High ceftazidime-avibactam resistance among carbapenem-resistant Enterobacter species: Data from the Antimicrobial Testing Leadership and Surveillance (ATLAS) programme, 2014–2021

Objectives: Trends in the susceptibility to ceftazidime-avibactam (CZA) and tigecycline (TGC) among Enterobacter species from different geographic areas are unknown.This study aimed to analyse the trends in CZA and TGC susceptibility changes across different continents from 2014 to 2021 utilizing Antimicrobial Testing Leadership and Surveillance (ATLAS) data. Methods: A total of 23 669 isolates of Enterobacter species were collected over an 8-y period. Results: The overall non-susceptibility rate of Enterobacter isolates to both CZA and TGC was 3.2%. India (16.5%), Guatemala (15.4%), and the Philippines (13.1%) exhibited the highest resistance to CZA. The increase in CZA resistance rates was particularly evident in Asia, with an increase from 4.0% to 8.3%, and in Latin America, from 1.5% to 5%. The non-susceptibility rate for TGC mildly increased in Africa/Middle East but decreased in other continents during the study period. The overall rate of carbapenem resistance increased from 2.9% in 2014–2017 to 4.3% in 2018–2021. Among carbapenem-resistant Enterobacter isolates, the CZA resistance rate was highest in Asia (87.4%), followed by Europe (69.2%) and Africa/Middle East (60.8%). Among the 380 Enterobacter isolates resistant to CZA and carbapenem, the most common genotype of carbapenemase genes was bla_NDM (59.2%), followed by bla_VIM (24.2%), bla_OXA (4.2%), bla_IMP (1.1%), and bla_KPC (1.1%). The susceptibility of carbapenem-resistant Enterobacter to TGC remained high, with an overall susceptibility rate of 90%. Conclusions: The heterogeneous distribution of CZA resistance rates among different geographical regions highlights the divergent therapeutic options for drug-resistant Enterobacter species.