广州市郊鼠中检出埃立克体样微生物

目的　了解曾经两次暴发犬埃立克体病流行的广州市郊某养犬基地野生啮齿动物感染埃立克体情况。方法　用 16SrRNA基因埃立克体属特异引物对抓捕的动物全血及脾脏样本进行PCR检测 ,阳性样本克隆测序 ,所得序列与Gen Bank中注册的核苷酸序列进行比较。结果　在所抓捕的 2 6只野生啮齿动物中 ,3份褐家鼠全血样本和一份脾样本检出埃立克体特异阳性带。序列测定结果显示 ,这 3只鼠所携带的埃立克体样微生物基因完全一致。该基因与核酸数据库中的埃立克体Schotti株有最大同源性 (99 0 4 % )。结论　此次发现的埃立克体与该基地流行的犬埃立克体Gzh982株和扁平埃立克体Gzh981株有很大差异。该菌在流行病学上的意义有待进一步研究。

Ehrlichia-like organism was found in Rattus norvegicuses in the suburban district of Guangzhou

Aim To investigate the wild rodent infected by Ehrlichia in suburban district of Guangzhou where canine ehrlichiosis was an outbreak twice between 1998 and 1999.Methods Samples of blood and spleen of wild rodent were detected by polymerase chain reaction using primers specific for the 16SrRNA gene of Ehrlichia genus.The DNA fragments amplified from the samples were cloned and sequenced.The obtained DNA sequences were searched the homologous sequences in GenBank.Results Four of 26 samples from wild rodents were positive in PCR assay;all of the positive samples were from rats(Rattus norvegicuses).The sequences of the positive DNA fragment in PCR assay were identified and most similar to that of Ehrlichia-like sp.Schotli variant(99.04%).Conclusion The Ehrlichia-like organism in the rats is different to E.canis Gzh982 and E.platys Gzh981 that caused the epidemic canine ehrlichiosis in this region in 1998.The effect of this ehrlichia-like agent in the epidemiology remains to be studied.