山东省临沭县鸭疫里默氏杆菌分离鉴定及生物特性分析OA

In order to investigate the serotype,drug resistance and pathogenicity of Riemerella anatipestifer(RA)in Linshu County,Shandong Province,heart blood,brain and liver tissues of dead ducks and geese suspected of being infected with RA were aseptically collected on 8 farms from May to June 2023.After bacterial isolation and culture,the isolates were identified by biochemical test and PCR assay,and then their serotypes were determined by slide agglutination test,followed by analysis on their drug sensitivity and pathogenicity.The results showed that there were 12 isolates whose colony characteristics,microscopic examination results,biochemical characteristics and 16S rRNA gene sequence were consistent with RA;7,2 and 3 strains of RA fell into serotype 1,2 and 11,respectively;all the strains were resistant to amikacin,gentamicin,neomycin and amoxicillin,but sensitive to ceftazidime,ceftriaxone and cefalexin.The three serotypes of RA,after challenge test,could make ducklings die of infection,with same clinical symptoms and pathological changes as the typical characteristics of RA infection.In conclusion,RA infection was widely available in Linshu County,mainly including three serotypes,in which serotype 1 was dominant;RA was resistant to various antibiotics with strong pathogenicity.Regular pathogen monitoring and drug resistance analysis should be strengthened,and targeted vaccines and antibiotics should be selected based on the biological characteristics of local strains to improve the effectiveness of RA prevention and control.