In-vitro activities of essential antimicrobial agents including aztreonam/avibactam, eravacycline, colistin and other comparators against carbapenem-resistant bacteria with different carbapenemase genes: A multi-centre study in China, 2021
Yun Wu, Jiawei Chen, Ge Zhang, Jin Li, Tong Wang, Wei Kang, Jingjia Zhang, Hongli Sun, Yali Liu, Yingchun Xu
Abstract
• The isolation rates of carbapenem-resistant Enterobacterales (CRE), carbapenem-resistant Acinetobacter baumannii (CRAB) and carbapenem-resistant Pseudomonas aeruginosa (CRPA) were 6.31% (332/5265), 62.95% (440/699) and 15.20% (152/1000), respectively. Aztreonam/avibactam, colistin and eravacycline exhibited high antimicrobial activity against different species producing various carbapenemases. • The two highest isolation rates for CRPA were found in respiratory and central nervous system (CNS) infections. For CRAB, the highest isolation rate was in CNS infections, followed by bloodstream infections, and skin and soft tissue infections. For CRE, the highest isolation rates were in CNS infections and urinary tract infections. • In CRE, aztreonam/avibactam exhibited higher antimicrobial activity than ceftazidime/avibactam. However, in CRPA, aztreonam/avibactam showed lower antibacterial activity than ceftazidime/avibactam. In a comparison of antimicrobial activity between tigecycline and eravacycline, eravacycline maintained higher antimicrobial activity in CRE and CRAB. • The association between different resistance mechanisms and antimicrobial activity was analysed, which is less commonly addressed in existing research. Carbapenem-resistant bacteria (CRB), including carbapenem-resistant Acinetobacter baumannii (CRAB), carbapenem-resistant Pseudomonas aeruginosa (CRPA) and carbapenem-resistant Enterobacterales (CRE), pose a considerable threat to public health in China. Eravacycline, aztreonam/avibactam and colistin are important antimicrobial agents for the treatment of serious infections caused by CRB. This study aimed to evaluate the prevalence of CRB strains, and the susceptibility of commonly used clinical antimicrobial agents against strains with different carbapenemase genes. In total, 7194 gram-negative bacteria strains were collected from different regions of China, and 924 carbapenem-resistant strains were identified. All strains were from confirmed infections. Antimicrobial susceptibility testing, covering 21 antimicrobial agents including aztreonam/avibactam, eravacycline, colistin and other comparators, was performed using the broth microdilution method. Carbapenemase genes ( bla KPC , bla NDM , bla OXA , bla IMP and bla VIM ) were screened using polymerase chain reaction amplification and sequence analysis. All statistical analyses were performed using Statistical Package for the Social Sciences Version 23.0. The isolation rates of CRE, CRAB and CRPA were 6.31% (332/5265), 62.95% (440/699) and 15.20% (152/1000), respectively. The predominant carbapenemase in carbapenem-resistant Escherichia coli (CRECO) was NDM, while in carbapenem-resistant Klebsiella pneumoniae (CRKP), it was KPC. All CRAB produced OXA-23, and 85.52% of CRPA did not produce any of the following carbapenemases: NDM, KPC, VIM, IMP and OXA. Aztreonam/avibactam, colistin and eravacycline exhibited high antimicrobial activity against different species producing various carbapenemases. Compared with ceftazidime/avibactam, aztreonam/avibactam demonstrated superior antimicrobial activity, particularly pronounced in CRECO and strains producing metallo-beta-lactamases. In comparisons between tigecycline and eravacycline, the latter maintained higher antimicrobial activity across different species. Antimicrobial agents exhibited varying levels of activity against strains with different resistance mechanisms. Using aztreonam/avibactam, eravacycline and colistin to treat infections caused by CRB offers significant advantages. These findings will guide clinical practice and optimize antimicrobial administration.