detail content area
mSYSTEMS, 2020.N, 1-13, DOI: https://doi.org/10.1128/mSystems.00459-20
Beneficial chromosomal integration of the genes for 1 CTX-M ESBL in Klebsiella pneumoniae for stable propagation
Eun-Jeong YOON, Bareum GWON, Changseung LIU, Dokyun KIM, Dongju WON, Sung Gyun PARK, Jong Rak CHOI, Seok Hoon JEONG
The acquired CTX-M-type extended-spectrum- -lactamase (ESBL)-producing Enterobacterales are of great concern in clinical settings because they limit therapeutic options for patients infected by the pathogens. An intriguing clonality of CTX-M ESBLproducing Klebsiella pneumoniae blood isolates was observed from a national cohort study, and comparative genomics were assessed for the 115 K. pneumoniae blood isolates carrying the blaCTX-M gene. The plasmid preference of particular clones of a sequence type (ST) was assessed by liquid mating. A quarter of the blaCTX-M genecarrying K. pneumoniae blood isolates harbor the gene in their chromosome, and most of those with the built-in blaCTX-M gene belonged either to ST307 or ST48. Notably, all 16 K. pneumoniae ST48 isolates harbored two copies of the blaCTX-M-15 gene in the chromosome. The chromosomal integration of the blaCTX-M-15 gene was mostly derived from the ISEcp1-targeting 5-bp AT-rich locus in the chromosome. The IS26-mediated chromosomal integration occurred when the upstream ISEcp1 from the blaCTX-M gene was truncated, targeting the anchor IS26 copy in the chromosome. Higher transfer efficiency of the blaCTX-M-15 gene-carrying FIA:R plasmid was observed in ST17 than that of the blaCTX-M-14 gene-carrying FIB:FII plasmid. The transfer efficiency of the plasmid differed by isolate among the ST307 members. The K. pneumoniae clones ST307 and ST48 harboring the blaCTX-M-15 gene in the chromosome were able to disseminate stably in clinical settings regardless of the environmental pressure, and the current population of K. pneumoniae blood isolates was constructed. Further follow-up is needed for the epidemiology of this antimicrobial resistance.
- DOI: https://doi.org/10.1128/mSystems.00459-20
- ISBN or ISSN: 2379-5077
- 본 연구는 질병관리본부 연구개발과제연구비를 지원받아 수행되었습니다.
- This research was supported by a fund by Research of Korea Centers for Disease Control and Prevention.