禽大肠杆菌耐药标记弱毒菌株O_2(Nor^r,Chl^s)和O_(78)(Chl^r,Nor^s)的培育

STUDIES ON DEVELOPMENT OF DRUG-TOLERANT AND ATTENUATED O 2 (Nor r,Chl s) AND O 78 (Chl r,Nor s) STRAINS OF Escherichia coli FROM POULTRY

选择最常见的禽致病性大肠杆菌Ｏ２和Ｏ７８菌株，分别以常用的抗菌药物氟哌酸和氯霉素诱导，培育成遗传性稳定的耐药标记弱毒菌株Ｏ２（Ｎｏｒｒ，Ｃｈｌｓ）和Ｏ７８（Ｃｈｌｒ，Ｎｏｒｓ）。

This paper reports the development process of drug-tolerant and attenuated Escherichia coli O 2 (Nor r,Chl s) and O 78 (Chl r,Nor s) strains. With Escherichia coli O 2 and O 78 which are the most important serotypes of E.coli in poultry colibacillosis as parent strains, drug resistant and attenuated O 2 (Nor r,Chl s) and O 78 (Chl r,Nor s ) strains of E.coli were induced by Norfloxacin and Chloramphenicol which are two antibacterial drugs most frequently used in veterinary practice. The essential characteristics of E.coli O 2 (Nor r,Chl s ) and O 78 (Chl r,Nor s) strains were examined. The results indicated that the drug-tolerance and the heredity of E.coli O 2 (Nor r,Chl s) and O 78 (Chl r,Nor s) strains were stable. This achievement might be a good beginning for further developing efficient and multivalent vaccines by using spheroplast fusion technique.