Geographic differences in susceptibility profiles of potential non-class B carbapenemase-producing Enterobacterales isolates against ceftazidime-avibactam, meropenem-vaborbactam, colistin, amikacin, gentamicin, and tigecycline: Data from the Antimicrobial Testing Leadership and Surveillance, 2018-2022.

To evaluate the susceptibility profiles of regional meropenem-resistant potential non-class B carbapenemase-producing Enterobacterales (CPE) isolates (without confirmation by phenotypic tests) against important antibiotics, we extracted data from the 2018-2022 Antimicrobial Testing Leadership and Surveillance. This data included susceptibility information of meropenem-resistant potential non-class B CPE isolates against indicated antibiotics - amikacin, gentamicin, ceftazidime-avibactam, colistin, meropenem-vaborbactam, and tigecycline - from sepsis patients hospitalized in intensive care units across six major regions. Carbapenemase-encoding genes of the tested CPE isolates, determined by multiplex PCR and Sanger sequencing, were also analyzed. Susceptibility breakpoints recommended by Clinical and Laboratory Standards Institute 2024 and US FDA criteria (for tigecycline only) against Enterobacterales were employed. A total of 1500 potential non-class B CPE isolates (89% of which were Klebsiella pneumoniae) were tested globally. Resistance rates to amikacin and gentamicin against the evaluated isolates were statistically higher in Africa/the Middle East, Europe, and India compared to other regions. A similar pattern was observed in the susceptibility of these potential CPE isolates to ceftazidime-avibactam and meropenem-vaborbactam. High colistin resistance rates were noted in Asia, Latin America, and Europe (29%-35%). Furthermore, the proportions of potential CPE isolates carrying genes encoding bla variants were notably higher among the tested CPE isolates in India, Europe, and Africa/the Middle East regions (99.2%, 53.3%, and 96.7%, respectively) compared to other regions. Trends in resistance to important antibiotics among potential non-class B CPE isolates warrant close monitoring.