Risk analysis of staphylococcal enterotoxin type G, H, I, and J in milk and meat.

近年来，许多新的葡萄球菌肠毒素(Ses)被报道。为了调查这些新发现的SE的病理生物学和流行病学，我们进行了如下1项研究。为了建立新鉴定的SE的免疫学检测方法，我们建立了SE的大肠杆菌表达系统，以获得大量纯化的SE。这些纯化的SEs免疫兔，获得了针对每个SEs的单特异性抗体。我们鉴定并鉴定了一种新的葡萄球菌肠毒素(SE)样推定毒素，命名为SER。Ser基因的核苷酸序列分析表明，Ser与seg基因关系最为密切。Ser基因产物SER在大肠杆菌表达系统中以重组蛋白形式成功表达，rSER具有明显的T细胞刺激活性。SER刺激T细胞需要MHC-II类分子。丝氨酸刺激T细胞表达受体Vβ3、11、12、13.2和14。这些结果提示…更确信的是，SER是一种超抗原。用抗rSER抗体进行Western印迹分析，证实了携带Ser的金黄色葡萄球菌产生了SER。此外，Ser至少由两种类型的质粒编码。特别是，一种编码Ser基因的质粒被称为Sed-和Sej-编码pIB485相关的质粒(感染和免疫71：6088,2003；感染和免疫72：3664,2004)。为了解葡萄球菌肠毒素(SE)A~R(SEA~SER)基因(SEA~SER)在金黄色葡萄球菌中的分布情况，我们建立了检测17种SE基因(SEA to SEE、SER~SER)和TSST-1基因的多重聚合酶链式反应方法。利用该多重聚合酶链式反应体系，对从日本牛生奶中分离到的155株金黄色葡萄球菌进行了SE基因分型。在大多数菌株中，这些SE基因与已知的基因组岛或质粒的SE基因图谱是一致的。这些结果表明，大多数金黄色葡萄球菌的SE基因型可能是由含有可移动遗传元件的组合决定的。(手稿正在准备中)。研究了不同浓度(15、25、35%)的脱脂牛奶在不同贮藏条件(15、25、35℃)下金黄色葡萄球菌的生长和肠毒素(SEA)的产生情况。35℃时金黄色葡萄球菌的生长速度比15和25℃时快，35℃时SEA产量最高。较少

In recent years, many new staphylococcal enterotoxins (SEs) have been reported. To investigate pathobiology and epidemiology of these newly identified SEs, we had undertaken studies shown in below.1. To establish immunological detection methods of newly identified SEs, we have developed E.coli expression system of SEs to obtain large amount of each purified SE. These purified SEs were immunized to rabbits, and we obtained monospecific antibodies to each SEs.2. We identified and characterized a novel staphylococcal entertoxin (SE)-like putative toxin, named SER. Nucleotides sequencing analysis of ser gene revealed that ser was most closely related to seg gene. The ser gene product, SER, was successfully expressed as recombinant protein in an Escherichia coli expression system, and rSER showed significant T cell stimulation activity. MHC class II molecules were required for T cell stimulation by SER. SER stimulated T cells bearing receptors Vβ 3, 11, 12, 13.2, and 14. These results sugge … More sted that SER acts as a superantigen. The SER production in ser harboring S.aureus strains was confirmed by Western blot analysis using anti-rSER antibody. Moreover, ser was seen to be encoded by at least two types of plasmids. In particular, one kind of plasmid encoding the ser gene has been known as sed-and sej-encoding pIB485-related plasmid (Infection and Immunity 71:6088, 2003 ; Infection and Immunity 72:3664, 2004).3. To investigate the distribution of staphylococcal enterotoxin (SE) A to R (SEA to SER) genes (sea to ser) in Staphylococcus aureus, we have developed multiplex PCR for detection of 17 kinds of SE genes (sea to see, seg to selr) and TSST-1 gene. Using this multiplex PCR system, we investigated SE-genotype of Staphylococcus aureus 155 isolates obtained from bovine raw milk in Japan. In almost strains, these SE-genotypes were consistent with known SEs gene profile of Genomic islands or plasmids. These results suggest that SE-genotype of most S.aureus would be determined by combination of harboring mobile genetic elements. (manuscript in preparation).4. We have investigated growth and enterotoxin (SEA) production of S.aureus in different concentrated skim milk (15, 25, 35%) at different storage (15, 25, 35℃). The growth rate of S.aureus was more rapid at 35℃ than 15 and 25℃ and SEA was produced most highly at 35℃ storage. Less