Prevalence of bla CTX-M Genes among ESBL-Producing Klebsiella pneumoniae in Bushehr Province, Iran

Introduction and Objectives: CTX-M-type extended-spectrum β-lactamases (ESBLs) are the most prevalent ESBLs in bacterial members of Enterobacteriaceae family including Klebsiella pneumoniae. The global spread of CTX-M-producing K. pneumoniae is a major concern in most countries as well as Iran. The aim of this study was to determine the prevalence of CTX-M types of β-lactamases in ESBL-producing K. pneumoniae. Materials and Methods: A total of 212 non-duplicate K. pneumoniae were collected from different clinical specimens and confirmed using amplification of malate dehydrogenase (mdh) gene. ESBL production was confirmed using combine disk test (CDT). In addition, PCR technique was used for genotypic detection of CTX-M types in ESBL-Producing isolates. Results: Fifty-six (26.41%) out of 212 isolates were confirmed as ESBL producer. Based on the results of PCR, bla CTX-M was found in 83.92% of ESBL-producing K. pneumoniae. The prevalence of bla CTX-M-1 and bla CTX-M-9 genes among CTX-M harboring isolates was 97.8% and 2.1%, respectively. Neither CTX-M-2 nor CTX-M-8 was found in our isolates. Conclusion: Our data revealed the low prevalence of ESBL-producing K. pneumoniae in Bushehr province although the prevalence of bla CTX-M-1 genes was high among ESBL-producing K. pneumoniae isolates. Screening of ESBL production in clinical isolates could help in controlling infection in healthcare and community settings.

Keywords:

Klebsiella pneumoniae , ESBLs , CTX-M genes , PCR.