Research on enterohaemorrhagic E.coli (EHEC) including its epidemiology, pathogenesis, and development of diagnosis and treatment..

1.流行病学：在冈山县和四冈县对牛，特别是犊牛进行了EHEC的调查，发现约有0.1-1.0%的小牛对EHEC O157呈阳性。对分离株进行生化特性、药敏试验和包括PFGE在内的分子检测，并对大阪府周边地区的临床医生进行EHEC感染的问卷调查。2.发病机制：建立小鼠、大鼠、兔等多种动物模型。这些实验表明VT对脑和肾小管上皮细胞具有直接毒性。3.诊断：建立了检测EHEC的DNA探针和聚合酶链式反应等分子遗传学技术。乳胶导向乳铁蛋白(中性粒细胞的一种指示物)检测使用腹泻粪便，用于快速怀疑EHEC感染。对部分VT和EHEC O157检测试剂盒进行了评价。4治疗：抗VT抗血清可预防VT所致的小鼠死亡，并检测了抗微生物制剂对EHEC产生VT的影响。

1.Epidemiology : Survey for EHEC in cattle, especially calf, was conducted in Okayama and Sizuoka prefectures and we found that about 0.1-1.0% of calf tested were positive for EHEC O157. The isolates were tested for biochemical character, antimicrobial sensitivity test, and molecular analyzes including PFGE.A questionnaire survey on EHEC infection was also conducted for clinicians around Osaka prefecture.2.Pathogenesis : Several animal models such as mouse, rat and rabbit were established. Those experiments suggested that VT showed direct toxicity to brain as well as renal tubular cells.3.Diagnosis : Molecular genetical techniques such as DNA-probe and PCR methods were developed for EHEC detection. Latex-oriented lactofferin (an indicator for neutrophil) assay using diarrheal stool was applied for quick suspicion of EHEC infection. Some detection kits for VT and EHEC O157 were also evaluated. Thrombomodulin in sera was revealed to be an indicator for early recongnition of HUS.4.Treatment : It was shown that anti-VT antiserum prevented mouse from lethality due to VT.Effect of anti-microbial agents on VT-production by EHEC was examined.