The characteristics of a bacterium strain M3, isolated from cultured flounder Paralichthys olivaceus with remarkable external sign of skin ulcer during an epizootic outbreak, indicated that the bacterium belonged to t...The characteristics of a bacterium strain M3, isolated from cultured flounder Paralichthys olivaceus with remarkable external sign of skin ulcer during an epizootic outbreak, indicated that the bacterium belonged to the species Vibrio anguillarum . Challenge by I.M. (intramuscular injection), bath, and oral administration with M3 showed that it was highly pathogenic for Paralichthys olivacues . The LD 50 dose was 5.144×10 3 CFU/ per fish infection by I.M. injection. Recovered inoculated bacteria from the surviving fish revealed that the asymptomatic carriers could be a latent contagious source. Study of the effect of bacterial culture CFS (cell free supernatant) showed that the exotoxins produced by M3 play an important role in its pathogenicity for flounder. The resistance of M3 to 36 out of 41 antibiotics indicated that the bacterial disease outbreak was mainly attributable to the frequent and excessive use of antimicrobial agents; and that vaccination would be an effective precaution against bacterial disease.展开更多
文摘The characteristics of a bacterium strain M3, isolated from cultured flounder Paralichthys olivaceus with remarkable external sign of skin ulcer during an epizootic outbreak, indicated that the bacterium belonged to the species Vibrio anguillarum . Challenge by I.M. (intramuscular injection), bath, and oral administration with M3 showed that it was highly pathogenic for Paralichthys olivacues . The LD 50 dose was 5.144×10 3 CFU/ per fish infection by I.M. injection. Recovered inoculated bacteria from the surviving fish revealed that the asymptomatic carriers could be a latent contagious source. Study of the effect of bacterial culture CFS (cell free supernatant) showed that the exotoxins produced by M3 play an important role in its pathogenicity for flounder. The resistance of M3 to 36 out of 41 antibiotics indicated that the bacterial disease outbreak was mainly attributable to the frequent and excessive use of antimicrobial agents; and that vaccination would be an effective precaution against bacterial disease.