Van Wyk J A, Gerber H M, Alves R M
Veterinary Research Institute, Onderstepoort, Republic of South Africa.
Onderstepoort J Vet Res. 1990 Mar;57(1):1-6.
Infective larvae of selected batched of the following nematode species from sheep and cattle were examined for survival and infectivity (by injection into either the abomasum, the duodenum, or the jugular vein) after having been stored in liquid nitrogen for 103-136 months: Haemonchus contortus, Haemonchus placei, Ostertagia circumcincta, Ostertagia ostertagi, Marshallagia marshalli, Cooperia spp., Trichostrongylus axei, Trichostrongylus colubriformis, Trichostrongylus falculatus, Nematodirus spathiger, Nematodirus helvetianus, Oesophagostomum columbianum, Oesophagostomum radiatum, Chabertia ovina and Dictyocaulus filaria. Excluding D. filaria, a mean of 97.7% of the ovine and 96.0% of the bovine nematode larvae were alive when thawed. Compared with previous investigations in this series, little or no reduction occurred with time in either the survival or the viability of the nematodes from cattle, or in the survival of those from sheep. In contrast, the larvae developed poorly in sheep, possibly owing to parenteral treatment of the animals with ivermectin at a dosage of 0.4 mg kg-1, either 6 or 8 days before they were infected.
对从绵羊和牛体内采集的以下线虫种类的选定批次的感染性幼虫，在液氮中储存103 - 136个月后，检查其存活情况和感染性（通过注入皱胃、十二指肠或颈静脉）：捻转血矛线虫、柏氏血矛线虫、环形奥斯特线虫、奥氏奥斯特线虫、马氏马歇尔线虫、古柏线虫属、斧形毛圆线虫、蛇形毛圆线虫、镰状毛圆线虫、斯氏细颈线虫、瑞士细颈线虫、哥伦比亚食道口线虫、辐射食道口线虫、绵羊夏伯特线虫和丝状网尾线虫。除丝状网尾线虫外，解冻时绵羊线虫幼虫平均97.7%存活，牛线虫幼虫平均96.0%存活。与本系列先前的研究相比，牛线虫的存活或活力以及绵羊线虫的存活随时间几乎没有减少或没有减少。相比之下，幼虫在绵羊体内发育不良，可能是因为在感染前6天或8天，给动物按0.4 mg kg-1的剂量注射了伊维菌素进行非肠道治疗。
