从患爆发性败血症斑点叉尾鮰肝、脾和肾分离到大量形态和色泽一致的细菌。随机挑选5株细菌注射健康斑点叉尾鮰，感染鱼72 h内全部死亡，且患病症状与自然发病症状一致，确认分离株为斑点叉尾鮰败血症的致病菌。依据其菌落形态、生理生化特征，结合其16S rRNA和gyrB基因序列分析，鉴定5个分离株为蜡样芽孢杆菌。用20种抗微生物药敏纸片对分离株进行药敏实验，发现5株菌均对7种喹诺酮类药物、5种氨基糖苷类药物，麦迪霉素，克林霉素和新生霉素敏感，而对2种头孢菌素类药物和复方新诺明有耐药性。
Large colonies with similar morphology and color were obtained from liver, spleen and kidney of channel catfish, Ictalurus punctatus with fulminate septicemia. The experiment was carried out with healthy juvenile channel catfish by means of injection with live 5 isolates randomly selected. All individuals of the fish injected died within 72 h. The symptom was similar to those of the naturally infected fish. Therefore, the isolates were suggested to be the pathogenic bacterium strain of Ictalurus punctatus with fulminate septicemia. These isolates were further identified as Bacillus cereus by phenotypic characters, analysis of their 16S rRNA and gyrB sequences. Antimicrobial sensitivity patterns of five strains were evaluated against 20 antimicrobial drugs. The result showed that they were all sensitive to seven quinolones, five aminoglycosides, midecamycin, clindamycin, novobiocin, and resistant to two cephalosporins and compound sulfamethoxazole.