[Role of Streptococcus salivarius in maintaining the ecologic balance of the human nasopharynx].

Most of Str. salivarius strains isolated from the nasopharynx of healthy persons suppressed the growth of meningococci in vitro. Their antagonistic activity varied within a wide range, which suggested that different strains were unequal in their capacity for protection from meningococcal infection. The monthly comparison of the activity of various strains also allowed revealing considerable differences. These results confirm the earlier hypothesis on the decisive role of Str. salivarius in the protection of the nasopharynx from colonization by meningococci.