反刍动物产志贺毒素大肠杆菌的分离鉴定和致病潜力分析

产志贺毒素大肠杆菌(Shiga toxin-producing Escherichia coli,STEC)是重要的食源性病原,而STEC往往以正常菌群的形式存在于牛羊等反刍动物肠道。【目的】本研究对牛羊粪便样品中的STEC分离和鉴定并对分离株进行致病潜力分析。从江苏、云南和河北等地共分离到羊源STEC菌株11株,牛源STEC菌株1株,另新疆农业大学佟盼盼组馈赠牛源菌株10株。【方法】通过细菌选择培养及特异性基因stx1和stx2的检测进行分离鉴定;并通过Vero细胞毒性试验、溶血活性试验和毒力因子的检测分析STEC分离株的致病潜力。【结果】分离到羊源分离株11株,分离率17.5%(11/63);分离得到牛源分离株1株,分离率0.7%(1/134);11株羊源分离株中有5株对Vero细胞具有强的毒性,3株有溶血活性;11株牛源分离株中有5株对Vero细胞具有强的毒性,3株有溶血活性。11株羊源STEC分离株eae基因携带率为63.6%(7/11),而11株牛源STEC分离株eae基因携带率仅为9.0%(1/11)。【结论】结果表明羊源STEC菌株的分离率和致病潜力高于牛源菌株,所以,除牛外,羊作为STEC菌株宿主也应该得到更多的重视。

Vaccination inhibits TLR2 transcription via suppression of GR nuclear translocation and binding to TLR2 promoter in porcine lung infected with Mycoplasma hyopneumoniae

Toll-like receptors(TLRs)and glucocorticoid receptor(GR)act as effectors of innate immune system and neuroendocrine system,respectively.The crosstalk between these two receptors is important to maintain homeostasis during immune response.It is well known that vaccination can boost adaptive immune responses to specific pathogens.However,it remains elusive whether and