Epidemiology and Genomic Characteristics of Bloodstream Infection Caused by Carbapenem-Resistant Klebsiella pneumoniae With Decreased Susceptibility to Aztreonam/Avibactam in China

• Published in: Frontiers in cellular and infection microbiology Vol. 12; p. 926209
• Main Authors: Yu, Wei, Shen, Ping, Chen, Yunbo, Zhou, Kai, Chi, Xiaohui, Xiao, Yonghong
• Format: Journal Article
• Language: English
• Published: Frontiers Media S.A 22.06.2022
• Subjects: aztreonam/avibactam; blaKPC; carbapenem-resistant Klebsiella pneumoniae; Cellular and Infection Microbiology; membrane porin; mutation
• ISSN: 2235-2988; 2235-2988
• DOI: 10.3389/fcimb.2022.926209

Aztreonam/avibactam (AZA), as one of the novel β-lactamases and β-lactamase inhibitor combinations, is considered to be a promising option for bloodstream infection (BSI) of carbapenem-resistant Klebsiella pneumoniae (CR-Kp). However, decreased susceptibility of AZA activity in Enterobacterales has been reported. The aim of this study was to identify the mechanisms of BSI CR-Kp with decreased susceptibility of AZA (minimal inhibitory concentration above 16/4 mg/L) (AZAH-Kp). Nine BSI AZAH-Kp isolates were screened from 317 CR-Kp isolates in Blood Bacterial Resistant Investigation Collaborative System (BRICS) program. Whole genome sequencing, bioinformatics analysis, and the relative expression of bla KPC , ompK35 , and ompK37 were explored for CR-Kp with decreased susceptibility to AZA. The results revealed that elevated inhibitory concentration of AZA has emerged in CR-Kp before previous clinical exposure. In addition, decreased AZA susceptibility was associated with higher KPC expression and changes in OmpK35-37.