Carbapenem antibiotic stress increases bla KPC ‐2 gene relative copy number and bacterial resistance levels of Klebsiella pneumoniae

作者：Huimin Chen, Na Li, Fang Wang, Lei Wang, Wei Liang · 发表于：Journal of Clinical Laboratory Analysis · 年份：2022 · DOI：10.1002/jcla.24519 · 被引用次数：14 · 研究领域：Antibiotic Resistance in Bacteria、Bacterial Genetics and Biotechnology、Antibiotics Pharmacokinetics and Efficacy

Abstract Background The clinical isolation rates of carbapenem‐resistant Klebsiella pneumoniae (CR‐KP) continue to increase. In China, clinical CR‐KP isolates are mainly attributed to the bla KPC‐2 gene carried on plasmids, and the bla KPC‐2 copy number correlates with the expression of KPC enzymes, which can cause elevated carbapenem MICs. Methods Thirty‐seven CR‐KP isolates were collected at the Second People’s Hospital of Lianyungang City between January 2020 and March 2021, with no duplicate isolates, and were screened for the bla KPC‐2 gene with PCR. Analysis of current CRKP resistance to clinically relevant antimicrobials using the bioMérieux VITEK ® 2 bacterial identification card. The multilocus sequence types of the strains were confirmed with PCR and DNA sequencing. Recombinant plasmids pET20b‐ bla KPC‐2 and pET20b‐CpsG were constructed, and the copy numbers of the recombinant plasmids per unit volume was calculated based on the molecular weight of the plasmids. After the genomes DNA of clinical isolates of K. pneumoniae carrying the bla KPC‐2 gene were purified, the bla KPC‐2 gene relative copy number in individual K. pneumoniae strains was indicated by the double standard curve method. Detection of MIC values changes of K. pneumoniae under imipenem selection pressure by broth microdilution method. Results Among the 37 CR‐KP strains isolated, only the bla KPC‐2 gene was detected in 30 strains, three strains were positive for the bla NDM‐1 gene, two strains carried ...