ABSTRACT
Background: An increase in extended spectrum β-lactamase (ESBL)-producing Escherichia coli (E. coli) has been observed. Aims: Of this study was done to detect the prevelance of ESBL, AmpC producing and ESBL and AmpC co-producing strains of Escherichia coli (E. coli) in urinary tract infections patients in Benha University Hospital and to evaluate the performance of CHROMagar™ ESBL media for rapid screening of ESBL producing E. coli. Place and Duration of Study: This is a Six-months Cross sectional study conducted in Urology and Microbiology & Immunology departments, Benha University, Egypt. Methodology: All patients under study were subjected to: Full history taking and clinical examination. Bacteriological study included; urine sample collection from each patient and subjected to urine analysis, urine culture on cysteine lactose electrolyte deficient agar (CLED) agar, CHROMagar™ ESBL media and MacConkey agar supplemented with 2 mg/liter ceftazidime (MCKC). ESBL detection in E. coli isolated on CLED agar by phenotypic screening by clinical and laboratory standards institute (CLSI) method then phenotypic confirmation by E. test. The presence AmpC beta-lactamase ESBL was detected by AmpC disc test and detection of AmpC beta-lactamase and ESBL coproducers by cefepime and Cefepime + Clavulanate E test. Results: In this study out of 45 E. coli strains 24 (53.3%) ESBL producers were detected by E. test (golden method for confirmation of ESBL according to CLSI) and 21(46.7%) strains were non ESBL producers. There was no significant difference between ESBL isolation from community acquired and health care associated UTI patients; out of the 24 isolated ESBL producing E.coli strains 9 (37.5%) were detected in community acquired UTI patients while 15 (62.5%) were detected in health care associated UTI patients. The sensitivity of both MCKC and CHROMagar™ ESBL media were 100% (95%CL: 85.6% to 100%).While specificity were 87.5% (95%CL:67.6% to 97.2%) and 80.8% (95%CL: 60.6% to 93.4%) respectively. In our study out of 45 isolated E. coli strains 14 (31.1%) were AmpC producers by AmpC test, 4 (8.9%) were AmpC and ESBL co-producers by cefepime/ cefepime clavulanic E.test. Conclusion: It is important to know the prevalence of ESBL, AmpC producing and ESBL&AmpC co-producing organisms so that judicious use of antibiotics could be done and increase awareness about the need for routine detection of AmpC and ESBL in clinical isolates. CHROMagar™ ESBL media detect ESBL producers from clinical specimen and give rapid presumptive identification by means of colony colour after 24h with good sensitivity and specificity.