Santos M C, Amarante M R V, Amarante A F T
Universidade Estadual Paulista (UNESP), Departamento de Parasitologia, Instituto de Biociências; Botucatu - SP, Brazil.
J Helminthol. 2019 Nov;93(6):697-703. doi: 10.1017/S0022149X18000743. Epub 2018 Sep 4.
This study aimed to evaluate the simultaneous infections of Haemonchus contortus and Haemonchus placei in sheep, as well as the production of hybrids. A parental group of lambs (n = 6) were mix-infected with 2000 infective larvae (L3) of H. placei and 2000 L3 of H. contortus. Faecal samples were taken from each of these six lambs to produce the first generation of L3 (F1-L3) in individual cultures. These F1-L3 were used to infect 12 lambs; six of them were euthanized at 42 days (Group F1-42) and six at 84 days (Group F1-84) post infection. Polymerase chain reaction (PCR) analysis, using species-specific primer pairs, was the gold standard method for identification of Haemonchus adult species and hybrids. The establishment rate of both species was similar in the parental group: 51.7% H. contortus and 48.3% H. placei. Of the 219 adult specimens from groups F1-42 and F1-84 analysed by PCR, eight (3.65%) were hybrids, 111 were H. contortus and 100 were H. placei. The morphological evaluation of the F1-L3 from the parental group showed a predominance of larvae with H. contortus size (51.5%) in comparison with H. placei (42.8%). In the second generation of L3 (F2-L3) produced by the F1-lambs, larvae with H. contortus morphology predominated, with 81.5% in the F1-42 group and 84.0% in the F1-84 group. In conclusion, an artificial mixed infection by H. contortus and H. placei was established in lambs and resulted in the production of a small number of hybrids among their offspring.
本研究旨在评估绵羊体内捻转血矛线虫和柏氏血矛线虫的同时感染情况以及杂交种的产生。一组亲代羔羊（n = 6）被混合感染2000条柏氏血矛线虫感染性幼虫（L3）和2000条捻转血矛线虫L3。从这6只羔羊中采集粪便样本，在个体培养中产生第一代L3（F1-L3）。这些F1-L3被用于感染12只羔羊；其中6只在感染后42天安乐死（F1-42组），6只在感染后84天安乐死（F1-84组）。使用物种特异性引物对的聚合酶链反应（PCR）分析是鉴定血矛线虫成虫种类和杂交种的金标准方法。在亲代组中，两种线虫的定植率相似：捻转血矛线虫为51.7%，柏氏血矛线虫为48.3%。通过PCR分析F1-42组和F1-84组的219个成虫样本，其中8个（3.65%）为杂交种，111个为捻转血矛线虫，100个为柏氏血矛线虫。对亲代组F1-L3的形态学评估显示，与柏氏血矛线虫（42.8%）相比，具有捻转血矛线虫大小的幼虫占优势（51.5%）。在F1代羔羊产生的第二代L3（F2-L3）中，具有捻转血矛线虫形态的幼虫占优势，F1-42组为81.5%，F1-84组为84.0%。总之，在羔羊中建立了捻转血矛线虫和柏氏血矛线虫的人工混合感染，并在其后代中产生了少量杂交种。
