Brisse Sylvain, Passet Virginie, Haugaard Anita Björk, Babosan Anamaria, Kassis-Chikhani Najiby, Struve Carsten, Decré Dominique
Institut Pasteur, Microbial Evolutionary Genomics, Paris, France.
J Clin Microbiol. 2013 Dec;51(12):4073-8. doi: 10.1128/JCM.01924-13. Epub 2013 Oct 2.
Pathogens of the genus Klebsiella have been classified into distinct capsular (K) types for nearly a century. K typing of Klebsiella species still has important applications in epidemiology and clinical microbiology, but the serological method has strong practical limitations. Our objective was to evaluate the sequencing of wzi, a gene conserved in all capsular types of Klebsiella pneumoniae that codes for an outer membrane protein involved in capsule attachment to the cell surface, as a simple and rapid method for the prediction of K type. The sequencing of a 447-nucleotide region of wzi distinguished the K-type reference strains with only nine exceptions. A reference wzi sequence database was created by the inclusion of multiple strains representing K types associated with high virulence and multidrug resistance. A collection of 119 prospective clinical isolates of K. pneumoniae were then analyzed in parallel by wzi sequencing and classical K typing. Whereas K typing achieved typeability for 81% and discrimination for 94.4% of the isolates, these figures were 98.1% and 98.3%, respectively, for wzi sequencing. The prediction of K type once the wzi allele was known was 94%. wzi sequencing is a rapid and simple method for the determination of the K types of most K. pneumoniae clinical isolates.
近一个世纪以来，克雷伯菌属的病原体已被分为不同的荚膜（K）型。克雷伯菌属的K分型在流行病学和临床微生物学中仍具有重要应用，但血清学方法存在很大的实际局限性。我们的目标是评估wzi基因测序作为一种简单快速预测K型的方法，wzi基因在所有肺炎克雷伯菌荚膜类型中均保守，编码一种参与荚膜附着于细胞表面的外膜蛋白。对wzi基因447个核苷酸区域进行测序，仅9个例外就区分出了K型参考菌株。通过纳入代表与高毒力和多重耐药相关的K型的多个菌株，创建了一个wzi参考序列数据库。然后，通过wzi测序和经典K分型对119株肺炎克雷伯菌临床前瞻性分离株进行了平行分析。K分型对81%的分离株实现了分型能力，对94.4%的分离株实现了鉴别能力，而wzi测序的这些数字分别为98.1%和98.3%。一旦知道wzi等位基因，K型的预测准确率为94%。wzi测序是一种快速简单的方法，可用于确定大多数肺炎克雷伯菌临床分离株的K型。
