Detection of FOX, MOX, and ACT Genes in ESBL-producing Klebsiella pneumoniae Strains

Background and An increasing emergence of multidrug resistance among Klebsiella pneumoniae nosocomial isolates has limited the therapeutic options for treatment. The beta-lactamases are the major defense of gram-negative bacteria against antibiotics. The aim of this study was the detection of ESBLs and Amp-C enzymes and MOX، FOX، and ACT genes in K. pneumoniae strains isolated from hospitalized patients in Tehran hospitals during 2011-2013. This study was conducted in 120 K. pneumoniae isolates from Imam Hossein، Taleghani and Mofid Children''s hospitals in Tehran، Iran. Antibiotic susceptibility tests were performed using Kirby-Bauer disc diffusion and Broth Microdilution methods. The detection of Amp-C and ESBLs enzymes was carried out according to CLSI guidelines. The MOX، FOX، and ACT genes were detected by PCR and sequencing methods. Among 120 K. pneumoniae strains، 24 (20%) and 68 (56. 8%) were Amp-C and ESBL positive، respectively. In this study colistin and tigecycline were found more active than other antibiotics. ACT، FOX، and MOX genes were detected in 16 (13%)، 46 (38. 33%) and 43 (35. 83%) of the isolates، respectively. The prevalence of antibiotic resistance genes detected in this study is of great concern and highlights the need for infection control measures including antibacterial management and identification of resistant isolates.