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van der Zee A, Kraak WB, Burggraaf A, Goessens WHF, Pirovano W, Ossewaarde JM, Tommassen J. Spread of Carbapenem Resistance by Transposition and Conjugation Among Pseudomonas aeruginosa. Front Microbiol 2018; 9:2057. [PMID: 30233535 PMCID: PMC6133989 DOI: 10.3389/fmicb.2018.02057] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Accepted: 08/13/2018] [Indexed: 12/14/2022] Open
Abstract
The emergence of carbapenem-resistant Pseudomonas aeruginosa represents a worldwide problem. To understand the carbapenem-resistance mechanisms and their spreading among P. aeruginosa strains, whole genome sequences were determined of two extensively drug-resistant strains that are endemic in Dutch hospitals. Strain Carb01 63 is of O-antigen serotype O12 and of sequence type ST111, whilst S04 90 is a serotype O11 strain of ST446. Both strains carry a gene for metallo-β-lactamase VIM-2 flanked by two aacA29 genes encoding aminoglycoside acetyltransferases on a class 1 integron. The integron is located on the chromosome in strain Carb01 63 and on a plasmid in strain S04 90. The backbone of the 159-kb plasmid, designated pS04 90, is similar to a previously described plasmid, pND6-2, from Pseudomonas putida. Analysis of the context of the integron showed that it is present in both strains on a ∼30-kb mosaic DNA segment composed of four different transposons that can presumably act together as a novel, active, composite transposon. Apart from the presence of a 1237-bp insertion sequence element in the composite transposon on pS04 90, these transposons show > 99% sequence identity indicating that transposition between plasmid and chromosome could have occurred only very recently. The pS04 90 plasmid could be transferred by conjugation to a susceptible P. aeruginosa strain. A second class 1 integron containing a gene for a CARB-2 β-lactamase flanked by an aacA4′-8 and an aadA2 gene, encoding an aminoglycoside acetyltransferase and adenylyltransferase, respectively, was present only in strain Carb01 63. This integron is located also on a composite transposon that is inserted in an integrative and conjugative element on the chromosome. Additionally, this strain contains a frameshift mutation in the oprD gene encoding a porin involved in the transport of carbapenems across the outer membrane. Together, the results demonstrate that integron-encoded carbapenem and carbapenicillin resistance can easily be disseminated by transposition and conjugation among Pseudomonas aeruginosa strains.
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Affiliation(s)
- Anneke van der Zee
- Laboratory of Medical Microbiology, Molecular Diagnostics Unit, Maasstad Hospital, Rotterdam, Netherlands
| | - W Bart Kraak
- Laboratory of Medical Microbiology, Molecular Diagnostics Unit, Maasstad Hospital, Rotterdam, Netherlands
| | - Arjan Burggraaf
- Laboratory of Medical Microbiology, Molecular Diagnostics Unit, Maasstad Hospital, Rotterdam, Netherlands
| | | | | | - Jacobus M Ossewaarde
- Laboratory of Medical Microbiology, Molecular Diagnostics Unit, Maasstad Hospital, Rotterdam, Netherlands.,Erasmus University Medical Center, Rotterdam, Netherlands
| | - Jan Tommassen
- Section Molecular Microbiology, Department of Biology, Faculty of Science, Utrecht University, Utrecht, Netherlands
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Frimodt-Møller J, Rossi E, Haagensen JAJ, Falcone M, Molin S, Johansen HK. Mutations causing low level antibiotic resistance ensure bacterial survival in antibiotic-treated hosts. Sci Rep 2018; 8:12512. [PMID: 30131514 PMCID: PMC6104031 DOI: 10.1038/s41598-018-30972-y] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 08/08/2018] [Indexed: 11/09/2022] Open
Abstract
In 474 genome sequenced Pseudomonas aeruginosa isolates from 34 cystic fibrosis (CF) patients, 40% of these harbor mutations in the mexZ gene encoding a negative regulator of the MexXY-OprM efflux pump associated with aminoglycoside and fluoroquinolone resistance. Surprisingly, resistance to aminoglycosides and fluoroquinolones of mexZ mutants was far below the breakpoint of clinical resistance. However, the fitness increase of the mutant bacteria in presence of the relevant antibiotics, as demonstrated in competition experiments between mutant and ancestor bacteria, showed that 1) very small phenotypic changes cause significant fitness increase with severe adaptive consequences, and 2) standardized phenotypic tests fail to detect such low-level variations. The frequent appearance of P. aeruginosa mexZ mutants in CF patients is directly connected to the intense use of the target antibiotics, and low-level antibiotic resistance, if left unnoticed, can result in accumulation of additional genetic changes leading to high-level resistance.
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Affiliation(s)
- Jakob Frimodt-Møller
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
- Center for Peptide-Based Antibiotics, University of Copenhagen, Copenhagen, Denmark
| | - Elio Rossi
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark
| | | | - Marilena Falcone
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark
| | - Søren Molin
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark.
| | - Helle Krogh Johansen
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark.
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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53
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Housseini B Issa K, Phan G, Broutin I. Functional Mechanism of the Efflux Pumps Transcription Regulators From Pseudomonas aeruginosa Based on 3D Structures. Front Mol Biosci 2018; 5:57. [PMID: 29971236 PMCID: PMC6018408 DOI: 10.3389/fmolb.2018.00057] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 05/31/2018] [Indexed: 01/19/2023] Open
Abstract
Bacterial antibiotic resistance is a worldwide health problem that deserves important research attention in order to develop new therapeutic strategies. Recently, the World Health Organization (WHO) classified Pseudomonas aeruginosa as one of the priority bacteria for which new antibiotics are urgently needed. In this opportunistic pathogen, antibiotics efflux is one of the most prevalent mechanisms where the drug is efficiently expulsed through the cell-wall. This resistance mechanism is highly correlated to the expression level of efflux pumps of the resistance-nodulation-cell division (RND) family, which is finely tuned by gene regulators. Thus, it is worthwhile considering the efflux pump regulators of P. aeruginosa as promising therapeutical targets alternative. Several families of regulators have been identified, including activators and repressors that control the genetic expression of the pumps in response to an extracellular signal, such as the presence of the antibiotic or other environmental modifications. In this review, based on different crystallographic structures solved from archetypal bacteria, we will first focus on the molecular mechanism of the regulator families involved in the RND efflux pump expression in P. aeruginosa, which are TetR, LysR, MarR, AraC, and the two-components system (TCS). Finally, the regulators of known structure from P. aeruginosa will be presented.
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Affiliation(s)
- Karim Housseini B Issa
- Laboratoire de Cristallographie et RMN Biologiques (UMR 8015), Centre National de la Recherche Scientifique, Faculté de Pharmacie, Université Paris Descartes, Université Sorbonne Paris Cité, Paris, France
| | - Gilles Phan
- Laboratoire de Cristallographie et RMN Biologiques (UMR 8015), Centre National de la Recherche Scientifique, Faculté de Pharmacie, Université Paris Descartes, Université Sorbonne Paris Cité, Paris, France
| | - Isabelle Broutin
- Laboratoire de Cristallographie et RMN Biologiques (UMR 8015), Centre National de la Recherche Scientifique, Faculté de Pharmacie, Université Paris Descartes, Université Sorbonne Paris Cité, Paris, France
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54
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López-Causapé C, Cabot G, Del Barrio-Tofiño E, Oliver A. The Versatile Mutational Resistome of Pseudomonas aeruginosa. Front Microbiol 2018; 9:685. [PMID: 29681898 PMCID: PMC5897538 DOI: 10.3389/fmicb.2018.00685] [Citation(s) in RCA: 130] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 03/23/2018] [Indexed: 12/11/2022] Open
Abstract
One of the most striking features of Pseudomonas aeruginosa is its outstanding capacity for developing antimicrobial resistance to nearly all available antipseudomonal agents through the selection of chromosomal mutations, leading to the failure of the treatment of severe hospital-acquired or chronic infections. Recent whole-genome sequencing (WGS) data obtained from in vitro assays on the evolution of antibiotic resistance, in vivo monitoring of antimicrobial resistance development, analysis of sequential cystic fibrosis isolates, and characterization of widespread epidemic high-risk clones have provided new insights into the evolutionary dynamics and mechanisms of P. aeruginosa antibiotic resistance, thus motivating this review. Indeed, the analysis of the WGS mutational resistome has proven to be useful for understanding the evolutionary dynamics of classical resistance pathways and to describe new mechanisms for the majority of antipseudomonal classes, including β-lactams, aminoglycosides, fluoroquinolones, or polymixins. Beyond addressing a relevant scientific question, the analysis of the P. aeruginosa mutational resistome is expected to be useful, together with the analysis of the horizontally-acquired resistance determinants, for establishing the antibiotic resistance genotype, which should correlate with the antibiotic resistance phenotype and as such, it should be useful for the design of therapeutic strategies and for monitoring the efficacy of administered antibiotic treatments. However, further experimental research and new bioinformatics tools are still needed to overcome the interpretation limitations imposed by the complex interactions (including those leading to collateral resistance or susceptibility) between the 100s of genes involved in the mutational resistome, as well as the frequent difficulties for differentiating relevant mutations from simple natural polymorphisms.
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Affiliation(s)
- Carla López-Causapé
- Servicio de Microbiología y Unidad de Investigación, Hospital Universitari Son Espases, Institut d'Investigació Sanitaria Illes Balears, Palma de Mallorca, Spain
| | - Gabriel Cabot
- Servicio de Microbiología y Unidad de Investigación, Hospital Universitari Son Espases, Institut d'Investigació Sanitaria Illes Balears, Palma de Mallorca, Spain
| | - Ester Del Barrio-Tofiño
- Servicio de Microbiología y Unidad de Investigación, Hospital Universitari Son Espases, Institut d'Investigació Sanitaria Illes Balears, Palma de Mallorca, Spain
| | - Antonio Oliver
- Servicio de Microbiología y Unidad de Investigación, Hospital Universitari Son Espases, Institut d'Investigació Sanitaria Illes Balears, Palma de Mallorca, Spain
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Evolution of the Pseudomonas aeruginosa Aminoglycoside Mutational Resistome In Vitro and in the Cystic Fibrosis Setting. Antimicrob Agents Chemother 2018; 62:AAC.02583-17. [PMID: 29437613 DOI: 10.1128/aac.02583-17] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 01/26/2018] [Indexed: 01/28/2023] Open
Abstract
Inhaled administration of high doses of aminoglycosides is a key maintenance treatment of Pseudomonas aeruginosa chronic respiratory infections in cystic fibrosis (CF). We analyzed the dynamics and mechanisms of stepwise high-level tobramycin resistance development in vitro and compared the results with those of isogenic pairs of susceptible and resistant clinical isolates. Resistance development correlated with fusA1 mutations in vitro and in vivo. pmrB mutations, conferring polymyxin resistance, were also frequently selected in vitro In contrast, mutational overexpression of MexXY, a hallmark of aminoglycoside resistance in CF, was not observed in in vitro evolution experiments.
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56
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Mutations in Gene fusA1 as a Novel Mechanism of Aminoglycoside Resistance in Clinical Strains of Pseudomonas aeruginosa. Antimicrob Agents Chemother 2018; 62:AAC.01835-17. [PMID: 29133559 DOI: 10.1128/aac.01835-17] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 11/05/2017] [Indexed: 01/03/2023] Open
Abstract
Resistance of clinical strains of Pseudomonas aeruginosa to aminoglycosides can result from production of transferable aminoglycoside-modifying enzymes, of 16S rRNA methylases, and/or mutational derepression of intrinsic multidrug efflux pump MexXY(OprM). We report here the characterization of a new type of mutant that is 4- to 8-fold more resistant to 2-deoxystreptamine derivatives (e.g., gentamicin, amikacin, and tobramycin) than the wild-type strain PAO1. The genetic alterations of three in vitro mutants were mapped on fusA1 and found to result in single amino acid substitutions in domains II, III, and V of elongation factor G (EF-G1A), a key component of translational machinery. Transfer of the mutated fusA1 alleles into PAO1 reproduced the resistance phenotype. Interestingly, fusA1 mutants with other amino acid changes in domains G, IV, and V of EF-G1A were identified among clinical strains with decreased susceptibility to aminoglycosides. Allelic-exchange experiments confirmed the relevance of these latter mutations and of three other previously reported alterations located in domains G and IV. Pump MexXY(OprM) partly contributed to the resistance conferred by the mutated EF-G1A variants and had additive effects on aminoglycoside MICs when mutationally upregulated. Altogether, our data demonstrate that cystic fibrosis (CF) and non-CF strains of P. aeruginosa can acquire a therapeutically significant resistance to important aminoglycosides via a new mechanism involving mutations in elongation factor EF-G1A.
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57
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Haenni M, Bour M, Châtre P, Madec JY, Plésiat P, Jeannot K. Resistance of Animal Strains of Pseudomonas aeruginosa to Carbapenems. Front Microbiol 2017; 8:1847. [PMID: 29033910 PMCID: PMC5626926 DOI: 10.3389/fmicb.2017.01847] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 09/11/2017] [Indexed: 12/31/2022] Open
Abstract
Carbapenems are major antibiotics reserved to human medicine. This study aimed to investigate the mechanisms of carbapenem resistance of a selection of Pseudomonas aeruginosa veterinary strains from the French network Resapath. Thirty (5.7%) imipenem and/or meropenem non-susceptible P. aeruginosa of canine (n = 24), feline (n = 5), or bovine (n = 1) origin were identified in a large collection of 527 veterinary strains gathered by the Resapath. These resistant isolates belonged to 25 MultiLocus Sequence Types (MLST), of which 17 (68%) are shared with clinical (human) strains, such as high risk clones ST233 and ST395. Interestingly, none of the veterinary strains produced a carbapenemase, and only six of them (20%) harbored deletions or insertion sequence (IS) disrupting the porin OprD gene. The remaining 24 strains contained mutations or IS in various loci resulting in down-regulation of gene oprD coupled with upregulation of efflux system CzcCBA (n = 3; activation of sensor kinase CzcS ± CopS), MexEF-OprN (n = 4; alteration of oxido reductase MexS), MexXY (n = 8; activation of two-component system ParRS), or MexAB-OprM (n = 12; alteration of regulator MexR, NalC ± NalD). Two efflux pumps were co-produced simultaneously in three mutants. Finally, in 11 out of 12 strains displaying an intact porin OprD, derepression of MexAB-OprM accounted for a decreased susceptibility to meropenem relative to imipenem. Though not treated by carbapenems, animals thus represent a reservoir of multidrug resistant P. aeruginosa strains potentially able to contaminate fragile outpatients.
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Affiliation(s)
- Marisa Haenni
- Unité Antibiorésistance et Virulence Bactériennes, ANSES-Université de LyonLyon, France
| | - Maxime Bour
- Centre National de Référence de la Résistance aux Antibiotiques, Centre Hospitalier Universitaire de BesançonBesançon, France
| | - Pierre Châtre
- Unité Antibiorésistance et Virulence Bactériennes, ANSES-Université de LyonLyon, France
| | - Jean-Yves Madec
- Unité Antibiorésistance et Virulence Bactériennes, ANSES-Université de LyonLyon, France
| | - Patrick Plésiat
- Centre National de Référence de la Résistance aux Antibiotiques, Centre Hospitalier Universitaire de BesançonBesançon, France
| | - Katy Jeannot
- Centre National de Référence de la Résistance aux Antibiotiques, Centre Hospitalier Universitaire de BesançonBesançon, France
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58
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Singh M, Yau YCW, Wang S, Waters V, Kumar A. MexXY efflux pump overexpression and aminoglycoside resistance in cystic fibrosis isolates of Pseudomonas aeruginosa from chronic infections. Can J Microbiol 2017; 63:929-938. [PMID: 28922614 DOI: 10.1139/cjm-2017-0380] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
In this study, we analyzed 15 multidrug-resistant cystic fibrosis isolates of Pseudomonas aeruginosa from chronic lung infections for expression of 4 different multidrug efflux systems (MexAB-OprM, MexCD-OprJ, MexEF-OprN, and MexXY), using quantitative reverse transcriptase PCR. Overexpression of MexXY pump was observed in all of the isolates tested. Analysis of regulatory genes that control the expression of these 4 efflux pumps revealed a number of previously uncharacterized mutations. Our work shows that MexXY pump overexpression is common in cystic fibrosis isolates and could be contributing to their reduced aminoglycoside susceptibility. Further, we also identified novel mutations in the regulatory genes of the 4 abovementioned Resistance-Nodulation-Division superfamily pumps that may be involved in the overexpression of these pumps.
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Affiliation(s)
- Manu Singh
- a Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Yvonne C W Yau
- b Division of Microbiology, Department of Paediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Shirley Wang
- a Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Valerie Waters
- c Division of Infectious Diseases, Department of Paediatrics, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Ayush Kumar
- a Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada.,d Manitoba Chemosensory Biology Group, University of Manitoba, Winnipeg, Manitoba, Canada
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Xu Z, Xu X, Qi D, Yang L, Li B, Li L, Li X, Chen D. Effect of aminoglycosides on the pathogenic characteristics of microbiology. Microb Pathog 2017; 113:357-364. [PMID: 28867624 DOI: 10.1016/j.micpath.2017.08.053] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Revised: 08/30/2017] [Accepted: 08/30/2017] [Indexed: 02/08/2023]
Abstract
Infections caused by pathogen remain to be one of the most important global health issues, and scientists are devoting themselves to seeking effective treatments. Aminoglycoside antibiotics are one kind of widely used antibiotics because of the good efficiency and broad antimicrobial-spectrum. However, it causes some unexpected effects on the pathogenic characteristics of microbiology during the treatment, such as drug resistance and biofilm promotion. Drug resistance is partly due to antibiotics abuse. Simultaneously, aminoglycoside is documented to make divergent effects on biofilm based on their concentrations. Here, we review the mechanism of drug resistance caused by long-term use of aminoglycoside antibiotics, the effects of antibiotic concentration on biofilm formation and the negative effects on intestinal flora to provide theoretical supports for rational use of antibiotics.
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Affiliation(s)
- Zhenbo Xu
- School of Food Science and Engineering, South China University of Technology, Guangzhou 510640, PR China; Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, Guangzhou, PR China; Department of Microbial Pathogenesis, School of Dentistry, University of Maryland, Baltimore, MD 21201, USA.
| | - Xingyong Xu
- School of Food Science and Engineering, South China University of Technology, Guangzhou 510640, PR China
| | - Da Qi
- BGI-Shenzhen, Shenzhen 518083, PR China
| | - Ling Yang
- Department of Laboratory Medicine, First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou 510120, PR China
| | - Bing Li
- School of Food Science and Engineering, South China University of Technology, Guangzhou 510640, PR China; Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, Guangzhou, PR China
| | - Lin Li
- School of Food Science and Engineering, South China University of Technology, Guangzhou 510640, PR China; Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, Guangzhou, PR China
| | - Xiaoxi Li
- School of Food Science and Engineering, South China University of Technology, Guangzhou 510640, PR China; Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, Guangzhou, PR China.
| | - Dingqiang Chen
- Department of Laboratory Medicine, First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou 510120, PR China
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60
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Role of AxyZ Transcriptional Regulator in Overproduction of AxyXY-OprZ Multidrug Efflux System in Achromobacter Species Mutants Selected by Tobramycin. Antimicrob Agents Chemother 2017; 61:AAC.00290-17. [PMID: 28584156 DOI: 10.1128/aac.00290-17] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 03/31/2017] [Indexed: 11/20/2022] Open
Abstract
AxyXY-OprZ is an RND-type efflux system that confers innate aminoglycoside resistance to Achromobacter spp. We investigated here a putative TetR family transcriptional regulator encoded by the axyZ gene located upstream of axyXY-oprZ An in-frame axyZ gene deletion assay led to increased MICs of antibiotic substrates of the efflux system, including aminoglycosides, cefepime, fluoroquinolones, tetracyclines, and erythromycin, indicating that the product of axyZ negatively regulates expression of axyXY-oprZ Moreover, we identified an amino acid substitution at position 29 of AxyZ (V29G) in a clinical Achromobacter strain that occurred during the course of chronic respiratory tract colonization in a cystic fibrosis (CF) patient. This substitution, also detected in three other strains exposed in vitro to tobramycin, led to an increase in the axyY transcription level (5- to 17-fold) together with an increase in antibiotic resistance level. This overproduction of AxyXY-OprZ is the first description of antibiotic resistance acquisition due to modification of a chromosomally encoded mechanism in Achromobacter and might have an impact on the management of infected CF patients. Indeed, tobramycin is widely used for aerosol therapy within this population, and we have demonstrated that it easily selects mutants with increased MICs of not only aminoglycosides but also fluoroquinolones, cefepime, and tetracyclines.
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61
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Sidorenko J, Jatsenko T, Kivisaar M. Ongoing evolution of Pseudomonas aeruginosa PAO1 sublines complicates studies of DNA damage repair and tolerance. Mutat Res 2017; 797-799:26-37. [PMID: 28340408 DOI: 10.1016/j.mrfmmm.2017.03.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 12/23/2016] [Accepted: 03/07/2017] [Indexed: 06/06/2023]
Abstract
Sublines of the major P. aeruginosa reference strain PAO1 are derivatives of the original PAO1 isolate, which are maintained in laboratories worldwide. These sublines display substantial genomic and phenotypic variation due to ongoing microevolution. Here, we examined four sublines, MPAO1, PAO1-L, PAO1-DSM and PAO1-UT, originated from different laboratories, and six DNA polymerase-deficient mutants from the P. aeruginosa MPAO1 transposon library for their employment in elucidation of DNA damage repair and tolerance mechanisms in P. aeruginosa. We found that PAO1 subline PAO1-UT carries a large deletion encompassing the DNA damage inducible imuA-imuB-imuC cassette (PA0669-PA0671), which is implied in mutagenesis in several species. Furthermore, the genetic changes leading to variation in the functionality of the MexEF-OprN efflux system contributed largely to the phenotypic discordance between P. aeruginosa PAO1 sublines. Specifically, we identified multiple mutations in the mexT gene, which encodes a transcriptional regulator of the mexEF-oprN genes, mutations in the mexF, and complete absence of these genes. Of the four tested sublines, MPAO1 was the only subline with the functional MexEF-OprN multidrug efflux system. Active efflux through MexEF-OprN rendered MPAO1 highly resistant to chloramphenicol and ciprofloxacin. Moreover, the functions of specialized DNA polymerase IV and nucleotide excision repair (NER) in 4-NQO-induced DNA damage tolerance appeared to be masked in MPAO1, while were easily detectable in other sublines. Finally, the frequencies of spontaneous and MMS-induced Rifr mutations were also significantly lower in MPAO1 in comparison to the PAO1 sublines with impaired MexEF-OprN efflux system. The MexEF-OprN-attributed differences were also observed between MPAO1 and MPAO1-derived transposon mutants from the two-allele transposon mutant collection. Thus, the accumulating mutations and discordant phenotypes of the PAO1 derivatives challenge the reproducibility and comparability of the results obtained with different PAO1 sublines and also limit the usage of the MPAO1 transposon library in DNA damage tolerance and mutagenesis studies.
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Affiliation(s)
- Julia Sidorenko
- Department of Genetics, Institute of Molecular and Cell Biology, University of Tartu, 23 Riia Street, 51010, Tartu, Estonia.
| | - Tatjana Jatsenko
- Department of Genetics, Institute of Molecular and Cell Biology, University of Tartu, 23 Riia Street, 51010, Tartu, Estonia
| | - Maia Kivisaar
- Department of Genetics, Institute of Molecular and Cell Biology, University of Tartu, 23 Riia Street, 51010, Tartu, Estonia.
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Amoh T, Murakami K, Kariyama R, Hori K, Irie Y, Viducic D, Hirota K, Igarashi J, Suga H, Kumon H, Miyake Y. A <i>Pseudomonas aeruginosa</i> Quorum-Sensing autoinducer analog enhances the activity of antibiotics against resistant strains. THE JOURNAL OF MEDICAL INVESTIGATION 2017; 64:101-109. [DOI: 10.2152/jmi.64.101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Takashi Amoh
- Department of Oral Microbiology, Institute of Biomedical Sciences, Tokushima University Graduate School
| | - Keiji Murakami
- Department of Oral Microbiology, Institute of Biomedical Sciences, Tokushima University Graduate School
| | - Reiko Kariyama
- Department of Urology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University
- Department of Food and Nutrition, Okayama Gakuin University
| | - Kenji Hori
- Innovation Center Okayama for Nanobio-targeted Therapy, Okayama University
| | | | - Darija Viducic
- Department of Oral Microbiology, Institute of Biomedical Sciences, Tokushima University Graduate School
| | - Katsuhiko Hirota
- Department of Oral Microbiology, Institute of Biomedical Sciences, Tokushima University Graduate School
| | - Jun Igarashi
- Discovery Research Lab., Otsuka Chemical Co. Ltd
| | - Hiroaki Suga
- Department of Chemistry, Graduate School of Science, the University of Tokyo
| | - Hiromi Kumon
- Department of Urology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University
| | - Yoichiro Miyake
- Department of Oral Microbiology, Institute of Biomedical Sciences, Tokushima University Graduate School
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63
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Deciphering the Resistome of the Widespread Pseudomonas aeruginosa Sequence Type 175 International High-Risk Clone through Whole-Genome Sequencing. Antimicrob Agents Chemother 2016; 60:7415-7423. [PMID: 27736752 DOI: 10.1128/aac.01720-16] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Accepted: 09/27/2016] [Indexed: 12/28/2022] Open
Abstract
Whole-genome sequencing (WGS) was used for the characterization of the frequently extensively drug resistant (XDR) Pseudomonas aeruginosa sequence type 175 (ST175) high-risk clone. A total of 18 ST175 isolates recovered from 8 different Spanish hospitals were analyzed; 4 isolates from 4 different French hospitals were included for comparison. The typical resistance profile of ST175 included penicillins, cephalosporins, monobactams, carbapenems, aminoglycosides, and fluoroquinolones. In the phylogenetic analysis, the four French isolates clustered together with two isolates from one of the Spanish regions. Sequence variation was analyzed for 146 chromosomal genes related to antimicrobial resistance, and horizontally acquired genes were explored using online databases. The resistome of ST175 was determined mainly by mutational events; resistance traits common to all or nearly all of the strains included specific ampR mutations leading to ampC overexpression, specific mutations in oprD conferring carbapenem resistance, or a mexZ mutation leading to MexXY overexpression. All isolates additionally harbored an aadB gene conferring gentamicin and tobramycin resistance. Several other resistance traits were specific to certain geographic areas, such as a streptomycin resistance gene, aadA13, detected in all four isolates from France and in the two isolates from the Cantabria region and a glpT mutation conferring fosfomycin resistance, detected in all but these six isolates. Finally, several unique resistance mutations were detected in single isolates; particularly interesting were those in genes encoding penicillin-binding proteins (PBP1A, PBP3, and PBP4). Thus, these results provide information valuable for understanding the genetic basis of resistance and the dynamics of the dissemination and evolution of high-risk clones.
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Molecular Epidemiology of Mutations in Antimicrobial Resistance Loci of Pseudomonas aeruginosa Isolates from Airways of Cystic Fibrosis Patients. Antimicrob Agents Chemother 2016; 60:6726-6734. [PMID: 27572404 DOI: 10.1128/aac.00724-16] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 08/23/2016] [Indexed: 01/30/2023] Open
Abstract
The chronic airway infections with Pseudomonas aeruginosa in people with cystic fibrosis (CF) are treated with aerosolized antibiotics, oral fluoroquinolones, and/or intravenous combination therapy with aminoglycosides and β-lactam antibiotics. An international strain collection of 361 P. aeruginosa isolates from 258 CF patients seen at 30 CF clinics was examined for mutations in 17 antimicrobial susceptibility and resistance loci that had been identified as hot spots of mutation by genome sequencing of serial isolates from a single CF clinic. Combinatorial amplicon sequencing of pooled PCR products identified 1,112 sequence variants that were not present in the genomes of representative strains of the 20 most common clones of the global P. aeruginosa population. A high frequency of singular coding variants was seen in spuE, mexA, gyrA, rpoB, fusA1, mexZ, mexY, oprD, ampD, parR, parS, and envZ (amgS), reflecting the pressure upon P. aeruginosa in lungs of CF patients to generate novel protein variants. The proportion of nonneutral amino acid exchanges was high. Of the 17 loci, mexA, mexZ, and pagL were most frequently affected by independent stop mutations. Private and de novo mutations seem to play a pivotal role in the response of P. aeruginosa populations to the antimicrobial load and the individual CF host.
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Goli HR, Nahaei MR, Rezaee MA, Hasani A, Samadi Kafil H, Aghazadeh M, Sheikhalizadeh V. Contribution of mexAB-oprM and mexXY (-oprA) efflux operons in antibiotic resistance of clinical Pseudomonas aeruginosa isolates in Tabriz, Iran. INFECTION GENETICS AND EVOLUTION 2016; 45:75-82. [PMID: 27562333 DOI: 10.1016/j.meegid.2016.08.022] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2015] [Revised: 08/20/2016] [Accepted: 08/20/2016] [Indexed: 10/21/2022]
Abstract
Overexpression of efflux pumps is one of the most important mechanisms that contributes to intrinsic and acquired resistance to antibiotics in Pseudomonas aeruginosa. The present study evaluated the role of MexAB-OprM and MexXY (-OprA) efflux pump overexpression in antibiotics resistance of P. aeruginosa clinical isolates. One-hundred clinical isolates of P. aeruginosa were obtained from four hospitals of Tabriz city in Northwest Iran. Isolates were identified and evaluated by the disk diffusion method and agar dilution in order to determine antibiotic resistance. Effect of Phenylalanine Arginine beta-Naphthylamide (PAβN) on susceptibility to various anti-Pseudomonas antimicrobials and expression levels of mexB and mexY using quantitative real-time PCR were determined in the clinical isolates. Random Amplified Polymorphic DNA Typing (RAPD-PCR) was used for genotyping of the isolates. The most and least effective antibiotics tested were colistin and ofloxacin, respectively. Seventy-one percent of the isolates were found as multidrug resistant (resistant to at least three different classes of antibiotics). Among ciprofloxacin and levofloxacin resistant isolates, 39.6% and 28.5% of them showed four-fold reduction in MIC with PAβN, respectively. Sixty-two percent and 65% of isolates overexpressed mexB and mexY, respectively. Sixty six isolates showed overexpression of both mexB and mexY efflux genes. Moreover, 76% and 88.7% of MDR isolates were mexB and mexY overexpressed, respectively. There were 30 different RAPD types in this study which were clustered into 6 clones. The study indicated that there is a significant correlation between the expression of efflux pumps and the resistance to most anti-pseudomonal antibiotics.
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Affiliation(s)
- Hamid Reza Goli
- Drug Applied Research Center, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Islamic Republic of Iran; Department of Medical Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Islamic Republic of Iran; Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Islamic Republic of Iran
| | - Mohammad Reza Nahaei
- Drug Applied Research Center, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Islamic Republic of Iran; Department of Medical Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Islamic Republic of Iran
| | - Mohammad Ahangarzadeh Rezaee
- Infectious Diseases and Tropical Medicine Research Center, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Islamic Republic of Iran; Department of Medical Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Islamic Republic of Iran
| | - Alka Hasani
- Infectious Diseases and Tropical Medicine Research Center, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Islamic Republic of Iran; Department of Medical Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Islamic Republic of Iran
| | - Hossein Samadi Kafil
- Drug Applied Research Center, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Islamic Republic of Iran; Department of Medical Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Islamic Republic of Iran
| | - Mohammad Aghazadeh
- Drug Applied Research Center, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Islamic Republic of Iran; Department of Medical Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Islamic Republic of Iran.
| | - Vajihe Sheikhalizadeh
- Department of Medical Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Islamic Republic of Iran
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Rees VE, Bulitta JB, Oliver A, Tsuji BT, Rayner CR, Nation RL, Landersdorfer CB. Resistance suppression by high-intensity, short-duration aminoglycoside exposure against hypermutable and non-hypermutable Pseudomonas aeruginosa. J Antimicrob Chemother 2016; 71:3157-3167. [PMID: 27521357 DOI: 10.1093/jac/dkw297] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 06/14/2016] [Accepted: 06/23/2016] [Indexed: 12/16/2022] Open
Abstract
OBJECTIVES Hypermutable bacteria are causing a drastic problem via their enhanced ability to become resistant. Our objectives were to compare bacterial killing and resistance emergence between differently shaped tobramycin concentration-time profiles at a given fAUC/MIC, and determine the tobramycin exposure durations that prevent resistance. METHODS Static concentration time-kill studies over 24 h used Pseudomonas aeruginosa WT strains (ATCC 27853 and PAO1) and hypermutable PAOΔmutS. fAUC/MIC values of 36, 72 and 168 were assessed at initial inocula of 106 and 104 cfu/mL (all strains) and 101.2 cfu/mL (PAOΔmutS only) in duplicate. Tobramycin was added at 0 h and removed at 1, 4, 10 or 24 h. Proportions of resistant bacteria and MICs were determined at 24 h. Mechanism-based modelling was conducted. RESULTS For all strains, high tobramycin concentrations over 1 and 4 h resulted in more rapid and extensive initial killing compared with 10 and 24 h exposures at a given fAUC/MIC. No resistance emerged for 1 and 4 h durations of exposure, although extensive regrowth of susceptible bacteria occurred. The 24 h duration of exposure revealed less regrowth, but tobramycin-resistant populations had completely replaced susceptible bacteria by 24 h for the 106 cfu/mL inoculum. The hypermutable PAOΔmutS showed the highest numbers of resistant bacteria. Total and resistant bacterial counts were described well by novel mechanism-based modelling. CONCLUSIONS Extensive resistance emerged for 10 and 24 h durations of exposure, but not for shorter durations. The tobramycin concentration-time profile shape is vital for resistance prevention and should aid the introduction of optimized combination regimens.
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Affiliation(s)
- Vanessa E Rees
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville campus), Parkville, Victoria 3052, Australia
| | - Jürgen B Bulitta
- Center for Pharmacometrics and Systems Pharmacology, College of Pharmacy, University of Florida, Orlando, FL, USA
| | - Antonio Oliver
- Servicio de Microbiología, Hospital Universitario Son Espases, Instituto de Investigación Sanitaria de Palma, Palma de Mallorca, Spain
| | - Brian T Tsuji
- School of Pharmacy and Pharmaceutical Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA
| | - Craig R Rayner
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville campus), Parkville, Victoria 3052, Australia.,d3 medicine LLC, Parsippany, NJ, USA
| | - Roger L Nation
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville campus), Parkville, Victoria 3052, Australia
| | - Cornelia B Landersdorfer
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville campus), Parkville, Victoria 3052, Australia .,School of Pharmacy and Pharmaceutical Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA
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67
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Morita Y, Nakashima KI, Nishino K, Kotani K, Tomida J, Inoue M, Kawamura Y. Berberine Is a Novel Type Efflux Inhibitor Which Attenuates the MexXY-Mediated Aminoglycoside Resistance in Pseudomonas aeruginosa. Front Microbiol 2016; 7:1223. [PMID: 27547203 PMCID: PMC4975076 DOI: 10.3389/fmicb.2016.01223] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 07/22/2016] [Indexed: 01/10/2023] Open
Abstract
The emergence and spread of multidrug-resistant P. aeruginosa infections is of great concern, as very few agents are effective against strains of this species. Methanolic extracts from the Coptidis Rhizoma (the rhizomes of Coptis japonica var. major Satake) or Phellodendri Cortex (the bark of Phellodendron chinense Schneider) markedly reduced resistance to anti-pseudomonal aminoglycosides (e.g., amikacin) in multidrug-resistant P. aeruginosa strains. Berberine, the most abundant benzylisoquinoline alkaloid in the two extracts, reduced aminoglycoside resistance of P. aeruginosa via a mechanism that required the MexXY multidrug efflux system; berberine also reduced aminoglycoside MICs in Achromobacter xylosoxidans and Burkholderia cepacia, two species that harbor intrinsic multidrug efflux systems very similar to the MexXY. Furthermore this compound inhibited MexXY-dependent antibiotic resistance of other classes including cephalosporins (cefepime), macrolides (erythromycin), and lincosamides (lincomycin) demonstrated using a pseudomonad lacking the four other major Mex pumps. Although phenylalanine-arginine beta-naphthylamide (PAβN), a well-known efflux inhibitor, antagonized aminoglycoside in a MexXY-dependent manner, a lower concentration of berberine was sufficient to reduce amikacin resistance of P. aeruginosa in the presence of PAβN. Moreover, berberine enhanced the synergistic effects of amikacin and piperacillin (and vice versa) in multidrug-resistant P. aeruginosa strains. Thus, berberine appears to be a novel type inhibitor of the MexXY-dependent aminoglycoside efflux in P. aeruginosa. As aminoglycosides are molecules of choice to treat severe infections the clinical impact is potentially important.
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Affiliation(s)
- Yuji Morita
- Department of Microbiology, School of Pharmacy, Aichi Gakuin University Nagoya, Japan
| | - Ken-Ichi Nakashima
- Laboratory of Medicinal Resources, School of Pharmacy, Aichi Gakuin University Nagoya, Japan
| | - Kunihiko Nishino
- Department of Biomolecular Science and Regulation, Institute of Scientific and Industrial Research, Osaka University Osaka, Japan
| | - Kenta Kotani
- Department of Microbiology, School of Pharmacy, Aichi Gakuin University Nagoya, Japan
| | - Junko Tomida
- Department of Microbiology, School of Pharmacy, Aichi Gakuin University Nagoya, Japan
| | - Makoto Inoue
- Laboratory of Medicinal Resources, School of Pharmacy, Aichi Gakuin University Nagoya, Japan
| | - Yoshiaki Kawamura
- Department of Microbiology, School of Pharmacy, Aichi Gakuin University Nagoya, Japan
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68
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Heinzl GA, Huang W, Yu W, Giardina BJ, Zhou Y, MacKerell AD, Wilks A, Xue F. Iminoguanidines as Allosteric Inhibitors of the Iron-Regulated Heme Oxygenase (HemO) of Pseudomonas aeruginosa. J Med Chem 2016; 59:6929-42. [PMID: 27353344 DOI: 10.1021/acs.jmedchem.6b00757] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
New therapeutic targets are required to combat multidrug resistant infections, such as the iron-regulated heme oxygenase (HemO) of Pseudomonas aeruginosa, due to links between iron and virulence and dependence on heme as an iron source during infection. Herein we report the synthesis and activity of a series of iminoguanidine-based inhibitors of HemO. Compound 23 showed a binding affinity of 5.7 μM and an MIC50 of 52.3 μg/mL against P. aeruginosa PAO1. An in cellulo activity assay was developed by coupling HemO activity to a biliverdin-IXα-dependent infrared fluorescent protein, in which compound 23 showed an EC50 of 11.3 μM. The compounds showed increased activity against clinical isolates of P. aeruginosa, further confirming the target pathway. This class of inhibitors acts by binding to an allosteric site; the novel binding site is proposed in silico and supported by saturation transfer difference (STD) NMR as well as by hydrogen exchange mass spectrometry (HXMS).
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Affiliation(s)
- Geoffrey A Heinzl
- University of Maryland Computer-Aided Drug Design Center, Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland , Baltimore, Maryland 21201, United States
| | - Weiliang Huang
- University of Maryland Computer-Aided Drug Design Center, Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland , Baltimore, Maryland 21201, United States
| | - Wenbo Yu
- University of Maryland Computer-Aided Drug Design Center, Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland , Baltimore, Maryland 21201, United States
| | - Bennett J Giardina
- University of Maryland Computer-Aided Drug Design Center, Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland , Baltimore, Maryland 21201, United States
| | - Yue Zhou
- University of Maryland Computer-Aided Drug Design Center, Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland , Baltimore, Maryland 21201, United States
| | - Alexander D MacKerell
- University of Maryland Computer-Aided Drug Design Center, Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland , Baltimore, Maryland 21201, United States
| | - Angela Wilks
- University of Maryland Computer-Aided Drug Design Center, Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland , Baltimore, Maryland 21201, United States
| | - Fengtian Xue
- University of Maryland Computer-Aided Drug Design Center, Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland , Baltimore, Maryland 21201, United States
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Margara LM, Fernández MM, Malchiodi EL, Argaraña CE, Monti MR. MutS regulates access of the error-prone DNA polymerase Pol IV to replication sites: a novel mechanism for maintaining replication fidelity. Nucleic Acids Res 2016; 44:7700-13. [PMID: 27257069 PMCID: PMC5027486 DOI: 10.1093/nar/gkw494] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 05/20/2016] [Indexed: 12/02/2022] Open
Abstract
Translesion DNA polymerases (Pol) function in the bypass of template lesions to relieve stalled replication forks but also display potentially deleterious mutagenic phenotypes that contribute to antibiotic resistance in bacteria and lead to human disease. Effective activity of these enzymes requires association with ring-shaped processivity factors, which dictate their access to sites of DNA synthesis. Here, we show for the first time that the mismatch repair protein MutS plays a role in regulating access of the conserved Y-family Pol IV to replication sites. Our biochemical data reveals that MutS inhibits the interaction of Pol IV with the β clamp processivity factor by competing for binding to the ring. Moreover, the MutS–β clamp association is critical for controlling Pol IV mutagenic replication under normal growth conditions. Thus, our findings reveal important insights into a non-canonical function of MutS in the regulation of a replication activity.
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Affiliation(s)
- Lucía M Margara
- Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), CONICET, Departamento de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba X5000HUA, Argentina
| | - Marisa M Fernández
- Cátedra de Inmunología and Instituto de Estudios de la Inmunidad Humoral Profesor Ricardo A. Margni, CONICET, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires C1113AAD, Argentina
| | - Emilio L Malchiodi
- Cátedra de Inmunología and Instituto de Estudios de la Inmunidad Humoral Profesor Ricardo A. Margni, CONICET, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires C1113AAD, Argentina
| | - Carlos E Argaraña
- Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), CONICET, Departamento de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba X5000HUA, Argentina
| | - Mariela R Monti
- Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), CONICET, Departamento de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba X5000HUA, Argentina
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Potentiation of Aminoglycoside Activity in Pseudomonas aeruginosa by Targeting the AmgRS Envelope Stress-Responsive Two-Component System. Antimicrob Agents Chemother 2016; 60:3509-18. [PMID: 27021319 DOI: 10.1128/aac.03069-15] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 03/17/2016] [Indexed: 02/06/2023] Open
Abstract
A screen for agents that potentiated the activity of paromomycin (PAR), a 4,5-linked aminoglycoside (AG), against wild-type Pseudomonas aeruginosa identified the RNA polymerase inhibitor rifampin (RIF). RIF potentiated additional 4,5-linked AGs, such as neomycin and ribostamycin, but not the clinically important 4,6-linked AGs amikacin and gentamicin. Potentiation was absent in a mutant lacking the AmgRS envelope stress response two-component system (TCS), which protects the organism from AG-generated membrane-damaging aberrant polypeptides and, thus, promotes AG resistance, an indication that RIF was acting via this TCS in potentiating 4,5-linked AG activity. Potentiation was also absent in a RIF-resistant RNA polymerase mutant, consistent with its potentiation of AG activity being dependent on RNA polymerase perturbation. PAR-inducible expression of the AmgRS-dependent genes htpX and yccA was reduced by RIF, suggesting that AG activation of this TCS was compromised by this agent. Still, RIF did not compromise the membrane-protective activity of AmgRS, an indication that it impacted some other function of this TCS. RIF potentiated the activities of 4,5-linked AGs against several AG-resistant clinical isolates, in two cases also potentiating the activity of the 4,6-linked AGs. These cases were, in one instance, explained by an observed AmgRS-dependent expression of the MexXY multidrug efflux system, which accommodates a range of AGs, with RIF targeting of AmgRS undermining mexXY expression and its promotion of resistance to 4,5- and 4,6-linked AGs. Given this link between AmgRS, MexXY expression, and pan-AG resistance in P. aeruginosa, RIF might be a useful adjuvant in the AG treatment of P. aeruginosa infections.
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Tan H, Zhang L, Weng Y, Chen R, Zhu F, Jin Y, Cheng Z, Jin S, Wu W. PA3297 Counteracts Antimicrobial Effects of Azithromycin in Pseudomonas aeruginosa. Front Microbiol 2016; 7:317. [PMID: 27014238 PMCID: PMC4792872 DOI: 10.3389/fmicb.2016.00317] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 02/29/2016] [Indexed: 01/08/2023] Open
Abstract
Pseudomonas aeruginosa causes acute and chronic infections in human. Its increasing resistance to antibiotics requires alternative treatments that are more effective than available strategies. Among the alternatives is the unconventional usage of conventional antibiotics, of which the macrolide antibiotic azithromycin (AZM) provides a paradigmatic example. AZM therapy is associated with a small but consistent improvement in respiratory function of cystic fibrosis patients suffering from chronic P. aeruginosa infection. Besides immunomodulating activities, AZM represses bacterial genes involved in virulence, quorum sensing, biofilm formation, and motility, all of which are due to stalling of ribosome and depletion of cellular tRNA pool. However, how P. aeruginosa responds to and counteracts the effects of AZM remain elusive. Here, we found that deficiency of PA3297, a gene encoding a DEAH-box helicase, intensified AZM-mediated bacterial killing, suppression of pyocyanin production and swarming motility, and hypersusceptibility to hydrogen peroxide. We demonstrated that expression of PA3297 is induced by the interaction between AZM and ribosome. Importantly, mutation of PA3297 resulted in elevated levels of unprocessed 23S-5S rRNA in the presence of AZM, which might lead to increased susceptibility to AZM-mediated effects. Our results revealed one of the bacterial responses in counteracting the detrimental effects of AZM.
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Affiliation(s)
- Hao Tan
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University Tianjin, China
| | - Lu Zhang
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University Tianjin, China
| | - Yuding Weng
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University Tianjin, China
| | - Ronghao Chen
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University Tianjin, China
| | - Feng Zhu
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University Tianjin, China
| | - Yongxin Jin
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University Tianjin, China
| | - Zhihui Cheng
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University Tianjin, China
| | - Shouguang Jin
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai UniversityTianjin, China; Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, GainesvilleFL, USA
| | - Weihui Wu
- State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University Tianjin, China
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Goli HR, Nahaei MR, Ahangarzadeh Rezaee M, Hasani A, Samadi Kafil H, Aghazadeh M. Emergence of colistin resistant Pseudomonas aeruginosa at Tabriz hospitals, Iran. IRANIAN JOURNAL OF MICROBIOLOGY 2016; 8:62-9. [PMID: 27092226 PMCID: PMC4833742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND AND OBJECTIVES The prevalence of multidrug resistant Pseudomonas aeruginosa is the main reason of new drugs resurgence such as colistin. The main objectives of this study were to determine the antibiotic resistance pattern and the rate of colistin resistance along with its correlation with overexpression of MexAB-OprM and MexXY-OprM efflux pumps among P. aeruginosa isolates. MATERIALS AND METHODS Hundred clinical isolates were collected from 100 patients during 6 months in 2014. Susceptibility to the eight antibiotics was investigated using Kirby-Bauer and agar dilution methods. The Quantitative Real-time PCR was used to determine the expression levels of efflux genes. RESULTS Resistance rates to various antibiotics were as follows: ticarcillin (73%), ciprofloxacin (65%), aztreonam (60%), ceftazidime (55%), gentamicin (55%), imipenem (49%), piperacillin/tazobactam (34%) and colistin (2%). In disk diffusion method, only two isolates were non susceptible to colistin, however in agar dilution method the two isolates were confirmed as resistant and two others were intermediate resistant. Sixty eight (68%) isolates were multi-drug resistant and 10 isolates were susceptible to all tested antibiotics. Both colistin resistant isolates showed overexpression of both efflux pumps, but two intermediate resistant isolates exhibited reduction of efflux genes expression. CONCLUSIONS Emergence of colistin resistance is increasing in P. aeruginosa indicating great challenge in the treatment of infections caused by MDR strains of this organism in Iran. ParRS may promote either induced or constitutive resistance to colistin through the activation of distinct mechanisms such as MDR efflux pumps, and LPS modification.
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Affiliation(s)
- Hamid Reza Goli
- Drug Applied Research Center, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran,Department of Medical Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Reza Nahaei
- Drug Applied Research Center, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran,Department of Medical Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Ahangarzadeh Rezaee
- Infectious Diseases and Tropical Medicine Research Center, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran,Department of Medical Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Alka Hasani
- Infectious Diseases and Tropical Medicine Research Center, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran,Department of Medical Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Hossein Samadi Kafil
- Drug Applied Research Center, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran,Department of Medical Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Aghazadeh
- Drug Applied Research Center, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran,Department of Medical Microbiology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran,Corresponding author: Mohammad Aghazadeh, Ph.D, Address: Drug Applied Research Center, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran. Tel: +989143134820, E-mail:
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Kazemizadeh AR, Shajari N, Shapouri R, Adibpour N, Teimuri-Mofrad R, Dinmohammadi P. One-pot, four-component synthesis of 1,3,4-oxadiazole derivatives containing a ferrocene unit and their antimicrobial activity. Appl Organomet Chem 2015. [DOI: 10.1002/aoc.3410] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Ali Reza Kazemizadeh
- Research Laboratory of MCR, Department of Chemistry, Zanjan Branch; Islamic Azad University; PO Box 49195-467 Zanjan Iran
| | - Nahid Shajari
- Research Laboratory of MCR, Department of Chemistry, Zanjan Branch; Islamic Azad University; PO Box 49195-467 Zanjan Iran
| | - Reza Shapouri
- Department of Microbiology, Zanjan Branch; Islamic Azad University; PO Box 49195-467 Zanjan Iran
| | - Neda Adibpour
- Department of Medicinal Chemistry, School of Pharmacy; Zanjan University of Medical Sciences; Postal Code 45139-56184 Zanjan Iran
| | - Reza Teimuri-Mofrad
- Organic Synthesis Research Laboratory, Department of Organic and Biochemistry, Faculty of Chemistry; University of Tabriz; 51664 Tabriz Iran
| | - Parisa Dinmohammadi
- Department of Microbiology, Zanjan Branch; Islamic Azad University; PO Box 49195-467 Zanjan Iran
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El Zowalaty ME, Al Thani AA, Webster TJ, El Zowalaty AE, Schweizer HP, Nasrallah GK, Marei HE, Ashour HM. Pseudomonas aeruginosa: arsenal of resistance mechanisms, decades of changing resistance profiles, and future antimicrobial therapies. Future Microbiol 2015; 10:1683-706. [PMID: 26439366 DOI: 10.2217/fmb.15.48] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Antimicrobial resistance is one of the most serious public health issues facing humans since the discovery of antimicrobial agents. The frequent, prolonged, and uncontrolled use of antimicrobial agents are major factors in the emergence of antimicrobial-resistant bacterial strains, including multidrug-resistant variants. Pseudomonas aeruginosa is a leading cause of nosocomial infections. The abundant data on the increased resistance to antipseudomonal agents support the need for global action. There is a paucity of new classes of antibiotics active against P. aeruginosa. Here, we discuss recent antibacterial resistance profiles and mechanisms of resistance by P. aeruginosa. We also review future potential methods for controlling antibiotic-resistant bacteria, such as phage therapy, nanotechnology and antipseudomonal vaccines.
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Affiliation(s)
- Mohamed E El Zowalaty
- Department of Microbiology & Immunology, Emory University School of Medicine, Atlanta, GA 30322, USA.,BioMedical Research Center, Qatar University, Doha, PO Box 2713, Qatar
| | - Asmaa A Al Thani
- BioMedical Research Center, Qatar University, Doha, PO Box 2713, Qatar.,Department of Health Sciences, College of Arts and Sciences, Qatar University, Doha 2713, Qatar
| | - Thomas J Webster
- Department of Chemical Engineering, Northeastern University, Boston, MA 02018, USA.,Center of Excellence for Advanced Materials Research, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia
| | - Ahmed E El Zowalaty
- Department of Physiology & Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA.,Interdisciplinary Toxicology Program, University of Georgia, Athens, GA 30602, USA
| | - Herbert P Schweizer
- Department of Molecular Genetics & Microbiology, College of Medicine, University of Florida, Gainesville, FL 32611, USA.,Emerging Pathogens Institute, Institute for Therapeutic Innovation, University of Florida Gainesville, FL 32611, USA
| | - Gheyath K Nasrallah
- BioMedical Research Center, Qatar University, Doha, PO Box 2713, Qatar.,Department of Health Sciences, College of Arts and Sciences, Qatar University, Doha 2713, Qatar
| | - Hany E Marei
- BioMedical Research Center, Qatar University, Doha, PO Box 2713, Qatar
| | - Hossam M Ashour
- Department of Microbiology & Immunology, Faculty of Pharmacy, Cairo University, Egypt.,Department of Pharmacy Practice, Eugene Applebaum College of Pharmacy & Health Sciences, Wayne State University, Detroit, MI, USA
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75
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Oliver A, Mulet X, López-Causapé C, Juan C. The increasing threat of Pseudomonas aeruginosa high-risk clones. Drug Resist Updat 2015; 21-22:41-59. [PMID: 26304792 DOI: 10.1016/j.drup.2015.08.002] [Citation(s) in RCA: 402] [Impact Index Per Article: 44.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2015] [Accepted: 08/04/2015] [Indexed: 01/01/2023]
Abstract
The increasing prevalence of chronic and hospital-acquired infections produced by multidrug-resistant (MDR) or extensively drug-resistant (XDR) Pseudomonas aeruginosa strains is associated with significant morbidity and mortality. This growing threat results from the extraordinary capacity of this pathogen for developing resistance through chromosomal mutations and from the increasing prevalence of transferable resistance determinants, particularly those encoding carbapenemases or extended-spectrum β-lactamases (ESBLs). P. aeruginosa has a nonclonal epidemic population structure, composed of a limited number of widespread clones which are selected from a background of a large quantity of rare and unrelated genotypes that are recombining at high frequency. Indeed, recent concerning reports have provided evidence of the existence of MDR/XDR global clones, denominated high-risk clones, disseminated in hospitals worldwide; ST235, ST111, and ST175 are likely those more widespread. Noteworthy, the vast majority of infections by MDR, and specially XDR, strains are produced by these and few other clones worldwide. Moreover, the association of high-risk clones, particularly ST235, with transferable resistance is overwhelming; nearly 100 different horizontally-acquired resistance elements and up to 39 different acquired β-lactamases have been reported so far among ST235 isolates. Likewise, MDR internationally-disseminated epidemic strains, such as the Liverpool Epidemic Strain (LES, ST146), have been noted as well among cystic fibrosis patients. Here we review the population structure, epidemiology, antimicrobial resistance mechanisms and virulence of the P. aeruginosa high-risk clones. The phenotypic and genetic factors potentially driving the success of high-risk clones, the aspects related to their detection in the clinical microbiology laboratory and the implications for infection control and public health are also discussed.
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Affiliation(s)
- Antonio Oliver
- Servicio de Microbiología and Unidad de Investigación, Hospital Universitario Son Espases, Instituto de Investigación Sanitaria de Palma (IdISPa), Ctra. Valldemossa 79, 07010 Palma de Mallorca, Spain.
| | - Xavier Mulet
- Servicio de Microbiología and Unidad de Investigación, Hospital Universitario Son Espases, Instituto de Investigación Sanitaria de Palma (IdISPa), Ctra. Valldemossa 79, 07010 Palma de Mallorca, Spain
| | - Carla López-Causapé
- Servicio de Microbiología and Unidad de Investigación, Hospital Universitario Son Espases, Instituto de Investigación Sanitaria de Palma (IdISPa), Ctra. Valldemossa 79, 07010 Palma de Mallorca, Spain
| | - Carlos Juan
- Servicio de Microbiología and Unidad de Investigación, Hospital Universitario Son Espases, Instituto de Investigación Sanitaria de Palma (IdISPa), Ctra. Valldemossa 79, 07010 Palma de Mallorca, Spain
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76
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Shi J, Jin Y, Bian T, Li K, Sun Z, Cheng Z, Jin S, Wu W. SuhB is a novel ribosome associated protein that regulates expression of MexXY by modulating ribosome stalling inPseudomonas aeruginosa. Mol Microbiol 2015; 98:370-83. [DOI: 10.1111/mmi.13126] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/29/2015] [Indexed: 01/14/2023]
Affiliation(s)
- Jing Shi
- State Key Laboratory of Medicinal Chemical Biology; Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education; Department of Microbiology; College of Life Sciences; Nankai University; Tianjin 300071 China
| | - Yongxin Jin
- State Key Laboratory of Medicinal Chemical Biology; Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education; Department of Microbiology; College of Life Sciences; Nankai University; Tianjin 300071 China
| | - Ting Bian
- State Key Laboratory of Medicinal Chemical Biology; Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education; Department of Microbiology; College of Life Sciences; Nankai University; Tianjin 300071 China
| | - Kewei Li
- State Key Laboratory of Medicinal Chemical Biology; Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education; Department of Microbiology; College of Life Sciences; Nankai University; Tianjin 300071 China
| | - Ziyu Sun
- State Key Laboratory of Medicinal Chemical Biology; Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education; Department of Microbiology; College of Life Sciences; Nankai University; Tianjin 300071 China
| | - Zhihui Cheng
- State Key Laboratory of Medicinal Chemical Biology; Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education; Department of Microbiology; College of Life Sciences; Nankai University; Tianjin 300071 China
| | - Shouguang Jin
- State Key Laboratory of Medicinal Chemical Biology; Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education; Department of Microbiology; College of Life Sciences; Nankai University; Tianjin 300071 China
- Department of Molecular Genetics and Microbiology; College of Medicine; University of Florida; Gainesville FL 32610 USA
| | - Weihui Wu
- State Key Laboratory of Medicinal Chemical Biology; Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education; Department of Microbiology; College of Life Sciences; Nankai University; Tianjin 300071 China
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77
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Antimicrobial Activity of Fosfomycin-Tobramycin Combination against Pseudomonas aeruginosa Isolates Assessed by Time-Kill Assays and Mutant Prevention Concentrations. Antimicrob Agents Chemother 2015. [PMID: 26195514 DOI: 10.1128/aac.00822-15] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The antibacterial activity of fosfomycin-tobramycin combination was studied by time-kill assay in eight Pseudomonas aeruginosa clinical isolates belonging to the fosfomycin wild-type population (MIC = 64 μg/ml) but with different tobramycin susceptibilities (MIC range, 1 to 64 μg/ml). The mutant prevention concentration (MPC) and mutant selection window (MSW) were determined in five of these strains (tobramycin MIC range, 1 to 64 μg/ml) in aerobic and anaerobic conditions simulating environments that are present in biofilm-mediated infections. Fosfomycin-tobramycin was synergistic and bactericidal for the isolates with mutations in the mexZ repressor gene, with a tobramycin MIC of 4 μg/ml. This effect was not observed in strains displaying tobramycin MICs of 1 to 2 μg/ml due to the strong bactericidal effect of tobramycin alone. Fosfomycin presented higher MPC values (range, 2,048 to >2,048 μg/ml) in aerobic and anaerobic conditions than did tobramycin (range, 16 to 256 μg/ml). Interestingly, the association rendered narrow or even null MSWs in the two conditions. However, for isolates with high-level tobramycin resistance that harbored aminoglycoside nucleotidyltransferases, time-kill assays showed no synergy, with wide MSWs in the two environments. glpT gene mutations responsible for fosfomycin resistance in P. aeruginosa were determined in fosfomycin-susceptible wild-type strains and mutant derivatives recovered from MPC studies. All mutant derivatives had changes in the GlpT amino acid sequence, which resulted in a truncated permease responsible for fosfomycin resistance. These results suggest that fosfomycin-tobramycin can be an alternative for infections due to P. aeruginosa since it has demonstrated synergistic and bactericidal activity in susceptible isolates and those with low-level tobramycin resistance. It also prevents the emergence of resistant mutants in either aerobic or anaerobic environments.
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78
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Li XZ, Plésiat P, Nikaido H. The challenge of efflux-mediated antibiotic resistance in Gram-negative bacteria. Clin Microbiol Rev 2015; 28:337-418. [PMID: 25788514 PMCID: PMC4402952 DOI: 10.1128/cmr.00117-14] [Citation(s) in RCA: 939] [Impact Index Per Article: 104.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The global emergence of multidrug-resistant Gram-negative bacteria is a growing threat to antibiotic therapy. The chromosomally encoded drug efflux mechanisms that are ubiquitous in these bacteria greatly contribute to antibiotic resistance and present a major challenge for antibiotic development. Multidrug pumps, particularly those represented by the clinically relevant AcrAB-TolC and Mex pumps of the resistance-nodulation-division (RND) superfamily, not only mediate intrinsic and acquired multidrug resistance (MDR) but also are involved in other functions, including the bacterial stress response and pathogenicity. Additionally, efflux pumps interact synergistically with other resistance mechanisms (e.g., with the outer membrane permeability barrier) to increase resistance levels. Since the discovery of RND pumps in the early 1990s, remarkable scientific and technological advances have allowed for an in-depth understanding of the structural and biochemical basis, substrate profiles, molecular regulation, and inhibition of MDR pumps. However, the development of clinically useful efflux pump inhibitors and/or new antibiotics that can bypass pump effects continues to be a challenge. Plasmid-borne efflux pump genes (including those for RND pumps) have increasingly been identified. This article highlights the recent progress obtained for organisms of clinical significance, together with methodological considerations for the characterization of MDR pumps.
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Affiliation(s)
- Xian-Zhi Li
- Human Safety Division, Veterinary Drugs Directorate, Health Products and Food Branch, Health Canada, Ottawa, Ontario, Canada
| | - Patrick Plésiat
- Laboratoire de Bactériologie, Faculté de Médecine-Pharmacie, Centre Hospitalier Régional Universitaire, Université de Franche-Comté, Besançon, France
| | - Hiroshi Nikaido
- Department of Molecular and Cell Biology, University of California, Berkeley, California, USA
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79
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Lau CHF, Krahn T, Gilmour C, Mullen E, Poole K. AmgRS-mediated envelope stress-inducible expression of the mexXY multidrug efflux operon of Pseudomonas aeruginosa. Microbiologyopen 2014; 4:121-35. [PMID: 25450797 PMCID: PMC4335980 DOI: 10.1002/mbo3.226] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 10/27/2014] [Accepted: 11/03/2014] [Indexed: 01/07/2023] Open
Abstract
AmgRS is an envelope stress-responsive two-component system and aminoglycoside resistance determinant in Pseudomonas aeruginosa that is proposed to protect cells from membrane damage caused by aminoglycoside-generated mistranslated polypeptides. Consistent with this, a ΔamgR strain showed increased aminoglycoside-promoted membrane damage, damage that was largely absent in AmgRS-activated amgS-mutant strains. Intriguingly, one such mutation, V121G, while providing for enhanced resistance to aminoglycosides, rendered P. aeruginosa susceptible to several ribosome-targeting nonaminoglycoside antimicrobials that are inducers and presumed substrates of the MexXY-OprM multidrug efflux system. Surprisingly, the amgSV 121G mutation increased mexXY expression threefold, suggesting that export of these nonaminoglycosides was compromised in the amgSV 121G mutant. Nonetheless, a link was established between AmgRS activation and mexXY expression and this was confirmed in studies showing that aminoglycoside-promoted mexXY expression is dependent on AmgRS. While nonaminoglycosides also induced mexXY expression, this was not AmgRS-dependent, consistent with these agents not generating mistranslated polypeptides and not activating AmgRS. The aminoglycoside inducibility of mexXY was abrogated in a mutant lacking the AmgRS target genes htpX and PA5528, encoding a presumed cytoplasmic membrane-associated protease and a membrane protein of unknown function, respectively. Thus, aminoglycoside induction of mexXY is a response to membrane damage and activation of the AmgRS two-component system.
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Affiliation(s)
- Calvin Ho-Fung Lau
- Department of Biomedical and Molecular Sciences, Botterell Hall, Queen's University, Kingston, Ontario, K7L 3N6, Canada.
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80
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Lucchetti-Miganeh C, Redelberger D, Chambonnier G, Rechenmann F, Elsen S, Bordi C, Jeannot K, Attrée I, Plésiat P, de Bentzmann S. Pseudomonas aeruginosa Genome Evolution in Patients and under the Hospital Environment. Pathogens 2014; 3:309-40. [PMID: 25437802 PMCID: PMC4243448 DOI: 10.3390/pathogens3020309] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Revised: 03/26/2014] [Accepted: 03/28/2014] [Indexed: 11/21/2022] Open
Abstract
Pseudomonas aeruginosa is a Gram-negative environmental species and an opportunistic microorganism, establishing itself in vulnerable patients, such as those with cystic fibrosis (CF) or those hospitalized in intensive care units (ICU). It has become a major cause of nosocomial infections worldwide and a serious threat to Public Health because of overuse and misuse of antibiotics that have selected highly resistant strains against which very few therapeutic options exist. Herein is illustrated the intraclonal evolution of the genome of sequential isolates collected in a single CF patient from the early phase of pulmonary colonization to the fatal outcome. We also examined at the whole genome scale a pair of genotypically-related strains made of a drug susceptible, environmental isolate recovered from an ICU sink and of its multidrug resistant counterpart found to infect an ICU patient. Multiple genetic changes accumulated in the CF isolates over the disease time course including SNPs, deletion events and reduction of whole genome size. The strain isolated from the ICU patient displayed an increase in the genome size of 4.8% with major genetic rearrangements as compared to the initial environmental strain. The annotated genomes are given in free access in an interactive web application WallGene designed to facilitate large-scale comparative analysis and thus allowing investigators to explore homologies and syntenies between P. aeruginosa strains, here PAO1 and the five clinical strains described.
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Affiliation(s)
| | - David Redelberger
- UMR7255-Laboratoire d'Ingénierie des Systèmes Macromoléculaires, CNRS-Aix Marseille University, Marseille 13402, France.
| | - Gaël Chambonnier
- UMR7255-Laboratoire d'Ingénierie des Systèmes Macromoléculaires, CNRS-Aix Marseille University, Marseille 13402, France.
| | | | - Sylvie Elsen
- INSERM, UMR-S 1036, Biology of Cancer and Infection, Grenoble 38054, France.
| | - Christophe Bordi
- UMR7255-Laboratoire d'Ingénierie des Systèmes Macromoléculaires, CNRS-Aix Marseille University, Marseille 13402, France.
| | - Katy Jeannot
- Laboratoire de Bactériologie, Faculté de Médecine-Pharmacie, Université de Franche-Comté, Besançon 25030, France.
| | - Ina Attrée
- INSERM, UMR-S 1036, Biology of Cancer and Infection, Grenoble 38054, France.
| | - Patrick Plésiat
- Laboratoire de Bactériologie, Faculté de Médecine-Pharmacie, Université de Franche-Comté, Besançon 25030, France.
| | - Sophie de Bentzmann
- UMR7255-Laboratoire d'Ingénierie des Systèmes Macromoléculaires, CNRS-Aix Marseille University, Marseille 13402, France.
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81
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Morita Y, Tomida J, Kawamura Y. Responses of Pseudomonas aeruginosa to antimicrobials. Front Microbiol 2014; 4:422. [PMID: 24409175 PMCID: PMC3884212 DOI: 10.3389/fmicb.2013.00422] [Citation(s) in RCA: 209] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 12/24/2013] [Indexed: 11/29/2022] Open
Abstract
Infections caused by Pseudomonas aeruginosa often are hard to treat; inappropriate chemotherapy readily selects multidrug-resistant P. aeruginosa. This organism can be exposed to a wide range of concentrations of antimicrobials during treatment; learning more about the responses of P. aeruginosa to antimicrobials is therefore important. We review here responses of the bacterium P. aeruginosa upon exposure to antimicrobials at levels below the inhibitory concentration. Carbapenems (e.g., imipenem) have been shown to induce the formation of thicker and more robust biofilms, while fluoroquinolones (e.g., ciprofloxacin) and aminoglycosides (e.g., tobramycin) have been shown to induce biofilm formation. Ciprofloxacin also has been demonstrated to enhance the frequency of mutation to carbapenem resistance. Conversely, although macrolides (e.g., azithromycin) typically are not effective against P. aeruginosa because of the pseudomonal outer-membrane impermeability and efflux, macrolides do lead to a reduction in virulence factor production. Similarly, tetracycline is not very effective against this organism, but is known to induce the type-III secretion system and consequently enhance cytotoxicity of P. aeruginosain vivo. Of special note are the effects of antibacterials and disinfectants on pseudomonal efflux systems. Sub-inhibitory concentrations of protein synthesis inhibitors (aminoglycosides, tetracycline, chloramphenicol, etc.) induce the MexXY multidrug efflux system. This response is known to be mediated by interference with the translation of the leader peptide PA5471.1, with consequent effects on expression of the PA5471 gene product. Additionally, induction of the MexCD-OprJ multidrug efflux system is observed upon exposure to sub-inhibitory concentrations of disinfectants such as chlorhexidine and benzalkonium. This response is known to be dependent upon the AlgU stress response factor. Altogether, these biological responses of P. aeruginosa provide useful clues for the improvement and optimization of chemotherapy in order to appropriately treat pseudomonal infections while minimizing the emergence of resistance.
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Affiliation(s)
- Yuji Morita
- Department of Microbiology, School of Pharmacy, Aichi Gakuin University, Nagoya Japan
| | - Junko Tomida
- Department of Microbiology, School of Pharmacy, Aichi Gakuin University, Nagoya Japan
| | - Yoshiaki Kawamura
- Department of Microbiology, School of Pharmacy, Aichi Gakuin University, Nagoya Japan
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