SEROGROUPS,VIRULENCE AND HEMOLYTIC ACTIVITY OF AEROMONAS HYDROPHILA WHICH CAUSED FISH BACTERIAL SEPTICAEMIA
引起鱼类暴发性流行病的嗜水气单胞菌的血清型、毒力及溶血性

A new infected disease called bacterial septicaemia occured in cyprinid fish throughout China during 1989-1992. A. hydrophila was known as the most important pathogen of this harmful disease. Thirty-three strains of A. hydrophila, most isolated from moribund fishes, were serogrouped by tube-agglutination with rabbit antisera. Most of the isolates could be grouped into two serotypes, TPS-30 and PBJS-76. These two groupes could be found not only in Zhejiang province but in other province in south China. It can be concluded that the two serogroups were the main Aeromonas groups caused this fishdisease. These isolates were virulent to Caressius auratus, with LD58 values of 104 to 106. The hemolytic activity ranged from liters of 1/8 to 1/16. No relationship were observed with the hemolytic activity and virulence.