Background: Escherichia coli (E.coli) bacteria are member of Enterobacteriaceae which are one of the common causes of urinary tract infections. Beta-lactamase enzymes are important factors for antibiotic resistance of beta-lactam family in gram-negative bacteria. According to increasing rate of urinary tract infections due to antibiotic resistant E. coli, the aim of this study was to study the antibiotic sensitivity pattern relative to beta-lactam antibiotics and the presence of SHV and TEM beta-lactamase genes in E. coli specimens isolated from patients with urinary tract infections.
Methods: In a descriptive study, 181 E.coli strains are collected from urine of patients with urinary tract infections and then the sensitivity of the antibiotic is measured by Disk diffusion method. Combined Disk test is used for confirming ESBL-producing E. coli phenotype and finally, the presence of SHV and TEM beta-lactamase genes in ESBL positive isolates were analyzed by multiplex PCR.
Results: From 181 isolates, 66 strains (36.46%) were resistant to cefotaxime and 82 strains (45.30%) were resistant to ceftazidime. Also, 58 percent of isolates were ESBL positive, 16 strains (33%) of them were the carrier of SHV gene and 28 strains (58%) were the carrier of TEM gene and also 3 isolates (6%) were the carrier of both TEM and SHV genes.
Conclusion: According to the production of ESBL which is considered as a great threat to society, it seems it is essential to use suitable molecular methods along with other phenotypic methods to identify this type of resistance.