Abstract
In our previous report, a proof has been given on the fact that there exists a variation from the mutabile type variant (M-type) to its galactose fermenting daughter (RT-type), and an inference was given, on the basis of its general biological charactcrs, that this RT variant might be the reverse mutant of M-type variant to its original type.
In the present study, in order to know the in vivo fate of those microorganisms, a culture of M-type variant of Salmonella typhi Ishikawa or Murata strain (VW form) was mixed with a culture of. the original type or with that of RT variant which is considered to be the reverse mutant, and inoculated intraperitoneally into mice for autopsy and culture.
Results of the experiment revealed that:
1. In the former case, the colonies of original type were easily demonstrable while the detection of the colonies of M-type variant was difficult.
2. In the latter case, the colonies of RT variant were easily demonstrable while the detection of M-type variant was difficult.
Namely, M-type variant showed a marked decrease within an hour afer intraperitoneal inoculation of the mixed cultures. And following the elapse of time, the colonies of original type or RT became predominant. When mucin bacterial suspensions were used, the experimental animal died of sepsis.
The microorganisms of M-type variant are considered to be easily killed and moreover their prolifelative activity is poor in vivo, whereas, the microorganisms of the original type and RT variant have much stronger resistance and prolifelative activity.
Since the starting mother of RT variant is M-type variant, the in vivo findings mentioned above too suggest that RT variant is a Reverse mutant from M-type variant to its original type.
Further experiments of this series will follow in the third report.
