1
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Long MB, Gilmour A, Kehl M, Tabor DE, Keller AE, Warrener P, Gopalakrishnan V, Rosengren S, Crichton ML, McIntosh E, Giam YH, Keir HR, Brailsford W, Hughes R, Belvisi MG, Sellman BR, DiGiandomenico A, Chalmers JD. A Bispecific Monoclonal Antibody Targeting Psl and PcrV Enhances Neutrophil-Mediated Killing of Pseudomonas aeruginosa in Patients with Bronchiectasis. Am J Respir Crit Care Med 2024; 210:35-46. [PMID: 38754132 DOI: 10.1164/rccm.202308-1403oc] [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: 08/11/2023] [Accepted: 05/16/2024] [Indexed: 05/18/2024] Open
Abstract
Rationale: Pseudomonas aeruginosa infection is associated with worse outcomes in bronchiectasis. Impaired neutrophil antimicrobial responses contribute to bacterial persistence. Gremubamab is a bivalent, bispecific monoclonal antibody targeting Psl exopolysaccharide and the type 3 secretion system component PcrV. Objectives: This study evaluated the efficacy of gremubamab to enhance killing of P. aeruginosa by neutrophils from patients with bronchiectasis and to prevent P. aeruginosa-associated cytotoxicity. Methods: P. aeruginosa isolates from a global bronchiectasis cohort (n = 100) underwent whole-genome sequencing to determine target prevalence. Functional activity of gremubamab against selected isolates was tested in vitro and in vivo. Patients with bronchiectasis (n = 11) and control subjects (n = 10) were enrolled, and the effect of gremubamab in peripheral blood neutrophil opsonophagocytic killing (OPK) assays against P. aeruginosa was evaluated. Serum antibody titers to Psl and PcrV were determined (n = 30; 19 chronic P. aeruginosa infection, 11 no known P. aeruginosa infection), as was the effect of gremubamab treatment in OPK and anti-cytotoxic activity assays. Measurements and Main Results: Psl and PcrV were conserved in isolates from chronically infected patients with bronchiectasis. Seventy-three of 100 isolates had a full psl locus, and 99 of 100 contained the pcrV gene, with 20 distinct full-length PcrV protein subtypes identified. PcrV subtypes were successfully bound by gremubamab and the monoclonal antibody-mediated potent protective activity against tested isolates. Gremubamab increased bronchiectasis patient neutrophil-mediated OPK (+34.6 ± 8.1%) and phagocytosis (+70.0 ± 48.8%), similar to effects observed in neutrophils from control subjects (OPK, +30.1 ± 7.6%). No evidence of competition between gremubamab and endogenous antibodies was found, with protection against P. aeruginosa-induced cytotoxicity and enhanced OPK demonstrated with and without addition of patient serum. Conclusions: Gremubamab enhanced bronchiectasis patient neutrophil phagocytosis and killing of P. aeruginosa and reduced virulence.
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Affiliation(s)
- Merete B Long
- Division of Molecular and Clinical Medicine, School of Medicine, University of Dundee, Dundee, United Kingdom
| | - Amy Gilmour
- Division of Molecular and Clinical Medicine, School of Medicine, University of Dundee, Dundee, United Kingdom
| | - Margaret Kehl
- Vaccine and Immune Therapies, BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, Maryland
| | - David E Tabor
- Vaccine and Immune Therapies, BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, Maryland
| | - Ashley E Keller
- Vaccine and Immune Therapies, BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, Maryland
| | - Paul Warrener
- Vaccine and Immune Therapies, BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, Maryland
| | | | - Sanna Rosengren
- Translational Science and Experimental Medicine, Respiratory & Immunology, Respiratory and Immunology, and
| | - Megan L Crichton
- Division of Molecular and Clinical Medicine, School of Medicine, University of Dundee, Dundee, United Kingdom
| | - Eve McIntosh
- Division of Molecular and Clinical Medicine, School of Medicine, University of Dundee, Dundee, United Kingdom
| | - Yan Hui Giam
- Division of Molecular and Clinical Medicine, School of Medicine, University of Dundee, Dundee, United Kingdom
| | - Holly R Keir
- Division of Molecular and Clinical Medicine, School of Medicine, University of Dundee, Dundee, United Kingdom
| | - Wayne Brailsford
- Respiratory and Immunology, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden; and
| | - Rod Hughes
- Respiratory and Immunology, BioPharmaceuticals R&D, AstraZeneca, Cambridge, United Kingdom
| | - Maria G Belvisi
- Respiratory and Immunology, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden; and
| | - Bret R Sellman
- Vaccine and Immune Therapies, BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, Maryland
| | - Antonio DiGiandomenico
- Vaccine and Immune Therapies, BioPharmaceuticals R&D, AstraZeneca, Gaithersburg, Maryland
| | - James D Chalmers
- Division of Molecular and Clinical Medicine, School of Medicine, University of Dundee, Dundee, United Kingdom
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Sara M, Yasir M, Kalaiselvan P, Hui A, Kuppusamy R, Kumar N, Chakraborty S, Yu TT, Wong EHH, Molchanova N, Jenssen H, Lin JS, Barron AE, Willcox M. The activity of antimicrobial peptoids against multidrug-resistant ocular pathogens. Cont Lens Anterior Eye 2024; 47:102124. [PMID: 38341309 PMCID: PMC11024869 DOI: 10.1016/j.clae.2024.102124] [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: 07/27/2023] [Revised: 01/11/2024] [Accepted: 02/04/2024] [Indexed: 02/12/2024]
Abstract
BACKGROUND Ocular infections caused by antibiotic-resistant pathogens can result in partial or complete vision loss. The development of pan-resistant microbial strains poses a significant challenge for clinicians as there are limited antimicrobial options available. Synthetic peptoids, which are sequence-specific oligo-N-substituted glycines, offer potential as alternative antimicrobial agents to target multidrug-resistant bacteria. METHODS The antimicrobial activity of synthesised peptoids against multidrug-resistant (MDR) ocular pathogens was evaluated using the microbroth dilution method. Hemolytic propensity was assessed using mammalian erythrocytes. Peptoids were also incubated with proteolytic enzymes, after which their minimum inhibitory activity against bacteria was re-evaluated. RESULTS Several alkylated and brominated peptoids showed good inhibitory activity against multidrug-resistant Pseudomonas aeruginosa strains at concentrations of ≤15 μg mL-1 (≤12 µM). Similarly, most brominated compounds inhibited the growth of methicillin-resistant Staphylococcus aureus at 1.9 to 15 μg mL-1 (12 µM). The N-terminally alkylated peptoids caused less toxicity to erythrocytes. The peptoid denoted as TM5 had a high therapeutic index, being non-toxic to either erythrocytes or corneal epithelial cells, even at 15 to 22 times its MIC. Additionally, the peptoids were resistant to protease activity. CONCLUSIONS Peptoids studied here demonstrated potent activity against various multidrug-resistant ocular pathogens. Their properties make them promising candidates for controlling vision-related morbidity associated with eye infections by antibiotic-resistant strains.
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Affiliation(s)
- Manjulatha Sara
- School of Optometry and Vision Science, UNSW Sydney, Australia.
| | - Muhammad Yasir
- School of Optometry and Vision Science, UNSW Sydney, Australia
| | | | - Alex Hui
- School of Optometry and Vision Science, UNSW Sydney, Australia; Centre for Ocular Research and Education, University of Waterloo, Canada
| | - Rajesh Kuppusamy
- School of Optometry and Vision Science, UNSW Sydney, Australia; School of Chemistry, UNSW Sydney, Australia
| | | | | | - Tsz Tin Yu
- School of Chemistry, UNSW Sydney, Australia
| | | | - Natalia Molchanova
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 4720, USA
| | - Håvard Jenssen
- Department of Science and Environment, Roskilde University, 4000 Roskilde, Denmark
| | - Jennifer S Lin
- Department of Bioengineering, School of Medicine & School of Engineering, Stanford University, Stanford, CA 9430, USA
| | - Annelise E Barron
- Department of Bioengineering, School of Medicine & School of Engineering, Stanford University, Stanford, CA 9430, USA
| | - Mark Willcox
- School of Optometry and Vision Science, UNSW Sydney, Australia.
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3
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Wang S, Chan SY, Deng Y, Khoo BL, Chua SL. Oxidative stress induced by Etoposide anti-cancer chemotherapy drives the emergence of tumor-associated bacteria resistance to fluoroquinolones. J Adv Res 2024; 55:33-44. [PMID: 36822389 PMCID: PMC10770098 DOI: 10.1016/j.jare.2023.02.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 02/14/2023] [Accepted: 02/16/2023] [Indexed: 02/24/2023] Open
Abstract
INTRODUCTION Antibiotic-resistant bacterial infections, such as Pseudomonas aeruginosa and Staphylococcus aureus, are prevalent in lung cancer patients, resulting in poor clinical outcomes and high mortality. Etoposide (ETO) is an FDA-approved chemotherapy drug that kills cancer cells by damaging DNA through oxidative stress. However, it is unclear if ETO can cause unintentional side effects on tumor-associated microbial pathogens, such as inducing antibiotic resistance. OBJECTIVES We aimed to show that prolonged ETO treatment could unintendedly confer fluoroquinolone antibiotic resistance to P. aeruginosa, and evaluate the effect of tumor-associated P. aeruginosa on tumor progression. METHODS We employed experimental evolution assay to treat P. aeruginosa with prolonged ETO exposure, evaluated the ciprofloxacin resistance, and elucidated the gene mutations by DNA sequencing. We also established a lung tumor-P. aeruginosa bacterial model to study the role of ETO-evolved intra-tumoral bacteria in tumor progression using immunostaining and confocal microscopy. RESULTS ETO could generate oxidative stress and lead to gene mutations in P. aeruginosa, especially the gyrase (gyrA) gene, resulting in acquired fluoroquinolone resistance. We further demonstrated using a microfluidic-based lung tumor-P. aeruginosa coculture model that bacteria can evolve ciprofloxacin (CIP) resistance in a tumor microenvironment. Moreover, ETO-induced CIP-resistant (EICR) mutants could form multicellular biofilms which protected tumor cells from ETO killing and enabled tumor progression. CONCLUSION Overall, our preclinical proof-of-concept provides insights into how anti-cancer chemotherapy could inadvertently allow tumor-associated bacteria to acquire antibiotic resistance mutations and shed new light on the development of novel anti-cancer treatments based on anti-bacterial strategies.
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Affiliation(s)
- Shan Wang
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong Special Administrative Region China
| | - Shepherd Yuen Chan
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Kowloon, Hong Kong Special Administrative Region China
| | - Yanlin Deng
- Hong Kong Center for Cerebro-Cardiovascular Health Engineering (COCHE), China
| | - Bee Luan Khoo
- Department of Biomedical Engineering, City University of Hong Kong, Hong Kong Special Administrative Region China; Hong Kong Center for Cerebro-Cardiovascular Health Engineering (COCHE), China; City University of Hong Kong-Shenzhen Futian Research Institute, Shenzhen, China.
| | - Song Lin Chua
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Kowloon, Hong Kong Special Administrative Region China; State Key Laboratory of Chemical Biology and Drug Discovery, The Hong Kong Polytechnic University, Kowloon, Hong Kong Special Administrative Region China; Shenzhen Key Laboratory of Food Biological Safety Control, Shenzhen, China; Research Centre for Deep Space Explorations (RCDSE), The Hong Kong Polytechnic University, Kowloon, Hong Kong Special Administrative Region China.
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Yamasaki S, Zwama M, Yoneda T, Hayashi-Nishino M, Nishino K. Drug resistance and physiological roles of RND multidrug efflux pumps in Salmonella enterica, Escherichia coli and Pseudomonas aeruginosa. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001322. [PMID: 37319001 PMCID: PMC10333786 DOI: 10.1099/mic.0.001322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 03/18/2023] [Indexed: 06/17/2023]
Abstract
Drug efflux pumps transport antimicrobial agents out of bacteria, thereby reducing the intracellular antimicrobial concentration, which is associated with intrinsic and acquired bacterial resistance to these antimicrobials. As genome analysis has advanced, many drug efflux pump genes have been detected in the genomes of bacterial species. In addition to drug resistance, these pumps are involved in various essential physiological functions, such as bacterial adaptation to hostile environments, toxin and metabolite efflux, biofilm formation and quorum sensing. In Gram-negative bacteria, efflux pumps in the resistance–nodulation–division (RND) superfamily play a clinically important role. In this review, we focus on Gram-negative bacteria, including Salmonella enterica , Escherichia coli and Pseudomonas aeruginosa , and discuss the role of RND efflux pumps in drug resistance and physiological functions.
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Affiliation(s)
- Seiji Yamasaki
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
- Institute for Advanced Co-Creation Studies, Osaka University, 1-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Martijn Zwama
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Tomohiro Yoneda
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Mitsuko Hayashi-Nishino
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Kunihiko Nishino
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
- Center for Infectious Disease Education and Research, 2-8 Yamadaoka, Osaka University, Suita, Osaka 565-0871, Japan
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5
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Overcoming Antibiotic Resistance with Novel Paradigms of Antibiotic Selection. Microorganisms 2022; 10:microorganisms10122383. [PMID: 36557636 PMCID: PMC9781420 DOI: 10.3390/microorganisms10122383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 11/25/2022] [Accepted: 11/28/2022] [Indexed: 12/04/2022] Open
Abstract
Conventional antimicrobial susceptibility tests, including phenotypic and genotypic methods, are insufficiently accurate and frequently fail to identify effective antibiotics. These methods predominantly select therapies based on the antibiotic response of only the lead bacterial pathogen within pure bacterial culture. However, this neglects the fact that, in the majority of human infections, the lead bacterial pathogens are present as a part of multispecies communities that modulate the response of these lead pathogens to antibiotics and that multiple pathogens can contribute to the infection simultaneously. This discrepancy is a major cause of the failure of antimicrobial susceptibility tests to detect antibiotics that are effective in vivo. This review article provides a comprehensive overview of the factors that are missed by conventional antimicrobial susceptibility tests and it explains how accounting for these methods can aid the development of novel diagnostic approaches.
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6
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Dulanto Chiang A, Patil PP, Beka L, Youn JH, Launay A, Bonomo RA, Khil PP, Dekker JP. Hypermutator strains of Pseudomonas aeruginosa reveal novel pathways of resistance to combinations of cephalosporin antibiotics and beta-lactamase inhibitors. PLoS Biol 2022; 20:e3001878. [PMID: 36399436 PMCID: PMC9718400 DOI: 10.1371/journal.pbio.3001878] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 12/02/2022] [Accepted: 10/13/2022] [Indexed: 11/19/2022] Open
Abstract
Hypermutation due to DNA mismatch repair (MMR) deficiencies can accelerate the development of antibiotic resistance in Pseudomonas aeruginosa. Whether hypermutators generate resistance through predominantly similar molecular mechanisms to wild-type (WT) strains is not fully understood. Here, we show that MMR-deficient P. aeruginosa can evolve resistance to important broad-spectrum cephalosporin/beta-lactamase inhibitor combination antibiotics through novel mechanisms not commonly observed in WT lineages. Using whole-genome sequencing (WGS) and transcriptional profiling of isolates that underwent in vitro adaptation to ceftazidime/avibactam (CZA), we characterized the detailed sequence of mutational and transcriptional changes underlying the development of resistance. Surprisingly, MMR-deficient lineages rapidly developed high-level resistance (>256 μg/mL) largely without corresponding fixed mutations or transcriptional changes in well-established resistance genes. Further investigation revealed that these isolates had paradoxically generated an early inactivating mutation in the mexB gene of the MexAB-OprM efflux pump, a primary mediator of CZA resistance in P. aeruginosa, potentially driving an evolutionary search for alternative resistance mechanisms. In addition to alterations in a number of genes not known to be associated with resistance, 2 mutations were observed in the operon encoding the RND efflux pump MexVW. These mutations resulted in a 4- to 6-fold increase in resistance to ceftazidime, CZA, cefepime, and ceftolozane-tazobactam when engineered into a WT strain, demonstrating a potentially important and previously unappreciated mechanism of resistance to these antibiotics in P. aeruginosa. Our results suggest that MMR-deficient isolates may rapidly evolve novel resistance mechanisms, sometimes with complex dynamics that reflect gene inactivation that occurs with hypermutation. The apparent ease with which hypermutators may switch to alternative resistance mechanisms for which antibiotics have not been developed may carry important clinical implications.
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Affiliation(s)
- Augusto Dulanto Chiang
- Bacterial Pathogenesis and Antimicrobial Resistance Unit, LCIM, NIAID, NIH, Bethesda, Maryland, United States of America
| | - Prashant P. Patil
- Bacterial Pathogenesis and Antimicrobial Resistance Unit, LCIM, NIAID, NIH, Bethesda, Maryland, United States of America
| | - Lidia Beka
- Bacterial Pathogenesis and Antimicrobial Resistance Unit, LCIM, NIAID, NIH, Bethesda, Maryland, United States of America
| | - Jung-Ho Youn
- Dept. Laboratory Medicine, NIH Clinical Center, NIH, Bethesda, Maryland, United States of America
| | - Adrien Launay
- Bacterial Pathogenesis and Antimicrobial Resistance Unit, LCIM, NIAID, NIH, Bethesda, Maryland, United States of America
| | - Robert A. Bonomo
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio, United States of America
- Departments of Pharmacology, Molecular Biology and Microbiology, Biochemistry, and Proteomics and Bioinformatics, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- CWRU-Cleveland VAMC Center for Antimicrobial Resistance and Epidemiology (Case VA CARES) Cleveland, Ohio, United States of America
| | - Pavel P. Khil
- Bacterial Pathogenesis and Antimicrobial Resistance Unit, LCIM, NIAID, NIH, Bethesda, Maryland, United States of America
- Dept. Laboratory Medicine, NIH Clinical Center, NIH, Bethesda, Maryland, United States of America
| | - John P. Dekker
- Bacterial Pathogenesis and Antimicrobial Resistance Unit, LCIM, NIAID, NIH, Bethesda, Maryland, United States of America
- Dept. Laboratory Medicine, NIH Clinical Center, NIH, Bethesda, Maryland, United States of America
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Chen X, Ling X, Liu G, Xiao J. Antimicrobial Coating: Tracheal Tube Application. Int J Nanomedicine 2022; 17:1483-1494. [PMID: 35378882 PMCID: PMC8976493 DOI: 10.2147/ijn.s353071] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 03/21/2022] [Indexed: 12/13/2022] Open
Abstract
Ventilator-associated pneumonia (VAP) is a common and serious nosocomial infection in mechanically ventilated patients, increasing mortality, prolonging the patient length of stay, and increasing costs. In recent years, extensive studies on ventilator-associated pneumonia have shown that tracheal intubation plays an essential role in the pathogenesis of VAP, with the primary mechanism being the rapid colonization of the tracheal intubation surface by microbiota. Antibiotics do not combat microbial airway colonization, and antimicrobial coating materials offer new ideas to solve this problem. This paper reviews the current research progress on the role of endotracheal tube (ET) biofilms in the pathogenesis of VAP and antimicrobial coating materials.
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Affiliation(s)
- Xuemeng Chen
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, People’s Republic of China
| | - Xiaomei Ling
- Department of Anesthesiology, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, People’s Republic of China
| | - Gaowang Liu
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, People’s Republic of China
| | - Jinfang Xiao
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, People’s Republic of China
- Correspondence: Jinfang Xiao, Department of Anaesthesiology, Nanfang Hospital, Southern Medical University, Jingxi Street, Guangzhou, 510515, Guangdong, People’s Republic of China, Tel +86 198 6518 2069, Email
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8
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Laborda P, Hernando-Amado S, Martínez JL, Sanz-García F. Antibiotic Resistance in Pseudomonas. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1386:117-143. [DOI: 10.1007/978-3-031-08491-1_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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9
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On YY, Welch M. The methylation-independent mismatch repair machinery in Pseudomonas aeruginosa. MICROBIOLOGY (READING, ENGLAND) 2021; 167. [PMID: 34882086 PMCID: PMC8744996 DOI: 10.1099/mic.0.001120] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Over the last 70 years, we've all gotten used to an Escherichia coli-centric view of the microbial world. However, genomics, as well as the development of improved tools for genetic manipulation in other species, is showing us that other bugs do things differently, and that we cannot simply extrapolate from E. coli to everything else. A particularly good example of this is encountered when considering the mechanism(s) involved in DNA mismatch repair by the opportunistic human pathogen, Pseudomonas aeruginosa (PA). This is a particularly relevant phenotype to examine in PA, since defects in the mismatch repair (MMR) machinery often give rise to the property of hypermutability. This, in turn, is linked with the vertical acquisition of important pathoadaptive traits in the organism, such as antimicrobial resistance. But it turns out that PA lacks some key genes associated with MMR in E. coli, and a closer inspection of what is known (or can be inferred) about the MMR enzymology reveals profound differences compared with other, well-characterized organisms. Here, we review these differences and comment on their biological implications.
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Affiliation(s)
- Yue Yuan On
- Department of Biochemistry, Hopkins Building, Tennis Court Road, Downing Site, University of Cambridge, Cambridge, CB2 1QW, UK
| | - Martin Welch
- Department of Biochemistry, Hopkins Building, Tennis Court Road, Downing Site, University of Cambridge, Cambridge, CB2 1QW, UK
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10
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Antimicrobial Resistance and Inorganic Nanoparticles. Int J Mol Sci 2021; 22:ijms222312890. [PMID: 34884695 PMCID: PMC8657868 DOI: 10.3390/ijms222312890] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/16/2021] [Accepted: 11/17/2021] [Indexed: 01/10/2023] Open
Abstract
Antibiotics are being less effective, which leads to high mortality in patients with infections and a high cost for the recovery of health, and the projections that are had for the future are not very encouraging which has led to consider antimicrobial resistance as a global health problem and to be the object of study by researchers. Although resistance to antibiotics occurs naturally, its appearance and spread have been increasing rapidly due to the inappropriate use of antibiotics in recent decades. A bacterium becomes resistant due to the transfer of genes encoding antibiotic resistance. Bacteria constantly mutate; therefore, their defense mechanisms mutate, as well. Nanotechnology plays a key role in antimicrobial resistance due to materials modified at the nanometer scale, allowing large numbers of molecules to assemble to have a dynamic interface. These nanomaterials act as carriers, and their design is mainly focused on introducing the temporal and spatial release of the payload of antibiotics. In addition, they generate new antimicrobial modalities for the bacteria, which are not capable of protecting themselves. So, nanoparticles are an adjunct mechanism to improve drug potency by reducing overall antibiotic exposure. These nanostructures can overcome cell barriers and deliver antibiotics to the cytoplasm to inhibit bacteria. This work aims to give a general vision between the antibiotics, the nanoparticles used as carriers, bacteria resistance, and the possible mechanisms that occur between them.
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11
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Wardell SJT, Gauthier J, Martin LW, Potvin M, Brockway B, Levesque RC, Lamont IL. Genome evolution drives transcriptomic and phenotypic adaptation in Pseudomonas aeruginosa during 20 years of infection. Microb Genom 2021; 7. [PMID: 34826267 PMCID: PMC8743555 DOI: 10.1099/mgen.0.000681] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The opportunistic pathogen Pseudomonas aeruginosa chronically infects the lungs of patients with cystic fibrosis (CF). During infection the bacteria evolve and adapt to the lung environment. Here we use genomic, transcriptomic and phenotypic approaches to compare multiple isolates of P. aeruginosa collected more than 20 years apart during a chronic infection in a CF patient. Complete genome sequencing of the isolates, using short- and long-read technologies, showed that a genetic bottleneck occurred during infection and was followed by diversification of the bacteria. A 125 kb deletion, an 0.9 Mb inversion and hundreds of smaller mutations occurred during evolution of the bacteria in the lung, with an average rate of 17 mutations per year. Many of the mutated genes are associated with infection or antibiotic resistance. RNA sequencing was used to compare the transcriptomes of an earlier and a later isolate. Substantial reprogramming of the transcriptional network had occurred, affecting multiple genes that contribute to continuing infection. Changes included greatly reduced expression of flagellar machinery and increased expression of genes for nutrient acquisition and biofilm formation, as well as altered expression of a large number of genes of unknown function. Phenotypic studies showed that most later isolates had increased cell adherence and antibiotic resistance, reduced motility, and reduced production of pyoverdine (an iron-scavenging siderophore), consistent with genomic and transcriptomic data. The approach of integrating genomic, transcriptomic and phenotypic analyses reveals, and helps to explain, the plethora of changes that P. aeruginosa undergoes to enable it to adapt to the environment of the CF lung during a chronic infection.
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Affiliation(s)
| | - Jeff Gauthier
- Institut de biologie intégrative et des Systèmes, Université Laval, Québec, Canada
| | - Lois W Martin
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Marianne Potvin
- Institut de biologie intégrative et des Systèmes, Université Laval, Québec, Canada
| | - Ben Brockway
- Department of Medicine, University of Otago, Dunedin, New Zealand
| | - Roger C Levesque
- Institut de biologie intégrative et des Systèmes, Université Laval, Québec, Canada
| | - Iain L Lamont
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
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Oxidative Stress Response in Pseudomonas aeruginosa. Pathogens 2021; 10:pathogens10091187. [PMID: 34578219 PMCID: PMC8466533 DOI: 10.3390/pathogens10091187] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 09/06/2021] [Accepted: 09/08/2021] [Indexed: 12/17/2022] Open
Abstract
Pseudomonas aeruginosa is a Gram-negative environmental and human opportunistic pathogen highly adapted to many different environmental conditions. It can cause a wide range of serious infections, including wounds, lungs, the urinary tract, and systemic infections. The high versatility and pathogenicity of this bacterium is attributed to its genomic complexity, the expression of several virulence factors, and its intrinsic resistance to various antimicrobials. However, to thrive and establish infection, P. aeruginosa must overcome several barriers. One of these barriers is the presence of oxidizing agents (e.g., hydrogen peroxide, superoxide, and hypochlorous acid) produced by the host immune system or that are commonly used as disinfectants in a variety of different environments including hospitals. These agents damage several cellular molecules and can cause cell death. Therefore, bacteria adapt to these harsh conditions by altering gene expression and eliciting several stress responses to survive under oxidative stress. Here, we used PubMed to evaluate the current knowledge on the oxidative stress responses adopted by P. aeruginosa. We will describe the genes that are often differently expressed under oxidative stress conditions, the pathways and proteins employed to sense and respond to oxidative stress, and how these changes in gene expression influence pathogenicity and the virulence of P. aeruginosa. Understanding these responses and changes in gene expression is critical to controlling bacterial pathogenicity and developing new therapeutic agents.
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14
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Chakravarty S, Ramos-Hegazy L, Gasparovic A, Anderson GG. DNA alternate polymerase PolB mediates inhibition of type III secretion in Pseudomonas aeruginosa. Microbes Infect 2020; 23:104777. [PMID: 33276123 DOI: 10.1016/j.micinf.2020.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 11/10/2020] [Accepted: 11/13/2020] [Indexed: 10/22/2022]
Abstract
Opportunistic pathogen Pseudomonas aeruginosa uses a variety of virulence factors to cause acute and chronic infections. We previously found that alternate DNA polymerase gene polB inhibits P. aeruginosa pyocyanin production. We investigated whether polB also affects T3SS expression. polB overexpression significantly reduced T3SS transcription and repressed translation of the master T3SS regulator ExsA, while not affecting exsA mRNA transcript abundance. Further, polB does not act through previously described genetic pathways that post-transcriptionally regulate ExsA. Our results show a novel T3SS regulatory component which may lead to development of future drugs to target this mechanism.
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Affiliation(s)
- Shubham Chakravarty
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN, USA
| | - Layla Ramos-Hegazy
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN, USA
| | - Abigail Gasparovic
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN, USA
| | - Gregory G Anderson
- Department of Biology, Indiana University Purdue University Indianapolis, Indianapolis, IN, USA.
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15
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Mechetin GV, Endutkin AV, Diatlova EA, Zharkov DO. Inhibitors of DNA Glycosylases as Prospective Drugs. Int J Mol Sci 2020; 21:ijms21093118. [PMID: 32354123 PMCID: PMC7247160 DOI: 10.3390/ijms21093118] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 04/24/2020] [Accepted: 04/27/2020] [Indexed: 12/22/2022] Open
Abstract
DNA glycosylases are enzymes that initiate the base excision repair pathway, a major biochemical process that protects the genomes of all living organisms from intrinsically and environmentally inflicted damage. Recently, base excision repair inhibition proved to be a viable strategy for the therapy of tumors that have lost alternative repair pathways, such as BRCA-deficient cancers sensitive to poly(ADP-ribose)polymerase inhibition. However, drugs targeting DNA glycosylases are still in development and so far have not advanced to clinical trials. In this review, we cover the attempts to validate DNA glycosylases as suitable targets for inhibition in the pharmacological treatment of cancer, neurodegenerative diseases, chronic inflammation, bacterial and viral infections. We discuss the glycosylase inhibitors described so far and survey the advances in the assays for DNA glycosylase reactions that may be used to screen pharmacological libraries for new active compounds.
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Affiliation(s)
- Grigory V. Mechetin
- SB RAS Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentieva Ave., 630090 Novosibirsk, Russia; (G.V.M.); (A.V.E.); (E.A.D.)
| | - Anton V. Endutkin
- SB RAS Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentieva Ave., 630090 Novosibirsk, Russia; (G.V.M.); (A.V.E.); (E.A.D.)
| | - Evgeniia A. Diatlova
- SB RAS Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentieva Ave., 630090 Novosibirsk, Russia; (G.V.M.); (A.V.E.); (E.A.D.)
| | - Dmitry O. Zharkov
- SB RAS Institute of Chemical Biology and Fundamental Medicine, 8 Lavrentieva Ave., 630090 Novosibirsk, Russia; (G.V.M.); (A.V.E.); (E.A.D.)
- Novosibirsk State University, 2 Pirogova St., 630090 Novosibirsk, Russia
- Correspondence: ; Tel.: +7-383-363-5187
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16
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Sanz-García F, Sánchez MB, Hernando-Amado S, Martínez JL. Evolutionary landscapes of Pseudomonas aeruginosa towards ribosome-targeting antibiotic resistance depend on selection strength. Int J Antimicrob Agents 2020; 55:105965. [PMID: 32325206 DOI: 10.1016/j.ijantimicag.2020.105965] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 02/21/2020] [Accepted: 03/29/2020] [Indexed: 02/08/2023]
Abstract
It is generally accepted that antibiotic-resistant mutants are selected in a range of concentrations ranging from the minimum inhibitory concentration (MIC) to the mutant preventive concentration. More recently, it has been found that antibiotic-resistant mutants can also be selected at concentrations below MIC, which expands the conditions where this selection may occur. Using experimental evolution approaches followed by whole-genome sequencing, the current study compares the evolutionary trajectories of Pseudomonas aeruginosa in the presence of tobramycin or tigecycline at lethal and sublethal concentrations. Mutants were selected at sublethal concentrations of tigecycline (1/10 and 1/50 MIC), whereas no mutants were selected in the case of tobramycin, indicating that the width of sub-MIC selective windows is antibiotic-specific. In addition, the patterns of evolution towards tigecycline resistance depend on selection strength. Sublethal concentrations of tigecycline select mutants with lower tigecycline MICs and higher MICs to other antibiotics belonging to different structural families than mutants selected under lethal concentrations. This indicates that the strength of the cross-resistance phenotype associated with tigecycline resistance is decoupled from selection strength. Accurate information on the sublethal selection window for each antibiotic of clinical value, including the phenotypes of cross-resistance of mutants selected at each antibiotic concentration, is needed to understand the role of ecosystems polluted with different antibiotic concentrations in the selection of antibiotic resistance. Integration of this information into clinical and environmental safety controls may help to tackle the problem of antibiotic resistance.
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Affiliation(s)
| | - María Blanca Sánchez
- Madrid Institute for Advanced Studies of Water (IMDEA Water Institute), Alcalá de Henares, Madrid, Spain
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17
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Fernández-Silva FS, Schulz ML, Alves IR, Freitas RR, da Rocha RP, Lopes-Kulishev CO, Medeiros MHG, Galhardo RS. Contribution of GO System Glycosylases to Mutation Prevention in Caulobacter crescentus. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:246-255. [PMID: 31569269 DOI: 10.1002/em.22335] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 08/29/2019] [Accepted: 09/12/2019] [Indexed: 06/10/2023]
Abstract
8-oxo-7,8-dihydroguanine, commonly referred to as 8-oxoG, is considered one of the most predominant oxidative lesions formed in DNA. Due to its ability to pair with adenines in its syn configuration, this lesion has a strong mutagenic potential in both eukaryotes and prokaryotes. Escherichia coli cells are endowed with the GO system, which protects them from the mutagenic properties of this lesion when formed both in cellular DNA and the nucleotide pool. MutY and MutM (Fpg) DNA glycosylases are crucial components of the GO system. A strong mutator phenotype of the Escherichia coli mutM mutY double mutant underscores the importance of 8-oxoG repair for genomic stability. Here, we report that in Caulobacter crescentus, a widely studied alpha-proteobacterium with a GC-rich genome, the combined lack of MutM and MutY glycosylases produces a more modest mutator phenotype when compared to E. coli. Genetic analysis indicates that other glycosylases and other repair pathways do not act synergistically with the GO system for spontaneous mutation prevention. We also show that there is not a statistically significant difference in the spontaneous levels 8-oxodGuo in E. coli and C. crescentus, suggesting that other yet to be identified differences in repair or replication probably account for the differential importance of the GO system between these two species. Environ. Mol. Mutagen. 61:246-255, 2020. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Frank S Fernández-Silva
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Mariane L Schulz
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, SP, Brazil
| | - Ingrid Reale Alves
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Rubia R Freitas
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Raquel Paes da Rocha
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Carina O Lopes-Kulishev
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Marisa H G Medeiros
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, SP, Brazil
| | - Rodrigo S Galhardo
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
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18
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Sim JXF, Khazandi M, Pi H, Venter H, Trott DJ, Deo P. Antimicrobial effects of cinnamon essential oil and cinnamaldehyde combined with EDTA against canine otitis externa pathogens. J Appl Microbiol 2019; 127:99-108. [PMID: 31050849 DOI: 10.1111/jam.14298] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 04/25/2019] [Accepted: 04/28/2019] [Indexed: 12/27/2022]
Abstract
AIMS The antimicrobial activity of cinnamon essential oil and cinnamaldehyde against bacterial and fungal pathogens associated with canine otitis externa, as well as the effect of their combination with EDTA were investigated. METHODS AND RESULTS Antimicrobial susceptibility testing was performed using the broth microdilution method while spot-plating technique was used to determine their bactericidal activity. Time-kill kinetics and checkerboard assays were performed to confirm the bactericidal activity and combination effects of the compounds. Cinnamon oil and cinnamaldehyde exhibited antimicrobial activity against Gram-positive and Gram-negative pathogens, as well as Malassezia pachydermatis. Synergistic interaction was shown when EDTA (672 μg ml-1 ) was combined with cinnamon oil (41 μg ml-1 ) and cinnamaldehyde (22 μg ml-1 ) against Pseudomonas aeruginosa. Cinnamaldehyde exhibited significantly stronger antimicrobial activity than cinnamon bark oil. CONCLUSIONS Cinnamon essential oil and cinnamaldehyde, either used alone or in combination with EDTA, were effective against the causative micro-organisms of canine otitis externa. The data suggest that cinnamaldehyde could be a promising antimicrobial agent against canine otitis externa. SIGNIFICANCE AND IMPACT OF THE STUDY This study shows that cinnamon essential oil and cinnamaldehyde, especially the latter, could be used in combination with EDTA as novel treatment for sensitive and resistant bacterial and fungal pathogens involved in canine otitis externa.
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Affiliation(s)
- J X F Sim
- School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, Australia
| | - M Khazandi
- School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, Australia.,Australian Centre for Antimicrobial Resistance Ecology, School of Animal and Veterinary Sciences, The University of Adelaide, Adelaide, SA, Australia
| | - H Pi
- Australian Centre for Antimicrobial Resistance Ecology, School of Animal and Veterinary Sciences, The University of Adelaide, Adelaide, SA, Australia
| | - H Venter
- School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, Australia
| | - D J Trott
- Australian Centre for Antimicrobial Resistance Ecology, School of Animal and Veterinary Sciences, The University of Adelaide, Adelaide, SA, Australia
| | - P Deo
- School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA, Australia
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19
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Rees VE, Deveson Lucas DS, López-Causapé C, Huang Y, Kotsimbos T, Bulitta JB, Rees MC, Barugahare A, Peleg AY, Nation RL, Oliver A, Boyce JD, Landersdorfer CB. Characterization of Hypermutator Pseudomonas aeruginosa Isolates from Patients with Cystic Fibrosis in Australia. Antimicrob Agents Chemother 2019; 63:e02538-18. [PMID: 30745381 PMCID: PMC6437500 DOI: 10.1128/aac.02538-18] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Accepted: 01/27/2019] [Indexed: 12/22/2022] Open
Abstract
Hypermutable Pseudomonas aeruginosa isolates (hypermutators) have been identified in patients with cystic fibrosis (CF) and are associated with reduced lung function. Hypermutators display a greatly increased mutation rate and an enhanced ability to become resistant to antibiotics during treatment. Their prevalence has been established among patients with CF, but it has not been determined for patients with CF in Australia. This study aimed to determine the prevalence of hypermutable P. aeruginosa isolates from adult patients with CF from a health care institution in Australia and to characterize the genetic diversity and antibiotic susceptibility of these isolates. A total of 59 P. aeruginosa clinical isolates from patients with CF were characterized. For all isolates, rifampin (RIF) mutation frequencies and susceptibility to a range of antibiotics were determined. Of the 59 isolates, 13 (22%) were hypermutable. Whole-genome sequences were determined for all hypermutable isolates. Core genome polymorphisms were used to assess genetic relatedness of the isolates, both to each other and to a sample of previously characterized P. aeruginosa strains. Phylogenetic analyses showed that the hypermutators were from divergent lineages and that hypermutator phenotype was mostly the result of mutations in mutL or, less commonly, in mutS Hypermutable isolates also contained a range of mutations that are likely associated with adaptation of P. aeruginosa to the CF lung environment. Multidrug resistance was more prevalent in hypermutable than nonhypermutable isolates (38% versus 22%). This study revealed that hypermutable P. aeruginosa strains are common among isolates from patients with CF in Australia and are implicated in the emergence of antibiotic resistance.
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Affiliation(s)
- Vanessa E Rees
- Centre for Medicine Use and Safety, Faculty of Pharmacy and Pharmaceutical Sciences, Monash University (Parkville Campus), Parkville, Victoria, Australia
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville Campus), Parkville, Victoria, Australia
| | - Deanna S Deveson Lucas
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne, Australia
| | - Carla López-Causapé
- Servicio de Microbiología, Hospital Universitario Son Espases, Instituto de Investigación Sanitaria de Palma, Palma de Mallorca, Spain
| | - Yuling Huang
- Centre for Medicine Use and Safety, Faculty of Pharmacy and Pharmaceutical Sciences, Monash University (Parkville Campus), Parkville, Victoria, Australia
| | - Tom Kotsimbos
- Allergy, Immunology and Respiratory Medicine Department, Monash University, Melbourne, Victoria, Australia
| | - Jürgen B Bulitta
- Center for Pharmacometrics and Systems Pharmacology, College of Pharmacy, University of Florida, Florida, USA
| | | | - Adele Barugahare
- Monash Bioinformatics Platform, Monash University, Clayton, Victoria, Australia
| | - Anton Y Peleg
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne, Australia
- Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Australia
| | - Roger L Nation
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville Campus), Parkville, Victoria, Australia
| | - Antonio Oliver
- Servicio de Microbiología, Hospital Universitario Son Espases, Instituto de Investigación Sanitaria de Palma, Palma de Mallorca, Spain
| | - John D Boyce
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Melbourne, Australia
| | - Cornelia B Landersdorfer
- Centre for Medicine Use and Safety, Faculty of Pharmacy and Pharmaceutical Sciences, Monash University (Parkville Campus), Parkville, Victoria, Australia
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville Campus), Parkville, Victoria, Australia
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20
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Pang Z, Raudonis R, Glick BR, Lin TJ, Cheng Z. Antibiotic resistance in Pseudomonas aeruginosa: mechanisms and alternative therapeutic strategies. Biotechnol Adv 2018; 37:177-192. [PMID: 30500353 DOI: 10.1016/j.biotechadv.2018.11.013] [Citation(s) in RCA: 942] [Impact Index Per Article: 157.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 11/21/2018] [Accepted: 11/24/2018] [Indexed: 01/09/2023]
Abstract
Pseudomonas aeruginosa is an opportunistic pathogen that is a leading cause of morbidity and mortality in cystic fibrosis patients and immunocompromised individuals. Eradication of P. aeruginosa has become increasingly difficult due to its remarkable capacity to resist antibiotics. Strains of Pseudomonas aeruginosa are known to utilize their high levels of intrinsic and acquired resistance mechanisms to counter most antibiotics. In addition, adaptive antibiotic resistance of P. aeruginosa is a recently characterized mechanism, which includes biofilm-mediated resistance and formation of multidrug-tolerant persister cells, and is responsible for recalcitrance and relapse of infections. The discovery and development of alternative therapeutic strategies that present novel avenues against P. aeruginosa infections are increasingly demanded and gaining more and more attention. Although mostly at the preclinical stages, many recent studies have reported several innovative therapeutic technologies that have demonstrated pronounced effectiveness in fighting against drug-resistant P. aeruginosa strains. This review highlights the mechanisms of antibiotic resistance in P. aeruginosa and discusses the current state of some novel therapeutic approaches for treatment of P. aeruginosa infections that can be further explored in clinical practice.
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Affiliation(s)
- Zheng Pang
- Department of Pathology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Renee Raudonis
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Bernard R Glick
- Department of Biology, University of Waterloo, Waterloo, ON N2L 3G1, Canada
| | - Tong-Jun Lin
- Department of Pathology, Dalhousie University, Halifax, NS B3H 4R2, Canada; Department of Microbiology and Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada; Department of Pediatrics, IWK Health Centre, Halifax, NS B3K 6R8, Canada
| | - Zhenyu Cheng
- Department of Pathology, Dalhousie University, Halifax, NS B3H 4R2, Canada; Department of Microbiology and Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada.
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21
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Hall CW, Mah TF. Molecular mechanisms of biofilm-based antibiotic resistance and tolerance in pathogenic bacteria. FEMS Microbiol Rev 2018; 41:276-301. [PMID: 28369412 DOI: 10.1093/femsre/fux010] [Citation(s) in RCA: 849] [Impact Index Per Article: 141.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 02/22/2017] [Indexed: 02/06/2023] Open
Abstract
Biofilms are surface-attached groups of microbial cells encased in an extracellular matrix that are significantly less susceptible to antimicrobial agents than non-adherent, planktonic cells. Biofilm-based infections are, as a result, extremely difficult to cure. A wide range of molecular mechanisms contribute to the high degree of recalcitrance that is characteristic of biofilm communities. These mechanisms include, among others, interaction of antimicrobials with biofilm matrix components, reduced growth rates and the various actions of specific genetic determinants of antibiotic resistance and tolerance. Alone, each of these mechanisms only partially accounts for the increased antimicrobial recalcitrance observed in biofilms. Acting in concert, however, these defences help to ensure the survival of biofilm cells in the face of even the most aggressive antimicrobial treatment regimens. This review summarises both historical and recent scientific data in support of the known biofilm resistance and tolerance mechanisms. Additionally, suggestions for future work in the field are provided.
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22
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Chua SL, Ding Y, Liu Y, Cai Z, Zhou J, Swarup S, Drautz-Moses DI, Schuster SC, Kjelleberg S, Givskov M, Yang L. Reactive oxygen species drive evolution of pro-biofilm variants in pathogens by modulating cyclic-di-GMP levels. Open Biol 2017; 6:rsob.160162. [PMID: 27881736 PMCID: PMC5133437 DOI: 10.1098/rsob.160162] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 10/23/2016] [Indexed: 12/14/2022] Open
Abstract
The host immune system offers a hostile environment with antimicrobials and reactive oxygen species (ROS) that are detrimental to bacterial pathogens, forcing them to adapt and evolve for survival. However, the contribution of oxidative stress to pathogen evolution remains elusive. Using an experimental evolution strategy, we show that exposure of the opportunistic pathogen Pseudomonas aeruginosa to sub-lethal hydrogen peroxide (H2O2) levels over 120 generations led to the emergence of pro-biofilm rough small colony variants (RSCVs), which could be abrogated by l-glutathione antioxidants. Comparative genomic analysis of the RSCVs revealed that mutations in the wspF gene, which encodes for a repressor of WspR diguanylate cyclase (DGC), were responsible for increased intracellular cyclic-di-GMP content and production of Psl exopolysaccharide. Psl provides the first line of defence against ROS and macrophages, ensuring the survival fitness of RSCVs over wild-type P. aeruginosa Our study demonstrated that ROS is an essential driving force for the selection of pro-biofilm forming pathogenic variants. Understanding the fundamental mechanism of these genotypic and phenotypic adaptations will improve treatment strategies for combating chronic infections.
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Affiliation(s)
- Song Lin Chua
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 639798 .,Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore 637551
| | - Yichen Ding
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore 637551.,Interdisciplinary Graduate School, Nanyang Technological University, Singapore 637551
| | - Yang Liu
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore 637551
| | - Zhao Cai
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore 637551.,Interdisciplinary Graduate School, Nanyang Technological University, Singapore 637551
| | - Jianuan Zhou
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore 637551.,Integrative Microbiology Research Centre, South China Agricultural University, Guangzhou 510642, People's Republic of China
| | - Sanjay Swarup
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore 637551.,Department of Biological Sciences, National University of Singapore, Singapore 117543.,NUS Environmental Research Institute, National University of Singapore, Singapore
| | - Daniela I Drautz-Moses
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore 637551
| | - Stephan Christoph Schuster
- School of Biological Sciences, Nanyang Technological University, Singapore 639798.,Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore 637551
| | - Staffan Kjelleberg
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore 637551.,Center for Marine Bio-Innovation and School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney 2052, Australia
| | - Michael Givskov
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore 637551.,Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, 2200 København N, Denmark
| | - Liang Yang
- School of Biological Sciences, Nanyang Technological University, Singapore 639798 .,Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore 637551
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23
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Chang RY, Wong J, Mathai A, Morales S, Kutter E, Britton W, Li J, Chan HK. Production of highly stable spray dried phage formulations for treatment of Pseudomonas aeruginosa lung infection. Eur J Pharm Biopharm 2017; 121:1-13. [PMID: 28890220 DOI: 10.1016/j.ejpb.2017.09.002] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 09/05/2017] [Accepted: 09/06/2017] [Indexed: 01/16/2023]
Abstract
The potential of bacteriophage therapy for the treatment of pulmonary infections caused by antibiotic-resistant bacteria has been well recognised. The purpose of this study was to investigate the effect of excipients on stabilisation and aerosolisation of spray dried powders of morphologically different phages - PEV podovirus and PEV myovirus. Seven anti-pseudomonal phages were screened against 90 clinical strains of bacterial hosts and three of the phages were selected for formulation study based on the host range. Design of experiments was utilised to assess the effect of different excipients on the stabilisation and aerosolisation of spray dried phages. Both podovirus and myovirus phages were stable in spray dried formulations containing trehalose or lactose and leucine as excipients with less than 1-log10 titre reduction during spray drying, with lactose providing superior phage protection over trehalose. Furthermore, the spray dried phage formulations dispersed in an Osmohaler at 85L/min produced a high fine particle fraction of over 50%. The results showed that the phages in this study can form respirable dry powder phage formulations using the same excipient composition. Spray dried various types of lytic phages hold significant potential for the treatment of pulmonary infections.
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Affiliation(s)
- Rachel Y Chang
- Faculty of Pharmacy, University of Sydney, Sydney, NSW 2006, Australia
| | - Jennifer Wong
- Faculty of Pharmacy, University of Sydney, Sydney, NSW 2006, Australia
| | - Ash Mathai
- Faculty of Pharmacy, University of Sydney, Sydney, NSW 2006, Australia
| | - Sandra Morales
- AmpliPhi Biosciences AU, 7/27 Dale Street, Brookvale, Sydney, NSW 2100, Australia
| | | | - Warwick Britton
- Centenary Institute of Cancer Medicine and Cell Biology, Royal Prince Alfred Hospital, Sydney, Australia
| | - Jian Li
- Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Victoria 3800, Australia
| | - Hak-Kim Chan
- Faculty of Pharmacy, University of Sydney, Sydney, NSW 2006, Australia.
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24
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Sadiq FA, Flint S, Li Y, Ou K, Yuan L, He GQ. Phenotypic and genetic heterogeneity within biofilms with particular emphasis on persistence and antimicrobial tolerance. Future Microbiol 2017; 12:1087-1107. [DOI: 10.2217/fmb-2017-0042] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Phenotypic changes or phase variation within biofilms is an important feature of bacterial dormant life. Enhanced resistance to antimicrobials is one of the distinct features displayed by a fraction of cells within biofilms. It is believed that persisters are mainly responsible for this phenotypic heterogeneity. However, there is still an unresolved debate on the formation of persisters. In this short review, we highlight all known genomic and proteomic changes encountered by bacterial cells within biofilms. We have also described all phenotypic changes displayed by bacterial cells within biofilms with particular emphasis on enhanced antimicrobial tolerance of biofilms with particular reference to persisters. In addition, all currently known models of persistence have been succinctly discussed.
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Affiliation(s)
- Faizan A Sadiq
- College of Biosystems Engineering & Food Science, Zhejiang University, Hangzhou 310058, China
| | - Steve Flint
- School of Food & Nutrition, Massey University, Private Bag 11 222, Palmerston North 4474, New Zealand
| | - YanJun Li
- Research Institute of Food Science, Hangzhou Wahaha Group Co, Ltd, Hangzhou 310018, China
| | - Kai Ou
- Research Institute of Food Science, Hangzhou Wahaha Group Co, Ltd, Hangzhou 310018, China
| | - Lei Yuan
- College of Biosystems Engineering & Food Science, Zhejiang University, Hangzhou 310058, China
| | - Guo Qing He
- College of Biosystems Engineering & Food Science, Zhejiang University, Hangzhou 310058, China
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25
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Stefani S, Campana S, Cariani L, Carnovale V, Colombo C, Lleo MM, Iula VD, Minicucci L, Morelli P, Pizzamiglio G, Taccetti G. Relevance of multidrug-resistant Pseudomonas aeruginosa infections in cystic fibrosis. Int J Med Microbiol 2017; 307:353-362. [PMID: 28754426 DOI: 10.1016/j.ijmm.2017.07.004] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 07/13/2017] [Accepted: 07/14/2017] [Indexed: 01/15/2023] Open
Abstract
Multidrug-resistant (MDR) Pseudomonas aeruginosa is an important issue for physicians who take care of patients with cystic fibrosis (CF). Here, we review the latest research on how P. aeruginosa infection causes lung function to decline and how several factors contribute to the emergence of antibiotic resistance in P. aeruginosa strains and influence the course of the infection course. However, many aspects of the practical management of patients with CF infected with MDR P. aeruginosa are still to be established. Less is known about the exact role of susceptibility testing in clinical strategies for dealing with resistant infections, and there is an urgent need to find a tool to assist in choosing the best therapeutic strategy for MDR P. aeruginosa infection. One current perception is that the selection of antibiotic therapy according to antibiogram results is an important component of the decision-making process, but other patient factors, such as previous infection history and antibiotic courses, also need to be evaluated. On the basis of the known issues and the best current data on respiratory infections caused by MDR P. aeruginosa, this review provides practical suggestions to optimize the diagnostic and therapeutic management of patients with CF who are infected with these pathogens.
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Affiliation(s)
- S Stefani
- Department of Biomedical and Biotechnological Sciences, Division of Microbiology, University of Catania, Catania, Italy.
| | - S Campana
- Department of Paediatric Medicine, Cystic Fibrosis Centre, Anna Meyer Children's University Hospital, Florence, Italy
| | - L Cariani
- Cystic Fibrosis Microbiology Laboratory, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - V Carnovale
- Department of Translational Medical Sciences, Cystic Fibrosis Center, University "Federico II", Naples, Italy
| | - C Colombo
- Cystic Fibrosis Center, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
| | - M M Lleo
- Department of Diagnostics and Public Health, University of Verona, Verona, Italy
| | - V D Iula
- Department of Molecular Medicine and Medical Biotechnology, Federico II University Medical School, Naples, Italy
| | - L Minicucci
- Microbiology Laboratory, Cystic Fibrosis Center, G. Gaslini Institute, Genoa, Italy
| | - P Morelli
- Department of Paediatric, Cystic Fibrosis Center, G. Gaslini Institute, Genoa, Italy
| | - G Pizzamiglio
- Respiratory Disease Department, Cystic Fibrosis Center Adult Section, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico Milano, Milan, Italy
| | - G Taccetti
- Department of Paediatric Medicine, Cystic Fibrosis Centre, Anna Meyer Children's University Hospital, Florence, Italy
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Kao WK, Gagnon PM, Vogel JP, Chole RA. Surface charge modification decreases Pseudomonas aeruginosa adherence in vitro and bacterial persistence in an in vivo implant model. Laryngoscope 2017; 127:1655-1661. [PMID: 28295372 PMCID: PMC5476480 DOI: 10.1002/lary.26499] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2016] [Revised: 11/30/2016] [Accepted: 12/23/2016] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Chronic, persistent infections complicate otologic procedures utilizing implantable devices such as cochlear implants or tympanostomy tubes. These infections are thought to be due to the establishment of microbial biofilms on implant surfaces. To address this issue, we hypothesized that surface charge modification may inhibit the formation of Pseudomonas aeruginosa biofilms on implant surfaces in vitro and in vivo. STUDY DESIGN We evaluated the effect of surface charge modification on bacterial biofilm formation by assessing the effect of the surface charge on bacterial adhesion in vitro and bacterial persistence in vivo. METHODS To study the effect of surface charge in vitro, the surface wells in culture plates were modified using a layer-by-layer polyelectrolyte assembly method. Bacterial adherence was measured at 30-, 60-, and 120-minute intervals. To study the effect of surface charge modification in vivo, the surface of titanium microscrews was similarly modified and then surgically implanted into the dorsal calvaria of adult rats and inoculated with bacteria. Two weeks after implantation and inoculation, the number of bacteria remaining in vivo was evaluated. RESULTS Surface charge modification results in a significant decrease in adherence of bacteria in vitro. Surface charge modification of titanium microscrew implants also resulted in a significant decrease in P. aeruginosa recovered 2 weeks after surgical implantation. CONCLUSION Charge modification decreases the number of bacteria adherent to a surface in vitro and decreases the risk and severity of implant infection in an in vivo rat infection model. These results have promising biomedical applications. LEVEL OF EVIDENCE NA. Laryngoscope, 127:1655-1661, 2017.
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Affiliation(s)
- W Katherine Kao
- Department of Otolaryngology, Washington University in St. Louis School of Medicine, St. Louis, Missouri, U.S.A
| | - Patricia M Gagnon
- Department of Otolaryngology, Washington University in St. Louis School of Medicine, St. Louis, Missouri, U.S.A
| | - Joseph P Vogel
- Department of Molecular Microbiology, Washington University in St. Louis School of Medicine, St. Louis, Missouri, U.S.A
| | - Richard A Chole
- Department of Otolaryngology, Washington University in St. Louis School of Medicine, St. Louis, Missouri, U.S.A
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27
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Ciofu O, Rojo-Molinero E, Macià MD, Oliver A. Antibiotic treatment of biofilm infections. APMIS 2017; 125:304-319. [PMID: 28407419 DOI: 10.1111/apm.12673] [Citation(s) in RCA: 237] [Impact Index Per Article: 33.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Accepted: 01/10/2017] [Indexed: 12/24/2022]
Abstract
Bacterial biofilms are associated with a wide range of infections, from those related to exogenous devices, such as catheters or prosthetic joints, to chronic tissue infections such as those occurring in the lungs of cystic fibrosis patients. Biofilms are recalcitrant to antibiotic treatment due to multiple tolerance mechanisms (phenotypic resistance). This causes persistence of biofilm infections in spite of antibiotic exposure which predisposes to antibiotic resistance development (genetic resistance). Understanding the interplay between phenotypic and genetic resistance mechanisms acting on biofilms, as well as appreciating the diversity of environmental conditions of biofilm infections which influence the effect of antibiotics are required in order to optimize the antibiotic treatment of biofilm infections. Here, we review the current knowledge on phenotypic and genetic resistance in biofilms and describe the potential strategies for the antibiotic treatment of biofilm infections. Of note is the optimization of PK/PD parameters in biofilms, high-dose topical treatments, combined and sequential/alternate therapies or the use antibiotic adjuvants.
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Affiliation(s)
- Oana Ciofu
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, Costerton Biofilm Center, University of Copenhagen, Copenhagen, Denmark
| | - Estrella Rojo-Molinero
- Servicio de Microbiología, Hospital Son Espases, Instituto de Investigación Sanitaria de Palma (IdISPa), Palma de Mallorca, Spain
| | - María D Macià
- Servicio de Microbiología, Hospital Son Espases, Instituto de Investigación Sanitaria de Palma (IdISPa), Palma de Mallorca, Spain
| | - Antonio Oliver
- Servicio de Microbiología, Hospital Son Espases, Instituto de Investigación Sanitaria de Palma (IdISPa), Palma de Mallorca, Spain
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28
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Davies EV, James CE, Brockhurst MA, Winstanley C. Evolutionary diversification of Pseudomonas aeruginosa in an artificial sputum model. BMC Microbiol 2017; 17:3. [PMID: 28056789 PMCID: PMC5216580 DOI: 10.1186/s12866-016-0916-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 12/15/2016] [Indexed: 12/20/2022] Open
Abstract
Background During chronic lung infections of cystic fibrosis patients Pseudomonas aeruginosa populations undergo extensive evolutionary diversification. However, the selective drivers of this evolutionary process are poorly understood. To test the effects of temperate phages on diversification in P. aeruginosa biofilms we experimentally evolved populations of P. aeruginosa for approximately 240 generations in artificial sputum medium with or without a community of three temperate phages. Results Analysis of end-point populations using a suite of phenotypic tests revealed extensive phenotypic diversification within populations, but no significant differences between the populations evolved with or without phages. The most common phenotypic variant observed was loss of all three types of motility (swimming, swarming and twitching) and resistance to all three phages. Despite the absence of selective pressure, some members of the population evolved antibiotic resistance. The frequency of antibiotic resistant isolates varied according to population and the antibiotic tested. However, resistance to ceftazidime and tazobactam-piperacillin was observed more frequently than resistance to other antibiotics, and was associated with higher prevelence of isolates exhibiting a hypermutable phenotype and increased beta-lactamase production. Conclusions We observed considerable within-population phenotypic diversity in P. aeruginosa populations evolving in the artificial sputum medium biofilm model. Replicate populations evolved both in the presence and absence of phages converged upon similar sets of phenotypes. The evolved phenotypes, including antimicrobial resistance, were similar to those observed amongst clinical isolates from cystic fibrosis infections. Electronic supplementary material The online version of this article (doi:10.1186/s12866-016-0916-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Emily V Davies
- Institute of Infection and Global Health, University of Liverpool, 8 West Derby Street, Liverpool, L69 7BE, UK
| | - Chloe E James
- Institute of Infection and Global Health, University of Liverpool, 8 West Derby Street, Liverpool, L69 7BE, UK.,School of Environment and Life Sciences, University of Salford, Manchester, M5 4WT, UK
| | | | - Craig Winstanley
- Institute of Infection and Global Health, University of Liverpool, 8 West Derby Street, Liverpool, L69 7BE, UK.
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29
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Ahmed KBA, Raman T, Veerappan A. Future prospects of antibacterial metal nanoparticles as enzyme inhibitor. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2016; 68:939-947. [PMID: 27524096 DOI: 10.1016/j.msec.2016.06.034] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 05/23/2016] [Accepted: 06/09/2016] [Indexed: 12/15/2022]
Abstract
Nanoparticles are being widely used as antibacterial agents with metal nanoparticles emerging as the most efficient antibacterial agents. There have been many studies which have reported the mechanism of antibacterial activity of nanoparticles on bacteria. In this review we aim to emphasize on all the possible mechanisms which are involved in the antibacterial activity of nanoparticles and also to understand their mode of action and role as bacterial enzyme inhibitor by comparing their antibacterial mechanism to that of antibiotics with enzyme inhibition as a major mechanism. With the emergence of widespread antibiotic resistance, nanoparticles offer a better alternative to our conventional arsenal of antibiotics. Once the biological safety of these nanoparticles is addressed, these nanoparticles can be of great medical importance in our fight against bacterial infections.
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Affiliation(s)
- Khan Behlol Ayaz Ahmed
- School of Chemical and Biotechnology, SASTRA University, Thanjavur 613 401, Tamil Nadu, India
| | - Thiagarajan Raman
- School of Chemical and Biotechnology, SASTRA University, Thanjavur 613 401, Tamil Nadu, India.
| | - Anbazhagan Veerappan
- School of Chemical and Biotechnology, SASTRA University, Thanjavur 613 401, Tamil Nadu, India.
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30
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Wassermann T, Meinike Jørgensen K, Ivanyshyn K, Bjarnsholt T, Khademi SMH, Jelsbak L, Høiby N, Ciofu O. The phenotypic evolution of Pseudomonas aeruginosa populations changes in the presence of subinhibitory concentrations of ciprofloxacin. MICROBIOLOGY-SGM 2016; 162:865-875. [PMID: 26953154 DOI: 10.1099/mic.0.000273] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Ciprofloxacin is a widely used antibiotic, in the class of quinolones, for treatment of Pseudomonas aeruginosa infections. The immediate response of P. aeruginosa to subinhibitory concentrations of ciprofloxacin has been investigated previously. However, the long-term phenotypic adaptation, which identifies the fitted phenotypes that have been selected during evolution with subinhibitory concentrations of ciprofloxacin, has not been studied. We chose an experimental evolution approach to investigate how exposure to subinhibitory concentrations of ciprofloxacin changes the evolution of P. aeruginosa populations compared to unexposed populations. Three replicate populations of P. aeruginosa PAO1 and its hypermutable mutant ΔmutS were cultured aerobically for approximately 940 generations by daily passages in LB medium with and without subinhibitory concentration of ciprofloxacin and aliquots of the bacterial populations were regularly sampled and kept at - 80 °C for further investigations. We investigate here phenotypic changes between the ancestor (50 colonies) and evolved populations (120 colonies/strain). Decreased protease activity and swimming motility, higher levels of quorum-sensing signal molecules and occurrence of mutator subpopulations were observed in the ciprofloxacin-exposed populations compared to the ancestor and control populations. Transcriptomic analysis showed downregulation of the type III secretion system in evolved populations compared to the ancestor population and upregulation of denitrification genes in ciprofloxacin-evolved populations. In conclusion, the presence of antibiotics at subinhibitory concentration in the environment affects bacterial evolution and further studies are needed to obtain insight into the dynamics of the phenotypes and the mechanisms involved.
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Affiliation(s)
- Tina Wassermann
- Department of Clinical Microbiology, University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Karin Meinike Jørgensen
- Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Karolina Ivanyshyn
- Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Thomas Bjarnsholt
- Department of Clinical Microbiology, University Hospital Rigshospitalet, Copenhagen, Denmark.,Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - S M Hossein Khademi
- Department of System Biology, Technical University of Denmark, Lyngby, Denmark
| | - Lars Jelsbak
- Department of System Biology, Technical University of Denmark, Lyngby, Denmark
| | - Niels Høiby
- Department of Clinical Microbiology, University Hospital Rigshospitalet, Copenhagen, Denmark.,Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Oana Ciofu
- Department of Immunology and Microbiology, Costerton Biofilm Center, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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31
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Gruber JD, Chen W, Parnham S, Beauchesne K, Moeller P, Flume PA, Zhang YM. The role of 2,4-dihydroxyquinoline (DHQ) in Pseudomonas aeruginosa pathogenicity. PeerJ 2016; 4:e1495. [PMID: 26788419 PMCID: PMC4715436 DOI: 10.7717/peerj.1495] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 11/22/2015] [Indexed: 11/20/2022] Open
Abstract
Bacteria synchronize group behaviors using quorum sensing, which is advantageous during an infection to thwart immune cell attack and resist deleterious changes in the environment. In Pseudomonas aeruginosa, the Pseudomonas quinolone signal (Pqs) quorum-sensing system is an important component of an interconnected intercellular communication network. Two alkylquinolones, 2-heptyl-4-quinolone (HHQ) and 2-heptyl-3-hydroxy-4-quinolone (PQS), activate transcriptional regulator PqsR to promote the production of quinolone signals and virulence factors. Our work focused on the most abundant quinolone produced from the Pqs system, 2,4-dihydroxyquinoline (DHQ), which was shown previously to sustain pyocyanin production and antifungal activity of P. aeruginosa. However, little is known about how DHQ affects P. aeruginosa pathogenicity. Using C. elegans as a model for P. aeruginosa infection, we found pqs mutants only able to produce DHQ maintained virulence towards the nematodes similar to wild-type. In addition, DHQ-only producing mutants displayed increased colonization of C. elegans and virulence factor production compared to a quinolone-null strain. DHQ also bound to PqsR and activated the transcription of pqs operon. More importantly, high extracellular concentration of DHQ was maintained in both aerobic and anaerobic growth. High levels of DHQ were also detected in the sputum samples of cystic fibrosis patients. Taken together, our findings suggest DHQ may play an important role in sustaining P. aeruginosa pathogenicity under oxygen-limiting conditions.
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Affiliation(s)
- Jordon D Gruber
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina , Charleston, SC , United States
| | - Wei Chen
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina , Charleston, SC , United States
| | - Stuart Parnham
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina , Charleston, SC , United States
| | - Kevin Beauchesne
- Natural Products Chemistry, National Ocean Service , Charleston, SC , United States
| | - Peter Moeller
- Natural Products Chemistry, National Ocean Service , Charleston, SC , United States
| | - Patrick A Flume
- Department of Medicine, Medical University of South Carolina , Charleston, SC , United States
| | - Yong-Mei Zhang
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina , Charleston, SC , United States
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32
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Dettman JR, Sztepanacz JL, Kassen R. The properties of spontaneous mutations in the opportunistic pathogen Pseudomonas aeruginosa. BMC Genomics 2016; 17:27. [PMID: 26732503 PMCID: PMC4702332 DOI: 10.1186/s12864-015-2244-3] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 11/25/2015] [Indexed: 12/23/2022] Open
Abstract
Background Natural genetic variation ultimately arises from the process of mutation. Knowledge of how the raw material for evolution is produced is necessary for a full understanding of several fundamental evolutionary concepts. We performed a mutation accumulation experiment with wild-type and mismatch-repair deficient, mutator lines of the pathogenic bacterium Pseudomonas aeruginosa, and used whole-genome sequencing to reveal the genome-wide rate, spectrum, distribution, leading/lagging bias, and context-dependency of spontaneous mutations. Results Wild-type base-pair mutation and indel rates were ~10−10 and ~10−11 per nucleotide per generation, respectively, and deficiencies in the mismatch-repair system caused rates to increase by over two orders of magnitude. A universal bias towards AT was observed in wild-type lines, but was reversed in mutator lines to a bias towards GC. Biases for which types of mutations occurred during replication of the leading versus lagging strand were detected reciprocally in both replichores. The distribution of mutations along the chromosome was non-random, with peaks near the terminus of replication and at positions intermediate to the replication origin and terminus. A similar distribution bias was observed along the chromosome in natural populations of P. aeruginosa. Site-specific mutation rates were higher when the focal nucleotide was immediately flanked by C:G pairings. Conclusions Whole-genome sequencing of mutation accumulation lines allowed the comprehensive identification of mutations and revealed what factors of molecular and genomic architecture affect the mutational process. Our study provides a more complete view of how several mechanisms of mutation, mutation repair, and bias act simultaneously to produce the raw material for evolution. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-2244-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jeremy R Dettman
- Department of Biology and Centre for Advanced Research in Environmental Genomics, University of Ottawa, Ottawa, ON, K1N 6N5, Canada.
| | | | - Rees Kassen
- Department of Biology and Centre for Advanced Research in Environmental Genomics, University of Ottawa, Ottawa, ON, K1N 6N5, Canada.
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33
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Raidt L, Idelevich EA, Dübbers A, Küster P, Drevinek P, Peters G, Kahl BC. Increased Prevalence and Resistance of Important Pathogens Recovered from Respiratory Specimens of Cystic Fibrosis Patients During a Decade. Pediatr Infect Dis J 2015; 34:700-5. [PMID: 25851069 DOI: 10.1097/inf.0000000000000714] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
BACKGROUND The study objective was to identify changes of prevalence and resistance of important pathogens in specimens of cystic fibrosis (CF) patients within a decade. METHODS Samples of 94 patients, who attended 2 CF centers from 2001 to 2011 were retrospectively analyzed. RESULTS Staphylococcus aureus was the most prevalent organism (74.5% in 2011) with an increase of methicillin-resistant S. aureus in patients (0% vs. 9.6%, n = 9). Resistance of S. aureus to gentamicin decreased (41.8% vs. 21%; P < 0.001), whereas resistance to rifampicin and trimethoprim/sulfamethoxazole (P < 0.05) increased significantly with a trend to increased resistance to clindamycin and erythromycin (P = 0.063). Methicillin-resistant S. aureus isolates belonged to 6 spa types (t003, t008, t011, t034, t045, t548). There was a significant increase of Pseudomonas aeruginosa prevalence (63.8% in 2011 vs. 46.8% in 2001, P = 0.019). Resistance of P. aeruginosa increased significantly to imipenem, gentamicin, amikacin, tobramycin, ciprofloxacin and fosfomycin, whereas resistance to piperacillin-tazobactam, meropenem and aztreonam decreased. Significantly fewer Stenotrophomonas maltophilia isolates were susceptible to all the analyzed antibiotics (trimethoprim/sulfamethoxazole, ciprofloxacin and colistin) in 2011 compared with 2001 (13.5% vs. 42.1%; P = 0.023), whereas the resistance to colistin increased significantly (11.1% vs. 62.2%; P < 0.001). Burkholderia cepacia complex and nontuberculous mycobacteria were not detected in 2001 but in 2011 in 7.4% (n = 9) and 7.4% (n = 9) of patients, respectively. B. cepacia complex isolates belonged to 8 multilocus sequence types. CONCLUSIONS Our retrospective analysis revealed an increase of important CF-related pathogens, the emergence of new pathogens and a substantial increase of multidrug-resistant CF-specific isolates. Our findings are of importance to clinicians for the alertness of local epidemiology, which may be useful for prevention and treatment strategies.
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Affiliation(s)
- Lena Raidt
- From the *Institute of Medical Microbiology, and †Department of Pediatrics, University Hospital Münster, Münster, Germany; ‡Department of Pediatrics, Clemenshospital Münster, Münster, Germany; and §Department of Medical Microbiology, University Hospital Motol, 2nd Faculty of Medicine, Charles University, Prague, Czech Republic
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Ciofu O, Tolker-Nielsen T, Jensen PØ, Wang H, Høiby N. Antimicrobial resistance, respiratory tract infections and role of biofilms in lung infections in cystic fibrosis patients. Adv Drug Deliv Rev 2015; 85:7-23. [PMID: 25477303 DOI: 10.1016/j.addr.2014.11.017] [Citation(s) in RCA: 206] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2014] [Revised: 11/11/2014] [Accepted: 11/23/2014] [Indexed: 02/08/2023]
Abstract
Lung infection is the main cause of morbidity and mortality in patients with cystic fibrosis and is mainly dominated by Pseudomonas aeruginosa. The biofilm mode of growth makes eradication of the infection impossible, and it causes a chronic inflammation in the airways. The general mechanisms of biofilm formation and antimicrobial tolerance and resistance are reviewed. Potential anti-biofilm therapeutic targets such as weakening of biofilms by quorum-sensing inhibitors or antibiotic killing guided by pharmacokinetics and pharmacodynamics of antibiotics are presented. The vicious circle of adaptive evolution of the persisting bacteria imposes important therapeutic challenges and requires development of new drug delivery systems able to reach the different niches occupied by the bacteria in the lung of cystic fibrosis patients.
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35
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Paris Ü, Mikkel K, Tavita K, Saumaa S, Teras R, Kivisaar M. NHEJ enzymes LigD and Ku participate in stationary-phase mutagenesis in Pseudomonas putida. DNA Repair (Amst) 2015; 31:11-8. [PMID: 25942369 DOI: 10.1016/j.dnarep.2015.04.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 03/30/2015] [Accepted: 04/21/2015] [Indexed: 11/17/2022]
Abstract
Under growth-restricting conditions bacterial populations can rapidly evolve by a process known as stationary-phase mutagenesis. Bacterial nonhomologous end-joining (NHEJ) system which consists of the DNA-end-binding enzyme Ku and the multifunctional DNA ligase LigD has been shown to be important for survival of bacteria especially during quiescent states, such as late stationary-phase populations or sporulation. In this study we provide genetic evidence that NHEJ enzymes participate in stationary-phase mutagenesis in a population of carbon-starved Pseudomonas putida. Both the absence of LigD or Ku resulted in characteristic spectra of stationary-phase mutations that differed from each other and also from the wild-type spectrum. This indicates that LigD and Ku may participate also in mutagenic pathways that are independent from each other. Our results also imply that both phosphoesterase (PE) and polymerase (POL) domains of the LigD protein are involved in the occurrence of mutations in starving P. putida. The participation of both Ku and LigD in the occurrence of stationary-phase mutations was further supported by the results of the analysis of mutation spectra in stationary-phase sigma factor RpoS-minus background. The spectra of mutations identified in the RpoS-minus background were also distinct if LigD or Ku was absent. Interestingly, the effects of the presence of these enzymes on the frequency of occurrence of certain types of mutations were different or even opposite in the RpoS-proficient and deficient backgrounds. These results imply that RpoS affects performance of mutagenic pathways in starving P. putida that utilize LigD and/or Ku.
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Affiliation(s)
- Ülvi Paris
- Department of Genetics, Institute of Molecular and Cell Biology, University of Tartu, 23 Riia Street, 51010 Tartu, Estonia
| | - Katren Mikkel
- Department of Genetics, Institute of Molecular and Cell Biology, University of Tartu, 23 Riia Street, 51010 Tartu, Estonia
| | - Kairi Tavita
- Department of Genetics, Institute of Molecular and Cell Biology, University of Tartu, 23 Riia Street, 51010 Tartu, Estonia
| | - Signe Saumaa
- Department of Genetics, Institute of Molecular and Cell Biology, University of Tartu, 23 Riia Street, 51010 Tartu, Estonia
| | - Riho Teras
- 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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Biofilm-related infections: bridging the gap between clinical management and fundamental aspects of recalcitrance toward antibiotics. Microbiol Mol Biol Rev 2015; 78:510-43. [PMID: 25184564 DOI: 10.1128/mmbr.00013-14] [Citation(s) in RCA: 751] [Impact Index Per Article: 83.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Surface-associated microbial communities, called biofilms, are present in all environments. Although biofilms play an important positive role in a variety of ecosystems, they also have many negative effects, including biofilm-related infections in medical settings. The ability of pathogenic biofilms to survive in the presence of high concentrations of antibiotics is called "recalcitrance" and is a characteristic property of the biofilm lifestyle, leading to treatment failure and infection recurrence. This review presents our current understanding of the molecular mechanisms of biofilm recalcitrance toward antibiotics and describes how recent progress has improved our capacity to design original and efficient strategies to prevent or eradicate biofilm-related infections.
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37
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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: 899] [Impact Index Per Article: 99.9] [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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38
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Rafii F, Hart ME. Antimicrobial resistance in clinically important biofilms. World J Pharmacol 2015; 4:31-46. [DOI: 10.5497/wjp.v4.i1.31] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 10/22/2014] [Accepted: 12/17/2014] [Indexed: 02/06/2023] Open
Abstract
A biofilm contains a consortium of cohesive bacterial cells forming a complex structure that is a sedentary, but dynamic, community. Biofilms adhere on biotic and abiotic surfaces, including the surfaces of practically all medical devices. Biofilms are reported to be responsible for approximately 60% of nosocomial infections due to implanted medical devices, such as intravenous catheters, and they also cause other foreign-body infections and chronic infections. The presence of biofilm on a medical device may result in the infection of surrounding tissues and failure of the device, necessitating the removal and replacement of the device. Bacteria from biofilms formed on medical devices may be released and disperse, with the potential for the formation of new biofilms in other locations and the development of a systemic infection. Regardless of their location, bacteria in biofilms are tolerant of the activities of the immune system, antimicrobial agents, and antiseptics. Concentrations of antimicrobial agents sufficient to eradicate planktonic cells have no effect on the same microorganism in a biofilm. Depending on the microbial consortium or component of the biofilm that is involved, various combinations of factors have been suggested to explain the recalcitrant nature of biofilms toward killing by antibiotics. In this mini-review, some of the factors contributing to antimicrobial resistance in biofilms are discussed.
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Tolker-Nielsen T. Pseudomonas aeruginosa biofilm infections: from molecular biofilm biology to new treatment possibilities. APMIS 2015:1-51. [PMID: 25399808 DOI: 10.1111/apm.12335] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Bacteria in natural, industrial and clinical settings predominantly live in biofilms, i.e., sessile structured microbial communities encased in self-produced extracellular matrix material. One of the most important characteristics of microbial biofilms is that the resident bacteria display a remarkable increased tolerance toward antimicrobial attack. Biofilms formed by opportunistic pathogenic bacteria are involved in devastating persistent medical device-associated infections, and chronic infections in individuals who are immune-compromised or otherwise impaired in the host defense. Because the use of conventional antimicrobial compounds in many cases cannot eradicate biofilms, there is an urgent need to develop alternative measures to combat biofilm infections. The present review is focussed on the important opportunistic pathogen and biofilm model organism Pseudomonas aeruginosa. Initially, biofilm infections where P. aeruginosa plays an important role are described. Subsequently, current insights into the molecular mechanisms involved in P. aeruginosa biofilm formation and the associated antimicrobial tolerance are reviewed. And finally, based on our knowledge about molecular biofilm biology, a number of therapeutic strategies for combat of P. aeruginosa biofilm infections are presented.
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Affiliation(s)
- Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of International Health, Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
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40
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López-Causapé C, Rojo-Molinero E, Macià MD, Oliver A. The problems of antibiotic resistance in cystic fibrosis and solutions. Expert Rev Respir Med 2014; 9:73-88. [PMID: 25541089 DOI: 10.1586/17476348.2015.995640] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Chronic respiratory infection is the main cause of morbidity and mortality in cystic fibrosis (CF) patients. One of the hallmarks of these infections, led by the opportunistic pathogen Pseudomonas aeruginosa, is their long-term (lifelong) persistence despite intensive antimicrobial therapy. Antimicrobial resistance in CF is indeed a multifactorial problem, which includes physiological changes, represented by the transition from the planktonic to the biofilm mode of growth and the acquisition of multiple (antibiotic resistance) adaptive mutations catalyzed by frequent mutator phenotypes. Emerging multidrug-resistant CF pathogens, transmissible epidemic strains and transferable genetic elements (such as those encoding class B carbapenemases) also significantly contribute to this concerning scenario. Strategies directed to combat biofilm growth, prevent the emergence of mutational resistance, promote the development of novel antimicrobial agents against multidrug-resistant strains and implement strict infection control measures are thus needed.
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Affiliation(s)
- 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
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41
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Involvement of stress-related genes polB and PA14_46880 in biofilm formation of Pseudomonas aeruginosa. Infect Immun 2014; 82:4746-57. [PMID: 25156741 DOI: 10.1128/iai.01915-14] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Chronic infections of Pseudomonas aeruginosa are generally established through production of biofilm. During biofilm formation, production of an extracellular matrix and establishment of a distinct bacterial phenotype make these infections difficult to eradicate. However, biofilm studies have been hampered by the fact that most assays utilize nonliving surfaces as biofilm attachment substrates. In an attempt to better understand the mechanisms behind P. aeruginosa biofilm formation, we performed a genetic screen to identify novel factors involved in biofilm formation on biotic and abiotic surfaces. We found that deletion of genes polB and PA14_46880 reduced biofilm formation significantly compared to that in the wild-type strain PA14 in an abiotic biofilm system. In a biotic biofilm model, wherein biofilms form on cultured airway cells, the ΔpolB and ΔPA14_46880 strains showed increased cytotoxic killing of the airway cells independent of the total number of bacteria bound. Notably, deletion mutant strains were more resistant to ciprofloxacin treatment. This phenotype was linked to decreased expression of algR, an alginate transcriptional regulatory gene, under ciprofloxacin pressure. Moreover, we found that pyocyanin production was increased in planktonic cells of mutant strains. These results indicate that inactivation of polB and PA14_46880 may inhibit transition of P. aeruginosa from a more acute infection lifestyle to the biofilm phenotype. Future investigation of these genes may lead to a better understanding of P. aeruginosa biofilm formation and chronic biofilm infections.
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Abstract
Cystic fibrosis is characterised by chronic polymicrobial infection and inflammation in the airways of patients. Antibiotic treatment regimens, targeting recognised pathogens, have substantially contributed to increased life expectancy of patients with this disease. Although the emergence of antimicrobial resistance and selection of highly antibiotic-resistant bacterial strains is of major concern, the clinical relevance in cystic fibrosis is yet to be defined. Resistance has been identified in recognised cystic fibrosis pathogens and in other bacteria (eg, Prevotella and Streptococcus spp) detected in the airway microbiota, but their role in the pathophysiology of infection and inflammation in chronic lung disease is unclear. Increased antibiotic resistance in cystic fibrosis might be attributed to a range of complex factors including horizontal gene transfer, hypoxia, and biofilm formation. Strategies to manage antimicrobial resistance consist of new antibiotics or localised delivery of antimicrobial agents, iron sequestration, inhibition of quorum-sensing, and resistome analysis. Determination of the contributions of every bacterial species to lung health or disease in cystic fibrosis might also have an important role in the management of antibiotic resistance.
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Affiliation(s)
- Laura J Sherrard
- CF and Airways Microbiology Group, Queen's University Belfast, Belfast, UK; School of Pharmacy, Queen's University Belfast, Belfast, UK
| | - Michael M Tunney
- CF and Airways Microbiology Group, Queen's University Belfast, Belfast, UK; School of Pharmacy, Queen's University Belfast, Belfast, UK
| | - J Stuart Elborn
- CF and Airways Microbiology Group, Queen's University Belfast, Belfast, UK; Centre for Infection and Immunity, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast, UK.
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Hoe S, Semler DD, Goudie AD, Lynch KH, Matinkhoo S, Finlay WH, Dennis JJ, Vehring R. Respirable Bacteriophages for the Treatment of Bacterial Lung Infections. J Aerosol Med Pulm Drug Deliv 2013; 26:317-35. [DOI: 10.1089/jamp.2012.1001] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Affiliation(s)
- Susan Hoe
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, T6G 2G8, Canada
| | - Diana D. Semler
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, T6G 2E9, Canada
| | - Amanda D. Goudie
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, T6G 2E9, Canada
| | - Karlene H. Lynch
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, T6G 2E9, Canada
| | - Sadaf Matinkhoo
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, T6G 2G8, Canada
| | - Warren H. Finlay
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, T6G 2G8, Canada
| | - Jonathan J. Dennis
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, T6G 2E9, Canada
| | - Reinhard Vehring
- Department of Mechanical Engineering, University of Alberta, Edmonton, Alberta, T6G 2G8, Canada
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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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Sriramulu D. Evolution and impact of bacterial drug resistance in the context of cystic fibrosis disease and nosocomial settings. Microbiol Insights 2013; 6:29-36. [PMID: 24826072 PMCID: PMC3987750 DOI: 10.4137/mbi.s10792] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The use of antibiotics is unavoidable in trying to treat acute infections and in the prevention and control of chronic infections. Over the years, an ever increasing number of infections has escalated the use of antibiotics, which has necessitated action against an emerging bacterial resistance. There seems to be a continuous acquisition of new resistance mechanisms among bacteria that switch niches between human, animals, and the environment. An antibiotic resistant strain emerges when it acquires the DNA that confers the added capacity needed to survive in an unusual niche. Once acquired, a new resistance mechanism evolves according to the dynamics of the microenvironment; there is then a high probability that it is transferred to other species or to an avirulent strain of the same species. A well understood model for studying emerging antibiotic resistance and its impact is Pseudomonas aeruginosa, an opportunistic pathogen which is able to cause acute and chronic infections in nosocomial settings. This bacterium has a huge genetic repertoire consisting of genes that encode both innate and acquired antibiotic resistance traits. Besides acute infections, chronic colonization of P. aeruginosa in the lungs of cystic fibrosis (CF) patients plays a significant role in morbidity and mortality. Antibiotics used in the treatment of such infections has increased the longevity of patients over the last several decades. However, emerging multidrug resistant strains and the eventual increase in the dosage of antibiotic(s) is of major concern. Though there are various infections that are treated by single/combined antibiotics, the particular case of P. aeruginosa infection in CF patients serves as a reference for understanding the impact of overuse of antibiotics and emerging antibiotic resistant strains. This mini review presents the need for judicious use of antibiotics to treat various types of infections, protecting patients and the environment, as well as achieving a better treatment outcome.
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Affiliation(s)
- Dinesh Sriramulu
- Shres Consultancy, Aparna Towers, Near Lakshmi Hospital, Chittur Road, Palakkad, Kerala, India
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46
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Ciofu O, Johansen HK, Aanaes K, Wassermann T, Alhede M, von Buchwald C, Høiby N. P. aeruginosa in the paranasal sinuses and transplanted lungs have similar adaptive mutations as isolates from chronically infected CF lungs. J Cyst Fibros 2013; 12:729-36. [PMID: 23478131 DOI: 10.1016/j.jcf.2013.02.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2012] [Revised: 02/06/2013] [Accepted: 02/11/2013] [Indexed: 01/02/2023]
Abstract
BACKGROUND Pseudomonas aeruginosa cells are present as biofilms in the paranasal sinuses and the lungs of chronically infected cystic fibrosis (CF) patients. Since different inflammatory responses and selective antibiotic pressures are acting in the sinuses compared with the lungs, we compared the adaptive profiles of mucoid and non-mucoid isolates from the two locations. METHODS We studied the genetic basis of phenotypic diversification and gene expression profiles in sequential lung and sinus P. aeruginosa isolates from four chronically infected CF patients, including pre- and post-lung transplantation isolates. RESULTS The same phenotypes caused by similar mutations and similar gene expression profiles were found in mucoid and non-mucoid isolates from the paranasal sinuses and from the lungs before and after transplantation. CONCLUSION Bilateral exchange of P. aeruginosa isolates between the paranasal sinuses and the lungs occurs in chronically infected patients and extensive sinus surgery before the lung transplantation might prevent infection of the new lung.
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Affiliation(s)
- Oana Ciofu
- Department of International Health, Immunology and Microbiology, Unit of Bacteriology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark.
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Mazzei F, Viel A, Bignami M. Role of MUTYH in human cancer. Mutat Res 2013; 743-744:33-43. [PMID: 23507534 DOI: 10.1016/j.mrfmmm.2013.03.003] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 03/06/2013] [Accepted: 03/09/2013] [Indexed: 06/01/2023]
Abstract
MUTYH, a human ortholog of MutY, is a post-replicative DNA glycosylase, highly conserved throughout evolution, involved in the correction of mismatches resulting from a faulty replication of the oxidized base 8-hydroxyguanine (8-oxodG). In particular removal of adenine from A:8-oxodG mispairs by MUTYH activity is followed by error-free base excision repair (BER) events, leading to the formation of C:8-oxodG base pairs. These are the substrate of another BER enzyme, the OGG1 DNA glycosylase, which then removes 8-oxodG from DNA. Thus the combined action of OGG1 and MUTYH prevents oxidative damage-induced mutations, i.e. GC->TA transversions. Germline mutations in MUTYH are associated with a recessively heritable colorectal polyposis, now referred to as MUTYH-associated polyposis (MAP). Here we will review the phenotype(s) associated with MUTYH inactivation from bacteria to mammals, the structure of the MUTYH protein, the molecular mechanisms of its enzymatic activity and the functional characterization of MUTYH variants. The relevance of these results will be discussed to define the role of specific human mutations in colorectal cancer risk together with the possible role of MUTYH inactivation in sporadic cancer.
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Affiliation(s)
- Filomena Mazzei
- Department of Environment, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Roma, Italy
| | - Alessandra Viel
- Experimental Oncology 1, Centro di Riferimento Oncologico, IRCCS, Via F.Gallini 2, 33081 Aviano, PN, Italy
| | - Margherita Bignami
- Department of Environment, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Roma, Italy.
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Evolution in fast forward: a potential role for mutators in accelerating Staphylococcus aureus pathoadaptation. J Bacteriol 2012. [PMID: 23204459 DOI: 10.1128/jb.00733-12] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Pathogen evolution and subsequent phenotypic heterogeneity during chronic infection are proposed to enhance Staphylococcus aureus survival during human infection. We tested this theory by genetically and phenotypically characterizing strains with mutations constructed in the mismatch repair (MMR) and oxidized guanine (GO) system, termed mutators, which exhibit increased spontaneous-mutation frequencies. Analysis of these mutators revealed not only strain-dependent increases in the spontaneous-mutation frequency but also shifts in mutational type and hot spots consistent with loss of GO or MMR functions. Although the GO and MMR systems are relied upon in some bacterial species to prevent reactive oxygen species-induced DNA damage, no deficit in hydrogen peroxide sensitivity was found when either of these DNA repair pathways was lost in S. aureus. To gain insight into the contribution of increased mutation supply to S. aureus pathoadaptation, we measured the rate of α-hemolysin and staphyloxanthin inactivation during serial passage. Detection of increased rates of α-hemolysin and staphyloxanthin inactivation in GO and MMR mutants suggests that these strains are capable of modifying virulence phenotypes implicated in mediating infection. Accelerated derivation of altered virulence phenotypes, combined with the absence of increased ROS sensitivity, highlights the potential of mutators to drive pathoadaptation in the host and serve as catalysts for persistent infections.
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Ciofu O, Mandsberg LF, Wang H, Høiby N. Phenotypes selected during chronic lung infection in cystic fibrosis patients: implications for the treatment ofPseudomonas aeruginosabiofilm infections. ACTA ACUST UNITED AC 2012; 65:215-25. [DOI: 10.1111/j.1574-695x.2012.00983.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2011] [Revised: 04/23/2012] [Accepted: 04/24/2012] [Indexed: 12/18/2022]
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50
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Jensen PØ, Lykkesfeldt J, Bjarnsholt T, Hougen HP, Høiby N, Ciofu O. Poor antioxidant status exacerbates oxidative stress and inflammatory response to Pseudomonas aeruginosa lung infection in guinea pigs. Basic Clin Pharmacol Toxicol 2011; 110:353-8. [PMID: 22008605 DOI: 10.1111/j.1742-7843.2011.00822.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Considerable evidence supports the presence of oxidative stress in cystic fibrosis (CF). The disease has long been associated with both increased production of reactive oxygen species and impaired antioxidant status, in particular during the chronic pulmonary infection with Pseudomonas aeruginosa, which is the main cause of morbidity and mortality in CF. Guinea pigs are unable to synthesize ascorbate (ASC) or vitamin C, a major antioxidant of the lung, and thus like human beings rely on its presence in the diet. On this basis, guinea pigs receiving ASC-deficient diet have been used as a model of oxidative stress. The aim of our study was to investigate the consequences of a 7-day biofilm-grown P. aeruginosa lung infection in 3-month-old guinea pigs receiving either ASC-sufficient or ASC-deficient diet for at least 2 months. The animals receiving ASC-deficient diet showed significantly higher mortality during infection and increased respiratory burst of peripheral polymorphonuclear neutrophils (PMNs) compared with the animals receiving ASC sufficient diet. The inflammatory response at the site of lung infection consisted of PMNs and mononuclear leucocytes (MN), and higher PMN/MN ratios were present in animals on ASC-deficient diet compared with animals on ASC sufficient diet. Measurements of the ASC levels in the lung were significantly decreased in infected compared with non-infected animals. Interestingly, the infection by itself decreased the antioxidant capacity of the plasma (measured as plasma oxidizability) more than the ASC-deficient diet, suggesting a high consumption of the antioxidants during infection. Our data show that poor antioxidant status exacerbates the outcome of biofilm-related infections.
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Affiliation(s)
- Peter Ø Jensen
- Department of Clinical Microbiology, University Hospital, Copenhagen, Denmark
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