Sahibi H, Rhalem A, Barriga O O
Department of Parasitology, Institute Agronomique et Veterinaire Hassan II, Rabat, Morocco.
Vet Parasitol. 1997 Mar;68(4):359-66. doi: 10.1016/s0304-4017(96)01082-5.
Tick concealed antigens have been successful in producing immunity that inhibits tick fertility, but require periodic revaccination and are little effective in preventing tick feeding, which is critical to stop pathogen transmission. Tick natural salivary antigens also induce important immunity, but revaccination may be unnecessary in enzootic areas. In addition these antigens may inhibit tick feeding. We immunized groups of three tick-naive calves with four prior infestations with Hyalomma marginatum marginatum, a salivary extract (SE), or an intestinal extract (IE) of the ticks. The calves were challenged with 100 pairs of homologous ticks and characteristics representing tick feeding or fertility were recorded and compared between groups. The percentage of attachment was inhibited by 46% by the infestation-generated immunity, 47% by the SE-generated immunity, and 0% by the IE-generated immunity. The percentage of engorgement was reduced 40% by the infestations, 57% by the SE, and 29% by the IE. The length of feeding was prolonged 92% by the infestations, shortened 44% by the SE, and not affected by the IE. The weight of the engorged females was decreased 67% by the infestations, 64% by the SE, and 31% by the IE. The percentage of engorged ticks that oviposited was inhibited 52% by the infestations, 27% by the SE, and 63% by the IE. The preoviposition period was prolonged 160% by the infestations, 80% by the SE, and 140% by the IE. The egg weight was reduced 60% by the infestations, 60% by the SE, and 66% by the IE. Taking into account mortality before oviposition, fertility was inhibited 88.2% by the infestations, 87.5% by SE, and 91.4% by the IE. The effect of IE immunization on tick feeding was not significant statistically.
蜱虫隐蔽抗原在产生抑制蜱虫繁殖力的免疫力方面已取得成功，但需要定期重新接种疫苗，且在阻止蜱虫叮咬方面效果甚微，而阻止蜱虫叮咬对于阻断病原体传播至关重要。蜱虫天然唾液抗原也能诱导重要的免疫力，但在地方病流行地区可能无需重新接种疫苗。此外，这些抗原可能会抑制蜱虫叮咬。我们用四批边缘璃眼蜱（Hyalomma marginatum marginatum）、唾液提取物（SE）或蜱虫肠道提取物（IE）对三组未曾接触过蜱虫的小牛进行免疫接种。用100对同源蜱虫对小牛进行攻毒，并记录代表蜱虫叮咬或繁殖力的特征，然后在各组之间进行比较。通过感染产生的免疫力使附着率降低了46%，通过SE产生的免疫力使附着率降低了47%，而通过IE产生的免疫力使附着率降低了0%。饱血率通过感染降低了40%，通过SE降低了57%，通过IE降低了29%。取食时长通过感染延长了92%，通过SE缩短了44%，而IE对其没有影响。饱血雌蜱的体重通过感染降低了67%，通过SE降低了64%，通过IE降低了31%。产卵的饱血蜱虫百分比通过感染受到52%的抑制，通过SE受到27%的抑制，通过IE受到63%的抑制。产卵前期通过感染延长了160%，通过SE延长了80%，通过IE延长了140%。卵重通过感染降低了60%，通过SE降低了60%，通过IE降低了66%。考虑到产卵前的死亡率，繁殖力通过感染受到88.2%的抑制，通过SE受到87.5%的抑制，通过IE受到91.4%的抑制。IE免疫对蜱虫叮咬的影响在统计学上不显著。
