RT Journal Article SR Electronic(1) A1 Lowbury, E. J. L. A1 Hurst, L.YR 1956 T1 Loss of Group and Type Reactions by Tetracycline-resistant Streptococcus pyogenes JF Microbiology, VO 15 IS 2 SP 324 OP 328 DO https://doi.org/10.1099/00221287-15-2-324 PB Microbiology Society, SN 1465-2080, AB SUMMARY: Four strains of Streptococcus pyogenes were found to have lost their group and type serological reactions after acquiring resistance to tetracycline antibiotics in vitro. These degraded variants were non-haemolytic and weakly fibrinolytic; they failed to grow in fresh human blood. Some of the degraded strains were found to have acquired the property of fermenting raffinose. Antisera prepared against three degraded strains revealed some antigenic relationship between degraded forms derived from different parent strains, and between degraded and parent organisms, UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-15-2-324