鸡源大肠杆菌的耐药性监测及生物学特性研究

从山东省诸城地区6个集约化养鸡场采集50只病死鸡病料，从中分离鉴定得到32株大肠杆菌，对其进行了12种常规药敏试验，发现分离的菌株有不同程度的耐药性。对14株优势血清型菌株进行了质粒DNA提取分析，然后用Hind Ⅲ限制性内切酶对质粒进行了酶切。结果表明，质粒的得率为100%，来源相同的菌株具有相同或相似的质粒图谱，也就是说它们有共同的起源；来源不同的菌株的质粒图谱一般不同，即有不同的起源。将血清型和质粒图谱比较，结果发现，同一血清型可以有不同的质粒图谱，不同血清型可以有相似的质粒图谱，血清型与质粒图谱没有直接的联系。

Inspection of Antibiotic Resistance and Study of Biologic Identity of Chicks Pathogenic E.coli

32 strains of Escherichia coli (E. coli) were isolated from 50 E. coli infected chickens in six farms in Shandong. As a result, all of them were resistant to 12 antibiotics to a greater or less degree. In the screening test of plasmid DNA of 14 strains E.coli isolates and plasmid DNA fragments generated by Hind Ⅲ, simple agarosegel electrophoresis was employed. The results showed that most of E.coli isolated from the same infected flocks on the same farm had similar plasmid profile, and its fragments sizes were similar too, and that these isolated had common plasmids. The results showed that those isolates from different chicken flocks and had different plasmids were in different serotypes, the plasmids could be transferred in different serotypes of E.coli.