Vaccination of goats against Haemonchus contortus with the gut membrane proteins H11/H-gal-GP
Vaccination of goats against Haemonchus contortus with the gut membrane proteins H11/H-gal-GP
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DOI：
10.1016/j.vetpar.2016.08.024
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发表时间：
2016-10-15
影响因子：
2.6
通讯作者：
Hertzberg, Hubertus
中科院分区：
文献类型：
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作者：
Meier, Lorena;Torgerson, Paul R.;Hertzberg, Hubertus
研究人员对40只2 ~ 5月龄的山羊进行了两种不同的免疫接种方案，接种了含有弯曲血蜱肠膜蛋白H11/1-1-gal-GP的疫苗，以评估在预污染的牧场上对弯曲血蜱的保护作用。山羊被分为4组，每组10只，其中3只在投票前接种了第一次疫苗。一组（V4）每隔4周接种一次疫苗，另两组（V6和V6SEP）每隔6周接种一次疫苗。对照组（CTRL）未接种疫苗。5月，在第二次接种疫苗后，所有的山羊都被赶出了之前被种羊感染过弯纹血蜱卵的牧场，为期6周。V4组、V6组和CTRL组一起放牧，V6SEP组分别放牧，放养率相同。每两周检测临床（PCV、FAMACHA、体重）、寄生虫学（粪卵数、FEC）和血清学（抗体效价）参数。所有山羊于10月饲养，用左旋咪唑浸湿，两周后感染5000 L3弯腹螺旋体，四周后屠宰，以测定胃蠕虫负荷。各组平均FEC在投票后42-56天达到峰值。在第28 ~ 70天，V6SEP组FEC明显低于对照组（p < 0.01）。各组平均产蛋量大幅下降，并在低水平上下波动，直至放牧期结束（D 154）。山羊对疫苗接种有反应，每次加强后抗体滴度增加达到峰值。与对照组相比，V4、V6和V6SEP组实验感染引起的平均蠕虫负担分别减少了89%、65%和47%。V4组差异有统计学意义（p < 0.01）。屠宰前14天测量的抗体滴度与蠕虫负荷没有统计学相关性。由此得出结论，接种方案不能在牧场上产生足够的保护，因为当山羊在牧场上暴露于幼虫污染时，抗体滴度仍然很低。(C) 2016 Elsevier B.V.版权所有
Forty goats, aged from 2 to 5 months were subjected to two different immunization protocols with a vaccine containing Haemonchus contortus gut membrane proteins H11/1-1-gal-GP to evaluate protection against H. contortus on pre-contaminated pastures. Goats were allocated to four groups of ten, three of them received their first vaccination before turnout. One group (V4) was then vaccinated at 4-week-intervals whereas another two groups (V6 and V6SEP) were vaccinated at 6-week-intervals. A control group (CTRL) remained unvaccinated. In May, after the second vaccination, all goats were turned out on pastures which had been previously contaminated with H. contortus eggs by seeder sheep for a period of six weeks. Goats of groups V4, V6 and CTRL were grazed together, whereas V6SEP was kept separately at an identical stocking rate. Clinical (PCV, FAMACHA, body weight), parasitological (faecal egg count, FEC) and serological (antibody titres) parameters were measured fortnightly. All goats were stabled in October, drenched with levamisole and two weeks later infected with 5000 L3 of H. contortus and slaughtered four weeks later for determination of abomasal worm burdens. Group mean FEC peaked 42-56 days after turnout. Significantly lower FEC were observed in V6SEP vs CTRL between D 28 and 70 (p < 0.01). Mean egg output of all groups decreased substantially and fluctuated at low levels until the end of the grazing period (D 154). Goats responded to vaccination with increasing antibody titres peaking after every booster. Mean worm burdens deriving from experimental infections were reduced by 89, 65 and 47% in groups V4, V6 and V6SEP, respectively, compared with the controls. The difference was significant for V4 (p < 0.01). Antibody titres measured 14 days before slaughter did not correlate statistically with the worm burdens. It was concluded that the vaccination protocol did not result in sufficient protection on pasture, as antibody titres were still low at the time the goats were exposed to larval contamination on pasture after turnout. (C) 2016 Elsevier B.V. All rights reserved.