MOLECULAR EPIDEMIOLOGY OF ANIMAL-PATHOGENIC STAPHYLOCOCCI,USING PULSED-FIELD GEL ELECTROPHORESIS

猪葡萄球菌（Staphylococcus hyicus）和中间葡萄球菌（Staphylococcus intermedius）与多种动物感染有关，但它们也分布于健康动物中。对于这些微生物的流行病学研究，需要一个适当的标记来区分强毒株和无毒毒株。为此，我们研究了是否基因组DNA指纹图谱，使用脉冲场凝胶电泳（PFGE），是适用的。首先确定了PFGE方法的适宜条件，并将其应用于不同动物源猪链球菌的分析。根据动物的种类，观察到特定的带型，这表明基于遗传背景的ecovars可能存在于S. hyicus。关于猪链球菌在动物中的感染，猪中的感染是最严重的问题。90%的病猪菌株显示特异性条带组合，而健康猪菌株显示多种多样的带型，表明PFGE是一种有效的方法。 ...更多信息 分析可使我们区分猪链球菌的强毒株。另一方面，在健康猪的部分菌株中也检测到了毒力带型。这可能表明，不仅在生物体方面，而且在动物宿主方面也存在表现疾病的因素。SDS-PAGE分析表明，强毒菌株含有大量的特异性蛋白，弱毒菌株含有少量或不含特异性蛋白，而中间型菌株的PFGE带型丰富，不能用于致病性的鉴定。结果表明，两种葡萄球菌均具有一定的异质性。PFGE分析不能反映菌株的毒力，提示宿主因素可能在这些疾病的发病机制中起重要作用。因此，PFGE分析是猪链球菌和中间链球菌流行病学或生态学研究的有力工具。少

Staphylococcus hyicus and Staphylococcus intermedius have been implicated in a variety of infections in animals, however, both of them are also distributed in healthy animals. For the epidemiologic study of these organisms, an appropriate marker is needed for differentiating virulent and avirulent strains. For that purpose, we investigated whether or not genomic DNA fingerprinting, using pulsed-fiels gel electrophoresis (PFGE), is applicable. First, appropriate conditions of PFGE method was determined, and applied to the analysis of S.hyicus strains from various animals species. Specific banding patterns were observed according to the animal species, suggesting that ecovars based on the genetic background may be present in S.hyicus. Regarding S.hyicus infections in animals, that in pigs is the most serious problem. Most (90%) of strains from diseased pigs showed a specific combination of bands, while strains from healthy ones showed a variety of banding patterns, suggesting that PFGE a … More nalysis may enable us to distinguish virulent strains of S.hyicus. On the other hand, the virulent banding patten was also detected in some strains from healthy pigs. This may suggest that not only in the side of organism but in the side of animal host factors for manifesting disease are present. Exoproteins of S.hyicus strains was analyzed by SDS-PAGE.Virulent strains of S.hyicus revealed an extensive amount of a specific protein, while avirulent ones did remarkablly less amount of the protein or not.With regard to S.intermedius, it showed a high degree of banding patterns in PFGE analysis, suggesting that the pathogenicity could not be assessed by the test. It was proved that strains of this organism are heterogeneous.A mouse model was applied to the analysis of the two species of Staphylococcus. It could not reveal the virulence of strains, suggesting that host factors may be important in pathogenesis of those diseases.We conclude that PFGE analysis is a powerful tool for epidemiologic or ecologic studies of S.hyicus and S.intermedius. Less