ISOLATION AND CHARACTERIZATION OF SPOTTED FEVER GROUP RICKETTSIA IN NONENDEMIC AREA OF JAPANESE SPOTTED FEVER

1995 - 2005年度，在河北省北幌市保护森林中采集野生小鼠，调查斑点热群立克次体（SFGR）抗体的流行情况。抗体的高流行率与蜱虫的侵袭有关。1996年在青森县东田市也采集到野生小鼠和蜱虫。该地区及北坡、别别市野生小鼠抗体阳性率和滴度均较高。分别采用小鼠接种法和离心法直接接种L细胞或Vero细胞的方法，从两地采集的野生小鼠和蜱中分离SFGR。它还没有成功地分离出SFGR或类似SFGR的生物。这种尝试现在仍在继续。此外，利用SFGR的通用引物对野生小鼠原始样品进行PCR，未发现SFGR的存在。结果将被解释为证明该抗体在野生小鼠中的流行是一个复杂的问题。由于SFGR在泰国的报道并不常见，因此使用20世纪70年代收集的野生大鼠血清调查了泰国SFGR与日本斑点热立克次体之间的关系。结果发现，印度斑虫是泰国SFGR的重要宿主之一，TT-118对人的致病性尚不清楚，或与抗原相关的生物高流行，但日本斑疹热SFGR在泰国并不常见。除南非和津巴布韦外，非洲南部的SFGR没有得到很好的调查。我们从赞比亚的三个地区获得了大约300份人类血清。在赞比亚牛生产中心的3个地区中，有2个地区发现了高流行率的SFGR抗体。

In 1995FY,wild mice were collected from the conserved forest in Nopporo, Ebetsu-shi and investigated prevalence of the antibody against spotted fever group rickettsia (SFGR). High prevalence of the antibody was correlated to infestation of ticks. In 1996FY wild mice and ticks were also collected from Towada-shi, Aomori prefecture. High prevalence and titer of the antibody in wild mice were found in the area as well as Nopporo.Ebetsu-shi.Attempts to isolate SFGR from wild mice and ticks collected from the both areas were performed by using mice inoculation and direct inoculation to L cells or Vero cells by centrifugation method. It has not succeeded in isolation of SFGR or SFGR like organisms. The attempts is continued still now. In addition, the existence of SFGR was not revealed in original samples from wild mice by PCR using common primers of SFGR.The result will be interpreted that evidence of the prevalence of the antibody in wild mice is complicated problems.Since the reports on SFGR is not so common in Thailand, the relationship between SFGR in Thailand and Japanese spotted fever rickettsia was investigated using wild rat sera collected in the 1970s. It was found that Bandicota indica was one of the important reservoirs of SFGR in Thailand and TT-118, pathogenisity for human of which was not clear, or antigenically related organisms was high prevalent but Japanese spotted fever SFGR was not so common in Thailand.SFGR in southern Africa except Rep.South Africa and Zimbabwe was not well investigated. We obtained about 300 human sera from 3 areas in Zambia. High prevalence of the antibody against SFGR (R.conorii) was found in 2 of the 3 areas where were cattle production center in Zambia.