Toxoplasma gondii-infected pigs play a major role as a source of infection for humans and detection of high-risk herds is essential to implement control measures at the farm level. The aim of this study was to determine whether oral fluid (OF) could be used as a matrix to detect antibodies against T. gondii in infected pigs by immunoblot (IB). For this, OF from experimentally inoculated sows (n = 8) (serial samples) and naturally exposed group-housed fatteners (n = 42 groups, one sample/group) were analysed for IgG and IgA against T. gondii-SAG1 antigen by IB. Simultaneously, each animal was serologically tested for anti-T. gondii IgG by ELISA. Specific IgG was detected in the sera of all inoculated sows from 2 to 3 weeks post inoculation (pi) and in 3.4 to 92% of the pigs in 13 out of 42 groups. Experimentally inoculated sows showed positive OF-IB results for IgA (100%) and IgG (87.5%) at 1.5 weeks pi and continued yielding positive results for IgA (87.5–75%) and IgG (50%) until 4 weeks pi; however, from 8 weeks pi the frequency of detection of both isotypes was lower, despite constantly positive IgG values in serum-ELISA. Interestingly, consecutive daily samplings for 4 days at 13 and 30 weeks pi showed inconsistent results for some sows, showing that the antibody concentration in OF is prone to timely variations. Pooled OF from groups with 91 and 92% of seropositive pigs yielded positive IB results for IgG and IgA. Fattener groups with ≤13% of seropositive pigs gave negative IB results to both isotypes. Our results showed that antibodies to T. gondii can be detected in OF from infected pigs, and that IgA seems to be a more adequate target than IgG. Although OF does not seem to be a robust matrix to assess the serological status for T. gondii in individual animals, this diagnostic approach represents an interesting non-invasive, low-cost and animal welfare friendly option as a screening method at the farm level to determine high exposure to T. gondii in the herd.

弓形虫感染的猪在人类感染中起着重要的作用，对高危人群的检测对于在农场一级实施控制措施至关重要。这项研究的目的是确定是否可以将口服液（OF）用作通过免疫印迹（IB）检测感染猪中弓形虫抗体的基质。为此，通过IB 分析了来自实验接种母猪（n =  8）（串行样品）和自然暴露的群养肥牛（n = 42组，一个样品/组）的OF抗弓形虫-SAG1抗原的IgG和IgA 。。同时，对每只动物进行了血清学测试，以检测弓形虫的抗性。通过ELISA的IgG。在接种后2至3周（pi），在所有接种母猪的血清中检测到特异性IgG，在42组中的13组中，在3.4至92％的猪中检测到了特异性IgG。实验接种的母猪在pi的1.5周时对IgA（100％）和IgG（87.5％）的OF-IB结果呈阳性，直到pi的4周持续产生对IgA（87.5-75％）和IgG（50％）的阳性结果。然而，尽管在血清ELISA中IgG值一直呈阳性，但从接种后第8周开始，两种同种型的检出频率均较低。有趣的是，在pi的第13和30周连续连续4天每天采样显示某些母猪的结果不一致，这表明OF中的抗体浓度易于及时变化。从血清阳性猪中有91％和92％的猪群中收集的OF得出IgG和IgA的IB阳性结果。血清阳性猪≤13％的肥胖组对两种同种型的IB结果均为阴性。我们的结果表明，针对可以在OF的感染猪中检测到弓形虫，而且IgA似乎比IgG更合适。尽管OF似乎不是评估单个动物弓形虫血清学状况的可靠矩阵，但这种诊断方法代表了一种有趣的非侵入性，低成本和动物福利友好型选择，可作为农场一级的筛查方法。确定在牛群中高暴露于弓形虫。