■耐碳青霉烯类和粘菌素的肠杆菌科,包括肺炎克雷伯菌,已经成为全球日益关注的问题,对公众健康构成重大威胁。目前,关于耐碳青霉烯类和粘菌素肺炎克雷伯菌在泰国感染人和犬的分离株的遗传背景信息有限.这项研究旨在表征6种耐药肺炎克雷伯菌临床分离株(3种来自人类,3种来自狗)中的碳青霉烯类和粘菌素耐药基因,这些分离株的脉冲场凝胶电泳谱不同。
■基质辅助激光解吸电离-飞行时间质谱(MALDI-TOFMS),抗菌药物敏感性试验,和全基因组测序用于鉴定和分析分离株。
■所有六个分离株都是产生碳青霉烯酶的肺炎克雷伯菌分离株,染色体携带blaSHV,FosA,oqxA和oqxB基因,以及9到21个毒力基因。这些分离株属于五种多位点序列类型(STs):一种来自人的分离株和一种来自狗的分离株属于ST16,另外两个人分离株来自ST340和ST1269,另外两个狗分离株是ST147和ST15。一个人分离株和两个狗分离株在ColKP3质粒上携带相同的blaOXA-232基因,一个狗分离株在IncFII质粒上携带blaOXA-48基因。值得注意的是,一种人分离株表现出对IncFII质粒上携带的mcr-3.5基因介导的粘菌素的抗性,与对其他抗生素的抗性决定因素共存,包括氨基糖苷类和喹诺酮类。总之,这项研究提供了一组来自泰国无关人和犬的肺炎克雷伯菌临床分离株的染色体和质粒介导的碳青霉烯类和粘菌素耐药性的综合特征。发现的相似性和差异有助于我们理解这些重要抗性基因在人类和动物临床分离株中的潜在广泛传播,这反过来又可能导致在医院环境中新出现的抗性克隆的爆发。
UNASSIGNED: Carbapenem and colistin-resistant Enterobacteriaceae, including Klebsiella pneumoniae, have become a growing global concern, posing a significant threat to public health. Currently, there is limited information about the genetic background of carbapenem and colistin-resistant K. pneumoniae isolates infecting humans and dogs in Thailand. This study aimed to characterize carbapenem and colistin-resistant genes in six resistant K. pneumoniae clinical isolates (three from humans and three from dogs) which differed in their pulse field gel electrophoresis profiles.
UNASSIGNED: Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), antimicrobial susceptibility testing, and whole-genome sequencing were employed to identify and analyze the isolates.
UNASSIGNED: All six isolates were carbapenemase-producing K. pneumoniae isolates with chromosomally carried blaSHV, fosA, oqxA and oqxB genes, as well as nine to 21 virulence genes. The isolates belonged to five multilocus sequence types (STs): one isolate from a human and one from a dog belonged to ST16, with the other two human isolates being from ST340 and ST1269 and the other two dog isolates were ST147 and ST15. One human isolate and two dog isolates harbored the same blaOXA-232 gene on the ColKP3 plasmid, and one dog isolate carried the blaOXA-48 gene on the IncFII plasmid. Notably, one human isolate exhibited resistance to colistin mediated by the mcr-3.5 gene carried on the IncFII plasmid, which co-existed with resistance determinants to other antibiotics, including aminoglycosides and quinolones. In conclusion, this study provides a comprehensive characterization of both chromosome- and plasmid-mediated carbapenem and colistin resistance in a set of K. pneumoniae clinical isolates from unrelated humans and dogs in Thailand. The similarities and differences found contribute to our understanding of the potential widescale dissemination of these important resistance genes among clinical isolates from humans and animals, which in turn may contribute to outbreaks of emerging resistant clones in hospital settings.