沙门氏菌分型研究进展

Advances in Salmonella subtyping—a review

摘要:

沙门氏菌是重要的致病菌之一，该菌属型别繁多。沙门氏菌的分型方法可分为以表型特征为依据的表型分型方法和以基因特征为依据的分子分型方法。沙门氏菌的表型分型主要有血清分型和噬菌体分型。分子分型主要有分子血清分型、脉冲场凝胶电泳(Pulsed field gel electrophoresis，PFGE)、多位点序列分析(Multi-locus sequence typing，MLST)、多位点可变重复序列分析(Multi-locus variable numbers tandem repeat analysis，MLVA)以及成簇的规律间隔的短回文重复序列分析(clustered regularly interspaced short palindromic repeats，CRISPR)等。与表型分型相比，分子分型技术具有快速、准确、重复性好等特点，现已得到广泛应用。其中，分子血清分型是鉴定沙门氏菌血清型的新方法，PFGE被认为是病原微生物分子分型的“金标准”，MLST和MLVA以其分辨率高、可重复性好和可比性强等优势满足了全球流行病学发展的要求，能实现序列数据交换和共享，成为新一代的分子分型新工具，而近年发现的CRISPR分型对同源性较高的同种血清型具有较高的分型能力。但每种分型方法也有各自的优缺点和使用条件及适用范围，因此可以根据菌株特性、分型目的和实验室拥有的条件选择最合适的分型方法。

关键词:沙门氏菌，血清分型，PFGE，MLST，MLVA，CRISPR

Abstract:

Salmonella is an important foodborne pathogenic bacterium, with more than 2 500 serotypes. A number of techniques have been developed for Salmonella subtyping, including phenotypic and genotypic techniques. Traditionally, Salmonella isolates are identified and typed by phenotypic techniques such as serotyping and phage typing. During the last two decades, genotypic techniques have been used for differentiation of Salmonella isolates and source tracing of foodborne outbreaks. These methods include molecular serotyping, pulsed field gel electrophoresis (PFGE), multi-locus sequence typing (MLST), multi-locus variable number of tandem repeats analysis (MLVA), and clustered regularly interspaced short palindromic repeats (CRISPR). Compared with phenotypic methods, genotypic methods are widely applied for Salmonella typing due to their high discriminatory power and good reproducibility. Molecular serotyping, as a new method, is to identify serotypes of Salmonella by PCR. PFGE is considered the “gold standard” for Salmonella subtyping. MLST and MLVA, as DNA sequencing-based methods, are publicly available online and can be compared readily between laboratories. CRISPR typing has a high distinguish capacity among the same serotype with homology and satisfying genotyping result. However, each typing method has different advantages and drawbacks, operating conditions, and applicability. Therefore, it is necessary to choose the suitable typing methods for genetic diversity analysis according to the characteristic of strains and experimental facilities available.

Key words:Samonella, serotype, PFGE, MLST, MLVA, CRISPR