Purpose

The aim of this study was to determine molecularly the species of larvae of trichostrongylid nematodes in arrested development in the abomasum of sheep from Iran and their seasonality.

Methods

A total of 240 sheep abomasa were randomly collected at different seasons from Ilam abattoir in 2017–2018. The adult nematodes were isolated and identified. The mucosa of the abomasum was removed and digested using a pepsin solution. DNA from different parts of the abomasum was extracted using a SinaPureTM kit. Polymerase chain reaction (PCR) amplification was performed; the ITS2-rRNA gene was amplified using specific primers. Amplified PCR products were purified and sequenced by Bioneer Corporation (South Korea). The obtained ITS2 sequences were aligned using BLAST analysis and submitted to GenBank.

Results

Morphologically, five species of adult nematodes of four genera including Haemonchus contortus, Marshallagia marshalli, Marshallagia occidentalis, Parabronema skrjabini, and Teladorsagia circumcincta were identified. Marshallagia marshalli (65.4%, 120.2 ± 28.5) had the highest prevalence during autumn. Molecularly, arrested development of larvae of M. marshalli and T. circumcincta were demonstrated in mucosa of the abomasum in autumn and early winter using PCR of the ITS-2 region of rRNA.

Conclusion

The results evidenced the first molecular characterization of the larvae of trichostrongylid nematodes from abomasum of sheep from Iran.

中文翻译：

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在伊朗自然感染绵羊的真胃中受阻发育的毛圆线虫幼虫的第一次分子特征和季节性。

目的

本研究的目的是从分子上确定伊朗绵羊真胃中生长停滞的毛圆线虫幼虫的种类及其季节性。

方法

2017-2018年从伊拉姆屠宰场在不同季节随机收集了240只羊皱眉。分离并鉴定成年线虫。去除真胃粘膜并使用胃蛋白酶溶液消化。使用 SinaPureTM 试剂盒提取真胃不同部位的 DNA。进行聚合酶链反应（PCR）扩增；使用特异性引物扩增 ITS2-rRNA 基因。扩增的 PCR 产物由 Bioneer Corporation（韩国）纯化和测序。使用BLAST分析比对获得的ITS2序列并提交给GenBank。

结果

在形态学上，鉴定出变形血球虫、Marshallagia marshalli、Marshallagia occidentalis、Parabronema skrjabin i 和Teladorsagia circlecincta 4 属5 种成虫。Marshallagia marshalli (65.4%, 120.2 ± 28.5) 在秋季的流行率最高。在分子上，使用 rRNA 的 ITS-2 区域的 PCR 在秋季和初冬的皱胃粘膜中证明了M. marshalli和T. circlecincta幼虫的发育停滞。

结论

结果证明了伊朗绵羊真胃毛圆线虫幼虫的第一个分子特征。