China Animal Husbandry and Veterinary Medicine ›› 2019, Vol. 46 ›› Issue (9): 2745-2752.doi: 10.16431/j.cnki.1671-7236.2019.09.030

• Basic Veterinary Medicine • Previous Articles     Next Articles

Isolation,Identification and Drug Resistance Analysis of Bacillus cereus Isolated from Fish

DOU Pengpeng1, WANG Li1, FANG Qing1, LI Juan2   

  1. 1. College of Life Sciences and Technology, Southwest Minzu University, Chengdu 610041, China;
    2. Qinghai-Tibet Research Institute, Southwest Minzu University, Chengdu 610041, China
  • Received:2019-04-18 Online:2019-09-20 Published:2019-09-21

Abstract: In order to explore the pathogenicity and drug resistance of Bacillus cereus isolated from fish and guide scientific drug use,morphological observation,physiological and biochemical characteristics analysis,16S rDNA gene amplification and phylogenetic tree construction were used to identify the isolated bacteria.Artificial infection test was used to determine the pathogenicity of the isolated bacteria,drug resistance gene detection and drug sensitivity test were used to determine the drug resistance of the strain.The results showed that the isolated strain formed irregular and non-smooth milky-white colonies,which were aerobic Gram-positive bacteria.The biochemical reactions such as glucose,nitrate and gelatin liquefaction were positive,while the biochemical reactions such as xylose,arabinose and mannitol were negative.The length of 16S rDNA gene fragment was 1 457 bp.In phylogenetic tree,the isolated strain had the closest relationship with Bacillus cereus RTR strain,and the homology of the isolated strain and Bacillus cereus reached more than 99%,so the isolated strain was identified as Bacillus cereus.Artificial infection test showed that the isolated strain had certain pathogenicity to Pelteobagrus fulvidraco.The results of resistance gene detection showed that two kinds of resistance genes (Sul1 and Sul2) were detected in the isolated strain.Drug sensitivity test showed that the strain was sensitive to gentamicin,piperacillin and minocycline,moderately sensitive to cefoperazone,and resistant to penicillin,ceftriaxone and ampicillin.The results provided scientific reference for the effective prevention and control of Bacillus cereus infection.

Key words: Bacillus cereus; identification; drug resistance; drug susceptibility test

CLC Number: