云南省香格里拉市猪肠气泡病病例的组织病理学观察与病原检测

Histopathological Observation and Pathogen Detection of Porcine Intestine Pneumatosis Cystoides in Shangri-La City of Yunnan Province

云南省香格里拉市某藏猪场育肥猪出栏屠宰时,陆续发现部分个体小肠肠系膜浆膜下有大量葡萄串状透明无味气泡,病因不明,但病猪在仔猪阶段有腹泻病史。为调查发病原因和致病机理,以便提出防控措施,采集该养猪场4头患病猪和1头正常猪的抗凝全血、小肠组织和肠系膜淋巴结,进行病毒核酸PCR扩增、细菌分离培养和组织病理显微观察。在患病猪中,未检出与腹泻有关的猪瘟病毒、猪流行性腹泻病毒、传染性胃肠炎病毒和轮状病毒核酸;血琼脂有氧和厌氧培养均只分离到大肠杆菌,并排除常见致病血清型及常见毒力基因;组织病理检查发现,肠黏膜下层有大量空泡,肠腺及其杯状细胞体积明显增大,组织间隙扩大,肠系膜及其淋巴结分别见嗜酸性粒细胞和巨噬细胞增多,病变肠系膜淤血。分析认为,该病病因应考虑养殖区域海拔较高,猪肠内大肠杆菌异常发酵产气的可能,但如何防治需进一步研究。

A large number of grape-shaped transparent odorless bubbles were successively found under serosa of small intestine mesenterium in some fattening pigs in a Tibetan pig farm in Shangri-La City of Yunnan Province when the pigs were sold for slaughtering,with unknown causes,while the sick pigs had suffered from diarrhea at the piglet stage.In order to investigate the cause and pathogenesis so as to put forward prevention and control measures,the anticoagulant whole blood,small intestine tissues and mesenteric lymph nodes were collected from four sick pigs and one normal pig for PCR amplification of viral nucleic acids,bacterial isolation and culture and microscopic observation of histopathology.No any classical swine fever virus,porcine epidemic diarrhea virus,transmissible gastroenteritis virus and rotavirus nucleic acid related to diarrhea were detected;only Escherichia coli was isolated by blood agar aerobic and anaerobic culture,and the common pathogenic serotypes and virulence genes were excluded;the following symptoms were found through pathological examination such as a large number of vacuoles in the intestinal submucosa,the increased volume of intestinal gland and its goblet cells,the widened space among various tissues,the increased eosinophils and macrophages in the mesentery and its lymph nodes,and congestion in the diseased mesentery.It was concluded that the disease was likely to be caused by higher altitude,abnormal fermentation and air produced by E.coli,and it was necessary to continue to study how to prevent and control it.