Extended-spectrum β-lactamase-producing Enterobacteriaceae in Cameroonian hospitals

Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae have been described worldwide, but there are few reports on the carriage of these bacteria in Cameroon. In order to investigate the types of ESBLs and to analyse some risk factors associated with ESBL carriage, faecal samples were collected between 3 January and 3 April 2009 from hospitalised patients at Yaounde Central Hospital and at two hospitals in Ngaoundere, Cameroon. Enterobacterial isolates resistant to third-generation cephalosporins were screened for ESBL production using the double-disk synergy test. Polymerase chain reaction (PCR) and DNA sequencing were performed in order to find out the different types of ESBL genes in presumptive ESBL-positive isolates. During the study period, a total of 121 different patients were screened for ESBL carriage. The prevalence among these patients whose faecal samples were found to contain ESBL-producers was 55.3 % (67/121). According to a univariate analysis, hospitalisation during the previous year was found to be associated with ESBL carriage. Of the 71 bacteria isolated, Escherichia coli was predominant and represented 48 % of all isolates. ESBL characterisation revealed two types of ESBLs, CTX-M-15 (96 %) and SHV-12 (4 %). The present study emphasises the importance of screening for ESBLs in laboratories in African countries. The monitoring and detection of ESBL-producing bacteria are important in the setting up of appropriate treatment of patients and to ensure effective infection control efforts.