Proportion of extended-spectrum ß-lactamase-producing <it>Enterobacteriaceae </it>in community setting in Ngaoundere, Cameroon

• Main Authors: Lonchel Carine, Meex Cécile, Gangoué-Piéboji Joseph, Boreux Raphaël, Assoumou Marie-Claire, Melin Pierrette, De Mol Patrick
• Format: Article
• Language: English
• Published: BMC 2012-03-01
• Series: BMC Infectious Diseases
• Online Access: http://www.biomedcentral.com/1471-2334/12/53

<p>Abstract</p> <p>Background</p> <p>There is no information regarding the resistance mechanisms of extended-spectrum ß-lactamase (ESBL)-producing <it>Enterobacteriaceae </it>in community setting in Cameroon. The current study aimed to determine the proportion of ESBLs in <it>Enterobacteriaceae </it>isolated in the community and to analyse some risk factors associated with ESBL carriage.</p> <p>Methods</p> <p>Faecal samples were collected from 208 different outpatients and 150 healthy student volunteers between 3 January and 3 April 2009. Enterobacterial isolates resistant to third-generation cephalosporins were screened for ESBL production by the double-disk synergy test. Presumptive ESBL-producing isolates with positive synergy test were identified by Mass Spectrometry using the BioTyper MALDI-TOF. For such ESBL positive isolates, antibiotic susceptibility was determined by the Vitek 2 system. PCR and sequencing were performed for the detection of different types of ESBL genes in presumptive ESBL-producing isolates. Statistical methods were used for the univariate calculation of risk factors.</p> <p>Results</p> <p>During the study period, a total of 358 faecal samples were analysed; 58 of such samples (16%) showed an ESBL phenotype and were confirmed by PCR. The proportion of ESBL producers in faecal carriage was statistically different between outpatients and student volunteers (23.1% vs. 6.7%: <it>p </it>< 0.000). According to a univariate analysis, previous use of antibiotics (ciprofloxacin) appeared to be a risk factor for ESBL carriage (<it>p </it>< 0.05).</p> <p><it>Escherichia coli </it>was the species most frequently isolated among the ESBL producers in outpatients (66.7%) and student volunteers (90%). Isolates showed additional resistance to gentamicin, ciprofloxacin and trimethoprim/sulfamethoxazole but none of them was resistant to temocillin, amikacin or meropenem. Most of the strains (97%) produced a CTX-M group 1 enzymes [CTX-M-15 (98%) or CTX-M-1 (2%)] and the remaining strains produced SHV-12 enzyme (3%).</p> <p>Conclusions</p> <p>The use of drugs such as amoxicillin, ciprofloxacin and trimethoprim/sulfamethoxazole does not seem appropriate for empirical treatment because of emerging resistance. The implementation in Cameroon or in other African countries of methods of screening ESBL-producing organisms in routine laboratories is of great importance in order for us to offer patients appropriate treatment and for infection control efforts to succeed.</p>