Bacterial species associated with houseflies (Musca domestica) and blowflies (Lucilia cuprina and L. sericata) at a market dumpsite and possible disease risk in Benin City, Nigeria

Abstract

Blowflies and houseflies are common fly species in Africa. Their lifestyle and external features allow them to do more than just be a nuisance in the environment; they also act as vectors for major diseases including bacterial. This study aimed to identify bacterial species associated with common flies—specifically, Musca domestica, Lucilia cuprina, and L. sericata—sampled from the dumpsite at Uselu Market in Benin City, Edo State, Nigeria. Flies were collected from the market dumpsite using sterilized equipment, sorted, and identified. Microbial analysis of the fly samples included bacterial isolation, identification, evaluation of phenotypic virulence properties, antimicrobial susceptibility, and calculation of the multiple antibiotic resistance (MAR) index. Statistical analyses were performed using Microsoft Excel and SPSS. Identified bacterial isolates include Escherichia coli, Bacillus subtilis, Enterobacter cloacae, Pseudomonas aeruginosa, , Proteus vulgaris and Serratia marcescens. Heterotrophic Bacterial Count (HBC) varied significantly among fly species (P < 0.05). Lucilia cuprina had the highest HBC (12,200 ± 1,555.64 cfu/g), while variation in the Coliform Count was significant (P < 0.05) only between L. cuprina and L. sericata. Determinants of phenotypic virulence in bacterial isolates differed across species. Enterobacter, Serratia and Proteus exhibited a multiple antibiotic resistance (MAR) index of 0.44, while other bacteria had MAR index of 0.33. The detection of antibiotic restistant bacteria from the flies is worrisome considering the risk it poses