[Capsule formation in Pasteurella multocida, serovar A]

In this work the process of capsule formation in P.multocida bovine strain, serovar A, has been studied. The cultures were grown on liquid and solid nutrient media prepared on the basis of Hottinger hydrolysate and synthetic culture medium 199. Extracellular material was detected by the method electron cytochemistry with ruthenium red and polycationic ferritin. As revealed by specific staining and labeling, P.multocida capsule of serovar A was found to contain material of the polysaccharide nature. But the capsular structures of obtained from agar-grown and broth cultures were different. The capsular layer on the surface of cells grown in Hottinger's broth was found to be more pronounced.