微生物的形态变异,往往导致其它性状的改变。近年来本所发现一些无钩的钩端螺旋体,它们由于形态变异而表现以下共同的特征:1.形态变长,运动缓慢。2.在培养基内生长良好。3.在机体内不能繁殖,存活数天后消失,因此,尿内不排菌,即致病力丧失。4.能刺激机体产生抗体,效价较有毒株低,出现快,消失快。5.能产生较强的免疫力,与抗体滴度并不平行。 Microbial morphological changes often lead to changes in other traits. In recent years, we found some hook-free leptospirosis, which due to the morphological variation of the following common characteristics: 1. Morphology longer, slow movement. Grow well in medium. 3 in the body can not breed, survive disappear after a few days, therefore, no bacteria in the urine, that is, loss of pathogenicity. 4. Can stimulate the body to produce antibodies, titers lower than the toxic strains, appear fast, disappear quickly. 5 can produce a stronger immunity, and antibody titers are not parallel.