Treatment of bone and joint infections by ceftazidime/avibactam and ceftolozane/tazobactam: a cohort study

•Ceftazidime/avibactam (C/A) and ceftolozane/tazobactam (C/T) are novel agents with efficacy against Gram-negative bacteria.•C/A and C/T are effective in treating bone and joint infections (BJIs).•C/A and C/T are safe for the treatment of BJIs.•C/A and C/T can be used to treat BJIs by multidrug-resistant bacteria. Ceftazidime/avibactam (C/A) and ceftolozane/tazobactam (C/T) are two novel antibacterials with known efficacy against Gram-negative bacteria (GNB). We aimed to describe the efficacy and safety of surgical management combined with C/A or C/T treatment for bone and joint infections (BJIs). We conducted an observational, bicentric study of patients treated with C/A or C/T for a BJI between May 2016 and June 2019. Failure was defined as the need for unplanned additional antibiotic treatment or orthopaedic surgery, or death due to the BJI up to the patient's latest visit. Overall, 15 patients were included. Nine patients were treated with C/A, mainly for polymicrobial BJI due to multidrug-resistant (MDR) bacteria (Enterobacteriaceae, n = 7). Six patients were male, the median age was 66 years and the median Charlson comorbidity index (CCI) was 5. It was the first septic episode at the site in 3/9 patients. The cure rate was 7/9 (median follow-up, 272 days). Two patients showed C/A-related confusion. Five patients were treated with C/T for BJI involving MDR Pseudomonas aeruginosa. Four patients were male, the median age was 53 years and the median CCI was 2. All patients had previous septic episodes at the infection site. The cure rate was 3/5 (median follow-up, 350 days). One patient was successfully treated by C/T then C/A for multistage spondylodiscitis. In our experience, C/A and C/T are two effective and safe options, even as salvage treatment for BJI due to MDR-GNB despite the absence of label, however more data are warranted.