Suspensions of group A streptococci were subjected to mechanical disruption by shaking with glass beads. The supernatant solutions produced severe delayed inflammatory reactions on intradermal injection into normal rabbits. Intravenous injections caused systemic reactions characterized by fever, leucopenia, and peripheral vasomotor phenomena. These effects were more pronounced in rabbits which ...

Many workers have shown that certain strains of supposed penicillin-sensitive bacteria may be resistant to penicillin. Since a clinical study of the effect of penicillin in infected root canals was contemplated it was thought desirable to ascertain the sensitivity of individual strains of streptococci, which are the organisms commonly isolated from infected root canals. At the same time it was ...

A new 4-h commercial system (API 20S; Analytab Products, Plainview, N.Y.) for the identification of streptococci was compared with the conventional biochemical profile method in the species identification of alpha-hemolytic streptococci. A total of 194 clinical isolates (including 74 isolated from blood cultures, 64 isolated from wound cultures, and 56 isolated from respiratory cultures) and 20...

Several presumptive tests were evaluated for their effectiveness in differentiating streptococci. When the tests were combined into a battery and the resulting reactions were interpreted as patterns, the overall presumptive identification rate was at least 97%. We used the hemolytic reaction, susceptibility to bacitracin and sulfamethoxazole plus trimethoprim (1.25 micrograms plus 23.75 microgr...

1\1 protein is well established as a determinant of virulence in lhuman infections due to the group A hemolytic streptococcus and as the stimulus for the production of type-specific MA protein antibodies(l). However, there are numerOUS instances documented(2-5) and undocumented, of infections as well as cases of rlheumatic fever and nephritis in wlhiclh strains of group A hemolytic streptococci...

Highly purified M proteins were used for determining cutaneous hypersensitivity and type-specific circulating antibodies in normal adults and infants. 80% of 91 adults and 8% of 59 infants exhibited a transient delayed cutaneous reaction to at least two of types 12, 14, and 24 M proteins. Antibodies assayed by passive hemagglutination were observed in 90% of the adults and 13% of the infants. V...