Comparative Genome Analysis Reveals Human Pathogenic Potential of ESBL-Escherichia coli Isolated from Swine Microbiomes

Background: Extended-spectrum β-lactamase-producing E. coli (ESBL-Ec) harbouring virulence genes in the microbiome of food animals could likely threaten human health but is poorly understood in Cameroon and South Africa. Here, we assessed the resistome, virulome and mobilome of ESBL-Ec isolated from swine microbiomes in these countries, using whole genome sequencing (WGS). Materials/methods: Eleven clonally-related phenotypic ESBL-Ec isolates were subjected to WGS. The isolates were de novo assembled using the CLC Genomics Workbench and SPAdes while RAST and PROKKA were used for annotation of the assembled contigs. Prediction of antibiotic resistance genes, virulence factors and plasmids was performed using ResFinder, VirulenceFinder and PlasmidFinder, respectively. Results: Diverse STs were detected with sequence types ST2144 and ST88 predominating and blaCTX-M-15 (55%) as principal ESBL genes. Although the isolates belonged mainly to commensal phylogroups A/B1 (45/28.3%) and C (18.18%), all harboured at least three extraintestinal pathogenic E. coli (ExPEC) VFs with one isolate harbouring up to 18 ExPEC VFs. Conclusion: The resistance and pathogenic potential of ESBL-Ec colonizing the gut microbiota of swine in both countries demonstrate the urgent need to implement effective strategies to contain the dissemination of virulent ESBL-Ec through the food chain in Cameroon and South Africa.