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Characterization of Oxacillinase and Metallo-β-Lactamas Genes and Molecular Typing of Clinical Isolates of Acinetobacter baumannii in Ahvaz, South-West of Iran

BACKGROUND: Carbapenem resistant Acinetobacter baumannii is an important nosocomial pathogen associated with a variety of infections. OBJECTIVES: The current study aimed to characterize the antimicrobial susceptibility, analyze the prevalence of oxacillinase and metallo-β-lactamase (MBL) genes and m...

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Autores principales: Shoja, Saeed, Moosavian, Mojtaba, Rostami, Soodabeh, Abbasi, Fariba, Tabatabaiefar, Mohammad Amin, Peymani, Amir
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Kowsar 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4976075/
https://www.ncbi.nlm.nih.gov/pubmed/27540456
http://dx.doi.org/10.5812/jjm.32388
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author Shoja, Saeed
Moosavian, Mojtaba
Rostami, Soodabeh
Abbasi, Fariba
Tabatabaiefar, Mohammad Amin
Peymani, Amir
author_facet Shoja, Saeed
Moosavian, Mojtaba
Rostami, Soodabeh
Abbasi, Fariba
Tabatabaiefar, Mohammad Amin
Peymani, Amir
author_sort Shoja, Saeed
collection PubMed
description BACKGROUND: Carbapenem resistant Acinetobacter baumannii is an important nosocomial pathogen associated with a variety of infections. OBJECTIVES: The current study aimed to characterize the antimicrobial susceptibility, analyze the prevalence of oxacillinase and metallo-β-lactamase (MBL) genes and molecular typing of clinical isolates of A. baumannii. MATERIALS AND METHODS: A total of 124 non-repetitive isolates of A. baumannii were collected from various clinical specimens in two teaching hospitals in Ahvaz, south-west of Iran. Antimicrobial susceptibility test was carried out by disk diffusion method. The minimum inhibitory concentrations (MICs) of imipenem, meropenem, colistin and tigecycline were determined using E-test. To screen for MBL production, double disk synergy (DDs) test and MBL E-test were performed. The presence of bla(OXA-23-like), bla(OXA-24-like), bla(OXA-51-like), bla(OXA-58-like), bla(VIM), bla(IMP) and bla(SPM) genes was assessed by polymerase chain reaction (PCR). To identify clonal relatedness, all isolates were subjected to repetitive sequence-based PCR (rep-PCR) RESULTS: Based on disk diffusion results, the highest rate of resistance was observed in rifampin (96.8%). Colistin and polymyxin-B were the most effective agents in vitro. According to the MIC results, the rate of resistance to imipenem, meropenem, colistin and tigecycline were 78.2%, 73.4%, 0.8% and 0, respectively. Metallo-β-lactamase production was positive in 42.3% and 79.4% of the isolates by DDs test and E-test, respectively. All isolates (100%) carried bla(OXA-51-like )gene. According to the results of multiplex PCR, bla(OXA-23-like) and bla(OXA-24-like )genes were detected in 85.6% and 6.2% of carbapenem resistant isolates, respectively. No bla(OXA-58- like), bla(VIM), bla(IMP) and bla(SPM) were detected. By rep-PCR, carbapenem resistant isolates were separated into six genotypes (A to F). Genotype A (30.9%) was the most prevalent (P value < 0.001). Genotypes B and C were found in 28.9% and 26.8% of the isolates, respectively. CONCLUSIONS: The rate of carbapenem resistant A. baumannii isolates were high in this study. Since, bla(OXA-58-like) or MBL genes were not detected, it seems that resistance to carbapenems is related to bla(OXA-23-like )and bla(OXA-24-like). Moreover, bla(OXA-23-like )was the most prevalent oxacillinase (OXA) gene. Most of the isolates belonged to one of the four dominant genotypes indicating clonal dissemination in the hospitals under study. In order to control the spread of carbapenem-resistant A. baumannii, infection- control strategies are needed.
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spelling pubmed-49760752016-08-18 Characterization of Oxacillinase and Metallo-β-Lactamas Genes and Molecular Typing of Clinical Isolates of Acinetobacter baumannii in Ahvaz, South-West of Iran Shoja, Saeed Moosavian, Mojtaba Rostami, Soodabeh Abbasi, Fariba Tabatabaiefar, Mohammad Amin Peymani, Amir Jundishapur J Microbiol Research Article BACKGROUND: Carbapenem resistant Acinetobacter baumannii is an important nosocomial pathogen associated with a variety of infections. OBJECTIVES: The current study aimed to characterize the antimicrobial susceptibility, analyze the prevalence of oxacillinase and metallo-β-lactamase (MBL) genes and molecular typing of clinical isolates of A. baumannii. MATERIALS AND METHODS: A total of 124 non-repetitive isolates of A. baumannii were collected from various clinical specimens in two teaching hospitals in Ahvaz, south-west of Iran. Antimicrobial susceptibility test was carried out by disk diffusion method. The minimum inhibitory concentrations (MICs) of imipenem, meropenem, colistin and tigecycline were determined using E-test. To screen for MBL production, double disk synergy (DDs) test and MBL E-test were performed. The presence of bla(OXA-23-like), bla(OXA-24-like), bla(OXA-51-like), bla(OXA-58-like), bla(VIM), bla(IMP) and bla(SPM) genes was assessed by polymerase chain reaction (PCR). To identify clonal relatedness, all isolates were subjected to repetitive sequence-based PCR (rep-PCR) RESULTS: Based on disk diffusion results, the highest rate of resistance was observed in rifampin (96.8%). Colistin and polymyxin-B were the most effective agents in vitro. According to the MIC results, the rate of resistance to imipenem, meropenem, colistin and tigecycline were 78.2%, 73.4%, 0.8% and 0, respectively. Metallo-β-lactamase production was positive in 42.3% and 79.4% of the isolates by DDs test and E-test, respectively. All isolates (100%) carried bla(OXA-51-like )gene. According to the results of multiplex PCR, bla(OXA-23-like) and bla(OXA-24-like )genes were detected in 85.6% and 6.2% of carbapenem resistant isolates, respectively. No bla(OXA-58- like), bla(VIM), bla(IMP) and bla(SPM) were detected. By rep-PCR, carbapenem resistant isolates were separated into six genotypes (A to F). Genotype A (30.9%) was the most prevalent (P value < 0.001). Genotypes B and C were found in 28.9% and 26.8% of the isolates, respectively. CONCLUSIONS: The rate of carbapenem resistant A. baumannii isolates were high in this study. Since, bla(OXA-58-like) or MBL genes were not detected, it seems that resistance to carbapenems is related to bla(OXA-23-like )and bla(OXA-24-like). Moreover, bla(OXA-23-like )was the most prevalent oxacillinase (OXA) gene. Most of the isolates belonged to one of the four dominant genotypes indicating clonal dissemination in the hospitals under study. In order to control the spread of carbapenem-resistant A. baumannii, infection- control strategies are needed. Kowsar 2016-02-13 /pmc/articles/PMC4976075/ /pubmed/27540456 http://dx.doi.org/10.5812/jjm.32388 Text en Copyright © 2016, Ahvaz Jundishapur University of Medical Sciences. http://creativecommons.org/licenses/by-nc/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly cited.
spellingShingle Research Article
Shoja, Saeed
Moosavian, Mojtaba
Rostami, Soodabeh
Abbasi, Fariba
Tabatabaiefar, Mohammad Amin
Peymani, Amir
Characterization of Oxacillinase and Metallo-β-Lactamas Genes and Molecular Typing of Clinical Isolates of Acinetobacter baumannii in Ahvaz, South-West of Iran
title Characterization of Oxacillinase and Metallo-β-Lactamas Genes and Molecular Typing of Clinical Isolates of Acinetobacter baumannii in Ahvaz, South-West of Iran
title_full Characterization of Oxacillinase and Metallo-β-Lactamas Genes and Molecular Typing of Clinical Isolates of Acinetobacter baumannii in Ahvaz, South-West of Iran
title_fullStr Characterization of Oxacillinase and Metallo-β-Lactamas Genes and Molecular Typing of Clinical Isolates of Acinetobacter baumannii in Ahvaz, South-West of Iran
title_full_unstemmed Characterization of Oxacillinase and Metallo-β-Lactamas Genes and Molecular Typing of Clinical Isolates of Acinetobacter baumannii in Ahvaz, South-West of Iran
title_short Characterization of Oxacillinase and Metallo-β-Lactamas Genes and Molecular Typing of Clinical Isolates of Acinetobacter baumannii in Ahvaz, South-West of Iran
title_sort characterization of oxacillinase and metallo-β-lactamas genes and molecular typing of clinical isolates of acinetobacter baumannii in ahvaz, south-west of iran
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4976075/
https://www.ncbi.nlm.nih.gov/pubmed/27540456
http://dx.doi.org/10.5812/jjm.32388
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