Prevalence of CTX-M-Type and PER extended-spectrum β-lactamases among klebsiella spp. isolated from clinical specimens in the Teaching Hospital of Kashan, Iran

الملخص EN

Background: Extended-spectrum β-lactamases (ESBLs) is one of the most important mechanisms of resistance to β-lactams especially among Enterobacteriaceae family including Klebsiella spp.

Different types of extended-spectrum β-lactamases including CTX-M-type and PER enzymes are identified among gram negative bacteria.

Objectives: The current study aimed to determine the prevalence of CTX-M-type and PER extended-spectrum β-lactamases among Klebsiella spp.

isolated from clinical specimens in the teaching hospital of Kashan, Iran.

Patients and Methods: One hundred Klebsiella spp.

were isolated from clinical specimens of hospitalized patients at Shahid-Beheshti hospital from December 2012 to November 2013.

Disk diffusion method was used to determine the susceptibility of these isolates to 14 different antimicrobial agents; disks were purchased from MAST company (United Kingdom).

The phenotypic double disk synergy confirmatory test was used to screen the isolates to produce extended-spectrum β-lactamase.

DNAs of isolates were extracted using boiling method and PCR assay was used to characterize the blaCTX-M type and blaPER genes.

The purified PCR products were sent to Macrogen research company (Korea) for sequencing.

Results: Of the total 100 Klebsiella isolates, %93 was susceptible to imipenem.

Resistance to ampicillin, ceftazidime, ceftriaxone, aztreonam and cefotaxime was (92%), (67%), (65%), (64%) and (59%), respectively.

The phenotypic confirmatory test (PCT) confirmed that 35% (n = 35) of the isolates were ESBL-producing Klebsiella strains.

The prevalence of blaCTX-M type and blaRER genes among Klebsiella isolates were 28% (n = 28) and 9% (n = 9), respectively.

Conclusions: The prevalence of ESBL-producing Klebsiella strains in Shahid-Beheshti hospital in Kashan has increased.

The study concluded that there was a high prevalence of the blaCTX-M type gene among ESBL positive isolates.