【摘要】 为鉴定一起引起滑鼠蛇死亡的致病菌,本研究对采集病理样品中分离菌进行了细菌形态学观察、生理生化特性测定、16S rDNA序列分析、耐药性测定及毒力相关基因检测。结果显示分离菌为嗜水气单胞菌。进化树分析表明该分离菌与来自中华鳖的嗜水气单胞菌N3株亲缘关系最近;药敏试验显示,分离菌株对强力霉素、庆大霉素、头孢呋辛等药物高度敏感,对四环素、阿奇霉素、链霉素等药物中敏,对头孢氨苄、青霉素、阿莫西林、林可霉素、万古霉素等药物完全耐药,表明该分离菌株具有多重耐药性;小鼠毒力试验和毒力相关基因检测显示,该菌含有的5种毒力相关基因为aer A、hly A、ahp A、ast及alt;并在3×108 cfu/0.3 mL的感染剂量下可致小鼠全部死亡。本研究结果表明引起此次蛇细菌感染的病原为嗜水气单胞菌,该菌的分离鉴定为其感染引起的传染病防治提供了实验依据。更多还原

【Abstract】 The study was aimed to identify the bacteria isolate which caused the death of Ptyas mucosus through morphological observation, physiological and biochemical assays, the sequence analysis of 16 S rDNA, drug susceptibility test and virulence gene detection. The results showed that the isolate was Aeromonas hydrophila. The phylogenetic analysis showed that the isolate was highly similar to the A.hydrophila N3 strain which was isolated from Chinese soft-shelled turtle. Drug susceptibility test indicated the isolate was highly sensitive to doxycycline, gentamicin and cefuroxime, moderately sensitive to tetracycline,azithromycin and streptomycin,fully resistant to cephalexin, penicillin, amoxicillin, clindamycin and vancomycin. The pathogenic test and virulence gene detections found that the isolate was highly pathogenic to the mice with a lethal dosage of 3 ×10~8cfu/0.3m L, and the virulence genes were aer A, hly A, ahp A, ast and alt. This study identified that the pathogen of the diseased snake was A.hydrophila, which provided the basis for the disease control.更多还原