Molecular Characteristics and Genetic Analysis of Extensively Drug-Resistant Isolates with different Tn3 Mobile Genetic Elements

• Published in: Current microbiology Vol. 80; no. 8; p. 246
• Main Authors: Wang, Jiazhen, Dong, Xin, Wang, Fengming, Jiang, Jinyi, Zhao, Ying, Gu, Jingyue, Xu, Jian, Mao, Xujian, Tu, Bowen
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.08.2023; Springer Nature B.V
• Subjects: Acinetobacter baumannii; Anti-Bacterial Agents - pharmacology; Antibiotic resistance; Antibiotics; Bacteria; beta-Lactamases - genetics; Biomedical and Life Sciences; Biotechnology; Drug resistance; Drug Resistance, Multiple, Bacterial - genetics; E coli; Electrophoresis; Epidemiology; Escherichia coli; Escherichia coli - genetics; Gene transfer; Genes; Genetic analysis; Genotypes; Health risks; Hospitals; Humans; Infectious diseases; Interspersed Repetitive Sequences; Klebsiella; Klebsiella Infections - epidemiology; Klebsiella Infections - microbiology; Klebsiella pneumoniae; Life Sciences; Microbial Sensitivity Tests; Microbiology; Multilocus Sequence Typing; Phenotypes; Plasmids; Public health; Risk management; Strains (organisms); Extensively drug-resistant; Molecular characterization; Tn3-relavent mobile genetic element; Carbapenemases
• ISSN: 0343-8651; 1432-0991
• DOI: 10.1007/s00284-023-03340-x

Extensively drug-resistant (XDR) bacteria are the main caues for causing clinical infectious diseases. Our aim was to distinguish the present molecular epidemiological situation of XDR Klebsiella pneumoniae , Acinetobacter baumannii , and Escherichia coli isolates recovered from local hospitals in Changzhou. Antibiotic susceptibility and phenotypic analysis, multilocus sequence typing and Pulsed Field Gel Electrophoresis were performed to trace these isolates. Resistant phenotype and gene analysis from 29 XDR strains demonstrated that they mainly included TEM, CTX-M-1/2, OXA-48, and KPC products. A. baumannii strains belonged to sequence type (ST) ST224, and carrying the bla CTX-M-2/TEM gene. The quinolone genes aac(6’)-ib-cr and qnrB were carrying only in A. baumannii and E.coli . Three (2.3%) of these strains were found to contain the bla NDM-1 or bla NDM-5 gene. A new genotype of K. pneumoniae was found as ST2639. Epidemic characteristics of the XDR clones showed that antibiotic resistance genes distributed unevenly in different wards in Changzhou’s local hospitals. With the sequencing of bla NDM carrying isolates, the plasmids often carrying a highly conservative Tn3-relavent mobile genetic element. The especially coupled insert sequence ISKox3 may be a distinctive resistance gene transfer loci. The genotypic diversity variation of XDRs suggested that tracking and isolating the sources of antibiotic resistance especially MBL-encoding genes such as bla NDM —will help manage the risk of infection by these XDRs.