Escherichia coli strain:E230738 Genome sequencing
Escherichia coli phylogroup A is generally associated with strains showing lower pathogenic potential and virulence compared to other phylogroups and are often of commensal origin. However, some phylogroup A E. coli isolates have been identified as opportunistic pathogens, causing extraintestinal infections such as urinary tract infections (UTIs). In occasion, they can harbour key virulence factor (VF) genes involved in bacterial adhesion and biofilm formation, or traits associated with UTIs establishment, and be linked to multidrug-resistant (MDR) phenotypes. In particular, the emergence and global dissemination of E. coli strains co-harbouring mcr (mobilised colistin resistance) and blaNDM (New Delhi metallo-beta-lactamase) genes is an increasingly significant concern due to their MDR phenotypes against last-resort antibiotics such rendering treatment options limited. Despite a 2023 European Centre for Disease Control (ECDC) report on increase in E. coli isolates carrying blaNDM-5 in the European Union (EU) and European Economic Area (EEA) resistance to colistin was predicted to be rare, with no instances to date reported in Ireland. The present study reports co-occurrence of mcr-1.1 and blaNDM-5 in a phylogroup A E. coli isolate associated with human colonisation in Ireland.