継代処置と新鮮血漿処理による鼠チフス菌のムタビール型変異 (村瀬) 菌中原型復帰の証明

抄録

Colonies fished from the pure culture of M-type variant, (Mutabile-type variant Murase) of Salmonella typhi-murium were subcultured in each of agar, broth, and peptone water media for 5-10 times repeatedly. The cultures of M-type variant were suspended with saline in a concentration of 1 mg/ml and 0.1 ml of which was inoculated in 1 ml of human citrated blood plasma. After about 15 minutes, a loopful of the material was plated on galactoseEndo plate so as to grow colonies separately. Sometimes, it was plated also on PR-peptone agar plate, in which RT colonies turned yellow when 10% galactose solution was poured, and kept for 1-2 hours in an incubator at 37°C as reported by us previously.
RT became easily distinguishable from M-type variant by the two kinds of treatments stated above. By these treatments, moreover, the detection of RT among M-type variant was feasible in each of the media used. The number of RT colonies obtained following 10 successive subcultures exceeded than that of 5 successive cultures.
It is believed, therefore, that RT might grow from M-type variant directly in the media, and M-type variant might be destroyed probably over 10000 times more intensely than RT by the influence of blood plasma in a short period of time. Thus, the increase of RT in the former and the decrease of M-type variant in the latter might result in the predominance of RT among M-type variant.
There are several methods to detect this RT. But the number of RT on galactose-Endo plate is similar to that on PR peptone agar plate. This finding may be very important for the discussion of the origin of RT.