The Phoenix system (Becton Dickinson Diagnostic Systems, Sparks, MD) was evaluated for identification (ID) to the species level of streptococci and enterococci. Two hundred clinical isolates were investigated: beta-hemolytic streptococci (n = 50), Streptococcus pneumoniae organisms (n = 46), viridans group streptococci (n = 31), Enterococcus faecium (n = 36), Enterococcus faecalis (n = 25), and...

One hundred thirty-seven isolates of beta-hemolytic streptococci were recovered from 623 pharyngeal cultures. Twenty-nine percent of these were group A, 10% were group B, 31% were group C, 11% were group F, 12% were group G, and 7% could not be grouped. The significance of non-group A isolates in pharyngitis could not be evaluated in the absence of viral and serological studies. Hemolytic strep...

A latex agglutination method for the rapid detection of beta-hemolytic streptococci from Lancefield serogroup C in throat swabs from 403 university students with symptomatic pharyngitis was evaluated. Compared with culture, the rapid test was poorly sensitive (34.4%) but very specific (98.4%) in detecting group C beta-hemolytic streptococci. The sensitivity of the rapid test improved with an in...

The methods of Lancefield and of Griffith for grouping and typing hemolytic streptococci have greatly facilitated studies on the relationship of the hemolytic streptococcus to human disease. Strains from human disease fall into Lancefield's Group A by the precipitin test.5 Exceptions occur, but they are rare.' Group A consists of about 30 types which can be identified by another precipitin test...

The optimal incubation conditions for isolation of group A streptococci from throat cultures are controversial. Therefore, we compared the effects of aerobic and anaerobic incubations after 24 and 48 h on the recovery of group A streptococci. Throat swabs submitted to the clinical laboratory were inoculated onto duplicate 5% sheep blood agar plates, incubated aerobically or anaerobically (GasPa...

1. Thirteen strains of hemolytic streptococci isolated from patients with acute rheumatic fever did not show any evidence of being related serologically. 2. Strains of hemolytic streptococci exist which, although identical by the agglutination test, do not show complete reciprocal agglutinin absorption. Sera prepared from such related strains may show some protective power in mice against anoth...

Latex agglutination was compared with fluorescent-antibody staining with group A conjugate and Lancefield precipitation for grouping of beta-hemolytic streptococci. Latex agglutination correctly grouped 98.8% of 82 group A streptococci and more than 95% of 187 group B, C, or G streptococci. Occasional cross-reactions occurred between groups A and C and groups B and G.