两株鸡源鸭疫里默氏菌的分离鉴定及OmpA基因序列分析OA

To identify the two strains of similar pathogenic bacteria isolated from the caseous exudate in the oviduct of broiler breeders and the yolks of their hatching eggs,the two isolates were subjected to Gram staining,serotype identification,drug sensitivity test and OmpA gene analysis.Additionally,patho-genicity tests were conducted on SPF chickens using the isolated bacteria.The results showed that both strains isolated from the oviduct and egg yolk were identified as type 1 Riemerella anatipestifer.Both strains were found to be sensitive to cefotaxime,florfenicol and doxycycline.Phylogenetic analysis of the OmpA gene revealed 100％homology between the two strains,while the homology with reference strains of Riemerella anatipestifer from chickens and ducks ranged from 93.9％～94.0％and 95.8％～99.9％,re-spectively.Injecting bacteria into SPF chickens resulted in gelatinous samples in the joints of chickens.Pathological changes included tubular epithelial cell edema or degeneration and neuronal edema or shrink-age.The experiment showed that broiler chickens can be infected with Riemerella anatipestifer,which may lead to damage to the reproductive system or leg joints following infection.