牛蛙脑膜炎黄杆菌病病原菌的研究

Studies on the Pathogens of Flavobacterium mningosepticum Diseases of Rana catesbianan

从广东省揭西县坪下牛蛙养殖场收集患黄杆菌病的病蛙,其症状是歪头、狂游、双眼白内障、肝脏肿大充血,腹水严重。从病蛙脑髓、眼底等处分离到62菌株。经急性毒性试验证明分离菌株对健康牛蛙有较强的致病性。选用其中有代表性的981229—1等菌株进行系统的生理生化试验结果显示,981229—3等菌株革兰氏染色阴性、短直杆菌、无动力、无芽孢、好氧型、不利用葡萄糖。内毒素试验阳性。经VITEK-AMS-60自动化检测系统鉴定为脑膜炎脓毒性黄杆菌(Flavobacterium meninosepticum)。选取47种抗菌药物,通过K—B纸片扩散法对分离菌进行耐药性试验结果显示,病原菌对40种试验药物耐药(85.11％)、中等敏感药物2种(4.26％)、敏感药物5种(10.64％)。以试管稀释法、测定分离菌株对5种敏感药物的平均 MIC分别是:利福平 0.24、环丙沙星 0.70、氧氟沙星 0.70、氟啶酸 1.20和麦迪霉素7.80μg/ml。

Sixty-two Pathogenic Strains were isolated from the sick Rana catesbianaes' brains from Pinxia culture farm in Jiexi prefecture, Guangdong province. The symptoms of the disease include askew heads ,swimming madly and cataract in both eyes. The acute tox-icity,tests proved the isolated strains to be highly pathogenic to Rana catesbiana. Systematic physiological and biochemical tests of the representative strain 981229 - 1 showed the pathogens were short - rod - shaped, 0. 5μm × 1.0-3.0μm, with rounded ends, nonmotile, Gram- negative, no endospores,no glucose utilization, aerobic and positive in endo to xin test. The strain 981229- 1 was identified to be Flavobacterium meningosepticum (99%) by VITEK- AMS- 60 automatic detecting system. The studies on drug resistance of the strains to 47 antimicrobial agents by K - B paper disk method showed that 40 tested antimicrobial agents (85.11%) were resistant, 2(4. 26%) intermediate and 5 (10. 64 %) susceptible. By the method of test tube dilution, the drug resistance of 60 isolated strains were tested with the 5 susceptible agents above. The average MIC of them were rifampicin 0.24, ofloxacin 0. 70,cipro-floxacin 0.70, enoxacin 1.20 and midecamycin 7.80μg/ml.