Isolation and identification of pathogen Vibrio alginolyticus from Acropora intermedia suffering from bleaching

Acropora intermedia in artificial breeding has albinism symptoms, which are increasingly serious, even leading to death. In order to find out the cause, we isolated a dominant strain JU-V039 from the basal lesion of the diseased coral, which was identified as Vibrio alginolyticus by Biolog system and 16S rRNA gene phylogenetic analysis. After artificial infection, V. alginolyticus was confirmed to be the pathogen of the coral bleaching. According to the drug susceptibility test, the resistance rate of the isolate strain JU-V039 to the 13 selected antimicrobial agents was 15.4%, and it was sensitive to 10 drugs of rifampicin, sulfamethoxazole, streptomycin, erythromycin, levofloxacin, cefotaxime, kanamycin, tetracycline, nalidixic acid and chloramphenicol, but resistant to penicillin G and ampicillin, and intermediate to polymyxin B. Thus, V. alginolyticus is directly related to the occurrence of coral bleaching in the breeding of A. intermedia, and the results help to further understand the pathogenic mechanism of coral bleaching and put forward an effective control method.