Abstract
OBJECTIVES: The objective of this study was to determine the population structure of Escherichia coli ST73 isolated from human bacteraemia and urinary tract infections.
METHODS: The genomes of 22 E. coli ST73 isolates were sequenced using the Illumina HiSeq platform. High-resolution SNP typing was used to create a phylogenetic tree. Comparative genomics were also performed using a pangenome approach. In silico and S1-PFGE plasmid profiling was conducted, and isolates were checked for their ability to survive exposure to human serum.
RESULTS: E. coli ST73 isolates circulating in clinically unrelated episodes show a high degree of diversity at a whole-genome level, but exhibit conservation in gene content, particularly in virulence-associated gene carriage. The isolates also contain a highly diverse plasmid pool that confers MDR via carriage of CTX-M genes.
CONCLUSIONS: Our data show that a rise in incidence of MDR E. coli ST73 clinical isolates is not due to a circulating outbreak strain as in E. coli ST131. Rather the ST73 circulating strains are distantly related and carry a diverse set of resistance plasmids. This suggests that the evolutionary events behind emergence of drug-resistant E. coli differ between lineages.
Original language | English |
---|---|
Pages (from-to) | 339-343 |
Number of pages | 5 |
Journal | Journal of Antimicrobial Chemotherapy |
Volume | 71 |
Issue number | 2 |
Early online date | 30 Oct 2015 |
DOIs | |
Publication status | Published - Feb 2016 |