Department of Pulmonary and Critical Care Medicine, Peking University Third Hospital, Beijing, China.
Institute of Medical Technology, Peking University Health Science Center, Beijing, China.
BMC Microbiol. 2024 Feb 12;24(1):56. doi: 10.1186/s12866-024-03205-8.
The occurrence of multidrug-resistant and hypervirulent Klebsiella pneumoniae (MDR-hvKp) worldwide poses a great challenge for public health. Few studies have focused on ST218 MDR-hvKp.
Retrospective genomic surveillance was conducted at the Peking University Third Hospital from 2017 and clinical information was obtained. To understand genomic and microbiological characteristics, antimicrobial susceptibility testing, plasmid conjugation and stability, biofilm formation, serum killing, growth curves and whole-genome sequencing were performed. We also assessed the clinical and microbiological characteristics of ST218 compared with ST23.
A total of eleven ST218 Kp isolates were included. The most common infection type was lower respiratory tract infection (72.7%, 8/11) in our hospital, whereas ST23 hvKp (72.7%, 8/11) was closely associated with bloodstream infection. Notably, nosocomial infections caused by ST218 (54.5%, 6/11) was slightly higher than ST23 (36.4%, 4/11). All of the ST218 and ST23 strains presented with the virulence genes combination of iucA + iroB + peg344 + rmpA + rmpA2. Interestingly, the virulence score of ST218 was lower than ST23, whereas one ST218 strain (pPEKP3107) exhibited resistance to carbapenems, cephalosporins, β-lactamase/inhibitors and quinolones and harbored an ~ 59-kb IncN type MDR plasmid carrying resistance genes including bla, dfrA14 and qnrS1. Importantly, bla and qnrS1 were flanked with IS26 located within the plasmid that could successfully transfer into E. coli J53. Additionally, PEKP2044 harbored an ~ 41-kb resistance plasmid located within tetA indicating resistance to doxycycline.
The emergence of bla revealed that there is great potential for ST218 Kp to become a high-risk clone for MDR-hvKp, indicating the urgent need for enhanced genomic surveillance.
全球范围内耐多药和高毒力肺炎克雷伯菌（MDR-hvKp）的出现对公共卫生构成了巨大挑战。 很少有研究关注 ST218 MDR-hvKp。
对 2017 年北京大学第三医院进行了回顾性基因组监测，并获得了临床信息。 为了了解基因组和微生物学特征，进行了药敏试验、质粒接合和稳定性、生物膜形成、血清杀菌、生长曲线和全基因组测序。 我们还评估了 ST218 与 ST23 的临床和微生物学特征。
共纳入 11 株 ST218 Kp 分离株。 我院最常见的感染类型是下呼吸道感染（72.7%，8/11），而 ST23 hvKp（72.7%，8/11）则与血流感染密切相关。 值得注意的是，ST218（54.5%，6/11）引起的医院感染略高于 ST23（36.4%，4/11）。 所有 ST218 和 ST23 株均呈现 iucA+iroB+peg344+rmpA+rmpA2 的毒力基因组合。 有趣的是，ST218 的毒力评分低于 ST23，而一株 ST218 株（pPEKP3107）对碳青霉烯类、头孢菌素类、β-内酰胺酶/抑制剂和喹诺酮类药物耐药，并携带一个约 59kb 的 IncN 型 MDR 质粒，携带 bla、dfrA14 和 qnrS1 等耐药基因。 重要的是，bla 和 qnrS1 被位于质粒内的 IS26 侧翼，能够成功转移到 E. coli J53 中。 此外，PEKP2044 携带一个位于 tetA 内的约 41kb 耐药质粒，表明对强力霉素耐药。
bla 的出现表明 ST218 Kp 有很大潜力成为 MDR-hvKp 的高危克隆，表明迫切需要加强基因组监测。
