Abstract :
Objectives: The study was aimed to identify the occurrence of extended spectrum of Beta lactamases
(ESBLs), to compare different phenotypic methods used for the confirmation and to evaluate the antibiotic resistance pattern in ESBL producing uropathogenic Escherichia coli.
Materials and Methods: The Escherichia coli strains were isolated from urine and the isolates resistance
to at least one of the three representative cephalosporins (cefotaxime, cefpodoxime and ceftazidime) was
tested for ESBL production by Double disc synergy test (DDST), Inhibitory potentiated disc diffusion
(IPDD) test and quantitative E-strip method.
Result: Of 120 Escherichia coli strains isolated, 62(51.6%) were resistant to at least one of the three cephalosporins and 28 (45.1%) were positive for ESBL by IPDD and E-strip test. However, 9 (14.5%) strains were positive by DDST method. Among third generation cephalosporins, cefpodoxime was (45.8%) better screening indicator followed by ceftazidime (40.0%) and cefotaxime (37.5%). Most of the ESBL producers (97.3%) were resistant to three or more drugs, compared to (51.2%) non-ESBL producers.
Conclusion: The acceptable method for detection of ESBL producing E.coli were IPDD and E-strip
tests compared to DDST with better sensitivity (100%), specificity (95.8%) and positive predictive value
(96.5%). ESBL producers showed significantly (p
amikacin compared to non ESBL producers.
Keyword :
Uropathogenic E coli, Drug resistance, Extended spectrum beta lactamase 2.