Shimoji Yoshihiro, Shiraiwa Kazumasa, Tominaga Haruka, Nishikawa Sayaka, Eguchi Masahiro, Hikono Hirokazu, Ogawa Yohsuke
National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan
Research Institute for Biomedical Sciences, Tokyo University of Science, Noda, Chiba, Japan.
J Clin Microbiol. 2020 May 26;58(6). doi: 10.1128/JCM.00315-20.
The Gram-positive bacterium is a zoonotic pathogen that causes erysipelas in a wide range of mammalian and avian species. Historically, has been differentiated from other species by serotyping. Among 28 serovars of species, specific serovars, namely, 1a, 1b, and 2 of , are associated mainly with the disease in pigs, poultry, and humans; however, other serovar strains are often simultaneously isolated from diseased and healthy animals, indicating the importance of isolate serotyping for epidemiology. The traditional serotyping protocol, which uses heat-stable peptidoglycan antigens and type-specific rabbit antisera in an agar-gel precipitation test, is time-consuming and labor-intensive. To develop a rapid serotyping scheme, we analyzed sequences of the 12- to 22-kb chromosomal region, which corresponds to the genetic region responsible for virulence of serovar 1a and 2 strains of , of the 28 serovars of species. We confirmed that the serovar 13 strain lacks the genomic region and that some serovar strains possess very similar or the same genetic structure, prohibiting differentiation of the serovars. We created 4 multiplex PCR sets allowing the simultaneous detection and differentiation of the majority of serovars. Together with a previously reported multiplex PCR that can differentiate serovars 1a, 1b, 2, and 5, the multiplex PCR-based assay developed in this study covers all but one (serovar 13) of the reported serovars of species and should be a valuable tool for etiological as well as epidemiological studies of infections.
革兰氏阳性菌是一种人畜共患病原体，可在多种哺乳动物和禽类中引起丹毒。历史上，它一直通过血清分型与其他物种区分开来。在该物种的28个血清型中，特定血清型，即该物种的1a、1b和2型，主要与猪、家禽和人类的疾病有关；然而，其他血清型菌株经常同时从患病和健康动物中分离出来，这表明分离株血清分型对流行病学研究的重要性。传统的血清分型方案在琼脂凝胶沉淀试验中使用热稳定的肽聚糖抗原和型特异性兔抗血清，既耗时又费力。为了开发一种快速血清分型方案，我们分析了该物种28个血清型中12至22 kb染色体区域的序列，该区域对应于负责1a和2型血清型菌株毒力的遗传区域。我们证实13型血清型菌株缺乏该基因组区域，并且一些血清型菌株具有非常相似或相同的遗传结构，无法区分这些血清型。我们创建了4套多重PCR，可同时检测和区分大多数该物种的血清型。结合之前报道的可区分1a、1b、2和5型血清型的多重PCR，本研究开发的基于多重PCR的检测方法涵盖了该物种除一个血清型（13型）外的所有已报道血清型，应该是用于该感染病因学及流行病学研究的宝贵工具。
