Fetal bovine Serum Promotes the Infection of Pasteurella multocida

Animal serums were widely used in clinical diagnostic, treatment and cell culture in vaccine production, but the side-effects of serum products in treatments were still need to concerned.Here, we found a significant enhancement infection of low-virulent Pasteurella multocida simultaneously injected with fetal bovine serum (FBS), or a few other commercial and stress animal serums in mice model. Transcriptome analysis showed that the immune function of mice was suppressed by FBS, resulting in serious infection of low virulent P. multocida. Cell level analysis showed that FBS inhibited the phagocytosis and inflammatory cytokines expression of macrophage in-vivo but not in-vitro, which led to the significant increase of bacterial loads and inflammatory reactions in organs and caused serious pathological damage leading to animal death.