人工感染鸡大肠杆菌病的研究

用大肠杆菌O1、O2、O78的16h培养菌液，发雏鸡大肠杆菌病的发生，通过比较发病程度的不同，采取颈部皮下注射的方法，以不同的感染剂量，人工诱来寻求最佳的感染剂量（菌数）范围。结果表明：雏鸡颈部皮下注射大肠杆菌O1、O2、O78的混合菌液1．0～1．8亿发病程度适中，是人工发病的最佳感染量范围，感染量低于1．0亿或高于1．8亿时发病过轻或过重，对人工发病来说是失败的。

Study on artificially infected Colibacilosis of chicks

In this experiment,E.coli O1,O2, O78 was cultivated in meat soup for 16 hours, the 12-day chicks were infected by injecting into their neckskin with these different amount of cultivating liquid after being divided into 9 groups. By judging the degree of Colibacilosis induced artificially of deferent groups, the best infection dosage range can be sought. The result shows that while the injecting amount of cultivating liquid of E.coli was lower than 100 millions, the illness caused are not obvious, but when the amount exceeded 180 millions, the illness was extremely serious. Both two dosage range were improper in artificial infected Colibacilosis, and the best amount scope is from 100 to 180 millions.