Phenotypic characterization of ESBL producing Enterobacter cloacae among children

Objective: The emergence of ESBL producing Enterobacter cloacae in clinical isolates is posing a serious threat for treating nosocomial infections. The aim of the study was to determine the frequency of extended spectrum beta-lactamase (ESBL) producing Enterobacter cloacae and to compare the phenotypic methods used for the characterization of ESBL producing strains. Methodology: This cross sectional observational study was conducted during April 2011 to March 2012 at Microbiology department of The Children's Hospital and Institute of Child Health, Lahore. A total number of 20,257 various clinical samples were analyzed during the study period. Enterobacter cloacae were identified using API 20E system and ESBL detection was carried out using double-disk synergy test (DDST) and CLSI confirmatory test. Results: Enterobacter cloacae were isolated from 221 samples, out of which 33 (14.93%) were ESBL producers and 188 (85.07%) were non-ESBL producers. The gender distribution of ESBL producing Enterobacter cloacae was 21 (63.6%) in males and 12 (36.4%) in females. Highest frequency (63%) of ESBL producing Enterobacter cloacae was detected in blood samples. Comparison of DDST and CLSI confirmatory test showed that 25 (75.75%) isolates were characterized by DDST and 33 (100%) using CLSI confirmatory test. Conclusion: The present study shows moderately high frequency of ESBL producing Enterobacter cloacae among children. DDST was found to be less efficient in ESBL detection as compared to CLSI confirmatory test.