副溶血弧菌对不同浓度多黏菌素B耐受性的实验研究

An experimental study on the tolerance of vibrio parahaemolyticus with different concentrations of polymyxin B

[目的]确定氯化钠多黏菌素B肉汤培养基中对副溶血性弧菌生长抑制的抗生素浓度[方法]首先测定12株副溶血性弧菌标准菌株对多黏菌素B的最小抑菌浓度（MIC）,同时参照中华人民共和国卫生行业标准《商业性微生物培养基质量检验规程》推荐的生长试验方法,观察12株一定菌量的标准菌株在不同抗生素浓度的培养基中生长情况,确定适宜的抗生素浓度。[结果]用液体培养试管稀释法,测出标准菌株对多黏菌素B的MIC范围集中在1024-512 IU/mL之间,其中MIC为512 IU/mL的菌株为58%（7株/12株）,12株标准菌株生长试验中生长的多黏菌素B浓度范围集中在10-100 IU/mL之间,在250 IU/mL浓度下不生长。[结论]标准中推荐的250 IU/mL虽然在副溶血性弧菌的MIC范围之内,但并没有达到生长试验方法的要求,该培养基中多黏菌素B浓度（250 IU/mL）过高。

[ Objective] To eonfirrn the most appropriate concentration of polymyxin B in broth that suppresses the growth of 12 standard bacteria of vibro parahaemolytieus. [ Methods] First determine the minimum inhibitory concentration （MIC） of polymyxin B with 12 standard bacteria of vibro parahaemolytieus. Then observe the growth of standard bacterium in different indicator of antihiotie according to industry standard. Finally confirm the most appropriate concentration of polymyxin B. [ Results ] The range of MIC was 1024 -512IU/nd. 512IU/nd was in proportion of 58%. And the range of polymyxin B in growth of broth medium was 10IU/nd - 100IU/nd. [ Conclusion] These results indicate the most appropriate concentration of polymyxin B in broth is about 100IU/nd. The standard asked for 250IU/nd is too high.