OCCURRENCE OF EXTRACELLULAR HYALURONIC-ACID AND HYALURONATLYASE IN STREPTOCOCCI OF GROUP-A, GROUP-B, GROUP-C, AND GROUP-G

Streptococci of serological groups A (GAS), B (GBS), C (GCS) and G (GG S) were examined in vitro using an optimized medium in respect of thei r ability to produce hyaluronic acid (HA) and hyaluronatlyase (HY). In this study, 614 GAS (including 123 streptococcal toxic shock syndrome strains, STSS), 247 GBS, 225 GCS and 143 GGS were investigated in qua litative and quantitative tests. Only 4% of GAS and 2.7% of GCS were a ble to express HA. In contrast to GAS, isolates of GCS showed a highly specific HA formation (to 1 g HA/g dry biomass). In all strains of GB S and GGS, not even a single isolate was positive for HA. HY expressio n was detectable in all four serological groups. In GAS, only 12.5% of strains were positive; the most common types being 22 and 4, whereas in GBS, GCS and GGS, 72.1%, 84% and 85.3% of isolates, respectively, c ould be reported as positive. The data suggest that the HA capsule onl y plays a secondary role in infections caused by GAS strains pathogeni c for humans.