Kumar Saroj, Garg Rajat, Banerjee P S, Ram Hira, Kundu K, Kumar Sunil, Mandal M
Division of Parasitology, ICAR-Indian Veterinary Research Institute, Izatnagar-243 122, Uttar Pradesh, India.
Division of Parasitology, ICAR-Indian Veterinary Research Institute, Izatnagar-243 122, Uttar Pradesh, India.
Infect Genet Evol. 2015 Dec;36:262-267. doi: 10.1016/j.meegid.2015.09.023. Epub 2015 Sep 28.
Coccidiosis, caused by apicomplexan parasites of the genus Eimeria, inflicts severe economic losses to the poultry industry around the globe. In the present study, ITS-1 based species specific nested PCR revealed prevalence of E. acervulina, E. brunetti, E. maxima, E. mitis, E. praecox, E. necatrix and E. tenella in 79.2%, 12.5%, 64.6%, 89.6%, 60.4%, 64.6% and 97.9% poultry farms of north India, respectively. The ITS-1 sequences of different Eimeria spp. from north India were generated and analyzed to establish their phylogenetic relationship. The sequence identity with available sequences ranged from 80 to 100% in E. tenella, 95 to 100% in E. acervulina, 64 to 97% in E. necatrix, 96 to 99% in E. brunetti and 97 to 98% in E. mitis. Only long ITS-1 sequences of E. maxima could be generated in the present study and it had 80-100% identity with published sequences. Two out of the four ITS-1 sequences of E. maxima had mismatches in the published nested primer sequences from Australia, while one sequence of E. necatrix had a mismatch near 3' end of both forward and reverse published nested primer sequences, warranting for the need of designing new set of degenerate primers for these two species of Eimeria. In the phylogenetic tree, all isolates of E. acervulina, E. brunetti, E. mitis, E. tenella and E. necatrix clustered in separate clades with high bootstrap value. E. maxima sequences of north Indian isolates grouped in a long form of E. maxima clade. Complete ITS-1 sequences of E. necatrix and E. mitis are reported for the first time from India. Further studies are required with more number of isolates to verify whether these differences are unique to geographical locations.
球虫病由艾美耳属顶复门寄生虫引起，给全球家禽业造成了严重的经济损失。在本研究中，基于内转录间隔区1（ITS-1）的种特异性巢式PCR显示，在印度北部的家禽养殖场中，堆型艾美耳球虫、布氏艾美耳球虫、巨型艾美耳球虫、缓艾美耳球虫、早熟艾美耳球虫、毒害艾美耳球虫和柔嫩艾美耳球虫的感染率分别为79.2%、12.5%、64.6%、89.6%、60.4%、64.6%和97.9%。对来自印度北部的不同艾美耳球虫种类的ITS-1序列进行了测定和分析，以确定它们的系统发育关系。与现有序列的序列同一性在柔嫩艾美耳球虫中为80%至100%，在堆型艾美耳球虫中为95%至100%，在毒害艾美耳球虫中为64%至97%，在布氏艾美耳球虫中为96%至99%，在缓艾美耳球虫中为97%至98%。在本研究中仅获得了巨型艾美耳球虫的长ITS-1序列，其与已发表序列的同一性为80%-100%。巨型艾美耳球虫的四个ITS-1序列中有两个在来自澳大利亚的已发表巢式引物序列中存在错配，而一个毒害艾美耳球虫序列在已发表的正向和反向巢式引物序列的3'端附近存在错配，这表明需要为这两种艾美耳球虫设计一套新的简并引物。在系统发育树中，堆型艾美耳球虫、布氏艾美耳球虫、缓艾美耳球虫、柔嫩艾美耳球虫和毒害艾美耳球虫的所有分离株都聚集在具有高自展值的独立分支中。印度北部分离株的巨型艾美耳球虫序列聚集在巨型艾美耳球虫分支的一个长分支中。毒害艾美耳球虫和缓艾美耳球虫的完整ITS-1序列首次从印度报道。需要对更多的分离株进行进一步研究，以验证这些差异是否是地理位置所特有的。
