Abstract
The present article is dealing with the so-called rugose or crape colony variation of a Salm. enteritidis. In the present part, discussions are made mainly on the systematic growth of the variant and the problems concerning the rugose forrows and crape formation.
This variant is usually obtainbale from old broth cultures or old peptone water cultures. This variant forms large, wet, translucent, flat spreading colony on solid media. Many crapes are seen on the sulface of that colony.
This crape colony is membraneous and rather adhesive to the solid media and not easily emulsified. After a few days, rugose forrows appear. The arrangement of this rugose forrows become concentric, radiated or mixed complex according to the cultural conditions (incubation temperature, medium, incubation period, humidity etc.) . However, the basic character of this variant is in the point that it forms translucent, flat spreading crape colony.
In liquid media, turbidity of the medium and the formation of wrinkled surface pellicle are observed.
In carbohydrate fermentationt tests, biochemical reactions, pathogenicity to mouse, agglutination reactions and S-R tests, this variant is quite resembling to its original type. Further, it belongs to smooth type. It is also reversible to S-type.
In the present paper, discussions are also made on the rugose variation and the alike phenomenon cited in the literatures. Discussions are also made on the problems as to whether the rugose variation is a phenomenon limited only to a certain special variant or not. The crape variant reported by Okamoto and Toyda was found most similar to this variant.
As the results of the present work, the following points were made clear.
1. This variant was found to be one of the systematic ones observed among Salmonella organisms.
2. The presence of oxygen was found essential for the occurrence and formation of the characteristic crape or pellicle. Consequently, this phenomenon was not observed under anaerobic condition. Deep colony of this variant was found smooth and lens-form. Even under aerobic condition, normal smooth colony was formed usually on 1% Sod. citrate agar.
3. In view of the above findings, the author believed that the crape or rugose colony formation is a phenomenon attached to a variation.
