河北省某牛场坏死杆菌的分离及鉴定

Isolation and identification of Fusobacterium necrophrum in a cattle farm in Hebei Province,China

目的对河北省张家口市某牛场奶牛腐烂蹄肢部组织坏死杆菌进行分离及鉴定。方法采集17份奶牛腐烂蹄肢部组织,在苛养厌氧培养基中进行培养,培养液涂片进行革兰染色,提取细菌基因组DNA,PCR法鉴定病料组织培养物基因组DNA,并进行测序。纯化后细菌进行生化鉴定及药敏试验。结果病牛蹄组织革兰染色阴性,部分菌体呈杆状或长丝状;17份病牛蹄组织中共检测出7份坏死杆菌阳性样品;纯化后阳性菌液的生理生化特性与坏死梭杆菌基本一致;对亚胺培南(泰能)高度敏感,对氨苄西林/舒巴坦、红霉素、妥布霉素中度敏感,对克林霉素、青霉素G、氨苄西林、头孢唑啉、哌拉西啉耐药。结论该牛场确认发生腐蹄病疫情,且主要由坏死杆菌引起。

Objective To isolate and identify Fusobacterium necrophrum from the rotten limb tissue of cows in a cattle farm in Zhangjiakou City,Hebei Province,China. Methods Seventeen rotten limb tissue samples were collected and cultured in caustic anaerobic medium,of which the smear of culture was subjected to Gram staining. Genomic DNA was extracted and identified by PCR and sequencing. The purified bacterial culture was subjected to biochemical identification and drug sensitivity test. Results The isolates from F. necrophrum were Gram negative,partial of which were in rob or filamentous shape. Seven of the 17 samples were positive for F. necrophrum. The physiological and biochemical characters of purified positive culture were basically consistent with those of F. necrophrum. The isolate was highly sensitive to Imipenem(Tienam),moderately sensitive to ampicillin combined with sulbactam,erythromycin and tobramycin,and resistant to clindamycin,penicillin G,ampicillin,cefazolin and piperacillin. Conclusion The epidemic of foot rot disease was confirmed in the cattle farm,which was mainly caused by F. necrophrum.