First report of TEM-104-, SHV-99-, SHV-108-, and SHV-110-producing Klebsiella pneumoniae from Iran

Abstract

Introduction: Extended-spectrum beta-lactamases (ESBLs) are bacterial enzymes capable of hydrolyzing beta-lactams. The aim of this study was to describe the prevalence of TEM- and SHV-type ESBL-producing Klebsiella pneumoniae strains in Zahedan, Southeast Iran. Methods: A total of 170 non-repetitive K. pneumoniae strains were collected from patients referred to three teaching hospitals of Zahedan. Antibiotic susceptibility testing was determined for 17 antibiotics using the Kirby-Bauer disc diffusion method. The frequency of ESBL-producing strains was calculated, and minimum inhibitory concentrations of ESBLproducing strains were determined for cefotaxime, ceftazidime, ceftriaxone, and cefpodoxime. The presence of blaTEM and blaSHV genes was tested in all ESBL-producing strains using polymerase chain reaction and DNA sequencing. Results: Among the 170 K. pneumoniae clinical isolates, 55 (32.4%) were ESBL producers; 92.7% (n=51) and 72.7% (n=40) of the isolates carried the blaSHV and blaTEM genes, respectively, and 67.3% (n=37) carried both genes. The sequencing results showed that all blaTEM types were blaTEM-1, except for two isolates that were blaTEM-104. The blaSHV types were blaSHV-1, blaSHV-11, blaSHV-12, blaSHV-99, blaSHV-108, and blaSHV-110. Conclusions: The percentage of blaTEM and blaSHV among ESBL-producing K. pneumoniae isolates from Zahedan is relatively high, indicating the need for further surveillance and consideration in antibiotic use. To the best of our knowledge, this is the first report of TEM-104-, SHV-99-, SHV-108-, and SHV-110-type ESBLs among clinical isolates of K. pneumoniae from Iran, and TEM-1, SHV-1, SHV-11, and SHV-12 appear to be the dominant ESBLs in this region.