E. coli ST10 are abundant commensals of a wide variety of species including humans, cattle, swine, poultry, dogs, migratory birds and rodents. Increasingly they are also observed as opportunistic extra-intestinal human pathogens causing urinary tract infections and associated pathologies. Furthermore they are often multi-drug resistant and may encode extended-spectrum beta-lactamases, including those of the CTX-M family.
We employed Illumina whole genome sequencing and a range of bioinformatic tools to compare multi-drug resistant E. coli ST10 from healthy swine with a number of human disease-associated isolates. We compared phylogeny, virulence associated genes, plasmid types, antimicrobial resistance genes and their genetic organisation in association with mobile elements. It was found that ST10 exhibit sub-clonal population structure with variable serotypes, virulence genes and antimicrobial resistance genes. We also observed a globally disseminated antimicrobial resistance gene locus that was shared between porcine and human isolates.
Given the current limited dataset it is unclear whether ST10 clones from animals are capable of causing human disease. However, the findings do suggest that ST10 E. coli can play a role in the dissemination of drug resistance in a variety of environments. Further research is required to determine whether separate niche-adapted populations of ST10 reside in animals and humans or whether there is significant crossover and a case for zoonosis.