The Prevalence of CTX-M-15 Extended-spectrum β-Lactamases Among spp. and spp. Isolated from three Iranian Hospitals.

Bacterial antimicrobial resistance mediated by the production of extended-spectrum β-lactamases (ESBLs) is considered a major threat for treatment of and infections. This study aimed to investigate antibiotic resistance patterns of and spp. and presence of CTX-M from three teaching hospitals in Iran. In the present study, 58 clinical and 91 isolates were recovered between 2009 and 2013 from 3 teaching hospitals in Iran. After culture and antimicrobial susceptibility testing, ESBL-positive isolates were subjected to further investigations. These included polymerase chain reaction (PCR) amplification and DNA sequencing of encoding plasmid. In both genera, high sensitivity to gentamicin and amikacin, but high resistance to ampicillin, tetracycline, and trimethoprim-sulfamethoxazole, was found. Molecular investigation showed that 31.8% isolates of spp. and 34.48% isolates of spp. were CTX-M positive and all of them were also positive for ISEcpI. Protein translation, comparing with reference sequences, showed that all CTX-M isolates belong to CTX-M-15. The present study suggests that the resistance of ESBLs-producing and spp. in Iran hospitals is very serious. Therefore, strategies to minimize the spread of ESBL-producing isolates should be implemented.