Characterization of CTX-M-Type Extend-Spectrum ?-Lactamase Producing Klebsiella spp. in Kashan, Iran.
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ABSTRACT: CONTEXT:The CTX-M family consists of more than 50 ?-lactamases, which are grouped on the basis of sequences into five subtypes including CTX-M-1, CTX-M-2, CTX-M-8, CTX-M-9 and CTX-M-25. OBJECTIVES:The current study aimed to detect subtypes of CTX-M extended-spectrum ?-lactamases (ESBLs) among ESBL positive Klebsiella isolates from patients in Kashan, Iran. MATERIALS AND METHODS:A total of 100 clinical isolates of Klebsiella were collected and the isolates, which showed resistance or reduced susceptibility to cefotaxime, ceftazidime and/or aztreonam by the disk diffusion method were selected. These isolates were identified as ESBL-producing isolates by double disk synergy tests using clavulanic acid, cefotaxime, ceftazidime and aztreonam. The blaCTX-M type determinants were identified by the Polymerase Chain Reaction (PCR) method followed by DNA sequencing. RESULTS:Of the 100 Klebsiella isolates, 41 (41%) demonstrated resistance or reduced susceptibility to ceftazidime and/or aztreonam and 35% (n = 35) were ESBL-producers. Twenty-eight (8o%) of the ESBL-producing isolates carried the blaCTX-M type genes. Based on PCR assays and sequencing of blaCTX-M genes, CTX-M-1, CTX-M-2 and CTX-M-9 were identified in 21 (60%), 15 (42%) and nine (34%) of these isolates, respectively (GenBank accession numbers KJ803828-KJ803829). CONCLUSIONS:Our study showed that the frequency of blaCTX-M genes among Klebsiella isolates in our region is at an alarming rate. Also, we found a high prevalence of blaCTX-M-1 ?-lactamase in Klebsiella isolates in Kashan.
SUBMITTER: Afzali H
PROVIDER: S-EPMC4644347 | biostudies-literature | 2015 Oct
REPOSITORIES: biostudies-literature
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