MTT-半固体培养基测定细菌动力的研究

MTT Semi-solid medium for the detection of bacterial motility

目的 制成一种容易测定细菌动力的半固体培养基。方法 根据Difco动力试验培养基配方 ,降低琼脂浓度 ,加入MTT代替TTC。培养基组成为 10 .0gTryptose ,5 .0gNaCl,3.5gagar ,10 0 0 .0ml蒸馏水 ,高压灭菌后 ,冷却至 5 0℃～ 6 0℃。无菌加入 1.5ml滤器除菌的 10g/LMTT水溶液。分装无菌管。结果 有动力菌株沿着穿刺线扩散 ,形成蓝色云雾状 ,而无动力菌株在穿刺线上生长只形成蓝线 ,蓝线周围培养基保持澄清。检测了 12 3株菌 ,鞭毛染色证实 94株有鞭毛、2 9株无鞭毛 ;有鞭毛的菌株中 ,90株菌培养 10～ 18h动力阳性 ,其余 4株大肠埃希菌培养 2 4h动力阳性 ,但这 4株菌应用Difco动力试验培养基需诱导传代才获得阳性结果。除此 4株外 ,还有 9株用Difco动力培养基需培养 48h才阳性。

Objective To develop a semi solid medium for the easy detection of bacterial motility. Methods The concentration of Bacto agar was reduced based on the formula of Difco motility test medium.MTT was added into the medium instead of TTC.Definite medium was composed of:tryptose 10.0 g,sodium chloride 5.0 g,Bacto agar 4.0 g and distilled water 1000 ml.After sterilization,cooling to 50℃～60℃,1.5 ml of 10 g/L MTT solution by filter sterilization was added into the medium and it was tubed in 3 ml～5 ml amounts. Results Motile organisms exhibited a blue turbid cloud which diffused throughout the area of the medium.Nonmotile organisms produced a blue line confined along stabline,and the surrounding medium remained clear.Among the 123 bacterial strains 94 strains were motile and 27 strains were nonmotile detected by flagella staining method.The correct results of 119 strains were won in 18 hours of incubation.With MTT semi solid medium,correct results of 119 strains were obtained in 18 hours and another 4 strains of E.coli. exhibited weak motility with a few tufts or rosettes in 24 hours of incubation.By using Difco motility test medium,the same 4 strains of E.coli. manifested positive results with Craigie tube method,and another 9 motile strains showed positive results after 48 hours of incubation. Conclusion This new medium is suitable for detecting bacterial motility,the weakly motile organisms also can be found by using it and they may exhibit fuzzy streaks of growth.