<i>bla</i> <sub>KPC-2</sub> -Encoding IncP-6 Plasmids in Citrobacter freundii and Klebsiella variicola Strains from Hospital Sewage in Japan
<i>bla</i> <sub>KPC-2</sub> -Encoding IncP-6 Plasmids in Citrobacter freundii and Klebsiella variicola Strains from Hospital Sewage in Japan
复制标题
<i>bla</i> <sub>KPC-2</sub> -编码来自日本医院污水的弗氏柠檬酸杆菌和水痘克雷伯菌菌株中的 IncP-6 质粒
DOI：
10.1128/aem.00019-22
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发表时间：
2022
影响因子：
4.4
通讯作者：
Saito Ryoichi
中科院分区：
文献类型：
--
作者：
Ota Yusuke;Prah Isaac;Nukui Yoko;Koike Ryuji;Saito Ryoichi
Klebsiella pneumoniae carbapenemase (KPC) producers are an emerging threat to global health, and the hospital water environment is considered an important reservoir of these life-threatening bacteria. We characterized plasmids of KPC-2-producing Citrobacter freundii and Klebsiella variicola isolates recovered from hospital sewage in Japan. Antimicrobial susceptibility testing, whole-genome sequencing analysis, bacterial conjugation, and transformation experiments were performed for both KPC-2 producers. TheblaKPC-2gene was located on the Tn3transposon-related region from an IncP-6 replicon plasmid that could not be transferred via conjugation. Compared to theblaKPC-2-encoding plasmid of the C. freundii isolate, alignment analysis of plasmids withblaKPC-2showed that theblaKPC-2-encoding plasmid of the K. variicola isolate was a novel IncP-6/IncF-like hybrid plasmid containing a 75,218-bp insertion sequence composed of IncF-like plasmid conjugative transfer proteins. Carbapenem-resistant transformants harboringblaKPC-2were obtained for both isolates. However, no IncF-like insertion region was found in the K. variicola donor plasmid of the transformant, suggesting that this IncF-like region is not readily functional for plasmid conjugative transfer and is maintained depending on the host cells. The findings on the KPC-2 producers and novel genetic content emphasize the key role of hospital sewage as a potential reservoir of pathogens and its linked dissemination ofblaKPC-2through the hospital water environment. Our results indicate that continuous monitoring for environmental emergence of antimicrobial-resistant bacteria might be needed to control the spread of these infectious bacteria. Moreover, it will help elucidate both the evolution and transmission pathways of these bacteria harboring antimicrobial resistance.IMPORTANCEAntimicrobial resistance is a significant problem for global health, and the hospital environment has been recognized as a reservoir of antimicrobial resistance. Here, we provide insight into the genomic features ofblaKPC-2-harboring isolates of Citrobacter freundii and Klebsiella variicola obtained from hospital sewage in Japan. The findings of carbapenem-resistant bacteria containing this novel genetic context emphasize that hospital sewage could act as a potential reservoir of pathogens and cause the subsequent spread ofblaKPC-2via horizontal gene transfer in the hospital water environment. This indicates that serial monitoring for environmental bacteria possessing antimicrobial resistance may help us control the spread of infection and also lead to elucidating the evolution and transmission pathways of these bacteria.
