Improved Growth Medium For Group A Streptococci

Growth Media for Typing Group a Streptococci.

It is frequently not possible to type group A streptococei. Only 33% of group A streptococei from Nashville children in a recent study (Quinn and Martin, Am. J. Hyg. 73:193, 1961) were typable, and there have been years when as few as 5% could be typed. This study was designed to test one possible reason for failure to type certain strains of group A streptococci, namely, inadequacy of growth m...

Evaluation of a new presumptive medium for group D streptococci.

A new medium designated as D streptococcus-enterococcus broth was formulated and evaluated for the enrichment and isolation of strains of serological group D streptococci. This medium was made by modifying Todd-Hewitt broth. Most-probable-number multiple-tube and membrane filter techniques were employed to estimate the numbers of enterococci in known cultures, wastewater, and other samples. Pre...

Improved recovery of group A beta-hemolytic streptococci with a new selective medium.

A new selective group A streptococcus agar (ssA) (BBL Microbiology Systems, Cockeysville, Md.) was evaluated for the recovery and direct plate identification of group A beta-hemolytic streptococci (GABHS) in comparison with sheep blood agar (SBA). A total of 265 GABHS were recovered from 1,116 throat swab specimens on both media, with detection rates of 98.9 and 91.7% for ssA and SBA, respectiv...

Selective broth medium for isolation of group B streptococci.

A selective medium containing Todd-Hewitt broth, sheep blood, nalidixic acid, and gentamicin sulfate was found to enhance significantly the isolation of group B streptococci from vaginal cultures. Preparation of the medium, which is stable for up to 4 weeks at 4 C, is simple and inexpensive. Use of such a medium should facilitate identification of vaginal colonization with group B streptococci.

New medium for enhancing pigment production of group B streptococci.