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Plasmid-Mediated Fluoroquinolone Resistance in Pseudomonas aeruginosa and Acinetobacter baumannii

Introduction   Pseudomonas aeruginosa and Acinetobacter baumannii are important pathogens in health care–associated infections. Fluoroquinolone resistance has emerged in these pathogens. In this study, we aimed to determine the occurrence of plasmid-mediated quinolone resistance (PMQR) determinants...

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Autores principales: Venkataramana, Geetha P., Lalitha, Aishwarya K.V., Mariappan, Shanthi, Sekar, Uma
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Thieme Medical and Scientific Publishers Pvt. Ltd. 2022
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9473940/
https://www.ncbi.nlm.nih.gov/pubmed/36119417
http://dx.doi.org/10.1055/s-0042-1742636
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author Venkataramana, Geetha P.
Lalitha, Aishwarya K.V.
Mariappan, Shanthi
Sekar, Uma
author_facet Venkataramana, Geetha P.
Lalitha, Aishwarya K.V.
Mariappan, Shanthi
Sekar, Uma
author_sort Venkataramana, Geetha P.
collection PubMed
description Introduction   Pseudomonas aeruginosa and Acinetobacter baumannii are important pathogens in health care–associated infections. Fluoroquinolone resistance has emerged in these pathogens. In this study, we aimed to determine the occurrence of plasmid-mediated quinolone resistance (PMQR) determinants ( qnrA , qnrB , qnrS , aac(6′)-Ib-cr , oqxAB , and qepA ) by polymerase chain reaction (PCR) and the transmissibility of plasmid-borne resistance determinants in clinical isolates of P. aeruginosa and A. baumannii . Materials and Methods  The study included P. aeruginosa (85) and A. baumannii (45) which were nonduplicate, clinically significant, and ciprofloxacin resistant. Antibiotic susceptibility testing was done by disk diffusion method for other antimicrobial agents, namely amikacin, ceftazidime, piperacillin/tazobactam, ofloxacin, levofloxacin, and imipenem. Minimum inhibitory concentration of ciprofloxacin was determined. Efflux pump activity was evaluated using carbonyl-cyanide m-chlorophenylhydrazone (CCCP). The presence of PMQR genes was screened by PCR amplification. Transferability of PMQR genes was determined by conjugation experiment, and plasmid-based replicon typing was performed. Results  Resistance to other classes of antimicrobial agents was as follows: ceftazidime (86.9%), piperacillin/tazobactam (73.8%), imipenem (69.2%), and amikacin (63.8%). The minimal inhibitory concentration (MIC)50 and MIC90 for ciprofloxacin were 64 and greater than or equal to 256 µg/mL, respectively. There was a reduction in MIC for 37 (28.4%) isolates with CCCP. In P. aeruginosa , 12 (14.1%) isolates harbored qnrB , 12 (14.1%) qnrS , 9 (10.5%) both qnrB and qnrS , 66 (77.6%) aac(6′)-Ib-cr , and 3 (3.5%) oqxAB gene. In A. baumannii , qnrB was detected in 2 (4.4%), 1 (2.2%) harbored both the qnrA and qnrS , 1 isolate harbored qnrB and qnrS , 21 (46.6%) aac(6′)-Ib-cr , and 1 (2.2%) isolate harbored oqxAB gene. Notably, qepA gene was not detected in any of the study isolates. Conjugation experiments revealed that 12 (9.2%) were transferable. Of the transconjugants, seven (58.3%) belonged to IncFII type plasmid replicon, followed by four (33.3%) IncA/C and one (8.3%) IncFIC type. Conclusion  The plasmid-mediated resistance aac(6′)-Ib-cr gene is primarily responsible for mediating fluoroquinolone resistance in clinical isolates of P . aeruginosa and A. baumannii . The predominant plasmid type is IncFII.
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spelling pubmed-94739402022-09-15 Plasmid-Mediated Fluoroquinolone Resistance in Pseudomonas aeruginosa and Acinetobacter baumannii Venkataramana, Geetha P. Lalitha, Aishwarya K.V. Mariappan, Shanthi Sekar, Uma J Lab Physicians Introduction   Pseudomonas aeruginosa and Acinetobacter baumannii are important pathogens in health care–associated infections. Fluoroquinolone resistance has emerged in these pathogens. In this study, we aimed to determine the occurrence of plasmid-mediated quinolone resistance (PMQR) determinants ( qnrA , qnrB , qnrS , aac(6′)-Ib-cr , oqxAB , and qepA ) by polymerase chain reaction (PCR) and the transmissibility of plasmid-borne resistance determinants in clinical isolates of P. aeruginosa and A. baumannii . Materials and Methods  The study included P. aeruginosa (85) and A. baumannii (45) which were nonduplicate, clinically significant, and ciprofloxacin resistant. Antibiotic susceptibility testing was done by disk diffusion method for other antimicrobial agents, namely amikacin, ceftazidime, piperacillin/tazobactam, ofloxacin, levofloxacin, and imipenem. Minimum inhibitory concentration of ciprofloxacin was determined. Efflux pump activity was evaluated using carbonyl-cyanide m-chlorophenylhydrazone (CCCP). The presence of PMQR genes was screened by PCR amplification. Transferability of PMQR genes was determined by conjugation experiment, and plasmid-based replicon typing was performed. Results  Resistance to other classes of antimicrobial agents was as follows: ceftazidime (86.9%), piperacillin/tazobactam (73.8%), imipenem (69.2%), and amikacin (63.8%). The minimal inhibitory concentration (MIC)50 and MIC90 for ciprofloxacin were 64 and greater than or equal to 256 µg/mL, respectively. There was a reduction in MIC for 37 (28.4%) isolates with CCCP. In P. aeruginosa , 12 (14.1%) isolates harbored qnrB , 12 (14.1%) qnrS , 9 (10.5%) both qnrB and qnrS , 66 (77.6%) aac(6′)-Ib-cr , and 3 (3.5%) oqxAB gene. In A. baumannii , qnrB was detected in 2 (4.4%), 1 (2.2%) harbored both the qnrA and qnrS , 1 isolate harbored qnrB and qnrS , 21 (46.6%) aac(6′)-Ib-cr , and 1 (2.2%) isolate harbored oqxAB gene. Notably, qepA gene was not detected in any of the study isolates. Conjugation experiments revealed that 12 (9.2%) were transferable. Of the transconjugants, seven (58.3%) belonged to IncFII type plasmid replicon, followed by four (33.3%) IncA/C and one (8.3%) IncFIC type. Conclusion  The plasmid-mediated resistance aac(6′)-Ib-cr gene is primarily responsible for mediating fluoroquinolone resistance in clinical isolates of P . aeruginosa and A. baumannii . The predominant plasmid type is IncFII. Thieme Medical and Scientific Publishers Pvt. Ltd. 2022-02-09 /pmc/articles/PMC9473940/ /pubmed/36119417 http://dx.doi.org/10.1055/s-0042-1742636 Text en The Indian Association of Laboratory Physicians. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. ( https://creativecommons.org/licenses/by-nc-nd/4.0/ ) https://creativecommons.org/licenses/by-nc-nd/4.0/This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License, which permits unrestricted reproduction and distribution, for non-commercial purposes only; and use and reproduction, but not distribution, of adapted material for non-commercial purposes only, provided the original work is properly cited.
spellingShingle Venkataramana, Geetha P.
Lalitha, Aishwarya K.V.
Mariappan, Shanthi
Sekar, Uma
Plasmid-Mediated Fluoroquinolone Resistance in Pseudomonas aeruginosa and Acinetobacter baumannii
title Plasmid-Mediated Fluoroquinolone Resistance in Pseudomonas aeruginosa and Acinetobacter baumannii
title_full Plasmid-Mediated Fluoroquinolone Resistance in Pseudomonas aeruginosa and Acinetobacter baumannii
title_fullStr Plasmid-Mediated Fluoroquinolone Resistance in Pseudomonas aeruginosa and Acinetobacter baumannii
title_full_unstemmed Plasmid-Mediated Fluoroquinolone Resistance in Pseudomonas aeruginosa and Acinetobacter baumannii
title_short Plasmid-Mediated Fluoroquinolone Resistance in Pseudomonas aeruginosa and Acinetobacter baumannii
title_sort plasmid-mediated fluoroquinolone resistance in pseudomonas aeruginosa and acinetobacter baumannii
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9473940/
https://www.ncbi.nlm.nih.gov/pubmed/36119417
http://dx.doi.org/10.1055/s-0042-1742636
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