[Autobacteriographic studies on the distribution and localization of Staphylococcus aureus in mice].

Autobacteriography was proposed as a bacteriological method to follow distribution and localization of bacteria in experimentally infected animals. Infectious organisms were restricted to rifampicin-resistant strains to prevent contamination during autobacteriography. Mice were infected with Staphylococcus aureus Smith diffuse type RFPr (rifampicin-resistant) by the intravenous route and frozen at various intervals after infection. Whole body sections (40-microns thick) of the mice were transferred onto selective agar medium containing rifampicin to incubate at 37 degrees C. On day 1 after infection, dense colonies of the infecting organism on the sections were distributed in the whole body. On day 3, few organisms were detected in the liver and many were observed in the spleen, kidney and intestinal tract. On days 7, 14 and 21, the organisms in the liver and spleen disappeared, and those in the kidney and intestine remained. The remaining infectious organisms were demonstrated in the kidney and intestinal tract by autobacteriography of mice infected with S. aureus Smith compact type RFPr. By cultivation of the homogenate of the gastrointestinal tissues and their contents, the infectious organisms were detected mainly in the lower small intestines, cecum and large intestines.