墨西哥钝口螈蜡样芽胞杆菌感染的分离鉴定与致病性研究  

Isolation,identification and pathogenicity analysis of Bacillus cereus from Ambystoma mexicanum

作　　者：黄潇航 李诗艺 占观平 李梦蕊 李永霞 黄志坚[1,2] 王磊 殷光文 HUANG Xiao-hang;LI Shi-yi;ZHAN Guan-ping;LI Meng-rui;LI Yong-xia;HUANG Zhi-jian;WANG Lei;YIN Guang-wen(College of Animal Sciences(College of Bee Science),Fujian Agriculture and Forestry University,Fuzhou 350002,China;Fujian Animal Medicine Engineering Laboratory,Fuzhou 350002,China;College of Life Sciences,Fujian Agriculture and Forestry University,Fuzhou 350002,China)

机构地区：[1]福建农林大学动物科学学院(蜂学学院),福建福州350002 [2]福建省动物药物工程实验室,福建福州350002 [3]福建农林大学生命科学学院,福建福州350002

出　　处：《中国兽医科学》2022年第9期1149-1156,共8页Chinese Veterinary Science

基　　金：国家自然科学基金项目(31872466);福建省禽病防治重点实验室课题资助项目(FKADL-2019-02);福建农林大学优秀硕士基金项目(1122YS01004);福建农林大学科技创新基金项目(CXZX2020125B,CXZX2019070G)。

摘　　要：福建省福州市某居民家饲养的观赏型墨西哥钝口螈发生未明原因死亡,为探究其死亡原因,本研究通过对病死钝口螈进行临床解剖观察和细菌分离,并对分离的细菌进行生化试验、药敏试验、动物感染试验、16S rDNA序列分析;在确定为蜡样芽胞杆菌(Bacillus cereus)的基础上,进行毒力因子基因扩增和对蝾螈的致病性研究。结果显示,该分离菌为革兰阳性短杆菌,在LB培养基中呈现圆形灰白色菌落,在血琼脂培养基中呈现β溶血。16S rDNA基因序列分析结果显示,该菌为蜡样芽胞杆菌,毒力因子扩增结果显示,该菌携带有hblA、hblB、hblC、hblD、nheA、nheB、nheC、entFM、cytK等至少9种毒力因子;药敏结果显示,该菌对红霉素敏感,对其余测试药物表现不同程度的耐药。人工感染试验结果显示,该菌可造成蝾螈的死亡。病理切片结果显示,该细菌感染后可导致蝾螈皮肤基底层出现坏死和炎性浸润,除皮肤溃疡外,导致肝、肺、肠等多脏器变性、坏死和炎性细胞浸润。综上,本试验从墨西哥钝口螈中分离到1株蜡样芽胞杆菌,并筛选出敏感药物,从而为该类细菌病的诊断和治疗提供了参考依据。A case of Ambystoma mexicanum died with a serious skin disease in Fuzhou,Fujian Province.To explore the cause of its death,clinical anatomical observation,bacteria isolation,biochemical test,drug susceptibility test,animal infection test,sequence analysis of 16S rDNA and amplification of virulence genes were used to study this bacterium.The bacterium was gram-positive short rob bacteria,with round grey-white colonies in Luria-Bertani medium and β hemolysis in blood agar medium.16S rDNA gene sequence analysis revealed the bacterium as Bacillus cereus,virulence genes amplification showed at least nine virulence genes such as hbl A,hbl B,hbl C,hbl D,nhe A,nhe B,nhe C,ent FM,cyt K exist in this bacterium;drug sensitivity showed that it is sensitive to antibiotics such as erythromycin;artificial infection tests showed that the bacteria can cause death of axolotl and mice.The results of pathological sections showed that the bacteria can lead to necrosis and inflammatory infiltration of the axolotl skin base,liver,lung,intestine were impaired with degeneration,necrosis,and inflammatory cell infiltration.In conclusion,a strain of B.cereus strain from Ambystoma mexicanum were isolated,this bacterium contains several virulence genes and can cause death of axolotl.The results would provide theoretical basis for prevention and cure of B.cereus.

关 键 词：蜡样芽胞杆菌 毒力因子 分离鉴定 16S rDNA 动物模型 

分 类 号：S852.616[农业科学—基础兽医学]