First detection of resistance genes and virulence factors in Escherichia coli and Salmonella spp in Togo: the case of imported chicken and frozen by-products

Background The importation of chickens into Togo has raised concerns about the microbiological quality and antimicrobial resistance of the pathogenic strains they may contain. As food safety is a critical public health priority, the main objective of this study was to investigate the resistance profile of pathogenic strains and resistance genes isolated from chickens imported into Togo. Methods This was a cross-sectional, prospective study, and samples were collected from 7 cold rooms in the Golfe prefecture in the greater Lomé commune. A total of 285 samples of imported poultry meat and cuts were analysed using the routine AFNOR methods. Antibiotic susceptibility tests were carried out on Salmonella spp. and Escherichia coli strains isolated using the disk diffusion method (CA-SFM). PCR carried out the search for genetic support for antibiotic resistance and virulence factors. Results The results showed a prevalence of 32.98% of Escherichia coli in relation to microbiological quality. On the other hand, 2.46% of non-conformities were recorded for Salmonella . The antibiogram revealed resistance to certain beta-lactams and quinolones, in particular: cefoxitin (14.28%), cefalexin, cefuroxime, ceftazidime, ceftriaxone and nalidixic acid, all with a prevalence of 28.57%. Analysis of the resistance observed in Escherichia coli strains enabled us to identify 9.44% of strains that were multi-resistant to B-lactams and quinolones. Molecular analysis of the resistance supports showed the presence of class 1 integrons (15.79%) whose cassettes mainly carry the aadA1 and dfr1 genes encoding resistance proteins. Class 2 and 3 integrons were absent from our study. The extrachromosomal qnrB gene was present in 5.26%. The emergence of C3G-resistant strains, most often manifested by the production of ESBLs, was revealed in our study by the presence of ESBL strains of the blaCTX (31.58%) and blaTEM (52.63%) types. Conclusions This study reveals a worrying level of antimicrobial resistance, underlining the need to strengthen health control measures and hygiene practices throughout the production and distribution chain for imported chickens.