Takahashi M, Ichiman Y, Yoshida K
Acta Microbiol Acad Sci Hung. 1981;28(4):413-7.
Using strain SME-12 of Escherichia coli and its variants A and B showing large round, diffuse and compact-type colonial morphology, respectively, in soft-agar medium, their capsule showed that although these strains were similar in toxicity, the parent strain exhibited a large capsule, a large cell volume and a high mouse virulence. Variant A had no capsule, its cell volume was remarkably lower than that of the original strain, and was avirulent; variant B had no capsule and displayed the lowest cell volume and mouse virulence. With 193 fresh isolates of E. coli, the majority of colonies of 16, 152 and 25 strains were of large round, diffuse and compact types, respectively. Fifteen strains of pure growth type from each of the three groups were tested for mouse virulence. The majority of strains showing large round-type growth was virulent, diffuse-type strains displayed a low virulence, while no mouse was killed by compact-type strains.
使用大肠杆菌菌株SME - 12及其变体A和B，它们在软琼脂培养基中分别呈现出大圆形、扩散型和紧密型的菌落形态。对它们的荚膜研究表明，尽管这些菌株在毒性方面相似，但亲本菌株具有大荚膜、大细胞体积和高小鼠毒力。变体A没有荚膜，其细胞体积明显低于原始菌株，并且无毒；变体B没有荚膜，细胞体积最小，小鼠毒力也最低。在193株新鲜分离的大肠杆菌中，16株、152株和25株的菌落大多数分别为大圆形、扩散型和紧密型。对来自这三组的每组15株纯生长型菌株进行小鼠毒力测试。大多数呈现大圆形生长的菌株具有毒力，扩散型菌株毒力较低，而紧密型菌株没有导致小鼠死亡。
