Department of Infectious Disease, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
Departments of Clinical Laboratory, Medical Center of Burn Plastic and Wound Repair, The First Affiliated Hospital of Nanchang University, Nanchang, China.
Front Cell Infect Microbiol. 2023 Sep 27;13:1194133. doi: 10.3389/fcimb.2023.1194133. eCollection 2023.
This study aimed to explore the epidemic, clinical characteristics, and molecular and virulence attributes of Klebsiella pneumoniae serotype K54 (K54-Kp). A retrospective study was conducted on 328 strains of Klebsiella pneumoniae screened in a Chinese hospital from January 2016 to December 2019. The virulence genes and antibiotic resistance genes (ARGs) were detected by PCR, and a drug sensitivity test was adopted to detect drug resistance. Multilocus sequence typing (MLST) and PFGE were performed to determine the clonal correlation between isolates. Biofilm formation assay, serum complement-mediated killing, and Galleria mellonella infection were used to characterize the virulence potential. Our results showed that thirty strains of K54-Kp were screened from 328 strains of bacteria, with an annual detection rate of 2.29%. K54-Kp had a high resistance rate to antibiotics commonly used in the clinic, and patients with hepatobiliary diseases were prone to K54-Kp infection. MLST typing showed 10 sequence typing, mainly ST29 (11/30), which concentrated in the B2 cluster. K54-Kp primarily carried virulence genes of aerobactin, silS, allS, wcaG, wabG, and mrkD, among which the terW gene was closely related to ST29 (p<0.05). The strains infected by the bloodstream had strong biofilm formation ability (p<0.05). Most strains were sensitive to serum. Still, the virulence of pLVPK-like virulence plasmid in ST29-K54 Klebsiella pneumoniae was lower than that of ST11 type and NTUH-K2044 in the Galleria mellonella model. Therefore, these findings supply a foundation to roundly comprehend K54-Kp, and clinicians should strengthen supervision and attention.
本研究旨在探讨肺炎克雷伯菌血清型 K54（K54-Kp）的流行情况、临床特征、分子和毒力特性。对 2016 年 1 月至 2019 年 12 月在中国某医院筛选的 328 株肺炎克雷伯菌进行回顾性研究。采用 PCR 法检测毒力基因和抗生素耐药基因（ARGs），药敏试验检测耐药性。采用多位点序列分型（MLST）和 PFGE 分析分离株之间的克隆相关性。采用生物膜形成试验、血清补体介导杀伤和大蜡螟感染来表征其毒力潜能。结果显示，从 328 株细菌中筛选出 30 株 K54-Kp，年检出率为 2.29%。K54-Kp 对临床常用抗生素具有较高的耐药率，肝胆疾病患者易发生 K54-Kp 感染。MLST 分型显示 10 种序列型，主要为 ST29（11/30），集中在 B2 簇。K54-Kp 主要携带类细菌素、silS、allS、wcaG、wabG 和 mrkD 等毒力基因，其中 terW 基因与 ST29 密切相关（p<0.05）。血流感染株具有较强的生物膜形成能力（p<0.05）。大多数菌株对血清敏感，但 ST29-K54 肺炎克雷伯菌 pLVPK 样毒力质粒的毒力低于 ST11 型和 NTUH-K2044 在大蜡螟模型中的毒力。因此，这些发现为全面了解 K54-Kp 提供了基础，临床医生应加强监督和关注。
