Fatemeh Ashrafian - ۱Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Fatemeh Fallah - Pediatric Infectious Research Center, Mofid Children Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Ali Hashemi - ۱Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Soroor Erfanimanesh - ۱Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Shokouh Amraei - ۱Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Samira Tarashi - ۱Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran

Background: The increasing pattern of Multi-Drug Resistant (MDR) bacteria has limited therapeutic options especially for nosocomial isolates of Klebsiella pneumoniae. Therefore, the aim of this study was the molecular detection of ۱۶S rRNA methylase and blaCTX-M-۱۵ among K. pneumoniae strains isolated from hospitalized patients in Mofid, Imam Hossein and Taleghani hospitals. Materials and Methods:This study was done with ۱۱۰ K.pneumoniae isolated of hospitals in Tehran, Iran. Antibiotic susceptibility tests were carried out by Kirby-Bauer disc diffusion and broth microdilution methods according to CLSI guidelines. ESBL, AmpC and KPC enzymes were detected by CDDT and MHT methods and the armA, rmtB, rmtC, rmtD and blaCTX-M-۱۵ genes were detected by PCR and sequencing techniques. Typing of antibiotic resistance isolates was carried out by PFGE technique. Results: In this study, Fosfomycin, colistin and tigecycline were more active than other antibiotics. Among the ۱۱۰ K. pneumoniae strains, ۶۰(۵۴.۵%), ۳۳(۳۰%) and ۵(۴.۵%) were ESBL, Amp-C and KPC positive, respectively. The existence of blaCTX-M-۱۵, armA and rmtC was detected in ۴۰(۳۶.۳%), ۱۵ (۱۳.۶%) and ۲ (۱.۸%) respectively. Of ۱۵ representative armA-producing K. pneumoniae isolates analyzed by PFGE, ۹ different pulsotypes (PF۱–۹) were identified with Dice coefficients of ;ge۹۰% similarity. Conclusions: High-level aminoglycoside resistance in human pathogens result of ۱۶S rRNA methylases is one of the serious concerns in Iran.

Klebsiella pneumoniae, ۱۶s rRNA methylase, β-lactamases