从患病中华鳖(Pelodiscus sinensis)肺组织中分离到优势菌1株,进行了表型特征分析和16S r DNA序列测定。结果表明,该菌为气单胞菌属的嗜水气单胞菌(Aeromonas hydrophila),通过对健康中华鳖进行人工感染,发现该菌具有致病性;选取20种常规药敏试纸进行药敏试验,结果表明,该嗜水气单胞菌对庆大霉素、头孢他啶、头孢西丁、链霉素、呋喃妥因敏感,对诺氟沙星、红霉素、阿米卡星、环丙沙星中敏,对其他11种抗生素具有耐药性。
The agglutination characteristics of serum agglutinin from Portunus trituberculatus were studied in this paper. The results showed that the serum agglutinin had no agglutination to crucian carp, Chinese soft shell turtle, grass carp, chicken or human group A, B or O blood cells, but had strong agglutination to blood cells of mice and rabbits. The activities of serum agglutinin from Portunus trituberculatus to mice blood cells reached 210, and to rabbit blood cells reached 28. Salinity had a greater effect on agglutinin activity. When the Na Cl concentration exceeded 0.6 mol/L,the serum agglutinin from Portunus trituberculatus was basically inactivated. The optimum p H for agglutinin activity was 6.0-7.4. The serum agglutinin from Portunus trituberculatus had obvious dependence to Ca2 ＋and Mg2 ＋, and EDTA could significantly inhibit its activity. The results of sugar inhibition test showed that the activity of agglutinin from Portunus trituberculatus can be specifically inhibited by N-acetylglucosamine and N-acetylmannosamine. The serum agglutinin from Portunus trituberculatus was isolated by ammonium sulfate gradient precipitation, and its activity was highest by the 25% ammonium sulfate precipitation system. The SDS polyacrylamide gel electrophoresis（SDS-PAGE） showed that the protein bands were mainly distributed within 72-95 ku.
