Detection of blaPSE and blaTEM genes encoding B-Lactamase in clinical samples of Salmonella typhimurium by Multiplex PCR

Background and Aim: B-Lactam antibiotics are widely used in the treatment of salmonellosis. Alarming reports have pointed out the rapid development of resistance to these agents, involving Salmonella serovars such as Enteritidis, Typhimurium, Panama, and Typhi in several countries. The aim of this study was to investigate the antibiotic resistance profiles and the prevalence of blaPSE and blaTEM genes among Salmonella typhimurium in humans in Tehran. Materials and Methods: All ۴۶ isolates were detected from a collection of human sampels in veterinary faculty, Islamic Azad University. Samples were tested to resist to ampicillin, chloramphenicol, tetracycline, cephalothin, ceftriaxone, ceftazidime, amoxicillin-clavulanate, gentamicin, trimethoprim-sulfamethoxazole and amikacin. Isolates examined by Polymerase chain reaction analysis to detect the presence of the blaPSE and blaTEM resistance genes. Results  and Conclusions: Results of antibiogram showed (۸۲.۶%) resistance to ampicillin, (۸۰.۴%) to chloramphenicol, (۶۹.۵%) to tetracycline, (۸۰.۴%) to cephalothin, (۵۶.۵%) to amoxicillin-clavulanate and (۴۳.۴%) to trimethoprim-sulfamethoxazole. Among ۴۶ Salmonella isolates, ۴۳ (۹۳.۴%) showed resistance to two or more antibiotic families. blaTEM gene were identified in ۱ (۲.۱%) Salmonella isolates. All the isolates were negative for blaPSE gene. Salmonella strains among humans were resistant to ampicillin, cephalothin, chloramphenicol, tetracycline, amoxicillin-clavulanic acid and trimethoprim-sulfamethoxazole.The identification of ESBL genes in Salmonella and MDR Multi Drug Resistance (۹۳.۴%) has considerable implications for public health. Carrying two or more beta-lactamase resistance gene is very worring, because certain combinations of genes could effectively limit all β-lactam therapeutic options. Besides, ESBL producing bacteria are typically associated with multidrug resistance