Over the last couple of decades, there has been an increase in bloodstream infections caused by Escherichia coli. Resistance of E. coli to several commonly used antimicrobial agents has also increased. To gain a better understanding, a team from Imperial, including Dr Elita Jauneikaite and Professor Shiranee Sriskandan, examined the impact of bacterial strain on clinical outcome. By analysing more than 500 E. coli genomes from samples collected in north-west London, the researchers were able to determine that a particular E. coli genotype (ST131-C2) was associated with longer stays in hospital and resistance to numerous antibiotics (including trimethoprim, amoxicillin/clavulanic acid, and cephalosporins as well as certain dual agent regimens). The authors concluded that ST131 has outcompeted other lineages in north-west London and their findings suggest that clinicians should show caution when deciding antibiotic regimens in areas where this strain is prevalent. Read the publication in the Journal of Antimicrobial Chemotherapy (2022).