title: Phenotypic determination of carbapenemase producing enterobacteriaceae isolates from clinical specimens at a tertiary hospital in Lagos, Nigeria.
abstract: OBJECTIVE
  Carbapenemase production among clinical isolates of Enterobacteriaceae has been widely reported with prevalence rates ranging from between 2.8% and 53.6%. The aim of this study was to assess the prevalence of carbapenemase production among clinical isolates of Enterobacteriaceae from a Tertiary Hospital in Lagos, Nigeria, and to characterize the type of carbapenemase produced.
  
  
  METHODS
  Carbapenemase production was detected phenotypically using a commercially available combination disc test (Rosco Diagnostica carbapenemase detection Neo-Sensitab) containing inhibitors to the various carbapenemase classes. The Neo-Sensitabs were used for Enterobacteriaceae isolates that were resistant after the initial antibiotic susceptibility testing with meropenem (10 μg).
  
  
  RESULTS
  A total of 177 Enterobacteriaceae isolates were investigated and 27 (15.2%) were carbapenem-resistant. From the 27 carbapenem non-susceptible isolates, 22 (12.4%) were carbapenemase producers while 5 (2.8%) exhibited carbapenem resistance due to extended spectrum beta-lactamase production. Of the 22 isolates that were positive for carbapenemase production, 15 (8.5%) were metallo beta-lactamase (MBL) producers, 6 (3.4%) produced oxacillinase-48 while 1 (0.5%) produced both MBL and Klebsiella pneumoniae carbapenemase. Hence, the overall prevalence of carbapenemase-producing Enterobacteriaceae in this study was 12.4%.
  
  
  CONCLUSIONS
  Carbapenemase-producing Enterobacteriaceae was indeed prevalent in our institution. The combination disc test was a cost effective and suitable method for the initial detection of carbapenemase-producing Enterobacteriaceae within the clinical setting especially when molecular detection methods are not available.
authors.forename: O O
authors.initials: OO
authors.lastname: Oduyebo
authors.affiliation: Department of Medical Microbiology and Parasitology, College of Medicine, University of Lagos, Idi-Araba, Lagos, Nigeria.
authors.forename: O M
authors.initials: OM
authors.lastname: Falayi
authors.forename: P
authors.initials: P
authors.lastname: Oshun
authors.forename: A O
authors.initials: AO
authors.lastname: Ettu