Consecutive P. aeruginosa isolates causing bacteraemia or hospital-onset lower respiratory tract infections were collected between 2014 and 2016 under the aegis of the BSAC Resistance Surveillance Programme.
We assessed the activity of ceftolozane/tazobactam against consecutive isolates collected in the BSACBacteraemia Surveillance from 2011 to 2015 and against 'problem' isolates sent to the UK national reference laboratory from July 2015, when routine testing began.
Ciprofloxacin-resistant, non-ESBL-producing E. coli isolates included nationally distributed isolates from the BSAC UK bacteraemia surveillance programme between 2001 and 2005, urinary isolates from a regional project in 2000 and local strains in 2006.