Frequency and Antimicrobial Resistance Pattern of Extended Spectrum Beta Lactamases Producing Escherichia coli Strains Isolated from Urinary Infections

Escherichia coli is the most common cause of urinary tract infections. The resistance of Escherichia coli strains to broad spectrum cephalosporins may be mediated by extended spectrum β-lactamases (ESBLs) has now raised in worldwide. Frequency and spectrum awareness of drug resistance in these isolates will be useful in choosing more effectivemethods of control and treatment. This cross - sectional study was done on 100 Uropathogenic E. coli strains collected from selected center and then were identified by biochemical tests. All of the samples were screened by DAD method. The phenotypes of ESBL were determined using the disk diffusion synergy test(DDST) as recommended by the interpretative guidelines of the NCCLS. SPSS16 was used for statistical analysis. A total of one hundred isolates,89(89%)were found to be resistant at least on of the indicators cephalosporin tested according to NCCLS guideline.55(55%)of the isolates were resistant to all the indicators tested. Sixty tree isolates (63%) were ESBL producers. The E. coli strains showed high susceptibility to imipenem (66/7%)and amikacin (65/1%). Our results show that the most appropriate antibiotic to be used for empirical therapy are imipenem and amikacin.High prevalence of ESBL in our hospital cannot be ignored. ESBL producers can be detected by DDST and phenotypic confirmatory test with equal efficacy.we recommend DDSTusing multiple antibiotics in all microbiology units as a routine screening test.