This study dealt with the toxicity of inactivated bacteria intended for veterinary autogenous vaccines toward a suitable control assay. Two in vitro methods were used. The [3-(4, 5 -dimethylthiazol-2-yl) -2,5 -diphenyltetrazolium bromide] (MTT) test, based on the metabolic reaction of a tetrazolium salt in vital cells, was adopted on the basis of previous positive results. The Interleukin (IL)-1 beta release assay on monocyte-derived pig macrophages was carried out for comparative purposes, to evaluate the possible role of the inflammatory response. MTT and IL-1 beta responses showed a significant correlation (P < 0.05) at defined test dilutions of bacterial antigens, whereas no correlation was demonstrated using MTT responses normalized on bacterial cell concentration. Furthermore, the toxic effects shown in the MTT test were positively correlated to the extracellular protein content. On the whole, the above results could be a useful basis for the development of a toxicity assay on inactivated bacterial vaccines. Also, our data point at bacterial autolysis as a major component underlying toxicity.

这项研究涉及打算用于兽医自体疫苗的灭活细菌对合适的对照试验的毒性。使用了两种体外方法。根据先前的阳性结果，基于活细胞中四唑盐的代谢反应，进行了[3-（4，5-二甲基噻唑-2-基）-2,5-二苯基四唑溴化物]（MTT）试验。 。为了进行比较，对单核细胞衍生的猪巨噬细胞进行了白介素（IL）-1β释放测定，以评估炎症反应的可能作用。MTT和IL-1β反应显示出显着的相关性（P 在规定的细菌抗原测试稀释度下，其浓度<0.05），而使用根据细菌细胞浓度归一化的MTT响应则没有相关性。此外，MTT试验中显示的毒性作用与细胞外蛋白质含量呈正相关。总体而言，以上结果可能是开发灭活细菌疫苗毒性试验的有用依据。同样，我们的数据表明细菌自溶是潜在的毒性主要成分。