Isolation of CTX-M1, CTX-M2, CTX-M3 Genes Producing Extended-Spectrum Beta-Lactamase in Clinical Samples of Salmonella typhimurium

The purpose of this study was to isolate CTX-M1 and CTX-M3 genes producing extended-spectrum beta-lactamase (ESBL) from clinical samples of Salmonella typhimurium isolated from poultry in Zabol, Iran. All the strains were cultured and identified in a clinical microbiology laboratory and were recovered from blood and urine cultures. The in vitro presence of ESBL was confirmed with Clinical and Laboratory Standard Institute double disc and PCR methods for CTX-M1 and CTX-M3. The results of this study showed that Salmonella typhimurium samples were resistant to ampicillin (41.66%), gentamycin (0%), cefazolin (0%), amoxi-clav (10%), and azithromycin (5%) antibiotics. The widespread use of ESBL antibiotics has increased the spread of ESBL enzymes in Iran and throughout the world and the use of these antibiotics is becoming more and more limited. Therefore, the complete identification of ESBL by experiments, the restriction of the use of beta-lactam antibiotics and the use of beta-lactamase inhibitors can maintain the efficacy of beta-lactam antibiotics as much as possible.