Phenotypic and molecular characterization of plasmid mediated AmpC ?-lactamases among Escherichia coli, Klebsiella spp., and Proteus mirabilis isolated from urinary tract infections in Egyptian hospitals
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Date
2014
Authors
Journal Title
Journal ISSN
Volume Title
Type
Article
Publisher
Hindawi Publishing Corporation
Series Info
BioMed Research International
2014
2014
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Abstract
The incidence of resistance by Enterobacteriaceae to ?-lactam/?- lactamase inhibitors combination is increasing in Egypt. Three phenotypic techniques, comprising AmpC disk diffusion and inhibition dependent methods using phenylboronic acid (PBA) and cloxacillin, were compared to PCR based method for detection of plasmid mediated AmpC ?-lactamase in common urinary tract isolates. A total of 143 isolates, including E. coli, Klebsiella pneumonia, and Proteus mirabilis, were collected from urinary tract infections cases in Egyptian hospitals. Plasmid encoded AmpC genes were detected by PCR in 88.46% of cefoxitin resistant isolates. The most prevalent AmpC gene family was CIT including CMY-2, CMY-4, and two CMY-2 variants. The second prevalent gene was DHA-1 which was detected in E. coli and Klebsiella pneumonia. The genes EBC, FOX, and MOX were also detected but in small percentage. Some isolates were identified as having more than one pAmpC gene. The overall sensitivity and specificity of phenotypic tests for detection of AmpC ?-lactamase showed that AmpC disk diffusion and inhibition dependent method by cloxacillin were the most sensitive and the most specific disk tests. PCR remains the gold standard for detection of AmpC ?-lactamases. This study represents the first report of CMY-2 variants of CMY-42 and CMY-102 ?-lactamase-producing E. coli, Klebsiella pneumonia, and Proteus mirabilis isolates in Egypt. � 2014 Mai M. Helmy and Reham Wasfi.
Description
Scopus
Keywords
bacterial enzyme, benzeneboronic acid, beta lactamase AmpC, cefoxitin, cloxacillin, plasmid DNA, AmpC beta-lactamases, bacterial protein, beta lactamase, antibiotic resistance, article, bacterial gene, bacterium detection, bacterium isolate, cmy 2 gene, cmy 4 gene, controlled study, disk diffusion, DNA template, ebc gene, Egypt, Escherichia coli, Escherichia coli infection, fox gene, genetic variability, gold standard, Klebsiella oxytoca, Klebsiella pneumoniae, Klebsiella pneumoniae infection, mox gene, multigene family, nonhuman, phenotype, plasmid, polymerase chain reaction, predictive value, Proteus infection, Proteus mirabilis, Proteus vulgaris, sensitivity and specificity, urinary tract infection, agar gel electrophoresis, enzymology, Escherichia coli, genetics, genotype, hospital, human, isolation and purification, Klebsiella, microbial sensitivity test, microbiology, phenotype, plasmid, Proteus mirabilis, urinary tract infection, Bacterial Proteins, beta-Lactamases, Egypt, Electrophoresis, Agar Gel, Escherichia coli, Genotype, Hospitals, Humans, Klebsiella, Microbial Sensitivity Tests, Phenotype, Plasmids, Proteus mirabilis, Urinary Tract Infections