[Formation of microvesicles in meningococcal cells during batch cultivation]

Both surface and intracytoplasmic vesiculae have been shown to appear in meningococcal cells, strains 132, 125, and 133 belonging, respectively, to serogroups A, B, and C, in the process of batch cultivation. The surface microvesiculae are formed from the outer membrane of the cell wall during the whole process of batch cultivation. The intracytoplasmic membrane structures are formed in the process of cell autolysis. As revealed in this investigation, the strains under study, irrespective of their serogroup, are characterized by similar mechanisms of the formation of microvesiculae. The surface microvesiculae have been found to fall into three main types: monolamellar, multilamellar, and large spheroid bodies. The presence of specific functional features in each type of surface microvesiculae is suggested, as these microvesiculae, besides having their characteristic ultrastructure, differ in their contents. The attenuated culture of meningococcal strain 133, whose cells are notable among other strains under study for their more active (quantitatively) formation of microvesiculae, has been shown to have the highest toxicity for rabbits.