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

猪葡萄球菌和中间葡萄球菌与多种动物感染有关，但在健康动物中也有分布。为了对这些生物进行流行病学研究，需要一个适当的标记来区分强毒和无毒菌株。为此，我们调查了使用脉冲菲尔斯凝胶电泳法(PFGE)的基因组DNA指纹分析是否适用。首先，确定了PFGE方法的适宜条件，并将其应用于各种动物来源的猪链球菌菌株的分析。根据动物种类观察到特定的带型，这表明可能存在基于遗传背景的生态变种。在动物感染猪链球菌方面，猪的感染是最严重的问题。大多数(90%)来自病猪的菌株表现出特定的条带组合，而来自健康猪的菌株则表现出不同的带型，这表明pfge a…。更多的分析可能使我们能够区分毒力强的猪链球菌。另一方面，在健康猪的一些品系中也检测到了毒力条带。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。对猪链球菌的外源蛋白进行了SDS-PAGE分析。猪链球菌强毒株具有丰富的特异性蛋白，而弱毒株的特异性蛋白含量明显减少，而对中间链霉菌的PFGE分析则显示出高度的带型，表明不能用该试验来评价其致病性。用小鼠模型对这两种葡萄球菌进行了分析。PFGE分析不能揭示菌株的毒力，提示宿主因素可能在这些疾病的发病机制中起重要作用。我们认为，PFGE分析是进行猪链球菌和中间链霉菌流行病学或生态学研究的有力工具。较少

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