Ten years of population-level genomic Escherichia coli and Klebsiella pneumoniae serotype surveillance informs vaccine development for invasive infections

The incidence of bloodstream infections (BSIs) caused by Enterobacteriaceae (e.g. Escherichia coli, Klebsiella pneumoniae ) continues to increase globally and the threat of untreatable disease is substantial 1 . Prophylactic vaccines represent an alternative approach to combating antimicrobial resistance (AMR) by reducing antibiotic usage and preventing infections caused by AMR-associated strains. To investigate their potential utility, we performed in silico serotyping on 4035 E. coli / K. pneumoniae BSI from population-level surveillance in Oxfordshire (2008-2018) in addition to 3678 isolates from previous studies. Most infections, including those associated with AMR, were caused by isolates with a small subset of O-antigens, with no evidence that the proportion of BSIs caused by these changed significantly over time. O-antigen targeted vaccines might therefore be useful in reducing the significant morbidity and mortality 2 associated with BSIs. Vaccines may also have a role in preventing the spread of carbapenem resistance genes into common serotypes associated with community-onset disease.