1
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Which missense mutations associated with DNA gyrase and topoisomerase IV are involved in Pseudomonas aeruginosa clinical isolates resistance to ciprofloxacin in Ardabil? GENE REPORTS 2021. [DOI: 10.1016/j.genrep.2021.101211] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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2
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Shaw E, Wuest WM. Virulence attenuating combination therapy: a potential multi-target synergy approach to treat Pseudomonas aeruginosa infections in cystic fibrosis patients. RSC Med Chem 2020; 11:358-369. [PMID: 33479641 PMCID: PMC7580779 DOI: 10.1039/c9md00566h] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 02/06/2020] [Indexed: 12/15/2022] Open
Abstract
The World Health Organization considers the discovery of new treatments for P. aeruginosa a top priority. Virulence attenuating combination therapy (VACT) is a pragmatic strategy to improve bacterial clearance, repurpose outmoded antibiotics, improve drug efficacy at lower doses, and reduce the evolution of resistance. In vitro and in vivo studies have shown that adding a quorum sensing inhibitor or an extracellular polymeric substance repressor to classical antibiotics synergistically improves antipseudomonal activity. This review highlights why VACT could specifically benefit cystic fibrosis patients harboring chronic P. aeruginosa infections, outlines the current landscape of synergistic combinations between virulence-targeting small-molecules and anti-pseudomonal drugs, and suggests future directions for VACT research.
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Affiliation(s)
- Elana Shaw
- Department of Chemistry , Emory University , 1515 Dickey Drive , Atlanta , Georgia 30322 , USA .
| | - William M Wuest
- Department of Chemistry , Emory University , 1515 Dickey Drive , Atlanta , Georgia 30322 , USA .
- Emory Antibiotic Resistance Center , Emory University School of Medicine , 201 Dowman Drive , Atlanta , Georgia 30322 , USA
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3
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Conjugation of LasR Quorum-Sensing Inhibitors with Ciprofloxacin Decreases the Antibiotic Tolerance of P. aeruginosaClinical Strains. J CHEM-NY 2019. [DOI: 10.1155/2019/8143739] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Pseudomonas aeruginosais a Gram-negative bacterium that commonly infects subjects with weakened immune system causing deadly infections above all at pulmonary level. During infection,P. aeruginosaproduces a well-organized bacterial structure, called biofilm, activating the quorum-sensing (QS) signaling, a mechanism of gene regulation. In this work, we synthesized already known QS inhibitors (QSi) designed on the scaffold of the N-(3-oxododecanoyl) homoserine lactone (3O-C12-HSL) QS molecule and conjugated them with ciprofloxacin to inhibitP. aeruginosabiofilm formation and increase the antibiotic susceptibility of clinical strains. We identified, for the first time, a QSi conjugated with ciprofloxacin (ET37), that is able to reduce the formation of biofilm and the onset of tolerant clones inP. aeruginosaclinical strains. This compound could have a wide application in clinical setting. The possibility to affect biofilm formation in chronically infected patients, such as patients affected by cystic fibrosis, and to reduce the onset of ciprofloxacin resistance would improve patient healing and allow to decrease antibiotic drug dosage.
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4
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Kidd TJ, Canton R, Ekkelenkamp M, Johansen HK, Gilligan P, LiPuma JJ, Bell SC, Elborn JS, Flume PA, VanDevanter DR, Waters VJ. Defining antimicrobial resistance in cystic fibrosis. J Cyst Fibros 2018; 17:696-704. [PMID: 30266518 DOI: 10.1016/j.jcf.2018.08.014] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 07/21/2018] [Accepted: 08/31/2018] [Indexed: 12/31/2022]
Abstract
Antimicrobial resistance (AMR) can present significant challenges in the treatment of cystic fibrosis (CF) lung infections. In CF and other chronic diseases, AMR has a different profile and clinical consequences compared to acute infections and this requires different diagnostic and treatment approaches. This review defines AMR, explains how it occurs, describes the methods used to measure AMR as well as their limitations, and concludes with future directions for research and development in the area of AMR in CF.
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Affiliation(s)
- Timothy J Kidd
- School of Chemistry and Molecular Biosciences, The University of Queensland, Lung Bacteria Group, QIMR Berghofer Medical Research Institute, Brisbane, Australia.
| | - Rafael Canton
- Servicio de Microbiología, Hospital Universitario Ramón y Cajal and Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Madrid, Spain.
| | - Miquel Ekkelenkamp
- Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands.
| | - Helle Krogh Johansen
- Department of Clinical Microbiology, Rigshospitalet, Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
| | - Peter Gilligan
- Clinical Microbiology-Immunology Laboratories, UNC HealthCare, Chapel Hill, NC, USA.
| | - John J LiPuma
- Department of Pediatrics and Communicable Diseases, University of Michigan Medical School, Ann Arbor, MI, USA.
| | - Scott C Bell
- Department of Thoracic Medicine, The Prince Charles Hospital and QIMR Berghofer Medical Researhc Institute, Brisbane, Australia.
| | - J Stuart Elborn
- Imperial College and Royal Brompton Hospital, London, Queen's University Belfast, United Kingdom.
| | - Patrick A Flume
- Departments of Medicine and Pediatrics, Medical University of South Carolina, Charleston, SC, USA.
| | - Donald R VanDevanter
- Department of Pediatrics, Case Western Reserve University School of Medicine, Cleveland, OH, USA.
| | - Valerie J Waters
- Division of Infectious Diseases, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, ON, USA.
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5
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Lucca F, Guarnieri M, Ros M, Muffato G, Rigoli R, Da Dalt L. Antibiotic resistance evolution of Pseudomonas aeruginosa in cystic fibrosis patients (2010-2013). CLINICAL RESPIRATORY JOURNAL 2018; 12:2189-2196. [PMID: 29498795 DOI: 10.1111/crj.12787] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 12/29/2017] [Accepted: 02/23/2018] [Indexed: 11/28/2022]
Abstract
INTRODUCTION Pseudomonas aeruginosa is the predominant pathogen responsible of chronic colonization of the airways in cystic fibrosis (CF) patients. There are few European data about antibiotic susceptibility evolution of P aeruginosa in CF patients. OBJECTIVES The aim of this study is to evaluate the evolution of antibiotic resistance in the period 2010-2013 in CF patients chronically colonized by P aeruginosa and to highlight the characteristics of this evolution in patients younger than 20 years. METHODS Clinical and microbiological data were extracted from two electronic databases and analyzed. Antibiotic resistance was defined according to European Committee of Antimicrobial Susceptibility Testing for levofloxacin, ciprofloxacin, meropenem, amikacin and ceftazidime. The between-group comparison was drawn with the Chi-square test for proportions, with the T-test for unpaired samples for normally distributed data and with Mann-Whitney test for non-normally distributed data. Significancy was defined by P < .05. RESULTS Fifty-seven CF patients, including thirteen subjects aged less than 20 years, were enrolled. P.. aeruginosa antibiotic sensitivity decreased significantly for fluoroquinolones, mainly in patients aged <20 years, while it increased for amikacin and colistin. The analysis of minimum inhibitory concentration confirmed these trends. In pediatric patients treated with more than three antibiotic cycles per year, greater resistance was found, except for amikacin and colistin. CONCLUSION An evolution in P aeruginosa antibiotic resistances is observed in the 4-year period studied. Responsible and informed use of antibiotics is mandatory in CF.
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Affiliation(s)
- Francesca Lucca
- Department of Woman's and Child's Health, University of Padova, Padova, Italy
| | | | - Mirco Ros
- Cystic Fibrosis Unit, Pediatric Department, Treviso Hospital, Treviso, Italy
| | | | - Roberto Rigoli
- Microbiology Department, Treviso Hospital, Treviso, Italy
| | - Liviana Da Dalt
- Department of Woman's and Child's Health, University of Padova, Padova, Italy
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6
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Macin S, Akarca M, Sener B, Akyon Y. Comparison of virulence factors and antibiotic resistance of Pseudomonas aeruginosa strains isolated from patients with and without cystic fibrosis. REV ROMANA MED LAB 2017. [DOI: 10.1515/rrlm-2017-0027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Abstract
Its rising incidence, virulence factors and antibiotic resistance rate makes it difficult to treat Pseudomonas aeruginosa infections. The aim of this study was to compare virulence factors and antibiotic resistance of P. aeruginosa isolates from cystic fibrosis (CF) and other lower respiratory tract infections. Isolates from patients (n=125) were divided into two groups. The isolates in the first group were from CF patients (n=64). And in the other group isolates were from lower respiratory tract samples, from patients that did not have CF (n=61). The antibiotic susceptibility tests were done by using disc diffusion method. As phenotypic tests; DNase, protease, elastase, hemolysis, and motility test were performed. The mucoid form of P. aeruginosa was detected in 29.7% of CF patients’ isolates, whereas in the other group (non-CF) this rate was 9.8% (p=0.011). Motility in the CF patients’ isolates was lower (84.4%) then the other group (96.7%). The presence of DNase was significantly low in CF patients’ isolates when compared to the other group (p=0.009). When the antibiotic resistance was compared; ceftazidime, imipenem and meropenem and piperacillin resistance was found significantly low in CF patients compared to isolates from the other group (p≤0.05). Information about virulence factor patterns and antibiotic resistance of P. aeruginosa isolates from patients with cystic fibrosis and the patients without cystic fibrosis can prevent the unnecessary usage of antibiotics and lead the way to new approaches in treatment.
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Affiliation(s)
- Salih Macin
- Selcuk University Faculty of Medicine, Department of Medical Microbiology, Konya , Turkey
| | - Meral Akarca
- Golbası State Hospital, Department of Medical Microbiology, Ankara , Turkey
| | - Burcin Sener
- Hacettepe University Faculty of Medicine, Department of Medical Microbiology, Ankara , Turkey
| | - Yakut Akyon
- Hacettepe University Faculty of Medicine, Department of Medical Microbiology, Ankara , Turkey
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7
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El Zowalaty ME, Al Thani AA, Webster TJ, El Zowalaty AE, Schweizer HP, Nasrallah GK, Marei HE, Ashour HM. Pseudomonas aeruginosa: arsenal of resistance mechanisms, decades of changing resistance profiles, and future antimicrobial therapies. Future Microbiol 2015; 10:1683-706. [PMID: 26439366 DOI: 10.2217/fmb.15.48] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Antimicrobial resistance is one of the most serious public health issues facing humans since the discovery of antimicrobial agents. The frequent, prolonged, and uncontrolled use of antimicrobial agents are major factors in the emergence of antimicrobial-resistant bacterial strains, including multidrug-resistant variants. Pseudomonas aeruginosa is a leading cause of nosocomial infections. The abundant data on the increased resistance to antipseudomonal agents support the need for global action. There is a paucity of new classes of antibiotics active against P. aeruginosa. Here, we discuss recent antibacterial resistance profiles and mechanisms of resistance by P. aeruginosa. We also review future potential methods for controlling antibiotic-resistant bacteria, such as phage therapy, nanotechnology and antipseudomonal vaccines.
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Affiliation(s)
- Mohamed E El Zowalaty
- Department of Microbiology & Immunology, Emory University School of Medicine, Atlanta, GA 30322, USA.,BioMedical Research Center, Qatar University, Doha, PO Box 2713, Qatar
| | - Asmaa A Al Thani
- BioMedical Research Center, Qatar University, Doha, PO Box 2713, Qatar.,Department of Health Sciences, College of Arts and Sciences, Qatar University, Doha 2713, Qatar
| | - Thomas J Webster
- Department of Chemical Engineering, Northeastern University, Boston, MA 02018, USA.,Center of Excellence for Advanced Materials Research, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia
| | - Ahmed E El Zowalaty
- Department of Physiology & Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA.,Interdisciplinary Toxicology Program, University of Georgia, Athens, GA 30602, USA
| | - Herbert P Schweizer
- Department of Molecular Genetics & Microbiology, College of Medicine, University of Florida, Gainesville, FL 32611, USA.,Emerging Pathogens Institute, Institute for Therapeutic Innovation, University of Florida Gainesville, FL 32611, USA
| | - Gheyath K Nasrallah
- BioMedical Research Center, Qatar University, Doha, PO Box 2713, Qatar.,Department of Health Sciences, College of Arts and Sciences, Qatar University, Doha 2713, Qatar
| | - Hany E Marei
- BioMedical Research Center, Qatar University, Doha, PO Box 2713, Qatar
| | - Hossam M Ashour
- Department of Microbiology & Immunology, Faculty of Pharmacy, Cairo University, Egypt.,Department of Pharmacy Practice, Eugene Applebaum College of Pharmacy & Health Sciences, Wayne State University, Detroit, MI, USA
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8
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Sousa AM, Pereira MO, Lourenço A. MorphoCol: An ontology-based knowledgebase for the characterisation of clinically significant bacterial colony morphologies. J Biomed Inform 2015; 55:55-63. [DOI: 10.1016/j.jbi.2015.03.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 01/24/2015] [Accepted: 03/20/2015] [Indexed: 01/09/2023]
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9
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Improvements on colony morphology identification towards bacterial profiling. J Microbiol Methods 2013; 95:327-35. [PMID: 24121049 DOI: 10.1016/j.mimet.2013.09.020] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 09/26/2013] [Accepted: 09/30/2013] [Indexed: 02/04/2023]
Abstract
Colony morphology may be an indicator of phenotypic variation, this being an important adaptive process adopted by bacteria to overcome environmental stressors. Furthermore, alterations in colony traits may reflect increased virulence and antimicrobial resistance. Despite the potential relevance of using colony morphological traits, the influence of experimental conditions on colony morphogenesis has been scarcely studied in detail. This study aims to clearly and systematically demonstrate the impact of some variables, such as colony growth time, plate colony density, culture medium, planktonic or biofilm mode of growth and strain genetic background, on bacterial colony morphology features using two Pseudomonas aeruginosa strains. Results, based on 5-replicate experiments, demonstrated that all variables influenced colony morphogenesis and 18 different morphotypes were identified, showing different sizes, forms, colours, textures and margins. Colony growth time and composition of the medium were the variables that caused the highest impact on colony differentiation both derived from planktonic and biofilm cultures. Colony morphology characterization before 45 h of incubation was considered inadequate and TSA, a non-selective medium, provided more colony diversity in contrast to P. aeruginosa selective media. In conclusion, data obtained emphasized the need to perform comparisons between colony morphologies in equivalent experimental conditions to avoid misinterpretation of microbial diagnostics and biomedical studies. Since colony morphotyping showed to be a reliable method to evaluate phenotypic switching and also to infer about bacterial diversity in biofilms, these unambiguous comparisons between morphotypes may offer a quite valuable input to clinical diagnosis, aiding the decision-making towards the selection of the most suitable antibiotic and supportive treatments.
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10
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Su HC, Khatun J, Kanavy DM, Giddings MC. Comparative genome analysis of ciprofloxacin-resistant Pseudomonas aeruginosa reveals genes within newly identified high variability regions associated with drug resistance development. Microb Drug Resist 2013; 19:428-36. [PMID: 23808957 DOI: 10.1089/mdr.2012.0258] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The alarming rise of ciprofloxacin-resistant Pseudomonas aeruginosa has been reported in several clinical studies. Though the mutation of resistance genes and their role in drug resistance has been researched, the process by which the bacterium acquires high-level resistance is still not well understood. How does the genomic evolution of P. aeruginosa affect resistance development? Could the exposure of antibiotics to the bacteria enrich genomic variants that lead to the development of resistance, and if so, how are these variants distributed through the genome? To answer these questions, we performed 454 pyrosequencing and a whole genome analysis both before and after exposure to ciprofloxacin. The comparative sequence data revealed 93 unique resistance strain variation sites, which included a mutation in the DNA gyrase subunit A gene. We generated variation-distribution maps comparing the wild and resistant types, and isolated 19 candidates from three discrete resistance-associated high variability regions that had available transposon mutants, to perform a ciprofloxacin exposure assay. Of these region candidates with transposon disruptions, 79% (15/19) showed a reduction in the ability to gain high-level resistance, suggesting that genes within these high variability regions might enrich for certain functions associated with resistance development.
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Affiliation(s)
- Hsun-Cheng Su
- 1 Department of Biochemistry & Biophysics, UNC School of Medicine , Chapel Hill, North Carolina
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11
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Dalhoff A. Global fluoroquinolone resistance epidemiology and implictions for clinical use. Interdiscip Perspect Infect Dis 2012; 2012:976273. [PMID: 23097666 PMCID: PMC3477668 DOI: 10.1155/2012/976273] [Citation(s) in RCA: 212] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2012] [Accepted: 06/26/2012] [Indexed: 12/22/2022] Open
Abstract
This paper on the fluoroquinolone resistance epidemiology stratifies the data according to the different prescription patterns by either primary or tertiary caregivers and by indication. Global surveillance studies demonstrate that fluoroquinolone resistance rates increased in the past years in almost all bacterial species except S. pneumoniae and H. influenzae, causing community-acquired respiratory tract infections. However, 10 to 30% of these isolates harbored first-step mutations conferring low level fluoroquinolone resistance. Fluoroquinolone resistance increased in Enterobacteriaceae causing community acquired or healthcare associated urinary tract infections and intraabdominal infections, exceeding 50% in some parts of the world, particularly in Asia. One to two-thirds of Enterobacteriaceae producing extended spectrum β-lactamases were fluoroquinolone resistant too. Furthermore, fluoroquinolones select for methicillin resistance in Staphylococci. Neisseria gonorrhoeae acquired fluoroquinolone resistance rapidly; actual resistance rates are highly variable and can be as high as almost 100%, particularly in Asia, whereas resistance rates in Europe and North America range from <10% in rural areas to >30% in established sexual networks. In general, the continued increase in fluoroquinolone resistance affects patient management and necessitates changes in some guidelines, for example, treatment of urinary tract, intra-abdominal, skin and skin structure infections, and traveller's diarrhea, or even precludes the use in indications like sexually transmitted diseases and enteric fever.
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Affiliation(s)
- Axel Dalhoff
- Institute for Infection-Medicine, Christian-Albrechts Univerity of Kiel and University Medical Center Schleswig-Holstein, Brunswiker Straße 4, 24105 Kiel, Germany
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12
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Determinants of intrinsic aminoglycoside resistance in Pseudomonas aeruginosa. Antimicrob Agents Chemother 2012; 56:5591-602. [PMID: 22908149 DOI: 10.1128/aac.01446-12] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Screening of a transposon insertion mutant library of Pseudomonas aeruginosa for increased susceptibility to paromomycin identified a number of genes whose disruption enhanced susceptibility of this organism to multiple aminoglycosides, including tobramycin, amikacin, and gentamicin. These included genes associated with lipid biosynthesis or metabolism (lptA, faoA), phosphate uptake (pstB), and two-component regulators (amgRS, PA2797-PA2798) and a gene of unknown function (PA0392). Deletion mutants lacking these showed enhanced panaminoglycoside susceptibility that was reversed by the cloned genes, confirming their contribution to intrinsic panaminoglycoside resistance. None of these mutants showed increased aminoglycoside permeation of the cell envelope, indicating that increased susceptibility was not related to enhanced aminoglycoside uptake owing to a reduced envelope barrier function. Several mutants (pstB, faoA, PA0392, amgR) did, however, show increased cytoplasmic membrane depolarization relative to wild type following gentamicin exposure, consistent with the membranes of these mutants being more prone to perturbation, likely by gentamicin-generated mistranslated polypeptides. Mutants lacking any two of these resistance genes in various combinations invariably showed increased aminoglycoside susceptibility relative to single-deletion mutants, confirming their independent contribution to resistance and highlighting the complexity of the intrinsic aminoglycoside resistome in P. aeruginosa. Deletion of these genes also compromised the high-level panaminoglycoside resistance of clinical isolates, emphasizing their important contribution to acquired resistance.
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Rao P, McCaughan J, McCalmont M, Goldsmith C, Hall V, Millar BC, McCann MA, Downey DG, Rendall JC, Elborn JS, Moore JE. Comparison of antibiotic susceptibility patterns in Pseudomonas aeruginosa isolated from adult patients with cystic fibrosis (CF) with invasive Pseudomonas aeruginosa from non-CF patients. J Cyst Fibros 2012; 11:349-52. [DOI: 10.1016/j.jcf.2012.01.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Revised: 01/03/2012] [Accepted: 01/18/2012] [Indexed: 10/14/2022]
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14
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Su HC, Ramkissoon K, Doolittle J, Clark M, Khatun J, Secrest A, Wolfgang MC, Giddings MC. The development of ciprofloxacin resistance in Pseudomonas aeruginosa involves multiple response stages and multiple proteins. Antimicrob Agents Chemother 2010; 54:4626-35. [PMID: 20696867 PMCID: PMC2976116 DOI: 10.1128/aac.00762-10] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Revised: 07/14/2010] [Accepted: 07/30/2010] [Indexed: 01/17/2023] Open
Abstract
Microbes have developed resistance to nearly every antibiotic, yet the steps leading to drug resistance remain unclear. Here we report a multistage process by which Pseudomonas aeruginosa acquires drug resistance following exposure to ciprofloxacin at levels ranging from 0.5× to 8× the initial MIC. In stage I, susceptible cells are killed en masse by the exposure. In stage II, a small, slow to nongrowing population survives antibiotic exposure that does not exhibit significantly increased resistance according to the MIC measure. In stage III, exhibited at 0.5× to 4× the MIC, a growing population emerges to reconstitute the population, and these cells display heritable increases in drug resistance of up to 50 times the original level. We studied the stage III cells by proteomic methods to uncover differences in the regulatory pathways that are involved in this phenotype, revealing upregulation of phosphorylation on two proteins, succinate-semialdehyde dehydrogenase (SSADH) and methylmalonate-semialdehyde dehydrogenase (MMSADH), and also revealing upregulation of a highly conserved protein of unknown function. Transposon disruption in the encoding genes for each of these targets substantially dampened the ability of cells to develop the stage III phenotype. Considering these results in combination with computational models of resistance and genomic sequencing results, we postulate that stage III heritable resistance develops from a combination of both genomic mutations and modulation of one or more preexisting cellular pathways.
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Affiliation(s)
- Hsun-Cheng Su
- Department of Microbiology and Immunology, Curriculum in Bioinformatics and Computational Biology, Cystic Fibrosis/Pulmonary Research and Treatment Center, Department of Biomedical Engineering, Department of Computer Science, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | - Kevin Ramkissoon
- Department of Microbiology and Immunology, Curriculum in Bioinformatics and Computational Biology, Cystic Fibrosis/Pulmonary Research and Treatment Center, Department of Biomedical Engineering, Department of Computer Science, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | - Janet Doolittle
- Department of Microbiology and Immunology, Curriculum in Bioinformatics and Computational Biology, Cystic Fibrosis/Pulmonary Research and Treatment Center, Department of Biomedical Engineering, Department of Computer Science, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | - Martha Clark
- Department of Microbiology and Immunology, Curriculum in Bioinformatics and Computational Biology, Cystic Fibrosis/Pulmonary Research and Treatment Center, Department of Biomedical Engineering, Department of Computer Science, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | - Jainab Khatun
- Department of Microbiology and Immunology, Curriculum in Bioinformatics and Computational Biology, Cystic Fibrosis/Pulmonary Research and Treatment Center, Department of Biomedical Engineering, Department of Computer Science, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | - Ashley Secrest
- Department of Microbiology and Immunology, Curriculum in Bioinformatics and Computational Biology, Cystic Fibrosis/Pulmonary Research and Treatment Center, Department of Biomedical Engineering, Department of Computer Science, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | - Matthew C. Wolfgang
- Department of Microbiology and Immunology, Curriculum in Bioinformatics and Computational Biology, Cystic Fibrosis/Pulmonary Research and Treatment Center, Department of Biomedical Engineering, Department of Computer Science, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | - Morgan C. Giddings
- Department of Microbiology and Immunology, Curriculum in Bioinformatics and Computational Biology, Cystic Fibrosis/Pulmonary Research and Treatment Center, Department of Biomedical Engineering, Department of Computer Science, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
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15
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Population pharmacokinetic comparison and pharmacodynamic breakpoints of ceftazidime in cystic fibrosis patients and healthy volunteers. Antimicrob Agents Chemother 2010; 54:1275-82. [PMID: 20065059 DOI: 10.1128/aac.00936-09] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Despite the promising activity of ceftazidime against Pseudomonas aeruginosa and Burkholderia cepacia, there has not yet been a study that directly compared the pharmacokinetics (PK) of ceftazidime in cystic fibrosis (CF) patients and healthy volunteers by population PK methodology. We assessed the population PK and PK/pharmacodynamic (PD) breakpoints of ceftazidime in CF patients and healthy volunteers. Eight CF patients (total body weight [WT] [average +/- standard deviation] = 42.9 +/- 18.4 kg) and seven healthy volunteers (WT = 66.2 +/- 4.9 kg) received 2 g ceftazidime as a 5-min intravenous infusion. High-performance liquid chromatography (HPLC) was used for drug analysis, and NONMEM (results reported), S-ADAPT, and NPAG were used for parametric and nonparametric population PK modeling. We considered linear and allometric body size models to scale clearance and volume of distribution. Monte Carlo simulations were based on a target time of non-protein-bound plasma concentration of ceftazidime above MIC of > or =65%, which represents near-maximal killing. Unscaled total clearance was 19% lower in CF patients, and volume of distribution was 36% lower. Total clearance was 7.82 liters/h for CF patients and 6.68 liters/h for healthy volunteers with 53 kg fat-free mass. Allometric scaling by fat-free mass reduced the between-subject variability by 32% for clearance and by 18 to 26% for volume of both peripheral compartments compared to linear scaling by WT. A 30-min ceftazidime infusion of 2 g/70 kg WT every 8 h (q8h) achieved robust (> or =90%) probabilities of target attainment (PTAs) for MICs of < or =1 mg/liter in CF patients and < or =3 mg/liter in healthy volunteers. Alternative modes of administration achieved robust PTAs up to markedly higher MICs of < or =8 to 12 mg/liter in CF patients for 5-h infusions of 2 g/70 kg WT q8h and < or =12 mg/liter for continuous infusion of 6 g/70 kg WT daily.
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16
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Wolf MF, Simon A. The use of piperacillin–tazobactam in neonatal and paediatric patients. Expert Opin Drug Metab Toxicol 2008; 5:57-69. [DOI: 10.1517/17425250802614688] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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17
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Treerat P, Widmer F, Middleton PG, Iredell J, George AM. In vitro interactions of tobramycin with various nonantibiotics against Pseudomonas aeruginosa and Burkholderia cenocepacia. FEMS Microbiol Lett 2008; 285:40-50. [PMID: 18513356 DOI: 10.1111/j.1574-6968.2008.01219.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Pseudomonas aeruginosa and Burkholderia cepacia are the major pathogens that colonize the airway surface and cause progressive respiratory failure and high mortality, especially in cystic fibrosis (CF) patients. Tobramycin is the treatment of choice, but persistent usage enables the infectious organisms to activate defence mechanisms, making eradication rarely successful. Combinations of antibiotic and nonantibiotic compounds have been tested in vitro against P. aeruginosa and B. cepacia, but with mixed results. Sodium ions interfere with the bacterial tobramycin uptake system, but amiloride partially reverses this antagonism. In this pilot study, we extend previous findings of the effectiveness of tobramycin in combination with amiloride and other nonantibiotics against a P. aeruginosa type strain, and against four P. aeruginosa strains and one Burkholderia cenocepacia strain isolated from CF patients. Significantly, the four clinical P. aeruginosa strains were tobramycin resistant. We also find that Na+ and K+, but not Cl(-), are the chief antagonists of tobramycin efficacy. These results suggest that chemotherapy for CF patients might not only be compromised by antibiotic-resistant pathogens alone, but by a lack of penetration of antibiotics caused either by bacterial biofilms or the high sodium flux in the CF lung, or by antagonistic effects of some drug combinations, any of which could allow the persistence of drug-susceptible bacteria.
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Affiliation(s)
- Puthayalai Treerat
- Department of Medical and Molecular Biosciences, Faculty of Science, University of Technology Sydney, New South Wales, Australia
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Martin CA, Hoven AD, Cook AM. Therapeutic frontiers: preventing and treating infectious diseases by inhibiting bacterial quorum sensing. Eur J Clin Microbiol Infect Dis 2008; 27:635-42. [DOI: 10.1007/s10096-008-0489-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2007] [Accepted: 02/07/2008] [Indexed: 10/22/2022]
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Bulitta JB, Duffull SB, Kinzig-Schippers M, Holzgrabe U, Stephan U, Drusano GL, Sörgel F. Systematic comparison of the population pharmacokinetics and pharmacodynamics of piperacillin in cystic fibrosis patients and healthy volunteers. Antimicrob Agents Chemother 2007; 51:2497-507. [PMID: 17485505 PMCID: PMC1913222 DOI: 10.1128/aac.01477-06] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2006] [Revised: 02/11/2007] [Accepted: 04/27/2007] [Indexed: 11/20/2022] Open
Abstract
Respiratory tract infections cause 90% of premature mortality in patients with cystic fibrosis (CF). Treatment of Pseudomonas aeruginosa infection is often very problematic. Piperacillin-tazobactam has good activity against P. aeruginosa, but its pharmacokinetics (PK) in CF patients has not been compared to the PK in healthy volunteers in a controlled clinical study. Therefore, we compared the population PK and pharmacodynamics (PD) of piperacillin between CF patients and healthy volunteers. We studied 8 adult (median age, 20 years) CF patients (average total body weight [WT], 43.1 +/- 7.8 kg) and 26 healthy volunteers (WT, 71.1 +/- 11.8 kg) who each received 4 g piperacillin as a 5-min intravenous infusion. We determined piperacillin levels by high-performance liquid chromatography, and we used NONMEM for population PK and Monte Carlo simulation. We used a target time of nonprotein-bound concentration above the MIC of 50%, which represents near-maximal bacterial killing. Unscaled total clearance was 25% lower, and the volume of distribution was 31% lower in CF patients. Allometric scaling by lean body mass reduced the unexplained (random) between-subject variability in clearance by 26% compared to the variability of linear scaling by WT. A standard dosage regimen of 3 g/70 kg body WT every 4 h as a 30-min infusion (daily dose, 18 g) achieved a robust (> or =90%) probability-of-target attainment (PTA) for MICs of < or =12 mg/liter in CF patients and < or =16 mg/liter in healthy volunteers. Alternative modes of administration allowed a marked dose reduction to 9 g daily. Prolonged (4-h) infusions of 3 g/70 kg WT every 8 h and continuous infusion (daily dose, 9 g), achieved a robust PTA for MICs of < or =16 mg/liter in both groups. Piperacillin achieved PTA expectation values of 64% and 89% against P. aeruginosa infection in CF patients, based on susceptibility data from two German CF clinics.
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Affiliation(s)
- J B Bulitta
- Institute for Biomedical and Pharmaceutical Research, Nürnberg-Heroldsberg, Germany
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Abstract
PURPOSE OF REVIEW This review will define pulmonary exacerbations in cystic fibrosis and explain their importance in the pathophysiology and progression of this condition. I will stress the importance of prevention, where this is possible, and prompt treatment, where prevention has failed. The management of chronic pulmonary infection with Pseudomonas aeruginosa will be discussed, together with other, less tenacious organisms. RECENT FINDINGS Developments in the treatment of chronic pulmonary infection with P. aeruginosa include new data on antibiotic selection through sensitivity testing and alternative antibiotic dosing regimens. Therapies which target the P. aeruginosa biofilm will be discussed, including those which are currently in use (such as azithromycin) as well as those being evaluated in preclinical studies. Supportive care and the role of noninvasive ventilation are discussed. SUMMARY The prevention and prompt treatment of pulmonary exacerbations is a central component of cystic fibrosis care.
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Affiliation(s)
- Alan Smyth
- Division of Respiratory Medicine, Nottingham City Hospital, Nottingham, UK.
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Roveta S, Schito AM, Marchese A, Schito GC. Microbiological rationale for the utilisation of prulifloxacin, a new fluoroquinolone, in the eradication of serious infections caused by Pseudomonas aeruginosa. Int J Antimicrob Agents 2005; 26:366-72. [PMID: 16216467 DOI: 10.1016/j.ijantimicag.2005.07.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2005] [Accepted: 07/29/2005] [Indexed: 11/21/2022]
Abstract
Minimal inhibitory concentrations (MICs) of prulifloxacin were evaluated in comparison with ciprofloxacin, levofloxacin and moxifloxacin against a large collection (N = 300) of Pseudomonas aeruginosa strains characterised according to the CLSI/NCCLS microdilution method. Additional in vitro tests (time-kill curves and mutant prevention concentration (MPC) determinations) were carried out. Assuming a susceptibility breakpoint for prulifloxacin identical to that of ciprofloxacin, the new fluoroquinolone emerged as the most potent antibiotic (72% of susceptible strains versus 65%, 61% and 23% for ciprofloxacin, levofloxacin and moxifloxacin, respectively). Time-kill tests at 4x MIC confirmed the pronounced bactericidal potency of the drug against P. aeruginosa. Amongst the members of the fluoroquinolone class assessed, prulifloxacin produced the lowest MPC values (< or = 4 mg/L). Our in vitro results indicate that prulifloxacin represents the most powerful antipseudomonal drug available today.
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Affiliation(s)
- Simona Roveta
- Microbiology Section, Di.SCAT Department, University of Genoa Medical School, Largo R. Benzi 10, 16132 Genoa, Italy
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Smyth E, David TJ, Patel L, Ashcroft P, Sanyal D, Vyas J. Prevalence of resistant Pseudomonas aeruginosa with elective and rescue intravenous antibiotic regimens in children with cystic fibrosis. Int J Antimicrob Agents 2005; 26:95-6. [PMID: 15970432 DOI: 10.1016/j.ijantimicag.2005.04.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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