猪源脑心肌炎病毒GXLC株对仔猪的致病性试验

为研究猪源脑心肌炎病毒(EMCV)GXLC株对仔猪的致病性,将其接种4周龄健康断乳仔猪,观察临床症状及病理变化,检测心、脑、脾组织及血清中的病毒含量,测定血清抗体效价,检测心、脑、脾组织中IL-1β、TNF-α、IL-6mRNA的表达水平。结果显示,仔猪感染后,出现体温升高、精神不振、腹泻等症状;剖检发现心包积液,心脏变软,脑充血;组织病理学观察发现心肌炎、脑炎,病理炎症分值显著提高;心、脑、脾、血清中均可检测到大量病毒;血清中出现高效价的中和抗体;感染仔猪心、脑、脾组织中IL-1β、TNF-α、IL-6mRNA的表达水平显著上调,而且细胞因子的表达高峰期与出现临床症状、病理损害的时间密切相关。表明,猪源EMCV GXLC株对仔猪具有致病性,IL-1β、TNF-α、IL-6等促炎细胞因子在EMCV对仔猪的致病过程中发挥重要作用。

Pathogenic experiment of porcine encephalomyocarditis virus GXLC strain to piglets

To evaluate the viral pathogenicity,the porcine encephalomyocarditis virus(EMCV) GXLC strain was inoculated to 4-week-old healthy piglets. The clinical signs,the pathological changes,the viral loads in heart,brain,spleen and serum,the antibody titers against EMCV in serum were recorded and tested;the mRNA expression levels of IL-1β,TNF-α and IL-6 in heart,brain and spleen were determined.The results showed that the infected piglets had a transient febrile responses,depression and diarrhea without death.At necropsy,excessive pericardiac fluids,enlargement and softness of the heart were observed,and hyperaemia of the brain were also evident.The histopathological observation showed interstitial myocarditis and encephalitis,with significant increase of their inflammatory scores.A large number of viruses were detected in brain,heart,spleen and serum,and the high titers of neutralizing antibody against EMCV were detected in serum.The mRNA expression levels of IL-1β,TNF-α and IL-6 in heart,brain and spleen were significant up regulated,with a closely positive corelationship to time of the obvious clinical manifestations and the macroscopical and histopathological lesions of various organs.The results indicated that porcine EMCV GXLC strain was pathogenic to piglets and the proinflammatory cytokines IL-1β,TNF-α and IL-6 played important roles in the pathogenesis of EMCV.