环丙沙星对噬菌体RAP44裂解鸭疫里默氏杆菌的影响

Effect of Ciprofloxacin on the Lysis Ability of Phage RAP44 Against Riemerella anatipestifer

为探明环丙沙星(CIP)对噬菌体裂解鸭疫里默氏杆菌的影响,采用微量稀释法测定CIP对鸭疫里默氏杆菌RAf71株的最小抑菌浓度(MIC),在亚MIC CIP下,测定不同浓度噬菌体RAP44对RAf71生长的影响、RAP44噬菌斑的形成、增殖效果、不同噬菌体株对RAf71的裂解效果。将RAf71人工感染番鸭,比较噬菌体(皮下注射噬菌体1×10^9pfu/只)、CIP(治疗剂量,浓度为250 mg/L CIP饮用)、噬菌体和治疗剂量CIP联合、噬菌体和减半治疗剂量CIP联合的治疗效果。结果显示:CIP对RAf71株的MIC为16μg/mL,亚MIC的CIP可以使噬菌体RAP44对RAf71的抑制作用提高2~8倍,不影响噬菌斑的形成,能促进RAP44的增殖,使部分噬菌体株获得对RAf71的裂解能力;RAP44可以降低RAf71株攻击引起的死亡,治疗剂量CIP与RAP44合用能起到协同作用,进一步降低死亡率。研究表明,治疗鸭疫里默氏杆菌感染,噬菌体和CIP具有协同作用。该研究为治疗鸭疫里默氏杆菌病提供了一种新的方法。

In order to explore the effect of ciprofloxacin(CIP)on the lysis ability of bacteriophage against Riemerella anatipestifer,the minimal inhibitory concentration(MIC)of CIP to RAf71 was determined by microdilution method.The effects of different concentrations of phage RAP44 on the growth of RAf71 and the formation of plaques and proliferation of RAP44 and the lysis ability of several phage strains against RAf71 were measured under the sub MIC concentration of CIP.The therapeutic effects of phage(phage injected subcutaneously with 1×10^9 pfu each duck),CIP(250 mg/L CIP of therapeutic dos),combination of phage and therapeutic dose CIP,combination of phage and half dose CIP were compared after artificially infecting Muscovy duck with RAf71.The results showed that the MIC against CIP to RAf71 was16μg/mL.The inhibition ability of RAP44 to the growth of RAf71 was increased 2 to 8 times but plaque formation was not affected and the proliferation of RAP44 were increased and some phage strains could obtain the lysis ability against RAf71 under sub MIC CIP.Phage RAP44 could reduce the death caused by RAf71 attack,and the combination of CIP and RAP44 could play a synergistic role,further reducing the death rate.The results showed that there were phage-ciprofloxacin synergy to the treatment of Riemerella anatipestifer infection.This study provided a new method for the treatment of infectious serositis Riemerella anatipestife infection.