Presence of extended-spectrum beta-lactamase-producing Enterobacteriaceae in waste waters, Kinshasa, the Democratic Republic of the Congo.

Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae are a major public health concern. We previously demonstrated the presence of ESBL-producing Enterobacteriaceae in sachet-packaged water bags sold in Kinshasa, the Democratic Republic of the Congo. In complement to the previous study, we aimed to assess the presence of ESBL-producing Enterobacteriaceae in waste waters in Kinshasa.Enterobacteriaceae isolates recovered from environmental water samples were screened and phenotypically confirmed as ESBL-producers by disk diffusion according to Clinical and Laboratory Standards Institute (CLSI) guidelines (CLSI M100-S21). Final identification to the species level and further antimicrobial susceptibility testing were carried out with MicroScan® NBC42 panels and the identification of bla (ESBL) coding genes was performed by a commercial multiplex ligation polymerase chain reaction (PCR) microarray (Check-Points CT 101, Wageningen, the Netherlands). Overall, 194 non-duplicate Enterobacteriaceae were recovered from several sewer and river sites in nine out of 24 municipalities of Kinshasa. Fourteen isolates (7.4 %) were confirmed as ESBL-producers, the main species being Enterobacter cloacae (46.6 %) and Klebsiella pneumoniae (40.0 %). Associated resistance to both aminoglycoside and fluoroquinolone antibiotics was observed in ten isolates; the remaining isolates showed co-resistance to either fluoroquinolone (n = 3) or to aminoglycoside (n = 1) alone. All but one isolate carried bla (CTX-M) genes belonging to the CTX-M-1 group. ESBL-producing Enterobacteriaceae are increasingly being reported from various sources in the community. The present results suggest that ESBL-producing Enterobacteriaceae are widespread in the environment in the community of Kinshasa. Cities in Central Africa should be added to the map of potentially ESBL-contaminated environments and highlight the need to reinforce safe water supply and public sanitation.