Frequency of CTX-M-1 gene in Escherichia coli isolates of ESBL-producing enzyme in clinical samples by polymerase chain reaction (PCR) in Yasuj

Resistance to β-lactam antibiotics in the clinical isolates, in most cases is caused by βlactamase enzymes. In recent years, The incidence of broad-spectrum β-lactamase enzymes (ESBLs) among clinical isolates especially E.coli is greatly increased, since the β-lactamase have several subfamilies, using universal primers designed to detect the following complete families could be useful. β-lactamase producing enzymes (ESBLs) of E. coli has created many problems for patients. β-lactamase CTX-M-1 gene is the cause of resistance. The aim of this study was to evaluate CTX-M-1gene in E.coli.

In this practical study, susceptibility of isolated bacteria to 13 antibiotics were indicated by disk diffusion method according to CLSI guidelines and strains were analyzed for the presence of widespread βlactamase enzymes via two-disc synergy method. Thus، the prevalence of CTX-M1 ESBL gene samples were determined using PCR and the data were analyzed using ANOVA.

A total of 200 isolates of E.coli were isolated. The presence of CTX-M-1 gene were also isolated using the PCR method. From 200 strains studied, 62 (31%), of strains produced ESBL. After PCR processing of 62 produced ESBL, 43 isolates (69.4%) were identified as CTX-M-1 genes. Also, antibiotic susceptibility test showed the highest percentage of resistance to Cotrimoxazole antibiotic (50%) and the lowest antibiotic resistance to imipenem (0%).

The results of this study showed the high percentage of β-lactamase resistance among of E.coli strains. This is a serious public hazard that should be pointed out to measures for preventing this hazard. Considering the sensitivity of the studied beta-lactam resistant isolates and isolates in Iran to imipenem, a carbapenem with a non-beta-lactam antibiotic is recommended for the treatment of nosocomial infections caused by these strains