养鸭场主要细菌分离鉴定及致病性研究

从贵州省三穗县6个规模养鸭场发病或濒死鸭各脏器中分离细菌,经细菌培养特性、染色、镜检并结合生化试验和PCR鉴定,共计分离出137株7个属的细菌,其中埃希氏菌、葡萄球菌、鸭疫里默氏杆菌为主要优势分离菌.随机选取3种优势菌稀释成含菌量为10⁹ CFU/mL的菌悬液,按0.3 mL/只腹腔注射BALB/c小鼠,统计其死亡率,并观察其临床症状和剖检病变,分析其致病性.结果显示,埃希氏菌和葡萄球菌均可引起BALB/c小鼠的死亡,致死率分别为23.3%和16.7%,对死亡小鼠进行剖检可见明显病变;而鸭疫里默氏杆菌对BALB/c小鼠基本无致病性,致死率为0;生理盐水对照组致死率为0.结果表明,养鸭场细菌性疾病存在混合感染且情况严重,3种主要分离菌中埃希氏菌和葡萄球菌对小鼠存在致病性,而鸭疫里默氏杆菌对小鼠基本无致病性.

Study on Isolation and Pathogenicity Test of Main Bacteria in Duck Farm

Bacteria were isolated from the duck organs of six duck farm in Guizhou province.According to the bacteria culture characteristics, gram stain's and microscope and biochemical properties, 137 strains bacteria of 7 genus were isolated, Escherichia, Staphylococcus and Riemerella were 3 main bacteria.Selecting main pathogenic bacteria to dilute into 10⁹ CFU/mL bacteria suspension, BALB/c mice were intraperitoneal injected 0.3 mL each, pathogenicity was analysed by statisticsing its mortality rate, observing its clinical symptoms and autopsy lesions.The results showed that the Escherichia and Staphylococcus caused the BALB/c mice to die and clearly visibled the autopsy lesions, fatality rate were 23.3% and 16.7%, respectively, while there was on pathogenicity and fatality rate was 0 when injected Riemerella, the control group was 0.The results indicated that there exists mixed infection in the 6 duckery, the Escherichia and Staphylococcus have pathogenicity to mice, however Riemerella has no pathogenicity to the mice.