1
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García-Villada L, Degtyareva NP, Brooks AM, Goldberg JB, Doetsch PW. A role for the stringent response in ciprofloxacin resistance in Pseudomonas aeruginosa. Sci Rep 2024; 14:8598. [PMID: 38615146 PMCID: PMC11016087 DOI: 10.1038/s41598-024-59188-z] [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: 02/01/2024] [Accepted: 04/08/2024] [Indexed: 04/15/2024] Open
Abstract
Pseudomonas aeruginosa is a major cause of nosocomial infections and the leading cause of chronic lung infections in cystic fibrosis and chronic obstructive pulmonary disease patients. Antibiotic treatment remains challenging because P. aeruginosa is resistant to high concentrations of antibiotics and has a remarkable ability to acquire mutations conferring resistance to multiple groups of antimicrobial agents. Here we report that when P. aeruginosa is plated on ciprofloxacin (cipro) plates, the majority of cipro-resistant (ciproR) colonies observed at and after 48 h of incubation carry mutations in genes related to the Stringent Response (SR). Mutations in one of the major SR components, spoT, were present in approximately 40% of the ciproR isolates. Compared to the wild-type strain, most of these isolates had decreased growth rate, longer lag phase and altered intracellular ppGpp content. Also, 75% of all sequenced mutations were insertions and deletions, with short deletions being the most frequently occurring mutation type. We present evidence that most of the observed mutations are induced on the selective plates in a subpopulation of cells that are not instantly killed by cipro. Our results suggests that the SR may be an important contributor to antibiotic resistance acquisition in P. aeruginosa.
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Affiliation(s)
| | | | - Ashley M Brooks
- Integrative Bioinformatics, Biostatistics and Computational Biology Branch, NIEHS, Durham, NC, USA
| | - Joanna B Goldberg
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
| | - Paul W Doetsch
- Genomic Integrity and Structural Biology Laboratory, NIEHS, Durham, NC, USA.
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2
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Nolan C, Behrends V. Sub-Inhibitory Antibiotic Exposure and Virulence in Pseudomonas aeruginosa. Antibiotics (Basel) 2021; 10:antibiotics10111393. [PMID: 34827331 PMCID: PMC8615142 DOI: 10.3390/antibiotics10111393] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 11/09/2021] [Accepted: 11/10/2021] [Indexed: 12/20/2022] Open
Abstract
Pseudomonas aeruginosa is a prime opportunistic pathogen, one of the most important causes of hospital-acquired infections and the major cause of morbidity and mortality in cystic fibrosis lung infections. One reason for the bacterium's pathogenic success is the large array of virulence factors that it can employ. Another is its high degree of intrinsic and acquired resistance to antibiotics. In this review, we first summarise the current knowledge about the regulation of virulence factor expression and production. We then look at the impact of sub-MIC antibiotic exposure and find that the virulence-antibiotic interaction for P. aeruginosa is antibiotic-specific, multifaceted, and complex. Most studies undertaken to date have been in vitro assays in batch culture systems, involving short-term (<24 h) antibiotic exposure. Therefore, we discuss the importance of long-term, in vivo-mimicking models for future work, particularly highlighting the need to account for bacterial physiology, which by extension governs both virulence factor expression and antibiotic tolerance/resistance.
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3
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Sanz-García F, Hernando-Amado S, Martínez JL. Evolution under low antibiotic concentrations: a risk for the selection of Pseudomonas aeruginosa multidrug-resistant mutants in nature. Environ Microbiol 2021; 24:1279-1293. [PMID: 34666420 DOI: 10.1111/1462-2920.15806] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 10/05/2021] [Indexed: 11/30/2022]
Abstract
Antibiotic pollution of non-clinical environments might have a relevant impact on human health if resistant pathogens are selected. However, this potential risk is often overlooked, since drug concentrations in nature are usually below their minimal inhibitory concentrations (MICs). Albeit, antibiotic resistant bacteria can be selected even at sub-MIC concentrations, in a range known as the sub-MIC selective window. Using short-term evolution experiments, we have determined the sub-MIC selective windows of the opportunistic pathogen Pseudomonas aeruginosa for seven antibiotics of clinical relevance, finding the ones of quinolones to be the widest, and the ones of polymyxin B and imipenem, the narrowest. Clinically relevant multidrug-resistant mutants arose within the sub-MIC selective windows of most antibiotics tested, being some of these phenotypes mediated by efflux pumps' activity. The fact that the concentration of antibiotics reported in aquatic ecosystems - colonizable by P. aeruginosa - are, in occasions, higher than the ones that select multidrug-resistant mutants in our assays, has implications for understanding the role of different ecosystems and conditions in the emergence of antibiotic resistance from a One-Health perspective. Further, it reinforces the importance of procuring accurate information on the sub-MIC selective windows for drugs of clinical value in pathogens with environmental niches.
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4
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Korry BJ, Lee SYE, Chakrabarti AK, Choi AH, Ganser C, Machan JT, Belenky P. Genotoxic Agents Produce Stressor-Specific Spectra of Spectinomycin Resistance Mutations Based on Mechanism of Action and Selection in Bacillus subtilis. Antimicrob Agents Chemother 2021; 65:e0089121. [PMID: 34339280 PMCID: PMC8448107 DOI: 10.1128/aac.00891-21] [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: 04/29/2021] [Accepted: 07/23/2021] [Indexed: 11/20/2022] Open
Abstract
Mutagenesis is integral for bacterial evolution and the development of antibiotic resistance. Environmental toxins and stressors are known to elevate the rate of mutagenesis through direct DNA toxicity, known as stress-associated mutagenesis, or via a more general stress-induced process that relies on intrinsic bacterial pathways. Here, we characterize the spectra of mutations induced by an array of different stressors using high-throughput sequencing to profile thousands of spectinomycin-resistant colonies of Bacillus subtilis. We found 69 unique mutations in the rpsE and rpsB genes, and that each stressor leads to a unique and specific spectrum of antibiotic-resistance mutations. While some mutations clearly reflected the DNA damage mechanism of the stress, others were likely the result of a more general stress-induced mechanism. To determine the relative fitness of these mutants under a range of antibiotic selection pressures, we used multistrain competitive fitness experiments and found an additional landscape of fitness and resistance. The data presented here support the idea that the environment in which the selection is applied (mutagenic stressors that are present), as well as changes in local drug concentration, can significantly alter the path to spectinomycin resistance in B. subtilis.
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Affiliation(s)
- Benjamin J. Korry
- Department of Molecular Microbiology and Immunology, Brown University, Providence, Rhode Island, USA
| | - Stella Ye Eun Lee
- Department of Molecular Microbiology and Immunology, Brown University, Providence, Rhode Island, USA
| | - Amit K. Chakrabarti
- Department of Molecular Microbiology and Immunology, Brown University, Providence, Rhode Island, USA
| | - Ashley H. Choi
- Department of Molecular Microbiology and Immunology, Brown University, Providence, Rhode Island, USA
| | - Collin Ganser
- Department of Molecular Microbiology and Immunology, Brown University, Providence, Rhode Island, USA
| | - Jason T. Machan
- Department of Orthopedics, Warren Alpert Medical School of Brown University, Providence, Rhode Island, USA
- Department of Surgery, Warren Alpert Medical School of Brown University, Providence, Rhode Island, USA
| | - Peter Belenky
- Department of Molecular Microbiology and Immunology, Brown University, Providence, Rhode Island, USA
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5
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Bhatia P, Sharma A, George AJ, Anvitha D, Kumar P, Dwivedi VP, Chandra NS. Antibacterial activity of medicinal plants against ESKAPE: An update. Heliyon 2021; 7:e06310. [PMID: 33718642 PMCID: PMC7920328 DOI: 10.1016/j.heliyon.2021.e06310] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 11/28/2020] [Accepted: 02/15/2021] [Indexed: 12/25/2022] Open
Abstract
Antibiotic resistance has emerged as a threat to global health, food security, and development today. Antibiotic resistance can occur naturally but mainly due to misuse or overuse of antibiotics, which results in recalcitrant infections and Antimicrobial Resistance (AMR) among bacterial pathogens. These mainly include the MDR strains (multi-drug resistant) of ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species). These bacterial pathogens have the potential to “escape” antibiotics and other traditional therapies. These bacterial pathogens are responsible for the major cases of Hospital-Acquired Infections (HAI) globally. ESKAPE Pathogens have been placed in the list of 12 bacteria by World Health Organisation (WHO), against which development of new antibiotics is vital. It not only results in prolonged hospital stays but also higher medical costs and higher mortality. Therefore, new antimicrobials need to be developed to battle the rapidly evolving pathogens. Plants are known to synthesize an array of secondary metabolites referred as phytochemicals that have disease prevention properties. Potential efficacy and minimum to no side effects are the key advantages of plant-derived products, making them suitable choices for medical treatments. Hence, this review attempts to highlight and discuss the application of plant-derived compounds and extracts against ESKAPE Pathogens.
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Affiliation(s)
- Priya Bhatia
- Department of Microbiology, Ram Lal Anand College, University of Delhi, Benito Juarez Road, New Delhi 110021, India
| | - Anushka Sharma
- Department of Microbiology, Ram Lal Anand College, University of Delhi, Benito Juarez Road, New Delhi 110021, India
| | - Abhilash J George
- Department of Microbiology, Ram Lal Anand College, University of Delhi, Benito Juarez Road, New Delhi 110021, India
| | - D Anvitha
- Department of Microbiology, Ram Lal Anand College, University of Delhi, Benito Juarez Road, New Delhi 110021, India
| | - Pragya Kumar
- Department of Microbiology, Ram Lal Anand College, University of Delhi, Benito Juarez Road, New Delhi 110021, India
| | - Ved Prakash Dwivedi
- Immunobiology Group, International Center for Genetic Engineering and Biotechnology, New Delhi 110067, India
| | - Nidhi S Chandra
- Department of Microbiology, Ram Lal Anand College, University of Delhi, Benito Juarez Road, New Delhi 110021, India
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6
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Díez-Aguilar M, Hernández-García M, Morosini MI, Fluit A, Tunney MM, Huertas N, del Campo R, Obrecht D, Bernardini F, Ekkelenkamp M, Cantón R. Murepavadin antimicrobial activity against and resistance development in cystic fibrosis Pseudomonas aeruginosa isolates. J Antimicrob Chemother 2020; 76:984-992. [DOI: 10.1093/jac/dkaa529] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 11/20/2020] [Indexed: 12/27/2022] Open
Abstract
Abstract
Background
Murepavadin, a novel peptidomimetic antibiotic, is being developed as an inhalation therapy for treatment of Pseudomonas aeruginosa respiratory infection in people with cystic fibrosis (CF). It blocks the activity of the LptD protein in P. aeruginosa causing outer membrane alterations.
Objectives
To determine the in vitro activity of murepavadin against CF P. aeruginosa isolates and to investigate potential mechanisms of resistance.
Methods
MIC values were determined by both broth microdilution and agar dilution and results compared. The effect of artificial sputum and lung surfactant on in vitro activity was also measured. Spontaneous mutation frequency was estimated. Bactericidal activity was investigated using time–kill assays. Resistant mutants were studied by WGS.
Results
The murepavadin MIC50 was 0.125 versus 4 mg/L and the MIC90 was 2 versus 32 mg/L by broth microdilution and agar dilution, respectively. Essential agreement was >90% when determining in vitro activity with artificial sputum or lung surfactant. It was bactericidal at a concentration of 32 mg/L against 95.4% of the strains within 1–5 h. Murepavadin MICs were 2–9 two-fold dilutions higher for the mutant derivatives (0.5 to >16 mg/L) than for the parental strains. Second-step mutants were obtained for the PAO mutS reference strain with an 8×MIC increase. WGS showed mutations in genes involved in LPS biosynthesis (lpxL1, lpxL2, bamA2, lptD, lpxT and msbA).
Conclusions
Murepavadin characteristics, such as its specific activity against P. aeruginosa, its unique mechanism of action and its strong antimicrobial activity, encourage the further clinical evaluation of this drug.
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Affiliation(s)
- María Díez-Aguilar
- Servicio de Microbiología, Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
- Red Española de Investigación en Patología Infecciosa (REIPI), Madrid, Spain
| | - Marta Hernández-García
- Servicio de Microbiología, Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
- Red Española de Investigación en Patología Infecciosa (REIPI), Madrid, Spain
| | - María-Isabel Morosini
- Servicio de Microbiología, Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
- Red Española de Investigación en Patología Infecciosa (REIPI), Madrid, Spain
| | - Ad Fluit
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | - Natalia Huertas
- Servicio de Microbiología, Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
| | - Rosa del Campo
- Servicio de Microbiología, Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
- Red Española de Investigación en Patología Infecciosa (REIPI), Madrid, Spain
| | | | | | - Miquel Ekkelenkamp
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Rafael Cantón
- Servicio de Microbiología, Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain
- Red Española de Investigación en Patología Infecciosa (REIPI), Madrid, Spain
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7
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Sheng H, Huang J, Han Z, Liu M, Lü Z, Zhang Q, Zhang J, Yang J, Cui S, Yang B. Genes and Proteomes Associated With Increased Mutation Frequency and Multidrug Resistance of Naturally Occurring Mismatch Repair-Deficient Salmonella Hypermutators. Front Microbiol 2020; 11:770. [PMID: 32457709 PMCID: PMC7225559 DOI: 10.3389/fmicb.2020.00770] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 03/31/2020] [Indexed: 11/23/2022] Open
Abstract
The emergence of antibiotic-resistant Salmonella through mutations led to mismatch repair (MMR) deficiency that represents a potential hazard to public health. Here, four representative MMR-deficient Salmonella hypermutator strains and Salmonella Typhimurium LT2 were used to comprehensively reveal the influence of MMR deficiency on antibiotic resistance among Salmonella. Our results indicated that the mutation frequency ranged from 3.39 × 10–4 to 5.46 × 10–2 in the hypermutator. Mutation sites in MutS, MutL, MutT, and UvrD of the four hypermutators were all located in the essential and core functional regions. Mutation frequency of the hypermutator was most highly correlated with the extent of mutation in MutS. Mutations in MMR genes (mutS, mutT, mutL, and uvrD) were correlated with increased mutation in antibiotic resistance genes, and the extent of antibiotic resistance was significantly correlated with the number of mutation sites in MutL and in ParC. The number of mutation sites in MMR genes and antibiotic resistance genes exhibited a significant positive correlation with the number of antibiotics resisted and with expression levels of mutS, mutT, and mutL. Compared to Salmonella Typhimurium LT2, a total of 137 differentially expressed and 110 specifically expressed proteins were identified in the four hypermutators. Functional enrichment analysis indicated that the proteins significantly overexpressed in the hypermutators primarily associated with translation and stress response. Interaction network analysis revealed that the ribosome pathway might be a critical factor for high mutation frequency and multidrug resistance in MMR-deficient Salmonella hypermutators. These results help elucidate the mutational dynamics that lead to hypermutation, antibiotic resistance, and activation of stress response pathways in Salmonella.
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Affiliation(s)
- Huanjing Sheng
- College of Food Science and Engineering, Northwest A&F University, Xianyang, China
| | - Jinling Huang
- College of Food Science and Engineering, Northwest A&F University, Xianyang, China
| | - Zhaoyu Han
- School of Pharmaceutical Sciences, Jiangnan University, Wuxi, China
| | - Mi Liu
- College of Food Science and Engineering, Northwest A&F University, Xianyang, China
| | - Zexun Lü
- College of Food Science and Engineering, Northwest A&F University, Xianyang, China
| | - Qian Zhang
- College of Food Science and Engineering, Northwest A&F University, Xianyang, China
| | - Jinlei Zhang
- College of Food Science and Engineering, Northwest A&F University, Xianyang, China
| | - Jun Yang
- College of Food Science and Engineering, Northwest A&F University, Xianyang, China
| | - Shenghui Cui
- National Institutes for Food and Drug Control, Beijing, China
| | - Baowei Yang
- College of Food Science and Engineering, Northwest A&F University, Xianyang, China
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8
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Heffernan AJ, Sime FB, Lipman J, Roberts JA. Individualising Therapy to Minimize Bacterial Multidrug Resistance. Drugs 2019; 78:621-641. [PMID: 29569104 DOI: 10.1007/s40265-018-0891-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The scourge of antibiotic resistance threatens modern healthcare delivery. A contributing factor to this significant issue may be antibiotic dosing, whereby standard antibiotic regimens are unable to suppress the emergence of antibiotic resistance. This article aims to review the role of pharmacokinetic and pharmacodynamic (PK/PD) measures for optimising antibiotic therapy to minimise resistance emergence. It also seeks to describe the utility of combination antibiotic therapy for suppression of resistance and summarise the role of biomarkers in individualising antibiotic therapy. Scientific journals indexed in PubMed and Web of Science were searched to identify relevant articles and summarise existing evidence. Studies suggest that optimising antibiotic dosing to attain defined PK/PD ratios may limit the emergence of resistance. A maximum aminoglycoside concentration to minimum inhibitory concentration (MIC) ratio of > 20, a fluoroquinolone area under the concentration-time curve to MIC ratio of > 285 and a β-lactam trough concentration of > 6 × MIC are likely required for resistance suppression. In vitro studies demonstrate a clear advantage for some antibiotic combinations. However, clinical evidence is limited, suggesting that the use of combination regimens should be assessed on an individual patient basis. Biomarkers, such as procalcitonin, may help to individualise and reduce the duration of antibiotic treatment, which may minimise antibiotic resistance emergence during therapy. Future studies should translate laboratory-based studies into clinical trials and validate the appropriate clinical PK/PD predictors required for resistance suppression in vivo. Other adjunct strategies, such as biomarker-guided therapy or the use of antibiotic combinations require further investigation.
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Affiliation(s)
- A J Heffernan
- School of Medicine, Griffith University, Gold Coast, Queensland, Australia
- Centre for Translational Anti-Infective Pharmacodynamics, School of Pharmacy, The University of Queensland, Brisbane, Queensland, Australia
| | - F B Sime
- Centre for Translational Anti-Infective Pharmacodynamics, School of Pharmacy, The University of Queensland, Brisbane, Queensland, Australia
- UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Building 71/918, Herston Rd, Herston, Queensland, 4029, Australia
| | - J Lipman
- UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Building 71/918, Herston Rd, Herston, Queensland, 4029, Australia
- Department of Intensive Care Medicine, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia
| | - J A Roberts
- Centre for Translational Anti-Infective Pharmacodynamics, School of Pharmacy, The University of Queensland, Brisbane, Queensland, Australia.
- UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Building 71/918, Herston Rd, Herston, Queensland, 4029, Australia.
- Department of Intensive Care Medicine, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia.
- Pharmacy Department, Royal Brisbane and Women's Hospital, Brisbane, Queensland, Australia.
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9
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Evolution of Antibiotic Resistance in Biofilm and Planktonic Pseudomonas aeruginosa Populations Exposed to Subinhibitory Levels of Ciprofloxacin. Antimicrob Agents Chemother 2018; 62:AAC.00320-18. [PMID: 29760140 DOI: 10.1128/aac.00320-18] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 05/01/2018] [Indexed: 11/20/2022] Open
Abstract
The opportunistic Gram-negative pathogen Pseudomonas aeruginosa, known for its intrinsic and acquired antibiotic resistance, has a notorious ability to form biofilms, which often facilitate chronic infections. The evolutionary paths to antibiotic resistance have mainly been investigated in planktonic cultures and are less studied in biofilms. We experimentally evolved P. aeruginosa PAO1 colony biofilms and stationary-phase planktonic cultures for seven passages in the presence of subinhibitory levels (0.1 mg/liter) of ciprofloxacin (CIP) and performed a genotypic (whole-bacterial population sequencing) and phenotypic assessment of the populations. We observed a higher proportion of CIP resistance in the CIP-evolved biofilm populations than in planktonic populations exposed to the same drug concentrations. However, the MICs of ciprofloxacin were lower in CIP-resistant isolates selected from the biofilm population than the MICs of CIP-resistant isolates from the planktonic cultures. We found common evolutionary trajectories between the different lineages, with mutations in known CIP resistance determinants as well as growth condition-dependent adaptations. We observed a general trend toward a reduction in type IV-pilus-dependent motility (twitching) in CIP-evolved populations and a loss of virulence-associated traits in the populations evolved in the absence of antibiotic. In conclusion, our data indicate that biofilms facilitate the development of low-level mutational resistance, probably due to the lower effective drug exposure than in planktonic cultures. These results provide a framework for the selection process of resistant variants and the evolutionary mechanisms involved under the two different growth conditions.
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10
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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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11
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Ahamad S, Rahman S, Khan FI, Dwivedi N, Ali S, Kim J, Imtaiyaz Hassan M. QSAR based therapeutic management of M. tuberculosis. Arch Pharm Res 2017; 40:676-694. [PMID: 28456911 DOI: 10.1007/s12272-017-0914-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 04/06/2017] [Indexed: 01/09/2023]
Abstract
Mycobacterium tuberculosis is responsible for severe mortality and morbidity worldwide but, under-developed and developing countries are more prone to infection. In search of effective and wide-spectrum anti-tubercular agents, interdisciplinary approaches are being explored. Of the several approaches used, computer based quantitative structure activity relationship (QSAR) have gained momentum. Structure-based drug design and discovery implies a combined knowledge of accurate prediction of ligand poses with the good prediction and interpretation of statistically validated models derived from the 3D-QSAR approach. The validated models are generally used to screen a small combinatorial library of potential synthetic candidates to identify hits which further subjected to docking to filter out compounds as novel potential emerging drug molecules to address multidrug-resistant tuberculosis. Several newer models are integrated to QSAR methods which include different types of chemical and biological data, and simultaneous prediction of pharmacological activities including toxicities and/or other safety profiles to get new compounds with desired activity. In the process, several newer molecules have been identified which are now being assessed for their clinical efficacy. Present review deals with the advances made in the field highlighting overall future prospects of the development of anti-tuberculosis drugs.
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Affiliation(s)
- Shahzaib Ahamad
- Department of Biotechnology, School of Engineering & Technology, IFTM University, Lodhipur-Rajput, Delhi Road, Moradabad, India
| | - Safikur Rahman
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan, 712-749, South Korea
| | - Faez Iqbal Khan
- School of Chemistry and Chemical Engineering, Henan University of Technology, Henan, 450001, China.,Department of Chemistry, Rhodes University, Grahamstown, 6140, South Africa
| | - Neeraja Dwivedi
- Department of Biotechnology, School of Engineering & Technology, IFTM University, Lodhipur-Rajput, Delhi Road, Moradabad, India
| | - Sher Ali
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi, 10025, India
| | - Jihoe Kim
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan, 712-749, South Korea.
| | - Md Imtaiyaz Hassan
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi, 10025, India.
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12
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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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13
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Khan S, Beattie TK, Knapp CW. The use of minimum selectable concentrations (MSCs) for determining the selection of antimicrobial resistant bacteria. ECOTOXICOLOGY (LONDON, ENGLAND) 2017; 26:283-292. [PMID: 28155034 PMCID: PMC5318476 DOI: 10.1007/s10646-017-1762-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/11/2017] [Indexed: 05/25/2023]
Abstract
The use of antimicrobial compounds is indispensable in many industries, especially drinking water production, to eradicate microorganisms. However, bacterial growth is not unusual in the presence of disinfectant concentrations that would be typically lethal, as bacterial populations can develop resistance. The common metric of population resistance has been based on the Minimum Inhibitory Concentration (MIC), which is based on bacteria lethality. However, sub-lethal concentrations may also select for resistant bacteria due to the differences in bacterial growth rates. This study determined the Minimal Selective Concentrations (MSCs) of bacterial populations exposed to free chlorine and monochloramine, representing a metric that possibly better reflects the selective pressures occurring at lower disinfectant levels than MIC. Pairs of phylogenetically similar bacteria were challenged to a range of concentrations of disinfectants. The MSCs of free chlorine and monochloramine were found to range between 0.021 and 0.39 mg L-1, which were concentrations 1/250 to 1/5 than the MICs of susceptible bacteria (MIC susc ). This study indicates that sub-lethal concentrations of disinfectants could result in the selection of resistant bacterial populations, and MSCs would be a more sensitive indicator of selective pressure, especially in environmental systems.
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Affiliation(s)
- Sadia Khan
- Department of Civil and Environmental Engineering, University of Strathclyde, James Weir Building, 75 Montrose Street, Glasgow, Scotland, G1 1XJ, UK.
- Department of Environmental Engineering, NED University of Engineering and Technology, University Road, Karachi, 75270, Pakistan.
| | - Tara K Beattie
- Department of Civil and Environmental Engineering, University of Strathclyde, James Weir Building, 75 Montrose Street, Glasgow, Scotland, G1 1XJ, UK
| | - Charles W Knapp
- Department of Civil and Environmental Engineering, University of Strathclyde, James Weir Building, 75 Montrose Street, Glasgow, Scotland, G1 1XJ, UK
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14
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Zaborskyte G, Andersen JB, Kragh KN, Ciofu O. Real-Time Monitoring of nfxB Mutant Occurrence and Dynamics in Pseudomonas aeruginosa Biofilm Exposed to Subinhibitory Concentrations of Ciprofloxacin. Antimicrob Agents Chemother 2017; 61:e02292-16. [PMID: 27993856 PMCID: PMC5328521 DOI: 10.1128/aac.02292-16] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 12/11/2016] [Indexed: 12/14/2022] Open
Abstract
Biofilm infections caused by Pseudomonas aeruginosa are frequently treated with ciprofloxacin (CIP); however, resistance rapidly develops. One of the primary resistance mechanisms is the overexpression of the MexCD-OprJ pump due to a mutation in nfxB, encoding the transcriptional repressor of this pump. The aim of this study was to investigate the effect of subinhibitory concentrations of CIP on the occurrence of nfxB mutants in the wild-type PAO1 flow cell biofilm model. For this purpose, we constructed fluorescent reporter strains (PAO1 background) with an mCherry tag for constitutive red fluorescence and chromosomal transcriptional fusion between the P mexCD promoter and gfp leading to green fluorescence upon mutation of nfxB We observed a rapid development of nfxB mutants by live confocal laser scanning microscopy (CLSM) imaging of the flow cell biofilm (reaching 80 to 90% of the whole population) when treated with 1/10 minimal biofilm inhibitory concentration of CIP for 24 h and 96 h. Based on the observed developmental stages, we propose that nfxB mutants emerged de novo in the biofilm during CIP treatment from filamentous cells, which might have arisen due to the stress responses induced by CIP. Identical nfxB mutations were found in fluorescent colonies from the same flow cell biofilm, especially in 24-h biofilms, suggesting selection and clonal expansion of the mutants during biofilm growth. Our findings point at the significant role of high-enough antibiotic dosages or appropriate combination therapy to avoid the emergence of resistant mutants in biofilms.
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Affiliation(s)
- Greta Zaborskyte
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Jens Bo Andersen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Kasper Nørskov Kragh
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Oana Ciofu
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
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15
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Bengtsson-Palme J, Hammarén R, Pal C, Östman M, Björlenius B, Flach CF, Fick J, Kristiansson E, Tysklind M, Larsson DGJ. Elucidating selection processes for antibiotic resistance in sewage treatment plants using metagenomics. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 572:697-712. [PMID: 27542633 DOI: 10.1016/j.scitotenv.2016.06.228] [Citation(s) in RCA: 157] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 06/28/2016] [Accepted: 06/28/2016] [Indexed: 05/20/2023]
Abstract
Sewage treatment plants (STPs) have repeatedly been suggested as "hotspots" for the emergence and dissemination of antibiotic-resistant bacteria. A critical question still unanswered is if selection pressures within STPs, caused by residual antibiotics or other co-selective agents, are sufficient to specifically promote resistance. To address this, we employed shotgun metagenomic sequencing of samples from different steps of the treatment process in three Swedish STPs. In parallel, concentrations of selected antibiotics, biocides and metals were analyzed. We found that concentrations of tetracycline and ciprofloxacin in the influent were above predicted concentrations for resistance selection, however, there was no consistent enrichment of resistance genes to any particular class of antibiotics in the STPs, neither for biocide and metal resistance genes. The most substantial change of the bacterial communities compared to human feces occurred already in the sewage pipes, manifested by a strong shift from obligate to facultative anaerobes. Through the treatment process, resistance genes against antibiotics, biocides and metals were not reduced to the same extent as fecal bacteria. The OXA-48 gene was consistently enriched in surplus and digested sludge. We find this worrying as OXA-48, still rare in Swedish clinical isolates, provides resistance to carbapenems, one of our most critically important classes of antibiotics. Taken together, metagenomics analyses did not provide clear support for specific antibiotic resistance selection. However, stronger selective forces affecting gross taxonomic composition, and with that resistance gene abundances, limit interpretability. Comprehensive analyses of resistant/non-resistant strains within relevant species are therefore warranted.
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Affiliation(s)
- Johan Bengtsson-Palme
- Department of Infectious Diseases, Institute of Biomedicine, The Sahlgrenska Academy, University of Gothenburg, Guldhedsgatan 10, SE-413 46 Gothenburg, Sweden; Centre for Antibiotic Resistance Research (CARe) at University of Gothenburg, Gothenburg, Sweden
| | - Rickard Hammarén
- Department of Infectious Diseases, Institute of Biomedicine, The Sahlgrenska Academy, University of Gothenburg, Guldhedsgatan 10, SE-413 46 Gothenburg, Sweden
| | - Chandan Pal
- Department of Infectious Diseases, Institute of Biomedicine, The Sahlgrenska Academy, University of Gothenburg, Guldhedsgatan 10, SE-413 46 Gothenburg, Sweden; Centre for Antibiotic Resistance Research (CARe) at University of Gothenburg, Gothenburg, Sweden
| | - Marcus Östman
- Department of Chemistry, Umeå University, Umeå, Sweden
| | - Berndt Björlenius
- Division of Industrial Biotechnology, School of Biotechnology, Royal Institute of Technology, Stockholm, Sweden
| | - Carl-Fredrik Flach
- Department of Infectious Diseases, Institute of Biomedicine, The Sahlgrenska Academy, University of Gothenburg, Guldhedsgatan 10, SE-413 46 Gothenburg, Sweden; Centre for Antibiotic Resistance Research (CARe) at University of Gothenburg, Gothenburg, Sweden
| | - Jerker Fick
- Department of Chemistry, Umeå University, Umeå, Sweden
| | - Erik Kristiansson
- Department of Mathematical Sciences, Chalmers University of Technology, Gothenburg, Sweden; Centre for Antibiotic Resistance Research (CARe) at University of Gothenburg, Gothenburg, Sweden
| | - Mats Tysklind
- Department of Chemistry, Umeå University, Umeå, Sweden
| | - D G Joakim Larsson
- Department of Infectious Diseases, Institute of Biomedicine, The Sahlgrenska Academy, University of Gothenburg, Guldhedsgatan 10, SE-413 46 Gothenburg, Sweden; Centre for Antibiotic Resistance Research (CARe) at University of Gothenburg, Gothenburg, Sweden.
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16
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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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17
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Malik M, Mustaev A, Schwanz HA, Luan G, Shah N, Oppegard LM, de Souza EC, Hiasa H, Zhao X, Kerns RJ, Drlica K. Suppression of gyrase-mediated resistance by C7 aryl fluoroquinolones. Nucleic Acids Res 2016; 44:3304-16. [PMID: 26984528 PMCID: PMC4838383 DOI: 10.1093/nar/gkw161] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 03/02/2016] [Indexed: 11/16/2022] Open
Abstract
Fluoroquinolones form drug-topoisomerase-DNA complexes that rapidly block transcription and replication. Crystallographic and biochemical studies show that quinolone binding involves a water/metal-ion bridge between the quinolone C3-C4 keto-acid and amino acids in helix-4 of the target proteins, GyrA (gyrase) and ParC (topoisomerase IV). A recent cross-linking study revealed a second drug-binding mode in which the other end of the quinolone, the C7 ring system, interacts with GyrA. We report that addition of a dinitrophenyl (DNP) moiety to the C7 end of ciprofloxacin (Cip-DNP) reduced protection due to resistance substitutions in Escherichia coli GyrA helix-4, consistent with the existence of a second drug-binding mode not evident in X-ray structures of drug-topoisomerase-DNA complexes. Several other C7 aryl fluoroquinolones behaved in a similar manner with particular GyrA mutants. Treatment of E. coli cultures with Cip-DNP selectively enriched an uncommon variant, GyrA-A119E, a change that may impede binding of the dinitrophenyl group at or near the GyrA-GyrA interface. Collectively the data support the existence of a secondary quinolone-binding mode in which the quinolone C7 ring system interacts with GyrA; the data also identify C7 aryl derivatives as a new way to obtain fluoroquinolones that overcome existing GyrA-mediated quinolone resistance.
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Affiliation(s)
- Muhammad Malik
- Public Heath Research Institute, New Jersey Medical School, Rutgers Biomedical and Health Science, 225 Warren Street, Newark, NJ 07103, USA
| | - Arkady Mustaev
- Public Heath Research Institute, New Jersey Medical School, Rutgers Biomedical and Health Science, 225 Warren Street, Newark, NJ 07103, USA
| | - Heidi A Schwanz
- University of Iowa, Division of Medicinal & Natural Products Chemistry, College of Pharmacy, Iowa City, IA 52246, USA
| | - Gan Luan
- Public Heath Research Institute, New Jersey Medical School, Rutgers Biomedical and Health Science, 225 Warren Street, Newark, NJ 07103, USA
| | - Nirali Shah
- Public Heath Research Institute, New Jersey Medical School, Rutgers Biomedical and Health Science, 225 Warren Street, Newark, NJ 07103, USA
| | - Lisa M Oppegard
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - Ernane C de Souza
- University of Iowa, Division of Medicinal & Natural Products Chemistry, College of Pharmacy, Iowa City, IA 52246, USA
| | - Hiroshi Hiasa
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN 55455, USA
| | - Xilin Zhao
- Public Heath Research Institute, New Jersey Medical School, Rutgers Biomedical and Health Science, 225 Warren Street, Newark, NJ 07103, USA Department of Microbiology, Biochemistry & Molecular Genetics, New Jersey Medical School, Rutgers Biomedical and Health Science, 225 Warren Street, Newark, NJ 07103, USA State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, South Xiang-An Road, Xiang-An District, Xiamen, Fujian Province 361102, China
| | - Robert J Kerns
- University of Iowa, Division of Medicinal & Natural Products Chemistry, College of Pharmacy, Iowa City, IA 52246, USA
| | - Karl Drlica
- Public Heath Research Institute, New Jersey Medical School, Rutgers Biomedical and Health Science, 225 Warren Street, Newark, NJ 07103, USA Department of Microbiology, Biochemistry & Molecular Genetics, New Jersey Medical School, Rutgers Biomedical and Health Science, 225 Warren Street, Newark, NJ 07103, USA
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18
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Bengtsson-Palme J, Larsson DGJ. Concentrations of antibiotics predicted to select for resistant bacteria: Proposed limits for environmental regulation. ENVIRONMENT INTERNATIONAL 2016; 86:140-9. [PMID: 26590482 DOI: 10.1016/j.envint.2015.10.015] [Citation(s) in RCA: 486] [Impact Index Per Article: 60.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 10/24/2015] [Accepted: 10/26/2015] [Indexed: 05/21/2023]
Abstract
There are concerns that selection pressure from antibiotics in the environment may accelerate the evolution and dissemination of antibiotic-resistant pathogens. Nevertheless, there is currently no regulatory system that takes such risks into account. In part, this is due to limited knowledge of environmental concentrations that might exert selection for resistant bacteria. To experimentally determine minimal selective concentrations in complex microbial ecosystems for all antibiotics would involve considerable effort. In this work, our aim was to estimate upper boundaries for selective concentrations for all common antibiotics, based on the assumption that selective concentrations a priori need to be lower than those completely inhibiting growth. Data on Minimal Inhibitory Concentrations (MICs) were obtained for 111 antibiotics from the public EUCAST database. The 1% lowest observed MICs were identified, and to compensate for limited species coverage, predicted lowest MICs adjusted for the number of tested species were extrapolated through modeling. Predicted No Effect Concentrations (PNECs) for resistance selection were then assessed using an assessment factor of 10 to account for differences between MICs and minimal selective concentrations. The resulting PNECs ranged from 8 ng/L to 64 μg/L. Furthermore, the link between taxonomic similarity between species and lowest MIC was weak. This work provides estimated upper boundaries for selective concentrations (lowest MICs) and PNECs for resistance selection for all common antibiotics. In most cases, PNECs for selection of resistance were below available PNECs for ecotoxicological effects. The generated PNECs can guide implementation of compound-specific emission limits that take into account risks for resistance promotion.
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Affiliation(s)
- Johan Bengtsson-Palme
- Department of Infectious Diseases, Institute of Biomedicine, The Sahlgrenska Academy, University of Gothenburg, Guldhedsgatan 10, SE-413 46 Gothenburg, Sweden.
| | - D G Joakim Larsson
- Department of Infectious Diseases, Institute of Biomedicine, The Sahlgrenska Academy, University of Gothenburg, Guldhedsgatan 10, SE-413 46 Gothenburg, Sweden.
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19
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Riou M, Avrain L, Carbonnelle S, El Garch F, Pirnay JP, De Vos D, Plésiat P, Tulkens PM, Van Bambeke F. Increase of efflux-mediated resistance in Pseudomonas aeruginosa during antibiotic treatment in patients suffering from nosocomial pneumonia. Int J Antimicrob Agents 2015; 47:77-83. [PMID: 26691019 DOI: 10.1016/j.ijantimicag.2015.11.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 11/03/2015] [Accepted: 11/04/2015] [Indexed: 11/17/2022]
Abstract
Increases in antibiotic minimum inhibitory concentrations (MICs) for Pseudomonas aeruginosa during treatment are commonly observed but their relationship to efflux overexpression remains poorly documented. In this study, pairs of first [at time of diagnosis (D0)] and last [during treatment (DL)] P. aeruginosa isolates were obtained from patients treated for suspicion of nosocomial pneumonia. Pair clonality was determined by repetitive extragenic palindromic PCR. Overexpression of mexA and mexX was assessed by real-time PCR, and expression of mexC and mexE was assessed by PCR. Antibiotics received by patients before and during treatment were determined from clinical charts. For D0 isolates, 24% were from patients without antibiotics for 1 month and 64% were negative for mexA/mexX overexpression and mexC/mexE expression. For DL isolates, approximately one-half of the patients had received piperacillin/tazobactam, amikacin, meropenem and/or cefepime, and 17% had received ciprofloxacin (alone or in combination); 38% did not show changes in expression of the four genes, whereas 38% showed increased expression for one gene (mainly mexA or mexX), 19% for two genes (mainly mexA and mexX) and 5% for three or four genes. Isolates overexpressing mexA or mexX had median MICs above EUCAST clinical resistance breakpoints for ciprofloxacin, cefepime and meropenem, or for ciprofloxacin, amikacin, cefepime and meropenem, respectively. mexA or mexX overexpression was statistically significantly associated with patients' exposure to ciprofloxacin and meropenem or cefepime and meropenem, respectively. Overexpression of genes encoding antibiotic transporters in P. aeruginosa during treatment is frequent and is associated with increases in MICs above EUCAST clinical susceptibility breakpoints.
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Affiliation(s)
- Mickaël Riou
- Pharmacologie cellulaire et moléculaire & Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | | | - Sylviane Carbonnelle
- Pharmacologie cellulaire et moléculaire & Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Farid El Garch
- Pharmacologie cellulaire et moléculaire & Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium; Laboratoire de microbiologie, CHU Dinant-Godinne UCL Namur, Yvoir, Belgium
| | - Jean-Paul Pirnay
- Laboratory for Molecular and Cellular Technology, Queen Astrid Military Hospital, Neder-over-Heembeek, Brussels, Belgium
| | - Daniel De Vos
- Laboratory for Molecular and Cellular Technology, Queen Astrid Military Hospital, Neder-over-Heembeek, Brussels, Belgium
| | - Patrick Plésiat
- Laboratoire de bactériologie, Faculté de médecine, Université de Franche-Comté, Besançon, France
| | - Paul M Tulkens
- Pharmacologie cellulaire et moléculaire & Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Françoise Van Bambeke
- Pharmacologie cellulaire et moléculaire & Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium.
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Solé M, Fàbrega A, Cobos-Trigueros N, Zamorano L, Ferrer-Navarro M, Ballesté-Delpierre C, Reustle A, Castro P, Nicolás JM, Oliver A, Martínez JA, Vila J. In vivo evolution of resistance of Pseudomonas aeruginosa strains isolated from patients admitted to an intensive care unit: mechanisms of resistance and antimicrobial exposure. J Antimicrob Chemother 2015; 70:3004-13. [PMID: 26260130 DOI: 10.1093/jac/dkv228] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 07/04/2015] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES The main objective of this study was to investigate the relationship among the in vivo acquisition of antimicrobial resistance in Pseudomonas aeruginosa clinical isolates, the underlying molecular mechanisms and previous exposure to antipseudomonal agents. METHODS PFGE was used to study the molecular relatedness of the strains. The MICs of ceftazidime, cefepime, piperacillin/tazobactam, imipenem, meropenem, ciprofloxacin and amikacin were determined. Outer membrane protein profiles were assessed to study OprD expression. RT-PCR was performed to analyse ampC, mexB, mexD, mexF and mexY expression. The presence of mutations was analysed through DNA sequencing. RESULTS We collected 17 clonally related paired isolates [including first positive samples (A) and those with MICs increased ≥4-fold (B)]. Most B isolates with increased MICs of imipenem, meropenem and ceftazidime became resistant to these drugs. The most prevalent resistance mechanisms detected were OprD loss (65%), mexB overexpression (53%), ampC derepression (29%), quinolone target gene mutations (24%) and increased mexY expression (24%). Five (29%) B isolates developed multidrug resistance. Meropenem was the most frequently (71%) received treatment, explaining the high prevalence of oprD mutations and likely mexB overexpression. Previous exposure to ceftazidime showed a higher impact on selection of increased MICs than previous exposure to piperacillin/tazobactam. CONCLUSIONS Stepwise acquisition of resistance has a critical impact on the resistance phenotypes of P. aeruginosa, leading to a complex scenario for finding effective antimicrobial regimens. In the clinical setting, meropenem seems to be the most frequent driver of multidrug resistance development, while piperacillin/tazobactam, in contrast to ceftazidime, seems to be the β-lactam least associated with the selection of resistance mechanisms.
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Affiliation(s)
- Mar Solé
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Anna Fàbrega
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | | | - Laura Zamorano
- University Hospital Son Espases, Palma de Mallorca, Spain
| | - Mario Ferrer-Navarro
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Clara Ballesté-Delpierre
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Anna Reustle
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain
| | - Pedro Castro
- Hospital Clínic, IDIBAPS, University of Barcelona, Barcelona, Spain
| | | | - Antonio Oliver
- University Hospital Son Espases, Palma de Mallorca, Spain
| | | | - Jordi Vila
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Spain Hospital Clínic, IDIBAPS, University of Barcelona, Barcelona, Spain
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21
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Wang Y, Liu C, Zhang Z, Hu Y, Cao C, Wang X, Xi M, Xia X, Yang B, Meng J. Distribution and Molecular Characterization of Salmonella enterica Hypermutators in Retail Food in China. J Food Prot 2015; 78:1481-7. [PMID: 26219361 DOI: 10.4315/0362-028x.jfp-14-462] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Hypermutable pathogens can easily acquire mutation opportunities, as well as antimicrobial resistance, and are tremendous hazards to food safety and public health. In this study, a total of 96 (7.6%) hypermutators were identified from 1,264 Salmonella isolates recovered from retail foods. Pulsed-field gel electrophoresis analysis indicated that hypermutators were genetically diverse. Amino acid substitution of Val421Phe was detected in MutS in one hypermutator and Val246Ala in 56 other hypermutators, while no mutation in MutS was found among the remaining 39 hypermutators. Hypermutators in Salmonella isolates recovered in 2010 (9.3%) and 2008 (7.7%) were significantly more prevalent than those in 2007 (1.4%). The rate of hypermutators in mutton (22.2%) was significantly higher than that in chicken (7.9%) and pork (4.7%). In Salmonella Leimo isolates (60.0%), hypermutators were most frequently detected, followed by Salmonella Essen (50.0%), Salmonella Indiana (36.6%), Salmonella Kallo (25.0%), Salmonella Heidelberg (23.8%), Salmonella Typhimurium (14.0%), Salmonella Shubra (13.0%), Salmonella Albany (11.1%), Salmonella Agona (7.0%), Salmonella Gueuletapee (6.3%), and Salmonella Enteritidis (1.7%). Salmonella hypermutators in isolates recovered from retail food stored at ambient temperature (15.7%) were significantly more prevalent than those stored in chilled (3.1%) and frozen (5.4%) condition. The overall distributions of mutation frequencies of the 96 hypermutators (selected by rifampin) were from 2.16 × 10(-5) to 4.25 × 10(-1). Mutation frequencies of hypermutators of Salmonella Leimo, Salmonella Essen, Salmonella Kallo, and Salmonella Agona were relative low, while those of Salmonella Typhimurium, Salmonella Indiana, and Salmonella Shubra were extremely high. No significant correlation was found between mutation frequency and antimicrobial resistance of the hypermutators.
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Affiliation(s)
- Yin Wang
- College of Food Science and Engineering, Northwest A&F University, 28 Xinong Road, Yangling, Shaanxi, People's Republic of China, 712100
| | - Chongyang Liu
- College of Food Science and Engineering, Northwest A&F University, 28 Xinong Road, Yangling, Shaanxi, People's Republic of China, 712100
| | - Zengfeng Zhang
- College of Food Science and Engineering, Northwest A&F University, 28 Xinong Road, Yangling, Shaanxi, People's Republic of China, 712100
| | - Yuanyuan Hu
- College of Food Science and Engineering, Northwest A&F University, 28 Xinong Road, Yangling, Shaanxi, People's Republic of China, 712100; College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi'an, Shaanxi, People's Republic of China, 710062
| | - Chenyang Cao
- College of Food Science and Engineering, Northwest A&F University, 28 Xinong Road, Yangling, Shaanxi, People's Republic of China, 712100
| | - Xin Wang
- College of Food Science and Engineering, Northwest A&F University, 28 Xinong Road, Yangling, Shaanxi, People's Republic of China, 712100
| | - Meili Xi
- College of Food Science and Engineering, Northwest A&F University, 28 Xinong Road, Yangling, Shaanxi, People's Republic of China, 712100
| | - Xiaodong Xia
- College of Food Science and Engineering, Northwest A&F University, 28 Xinong Road, Yangling, Shaanxi, People's Republic of China, 712100
| | - Baowei Yang
- College of Food Science and Engineering, Northwest A&F University, 28 Xinong Road, Yangling, Shaanxi, People's Republic of China, 712100.
| | - Jianghong Meng
- College of Food Science and Engineering, Northwest A&F University, 28 Xinong Road, Yangling, Shaanxi, People's Republic of China, 712100
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22
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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: 920] [Impact Index Per Article: 102.2] [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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23
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Fair RJ, Tor Y. Antibiotics and bacterial resistance in the 21st century. PERSPECTIVES IN MEDICINAL CHEMISTRY 2014; 6:25-64. [PMID: 25232278 PMCID: PMC4159373 DOI: 10.4137/pmc.s14459] [Citation(s) in RCA: 854] [Impact Index Per Article: 85.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 06/24/2014] [Accepted: 06/24/2014] [Indexed: 12/11/2022]
Abstract
Dangerous, antibiotic resistant bacteria have been observed with increasing frequency over the past several decades. In this review the factors that have been linked to this phenomenon are addressed. Profiles of bacterial species that are deemed to be particularly concerning at the present time are illustrated. Factors including economic impact, intrinsic and acquired drug resistance, morbidity and mortality rates, and means of infection are taken into account. Synchronously with the waxing of bacterial resistance there has been waning antibiotic development. The approaches that scientists are employing in the pursuit of new antibacterial agents are briefly described. The standings of established antibiotic classes as well as potentially emerging classes are assessed with an emphasis on molecules that have been clinically approved or are in advanced stages of development. Historical perspectives, mechanisms of action and resistance, spectrum of activity, and preeminent members of each class are discussed.
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Affiliation(s)
- Richard J Fair
- Department for Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, Berlin, Germany
| | - Yitzhak Tor
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA
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24
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Wang YT, Lee MF, Peng CF. Mutations in the quinolone resistance-determining regions associated with ciprofloxacin resistance in Pseudomonas aeruginosa isolates from Southern Taiwan. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/j.bgm.2014.03.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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25
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Higuchi S, Shikata M, Chiba M, Hoshino K, Gotoh N. Characteristics of antibiotic resistance and sequence type of Acinetobacter baumannii clinical isolates in Japan and the antibacterial activity of DS-8587. J Infect Chemother 2014; 20:256-61. [DOI: 10.1016/j.jiac.2013.12.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 11/28/2013] [Accepted: 12/16/2013] [Indexed: 10/25/2022]
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26
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Maillard JY, Bloomfield S, Coelho JR, Collier P, Cookson B, Fanning S, Hill A, Hartemann P, Mcbain AJ, Oggioni M, Sattar S, Schweizer HP, Threlfall J. Does Microbicide Use in Consumer Products Promote Antimicrobial Resistance? A Critical Review and Recommendations for a Cohesive Approach to Risk Assessment. Microb Drug Resist 2013; 19:344-54. [DOI: 10.1089/mdr.2013.0039] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Affiliation(s)
- Jean-Yves Maillard
- Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, United Kingdom
| | - Sally Bloomfield
- London School of Hygiene and Tropical Medicine, International Scientific Forum on Home Hygiene, London, United Kingdom
| | | | - Phillip Collier
- School of Contemporary Sciences, University of Abertay Dundee, Dundee, United Kingdom
| | - Barry Cookson
- Division of Infection & Immunity, Faculty of Medical Sciences, University College London, London, United Kingdom
| | - Séamus Fanning
- UCD Centres for Food Safety and Molecular Innovation & Drug Design, School of Public Health, Physiotherapy & Population Science, University College Dublin, Dublin, Ireland
| | - Andrew Hill
- Epidemiology, Surveillance and Risk Group, Animal Health and Veterinary Laboratories Agency, Weybridge, United Kingdom
| | - Philippe Hartemann
- Départment Environment et Santé Publique, Faculté de Médecine, Vandoeuvre-les-Nancy, France
| | - Andrew J. Mcbain
- School of Pharmacy and Pharmaceutical Sciences, the University of Manchester, Manchester, United Kingdom
| | - Marco Oggioni
- Laboratory of Molecular Microbiology and Biotechnology, Università degli Studi di Siena, Siena, Italy
| | - Syed Sattar
- Centre for Research on Environmental Microbiology, University of Ottawa, Ottawa, Ontario, Canada
| | - Herbert P. Schweizer
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado
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27
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Kovacs B, Le Gall-David S, Vincent P, Le Bars H, Buffet-Bataillon S, Bonnaure-Mallet M, Jolivet-Gougeon A. Is biofilm formation related to the hypermutator phenotype in clinical Enterobacteriaceae isolates? FEMS Microbiol Lett 2013; 347:116-22. [PMID: 23909976 DOI: 10.1111/1574-6968.12229] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Revised: 06/18/2013] [Accepted: 07/26/2013] [Indexed: 12/29/2022] Open
Abstract
In bacteria, complex adaptive processes are involved during transition from the planktonic to the biofilm mode of growth, and mutator strains are more prone to producing biofilms. Enterobacteriaceae species were isolated from urinary tract infections (UTIs; 222 strains) and from bloodstream infections (BSIs; 213 strains). Relationship between the hypermutable phenotype and biofilm forming capacity was investigated in these clinical strains. Mutation frequencies were estimated by monitoring the capacity of each strain to generate mutations that conferred rifampicin resistance on supplemented medium. Initiation of biofilm formation was assayed by determining the ability of the cells to adhere to a 96-well polystyrene microtitre plate. UTI Enterobacteriaceae strains showed significantly higher biofilm-forming capacity: 63.1% (54.0% for E. coli strains) vs. 42.3% for BSI strains (47.7% for E. coli). Strains isolated from UTIs did not present higher mutation frequencies than those from BSIs: contrary to what has been widely described for P. aeruginosa strains, isolated from pulmonary samples in patients suffering from cystic fibrosis, no relationship was found between the hypermutator phenotype in Enterobacteriaceae and the ability to initiate a biofilm.
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Affiliation(s)
- Bela Kovacs
- Department of Urology, Jahn Ferenc South-Pest Hospital, Budapest, Hungary
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28
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Pendleton JN, Gorman SP, Gilmore BF. Clinical relevance of the ESKAPE pathogens. Expert Rev Anti Infect Ther 2013; 11:297-308. [PMID: 23458769 DOI: 10.1586/eri.13.12] [Citation(s) in RCA: 869] [Impact Index Per Article: 79.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
In recent years, the Infectious Diseases Society of America has highlighted a faction of antibiotic-resistant bacteria (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter spp.) - acronymically dubbed 'the ESKAPE pathogens' - capable of 'escaping' the biocidal action of antibiotics and mutually representing new paradigms in pathogenesis, transmission and resistance. This review aims to consolidate clinically relevant background information on the ESKAPE pathogens and provide a contemporary summary of bacterial resistance, alongside pertinent microbiological considerations necessary to face the mounting threat of antimicrobial resistance.
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Affiliation(s)
- Jack N Pendleton
- School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast, BT9 7BL, UK
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29
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Sublethal ciprofloxacin treatment leads to rapid development of high-level ciprofloxacin resistance during long-term experimental evolution of Pseudomonas aeruginosa. Antimicrob Agents Chemother 2013; 57:4215-21. [PMID: 23774442 DOI: 10.1128/aac.00493-13] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The dynamics of occurrence and the genetic basis of ciprofloxacin resistance were studied in a long-term evolution experiment (940 generations) in wild-type, reference strain (PAO1) and hypermutable (PAOΔmutS and PAOMY-Mgm) P. aeruginosa populations continuously exposed to sub-MICs (1/4) of ciprofloxacin. A rapid occurrence of ciprofloxacin-resistant mutants (MIC of ≥12 μg/ml, representing 100 times the MIC of the original population) were observed in all ciprofloxacin-exposed lineages of PAOΔmutS and PAOMY-Mgm populations after 100 and 170 generations, respectively, and in one of the PAO1 lineages after 240 generations. The genetic basis of resistance was mutations in gyrA (C248T and G259T) and gyrB (C1397A). Cross-resistance to beta-lactam antibiotics was observed in the bacterial populations that evolved during exposure to sublethal concentrations of ciprofloxacin. Our study shows that mutants with high-level ciprofloxacin resistance are selected in P. aeruginosa bacterial populations exposed to sub-MICs of ciprofloxacin. This can have implications for the long-term persistence of resistant bacteria and spread of antibiotic resistance by exposure of commensal bacterial flora to low antibiotic concentrations.
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30
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Monti MR, Morero NR, Miguel V, Argaraña CE. nfxB as a novel target for analysis of mutation spectra in Pseudomonas aeruginosa. PLoS One 2013; 8:e66236. [PMID: 23762483 PMCID: PMC3676378 DOI: 10.1371/journal.pone.0066236] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 05/02/2013] [Indexed: 02/06/2023] Open
Abstract
nfxB encodes a negative regulator of the mexCD-oprJ genes for drug efflux in the opportunistic pathogen Pseudomonas aeruginosa. Inactivating mutations in this transcriptional regulator constitute one of the main mechanisms of resistance to ciprofloxacin (Cipr). In this work, we evaluated the use of nfxB/Cipr as a new test system to study mutation spectra in P. aeruginosa. The analysis of 240 mutations in nfxB occurring spontaneously in the wild-type and mutator backgrounds or induced by mutagens showed that nfxB/Cipr offers several advantages compared with other mutation detection systems. Identification of nfxB mutations was easy since the entire open reading frame and its promoter region were sequenced from the chromosome using a single primer. Mutations detected in nfxB included all transitions and transversions, 1-bp deletions and insertions, >1-bp deletions and duplications. The broad mutation spectrum observed in nfxB relies on the selection of loss-of-function changes, as we confirmed by generating a structural model of the NfxB repressor and evaluating the significance of each detected mutation. The mutation spectra characterized in the mutS, mutT, mutY and mutM mutator backgrounds or induced by the mutagenic agents 2-aminopurine, cisplatin and hydrogen peroxide were in agreement with their predicted mutational specificities. Additionally, this system allowed the analysis of sequence context effects since point mutations occurred at 85 different sites distributed over the entire nfxB. Significant hotspots and preferred sequence contexts were observed for spontaneous and mutagen-induced mutation spectra. Finally, we demonstrated the utility of a luminescence-based reporter for identification of nfxB mutants previous to sequencing analysis. Thus, the nfxB/Cipr system in combination with the luminescent reporter may be a valuable tool for studying mutational processes in Pseudomonas spp. wherein the genes encoding the NfxB repressor and the associated efflux pump are conserved.
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Affiliation(s)
- 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, Argentina
| | - Natalia R. Morero
- 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, Argentina
| | - Virginia Miguel
- 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, 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, Argentina
- * E-mail:
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31
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Yamachika S, Sugihara C, Kamai Y, Yamashita M. Correlation between penicillin-binding protein 2 mutations and carbapenem resistance in Escherichia coli. J Med Microbiol 2013; 62:429-436. [DOI: 10.1099/jmm.0.051631-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Shinichiro Yamachika
- Oncology Research Laboratories, Daiichi Sankyo Co. Ltd, 1-16-13 Kitakasai, Edogawa-ku, Tokyo 134-8630, Japan
| | - Chika Sugihara
- Lead Discovery & Optimization Research Laboratories II, Daiichi Sankyo Co. Ltd, 1-16-13 Kitakasai, Edogawa-ku, Tokyo 134-8630, Japan
| | - Yasuki Kamai
- Oncology Research Laboratories, Daiichi Sankyo Co. Ltd, 1-16-13 Kitakasai, Edogawa-ku, Tokyo 134-8630, Japan
| | - Makoto Yamashita
- Biological Research Laboratories, Daiichi Sankyo Co. Ltd, 1-16-13 Kitakasai, Edogawa-ku, Tokyo 134-8630, Japan
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32
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Induction of mycobacterial resistance to quinolone class antimicrobials. Antimicrob Agents Chemother 2012; 56:3879-87. [PMID: 22564842 DOI: 10.1128/aac.00474-12] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
An agar plate assay was developed for detecting the induction of drug-resistant mycobacterial mutants during exposure to inhibitors of DNA gyrase. When Mycobacterium smegmatis on drug-containing agar, resistant colonies arose over a period of 2 weeks. A recA deficiency reduced mutant recovery, consistent with involvement of the SOS response in mutant induction. The C-8-methoxy compounds gatifloxacin and moxifloxacin allowed the recovery of fewer resistant mutants than either ciprofloxacin or levofloxacin when present at the same multiple of the MIC; a quinolone-like 8-methoxy-quinazoline-2,4-dione was more effective at restricting the emergence of resistant mutants than its cognate fluoroquinolone. Thus, the structure of fluoroquinolone-like compounds affects mutant recovery. A spontaneous mutator mutant of M. smegmatis, obtained by growth in medium containing both isoniazid and rifampin, increased mutant induction during exposure to ciprofloxacin. Moreover, the mutator increased the size of spontaneous resistant mutant subpopulations, as detected by population analysis. Induction of ciprofloxacin resistance was also observed with Mycobacterium tuberculosis H37Rv. When measured with clinical isolates, no difference in mutant recovery was observed between multidrug-resistant (MDR) and pansusceptible isolates. This finding is consistent with at least some MDR isolates of M. tuberculosis lacking mutators detectable by the agar plate assay. Collectively, the data indicate that the use of fluoroquinolones against tuberculosis may induce resistance and that the choice of quinolone may be important for restricting the recovery of induced mutants.
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33
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Functional analysis of the interaction between the mismatch repair protein MutS and the replication processivity factor β clamp in Pseudomonas aeruginosa. DNA Repair (Amst) 2012; 11:463-9. [DOI: 10.1016/j.dnarep.2012.01.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 01/19/2012] [Accepted: 01/26/2012] [Indexed: 11/17/2022]
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34
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In the Literature. Clin Infect Dis 2011. [DOI: 10.1093/cid/cir816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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