieve this goal. Although these transport machineries seem to be radically different, many of them actually depend on a member of the secretin protein family for their function. Recent results show that secretins form a large complex in the outer membrane, which constitutes the actual translocation channel. Understanding the working mechanism of this protein translocation channel could open up new strategies to target molecular machineries at the heart of many important virulence factors.
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Affiliation(s)
- Wilbert Bitter
- Department of Medical Microbiology and Infection Control, VU University Medical Centre, Van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands.
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Ma Q, Zhai Y, Schneider JC, Ramseier TM, Saier MH. Protein secretion systems of Pseudomonas aeruginosa and P fluorescens. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1611:223-33. [PMID: 12659964 DOI: 10.1016/s0005-2736(03)00059-2] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Gram-negative bacteria have evolved numerous systems for the export of proteins across their dual-membrane envelopes. Three of these systems (types I, III and IV) secrete proteins across both membranes in a single energy-coupled step. Four systems (Sec, Tat, MscL and Holins) secrete only across the inner membrane, and four systems [the main terminal branch (MTB), fimbrial usher porin (FUP), autotransporter (AT) and two-partner secretion families (TPS)] secrete only across the outer membrane. We have examined the genome sequences of Pseudomonas aeruginosa PAO1 and Pseudomonas fluorescens Pf0-1 for these systems. All systems except type IV were found in P. aeruginosa, and all except types III and IV were found in P. fluorescens. The numbers of each such system were variable depending on the system and species examined. Biochemical and physiological functions were assigned to these systems when possible, and the structural constituents were analyzed. Available information regarding the mechanisms of transport and energy coupling as well as physiological functions is summarized. This report serves to identify and characterize protein secretion systems in two divergent pseudomonads, one an opportunistic human pathogen, the other a plant symbiont.
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Affiliation(s)
- Qinhong Ma
- Division of Biological Sciences, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0116, USA
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Abstract
The genome sequence of Pseudomonas aeruginosa strain PAO1 has been determined to facilitate postgenomic studies aimed at understanding the capacity of adaptation of this ubiquitous opportunistic pathogen. P. aeruginosa produces toxins and hydrolytic enzymes that are secreted via the type II secretory pathway using the Xcp machinery or 'secreton'. In this study, we characterized a novel gene cluster, called hxc for homologous to xcp. Characterization of an hxcR mutant, grown in phosphate-limiting medium, revealed the absence of a 40 kDa protein found in the culture supernatant of wild-type or xcp derivative mutant strains. The protein corresponded to the alkaline phosphatase L-AP, renamed LapA, which is secreted in an xcp-independent but hxc-dependent manner. Finally, we showed that expression of the hxc gene cluster is under phosphate regulation. This is the first report of the existence of two functional type II secretory pathways within the same organism, which could be related to the high adaptation potential of P. aeruginosa.
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Affiliation(s)
- Geneviève Ball
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires, UPR9027, IBSM/CNRS, Marseille, France
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