title: Phenotypic characterization of ESBL producing Enterobacter cloacae among children.
abstract: 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 β-lactamase (ESBL) producing Enterobacter cloacae and to compare the phenotypic methods used for the characterization of ESBL producing strains.
  
  
  METHODS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Hafsa Amin, (M.Phil), Institute of Molecular Biology and Biotechnology, The University of Lahore, Lahore, Pakistan.
authors.forename: Hafsa
authors.initials: H
authors.lastname: Amin
authors.affiliation: Aizza Zafar, (M.Phil), Department of Microbiology, The Children's Hospital and Institute of Child Health, Lahore, Pakistan.
authors.forename: Aizza
authors.initials: A
authors.lastname: Zafar
authors.affiliation: Hasan Ejaz, (M.Phil), Department of Microbiology, The Children's Hospital and Institute of Child Health, Lahore, Pakistan.
authors.forename: Hasan
authors.initials: H
authors.lastname: Ejaz
authors.affiliation: Noor-ul-Ain Jameel, (M.Phil), Institute of Molecular Biology and Biotechnology, The University of Lahore, Lahore, Pakistan.
authors.forename: Noor-Ul-Ain
authors.initials: NU
authors.lastname: Jameel
keywords: CLSI confirmatory test; Characterization of ESBL; Double-disk synergy test (DDST); ESBL producing Enterobacter cloacae