Detection and molecular characterization of multiresistant Enterobacteriaceae carried by houseflies in the city of Bobo-Dioulasso, Burkina Faso

Background and Aim: Houseflies (Musca domestica) are synanthropic insects that are vectors of a wide range of multidrug-resistant pathogens responsible for infectious diseases. The aim of this study was to detect and characterize multidrug-resistant Enterobacteriaceae carried by houseflies in Bobo-Dioulasso. Materials and Methods: A total of 500 houseflies were captured in hospital and non-hospital environments in the city of Bobo-Dioulasso. For bacteriological analysis, they were divided into 125 batches of five flies each. Multidrug-resistant bacteria isolated on MacConkey agar supplemented with 4 μg/mL cefotaxime were identified on the basis of biochemical characteristics. Antibiotic susceptibility profiles were determined using the agar diffusion method. blaCTX-M resistance genes and quinolone resistance genes (plasmid-mediated quinolone resistance) were detected by conventional polymerase chain reaction. Results: Among 115 bacterial strains obtained, 26 were extended-spectrum beta-lactamase (ESBL)-producing enterobacteria: Escherichia coli (15), Klebsiella pneumoniae (6), Enterobacter cloacae (4), and Morganella morganii (1). Carriers were statistically more important in hospitals (12/26, p = 0.03). No carbapenem-resistance strains were observed. We identified ESBL resistance genes (Cefotaximase Munich; CTX-M group 1) (25/26) and quinolone resistance genes (QnrS) (6/26). Conclusion: Houseflies in the city of Bobo-Dioulasso are vectors for the transmission of multidrug-resistant enterobacteria. There is a need to monitor the associated risks for public health.