The characteristic of virulence and antibiotic resistance of metallo-carbapenemases-producing Klebsiella spp. in a tertiary hospital in China.

The emergence and global dissemination of carbapenem-resistant Klebsiella spp. have seriously threatened global public health. Few genomic analyses of ceftazidime-avibactam-resistant and carbapenem-resistant Klebsiella spp. (CAR-CRKS) have been performed to date. This was a retrospective study of 12 CAR - CRKS isolates from 99 Klebsiella spp. collected in a Chinese tertiary hospital between 2018 and 2020. K. pneumoniae (eight cases, 66.67%), K. variicola (two cases, 16.67%), and K. quasipneumoniae (two cases, 16.67%) were identified in these isolates. Most of these patients had underlying hepatobiliary diseases or a history of receiving interventional procedures, and were hospitalised recurrently. The isolates were sensitive to amikacin, tigecycline, and polymyxin. blaIMP-4 was detected in six isolates, whereas blaNDM-1, blaNDM-5 and blaNDM-9 were detected in three, two, and one isolates, respectively. Only one strain harboured the rmpA, and exhibited a hypermucinous phenotype. The aerobactin (iucABCD) and yersiniabactin genes were absent in most of the strains. The strains containing blaIMP-4 exhibited higher virulence. These findings are of great significance for understanding the characteristics of CAR - CRKS and developing treatment strategies.