[Characteristics of strains of Citrobacter 037 (5396/38) isolated from guinea pigs in a gnotobiologic experiment].

No changes in the principal biochemical properties characteristic of the given genus occurred in a gnotobiological experiment of passing Citrobacter bacteria through microbe free and exmicrobe-free animals. Of 28 strains of this genus isolated in the course of investigation two strains lost their arginine-decarboxylase activity. In the cultures studied the quantitative content of the Vi-antigen had a tendency to reduction in comparison with the initial culture used for the association. some of the strains studied had one more common antigen with typhoid bacilli (strain Ty2-4446) along with theknown cross by the Vi-antigen. Bacteria of the Enterobacter and Excherichia genus isolated after the conventionalization had common antigens with typhoid bacilli (Ty2-4446).