Rash N L, Robinson C, DeSouza N, Nair S, Hodgson H, Steward K, Waller A S, Paillot R
Centre for Preventive Medicine, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, UK.
Centre for Preventive Medicine, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk CB8 7UU, UK.
Res Vet Sci. 2014 Dec;97(3):481-7. doi: 10.1016/j.rvsc.2014.09.001. Epub 2014 Sep 16.
Streptococcus equi subspecies zooepidemicus (S. zooepidemicus) causes a variety of infections in a broad range of species. This study broadens prevalence data for three recently identified novel superantigens (szeF, szeN, and szeP) to define links between their presence and disease type. Screening of 437 strains across 190 sequence types (STs) revealed that 50% of strains contained superantigen genes. Results confirmed that the presence of S. zooepidemicus superantigen genes is significantly associated with non-Strangles lymph node abscessation in the horse (p-value = 0.003) and their absence is associated with uterine infection/abortion (p-value = 0.006). This study also investigated the lack of mitogenicity observed in szeF only. Results show that szeF is polymorphic, with 23 different alleles, and mutations altering the protein sequence. Gene expression differences are not responsible for lack of mitogenic activity in these strains. Taken together, these findings suggest that superantigens are important for S. zooepidemicus pathogenesis but SzeF probably has little involvement.
马链球菌兽疫亚种（兽疫链球菌）可在多种物种中引发多种感染。本研究拓宽了三种最近鉴定出的新型超抗原（szeF、szeN和szeP）的流行数据，以确定它们的存在与疾病类型之间的联系。对190个序列类型（STs）的437株菌株进行筛选后发现，50%的菌株含有超抗原基因。结果证实，兽疫链球菌超抗原基因的存在与马的非Strangles淋巴结脓肿显著相关（p值 = 0.003），而其缺失与子宫感染/流产相关（p值 = 0.006）。本研究还调查了仅在szeF中观察到的无促有丝分裂活性现象。结果表明，szeF具有多态性，有23种不同的等位基因，且突变会改变蛋白质序列。基因表达差异并非这些菌株缺乏促有丝分裂活性的原因。综上所述，这些发现表明超抗原对兽疫链球菌的发病机制很重要，但SzeF可能几乎没有参与其中。
