Ceftazidime-avibactam and comparators against Pseudomonas aeruginosa isolates collected globally and in each geographical region between 2017-2020.

OBJECTIVES: The objective of this study was to assess the distribution and antimicrobial susceptibility of P. aeruginosa isolates against ceftazidime-avibactam (CAZ-AVI) and a panel of comparator agents collected globally and in each region from 2017-2020 from the Antimicrobial Testing Leadership and Surveillance (ATLAS) program.

METHODS: Susceptibility and minimum inhibitory concentration (MIC) of all P. aeruginosa isolates were determined using broth microdilution methodology for according to the Clinical and Laboratory Standards Institute guidelines.

RESULTS: Of the total 29,746 isolates of P. aeruginosa collected, 20.9% were multidrug resistant (MDR), 20.7% were extremely drug resistant (XDR), 8.4% were CAZ-AVI-resistant (CAZ-AVI-R), and 3.0% were MBL-positive. Amongst the MBL-positive isolates, the proportion of VIM-positive isolates was highest (77.8%). The highest proportion of MDR (25.5%), XDR (25.0%), MBL (5.7%), and CAZ-AVI-R (12.3%) isolates were in Latin America. Amongst the sources, the highest proportion of isolates were from respiratory sources (43.0%) and the majority of isolates were from non-ICU wards (71.2%). Overall, CAZ-AVI showed high susceptibility to all P. aeruginosa isolates (90.9%). However, MDR and XDR isolates were less susceptible to CAZ-AVI (≤60.7). Amongst the comparators, only colistin (99.1%) and amikacin (90.5%) showed good overall susceptibility to all isolates of P. aeruginosa. However, only colistin was active (≥98.3%) against all the resistant isolates.

CONCLUSION: CAZ-AVI presents a potential treatment option against P. aeruginosa infections. However, active monitoring and surveillance, especially of the resistant phenotypes is warranted for effective treatment of infections caused by P. aeruginosa.