| Abstract: | The processes of dissociation occurring under the influence of soluble starch and some substances with surface activity (Tween-80, cattle bile and sodium desoxycholate) in 4 pneumococcal strains (Nos. 204, 205, 1225, 1317) isolated from patients with acute and chronic inflammatory lung diseases have been studied in vitro. Stable pneumococcal R-forms have been obtained by treatment with 0.1% sodium desoxycholate and 0. 5% bile and subsequent selection. The colonies of pneumococcal R-forms are characterized by a large size, a rough surface, uneven edges and pronounced alpha-hemolysis. The features typical of the population of these cultures are the polymorphism of cell element, the formation of long diplococcal chains, the almost complete disappearance of the capsule, as well as the negative results of the slide agglutination test and Neufeld s test with "omni" and typing pneumococcal antisera. Besides, the pneumococcal R-forms thus obtained have proved to be resistant to optochine (6 micrograms/ml) and bile (10-20%) and to possess low virulence. |
