Isolation,Identification and Histopathologic Observation of a Pathogen from Hemorrhage Tilapia
Huang Huili · Journal of Huaqiao University · 2012
A highly pathogenic bacterium(No.BC-2) was isolated from the infected hemorrhage tilapia.Combination of the colonial morphology observation,the biochemistry test and 16S rDNA sequencing,the highly pathogenic bacterium was determined as Bacillus cereus,which could cause tilapia dead.Then infective test was carried out to normal tilapias with different concentrations of the pathogen,and the qualitative probability data analysis results showed that the logarithmic concentration of LD50 was 7.534 8 with the confidence interval 95% when the infective concentration was 3.4×107 cfu·mL-1.After observing the pathological structure of different tissue and organ sections from infected tilapia,we found gill and intestine were the most evident lesion parts.