Zen-noh Institute of Animal Health, 7 Ohja-machi, Sakura, Chiba 285-0043, Japan.
Vet Microbiol. 2013 Feb 22;162(1):219-23. doi: 10.1016/j.vetmic.2012.10.004. Epub 2012 Oct 16.
We previously reported that prior porcine circovirus type 2 (PCV2) infection potentiates the severity of clinical signs, lung lesions, and fecal shedding and tissue dissemination of Salmonella enterica serovar Choleraesuis in infected pigs. Here, we evaluated whether PCV2 vaccination is effective in reducing fecal shedding and tissue dissemination of S. Choleraesuis and improving clinical signs associated with PCV2 and S. Choleraesuis infection in 15 Cesarean-derived, colostrum-deprived pigs randomly assigned to 3 groups (n=5/group). The vaccinated and co-infected (VAC-COINF) group received 2 ml of a commercial PCV2 vaccine at age 3 weeks. The VAC-COINF and co-infected (COINF) groups were inoculated intranasally with PCV2 and S. Choleraesuis at 5 and 7 weeks of age, respectively. The CONTROL group pigs received a similar volume of PBS for sham-vaccination and sham-inoculation. PCV2 vaccination clearly reduced PCV2 DNA load in the serum and postmortem tissue samples and decreased PCV2 antigen levels in tissue samples of the VAC-COINF group. After S. Choleraesuis infection, the incidence of several clinical signs increased in the VAC-COINF group compared to that in the COINF group. The microscopic lung lesions and weight gain, fecal shedding and tissue dissemination of S. Choleraesuis except in the spleen were not significantly different in the VAC-COINF and COINF groups. Thus, PCV2 vaccination reduced PCV2 in the S. Choleraesuis and PCV2 coinfection model and the effects on S. Choleraesuis were minimal.
我们之前报道过，先前的猪圆环病毒 2 型（PCV2）感染会增强临床症状、肺部病变和粪便排出以及组织传播的严重程度沙门氏菌肠亚种霍乱在感染猪中。在这里，我们评估了 PCV2 疫苗接种是否能有效减少粪便排出和组织传播的 S. Choleraesuis 并改善与 PCV2 和 S. Choleraesuis 感染相关的临床症状在 15 头剖腹产、初乳缺乏的猪中随机分为 3 组（每组 5 头）。接种和混合感染（VAC-COINF）组在 3 周龄时接受 2 毫升商业 PCV2 疫苗。VAC-COINF 和混合感染（COINF）组分别在 5 和 7 周龄时鼻内接种 PCV2 和 S. Choleraesuis。CONTRO 组猪接受类似体积的 PBS 进行假疫苗接种和假接种。PCV2 疫苗接种明显降低了血清和尸检组织样本中的 PCV2 DNA 载量，并降低了 VAC-COINF 组组织样本中的 PCV2 抗原水平。在 S. Choleraesuis 感染后，与 COINF 组相比，VAC-COINF 组的几种临床症状发生率增加。在 VAC-COINF 和 COINF 组中，除脾脏外，肺部显微镜下病变和体重增加、粪便排出和组织传播的 S. Choleraesuis 没有显著差异。因此，PCV2 疫苗接种减少了 S. Choleraesuis 和 PCV2 混合感染模型中的 PCV2，对 S. Choleraesuis 的影响很小。
