Distribution and molecular epidemiology of 56 strains of hypervirulent Klebsiella pneumoniae in Dongguan, Guangdong

Abstract

Objective To study the clinical infection distribution and homology between strains of hypervirulent Klebsiella pneumoniae, analyze its molecular epidemiological characteristics, and we provide a laboratory basis for preventing and control⁃ ling the clonal spread of hypervirulent Klebsiella pneumoniae.

Methods Clinically isolated 56 non-repetitive strains of hyper⁃ virulent Klebsiella pneumoniae from Dongguan People’s Hospital were used to detect and sequence their capsular serotypes us⁃ ing PCR amplification techniques. Multi-locus sequence typing (MLST) and Enterobacteriaceae were used, in order to under⁃ stand the molecular epidemiological characteristics of homologous, repeat sequence PCR (ERIC-PCR) for homology analysis.

Results The majority of the 56 hypervirulent Klebsiella pneumoniae specimens were from respiratory specimens, 22 strains (39.3%); 14 blood samples (25.0%); 9 liver drainage fluids (16.1%); 5 urine samples (8.9%); and 6 other specimens (10.7%). The departments were mainly distributed in ICU, general surgery area 3，neurosurgery area 2 and general departments. The cap⁃ sular serotypes were mainly Kl, K2, and K57, and K1 and K57 each accounted for 25.0% (14/56), and the K2 was slightly high⁃ er, accounting for 26.8% (15/56); among different specimen types, K1 had the highest proportion in blood specimens, which was 35.7% (5/14); K2, K57 types were mainly found in respiratory specimens. ERIC-PCR products were divided into 22 types: 10 strains of type I, 9 strains of type II, 7 strains of type III, 5 strains of type IV, 4 strains of type V, each 2 strains of Ⅵ- Ⅶ, each 2 strains of Ⅷ- Ⅸ, the remaining 13 types was each one strain; MLST of multi-site sequence analysis showed 16 types of ST, mainly three types of ST23, ST86, and ST218, of which ST23 was all K1 (100.0%) hypervirulent Klebsiella pneumoniae; The homology analysis of HvKP in different patients of different departments found that I / ST23 K1 type was predominant, of which ICU was predominantly Ⅳ/ST23 K1 type and Ⅶ/ ST11 K54 type; the general surgery area 3 were mainly prevalent Ⅰ/ST23 K1 type and II/ST218 K57 Type; Respiratory department was mainly prevalent Ⅰ/ST23 K1 type, MLST and ERIC-PCR analysis results were different.

Conclusion Hypervirulent Klebsiella pneumoniae in this area is mainly cloned with Ⅰ/ST23 K1 clones. The laboratory conducted molecular epidemiological investigation on hypervirulent Klebsiella pneumoniae to understand the risk factors of high-risk areas, high incidence areas, and susceptible populations, and promptly inform the clinical feedback. It can effectively prevent and control the clonal spread of hypervirulent Klebsiella pneumoniae.

Abstract

摘要： 目的 研究高毒力肺炎克雷伯菌( hypervirulent Klebsiella pneumoniae, HvKP ) 临床感染分布及菌株间的同源 性，分析其分子流行病学特征，为预防和控制高毒力肺炎克雷伯菌的克隆传播提供实验依据。 方法 收集东莞市人民 医院临床分离非重复的 56 株 HvKP，应用 PCR 扩增技术检测其荚膜血清型并测序，运用多位点序列分型(MLST)和肠杆 菌科基因间一致重复序列 PCR(ERIC—PCR)进行同源性分析，了解其分子流行病学特征。 结果 56 株 HvKP 标本来源 以呼吸道标本为主，为 22 株(39.3%)；其次为血液 14 株(25.0%)；肝脓肿引流液 9 株(16.1%)，尿液 5 株(8.9%)，其他标本 6 株(10.7%)。科室主要分布 ICU、普外三区、神经外科二区、综合科；荚膜血清型以 Kl、K2、K57 型为主，K1、K57 型各占25.0%(14/56)，K2 型略高，占 26.8%(15/56)；不同标本类型中，K1 在血液标本占比最高，为 35.7%(5/14)；K2、K57 型主要 见于呼吸道标本。ERIC-PCR 产物分为 22 个型别：Ⅰ型 10 株、Ⅱ 型 9 株、Ⅲ型 7 株、Ⅳ型 5 株、Ⅴ型 4 株、Ⅵ~Ⅶ各 2 株、Ⅷ~Ⅸ各 2 株，其余 13 个型别各 1 株；多位点序列分析 MLST 显示 16 种 ST 型，主要以 ST23、ST86、ST218 这 3 种型别为主， 其中 ST23 全部是 K1 型(100.0%)HvKP；不同科室的不同患者高毒力肺炎克雷伯菌进行同源性分析发现，Ⅰ/ST23 K1 型居多，其中 ICU 主要流行Ⅳ/ST23 K1 型和Ⅶ/ST11 K54 型;普外三区主要流行Ⅰ/ST23 K1 型和Ⅱ/ST218 K57 型；呼吸科 主要流行Ⅰ/ST23 K1 型,MLST 与 ERIC-PCR 分析结果有所差别。 结论 东莞市 HvKP 以Ⅰ/ST23 K1 型 和以痰液、血液 和肝脓肿引流液标本来源为主，应对高毒力肺炎克雷伯菌进行分子流行病学调查，以有效预防和控制 HvKP 传播。