The Test of Polyinfection of Bovine Rotavirus and Escherichia coli

Newborn calves in a dairy farms suffered from severe diarrhea disease with high mortality in Heilongjiang province.In order to make a definite diagnosis,the pathological samples were collected aseptically and the viral antigens and microorganism were detected by virus detection,bacteria separation,biochemical test,PCR for the specific gene of virus and bacteria,animal pathogenicity test and antimicrobial susceptibility test. The results showed that the virus detection of bovine rotavirus was positive and specific gene fragment of bovine rotavirus was amplified. One E. coli strain with K99 and F41 adhesin antigens which belonged to highly pathogenic enterotoxigenic E. coli was isolated. This strain was sensitive to enrofloxacin,cefamedin and chloramphenicol,however,it showed resistance for other antibiotics. A polyinfection of bovine rotavirus and E. coli were eventually confirmed through epidemic investigation and pathological diagnosis. It had significant preventive effect by taking effective measures according to the diagnosis results.