早熟艾美耳球虫上海株的分离鉴定及生物学特性观察

Identification and biological characterization of Eimeria praecox Shanghai isolate

为分离和鉴定早熟艾美尔球虫(Eimeria praecox),观察其主要生物学特性,本研究采用单卵囊感染技术分离单一虫株,通过卵囊形态学、PCR技术和18SrRNA基因检测,对其进行性状观察、虫种鉴定和系统发生关系分析。在获得的5株单一虫株中,对其中一株的卵囊形态、寄生部位、最短孢子化时间和最短潜在期进行观察。结果表明:该株球虫具有E. praecox的主要生物学特征;分离自肠道的卵囊明显小于分离自粪便的卵囊;最短潜在期为81h;经PCR鉴定为E. praecox,命名为E. praecox上海株。测序结果显示,其18SrRNA基因序列长1747bp,与GenBank登录的相关基因序列同源性为99.4%;该虫株对雏鸡呈轻度致病性。该虫株的分离和鉴定为丰富我国鸡球虫虫种资源,开展球虫病防治研究提供了依据。

To study the biological characters of Eimeria praecox isolated in Shanghai,5 Eimeria isolates were obtained by a single oocyst infection and the oocysts shape and size,the parasitized region,the minimum sporulation time and the prepatent period of the strain were observed.The 18S rRNA sequences of these isolates were amplified by PCR for phylogenetic analysis.The results showed that the isolate possesses the main biological characters of E.praecox.The size of oocysts isolated from small intestine was visibly smaller than that from fecal and the prepatent period was only 81 h.The 18S rRNA gene was 1 747 bp in length and showed 99.4 % homology to the sequence in GenBank.The isolate had mild morbidity to 2 weeks old chicken.The E.praecox Shanghai isolate provieded useful addition to the resource in the prevention and control studies of coccidian.