Applications and benefits of the British Society for Antimicrobial Chemotherapy Resistance Surveillance Project-legacy and future.

The BSAC Resistance Surveillance Project ran from 1999 to 2019, amassing an unrivalled collection of almost 100 000 bacterial isolates from bloodstream and lower respiratory tract infections in the UK and Ireland. It was initiated in response to increasing antimicrobial resistance and supplemented existing surveillance schemes, enhancing the understanding of resistance epidemiology by estimating species prevalence within collection groups together with levels of antibacterial resistance, presented in terms of MICs and percentage susceptibility for each species/antibiotic combination tested. Generated data were explored to monitor and identify factors shaping resistance trends, and to profile antibacterial resistance patterns in specific geographies, settings and patient populations. The release of data and/or bacterial isolates led to a rich repository of published peer-reviewed papers. Additionally, the promotion of the BSAC standardized susceptibility testing method resulted in greater uniformity of antimicrobial susceptibility testing in hospital microbiology laboratories. Over time, public health laboratories' surveillance systems became increasingly comprehensive, and the BSAC Project ceased in 2019. This invaluable collection is now housed in the University of Dundee, in collaboration with the University of St Andrews. We highlight the collection's unique timeliness, and how the BSAC Project contributed to key interventions for infection prevention and control, public health and antimicrobial stewardship. We demonstrate the utility and benefits of the Project outlining the collection's future applications as an important bioresource. It comprises well-defined bacterial isolates-many now sequenced-with MIC data and demographic information. This legacy is available to researchers via the Tayside Biorepository and custodian contacts.