Wang Yitong, Qin Si, Guo Hongxiong
School of Public Health, Nanjing Medical University, Nanjing, China.
Nanjing Lishui District Hospital of Traditional Chinese Medicine, Nanjing, China.
Front Microbiol. 2025 Jul 9;16:1575216. doi: 10.3389/fmicb.2025.1575216. eCollection 2025.
(KP) poses a global health threat, with variations observed across different regions. However, data on the genomic characteristics and drug resistance profiles of KP isolates in Eastern China are limited. To address this gap, we collected KP isolates from a traditional Chinese medicine hospital in Jiangsu Province, China, in order to characterize these features.
From February 2023 to February 2024, 117 KP isolates were collected from a Chinese traditional medicine hospital in Jiangsu province, China. Antimicrobial susceptibility testing and whole-genome sequencing were performed on all isolates. Then, capsular serotype, multi-locus sequence typing, virulence genes, and resistance genes were identified using Prokka and Kleborate software tools. The hypermucoviscosity phenotype was detected using the string test. Antimicrobial susceptibility was tested following the guidelines by the Clinical and Laboratory Standards Institute, using a commercially prepared and dehydrated panel. A chi-squared test was performed to assess the differences in virulence gene profiles between hypermucoviscous and non-hypermucoviscous isolates.
A high resistance rate to ampicillin (98.7%) and doxycycline (41.0%) was observed in the KP strains. The resistance rate to cephalosporins ranged from 10 to 20%, and 23.7% of the strains were multidrug-resistant (MDR). A total of 66 resistance genes from 13 categories were identified, including carbapenem-resistant genes in four KP strains. The most common capsular serotypes were K1 and K2 (24.0% of the isolates). O1 was the dominant O antigen type (52.1%). The KP strains were classified into 62 sequence types (STs), with ST23, ST29, ST412, and ST111 being the most prevalent (each accounting for >5.0% of the isolates). The carriage rates of the virulence genes aerobactin, yersiniabactin, colibactin, salmochelin, RmpADC, and RmpA2 were 44.4, 47.9, 11.1, 54.7, 55.6, and 31.6%, respectively. All ST23 KP strains carried virulence plasmids other than RmpADC. Hypermucoviscous (HM) KP was observed in 23.4% of the isolates. HM KP strains carried a higher number of virulence genes compared to the non-HM KP strains.
Although no single dominant (KP) clone, serotype, or sequence type was identified among the isolated KP strains from this hospital, the overall resistance rates remained relatively low. However, the relatively prevalent ST23 KP strains, which carry multiple virulence genes, are a concern due to their potential to acquire carbapenem-resistant genes.
肺炎克雷伯菌（KP）对全球健康构成威胁，不同地区存在差异。然而，中国东部地区KP分离株的基因组特征和耐药谱数据有限。为填补这一空白，我们从中国江苏省的一家中医院收集了KP分离株，以表征这些特征。
2023年2月至2024年2月，从中国江苏省的一家中医院收集了117株KP分离株。对所有分离株进行了药敏试验和全基因组测序。然后，使用Prokka和Kleborate软件工具鉴定荚膜血清型、多位点序列分型、毒力基因和耐药基因。使用悬丝试验检测高黏液性表型。按照临床和实验室标准协会的指南，使用商业制备的脱水平板进行药敏试验。进行卡方检验以评估高黏液性和非高黏液性分离株之间毒力基因谱的差异。
在KP菌株中观察到对氨苄西林（98.7%）和多西环素（41.0%）的高耐药率。对头孢菌素的耐药率在10%至20%之间，23.7%的菌株为多重耐药（MDR）。共鉴定出13类66个耐药基因，包括4株KP菌株中的碳青霉烯耐药基因。最常见的荚膜血清型是K1和K2（占分离株的24.0%）。O1是主要的O抗原类型（52.1%）。KP菌株被分为62个序列型（STs），其中ST23、ST29、ST412和ST111最为常见（各占分离株的>5.0%）。气杆菌素、耶尔森菌素、大肠杆菌素、沙门菌素、RmpADC和RmpA2毒力基因的携带率分别为44.4%、47.9%、11.1%、54.7%、55.6%和31.6%。所有ST23 KP菌株除携带RmpADC外还携带毒力质粒。在23.4%的分离株中观察到高黏液性（HM）KP。与非HM KP菌株相比，HM KP菌株携带更多的毒力基因。
尽管在这家医院分离的KP菌株中未鉴定出单一的优势克隆、血清型或序列型，但总体耐药率仍然相对较低。然而，携带多个毒力基因的相对普遍的ST23 KP菌株因其获得碳青霉烯耐药基因的潜力而令人担忧。
