Abstract
1) The oral administration to a mouse of antibiotics as SM and others gives changes to the fecal bacterial flora, and Yeast-like bacteria having resistive power to these drugs extraordinarily increase, and the susceptibility to the oral infection of salmonella enteritidis enhanced.
2) This phenomenon above is remarkably suppressed with the administration of drug resistant Str. fecalis.
3) On the suppressive power of Str. fecalis over Yeast-like bacteria according to the result of the examination in vitro of the antagonistic phenomenon of the two, it is considered that the mechanism of the suppresion of Str. fecalis over Yeast-like bacteria is not so much due to acid generated by the former as to the difference of the quantity of their consumptive power of glucose in media.
