BD BBL™ Prepared Plated Media, Group A Selective Strep Agar with 5% Sheep Blood Plate, 20/pk 221779

Features & Benefits:

• Infection with Lancefield group A streptococci (S. pyogenes) may produce serious sequelae such as rheumatic fever and acute glomerulonephritis. Therefore, early detection and identification are important.
• Because of the overgrowth of normal flora present in throat culture specimens inoculated onto routine blood agar plates, selective ingredients have been added to sheep blood agar to enhance the detection of group A streptococci.
• Evaluation of various antimicrobial agents in laboratories resulted in a combination with improved selectivity over other selective media tested.
• This medium (ssA) allows presumptive identification of group A streptococci, based on bacitracin susceptibility and beta hemolysis, within 24 h after inoculation with the specimen when the medium is incubated in a CO2- enriched atmosphere.
• The JEMBEC system offers a convenient CO2 atmosphere for an individual plate. It consists of the selective culture medium (ssA) in a rectangular plate with a special well to hold a CO2-generating tablet.
• A resealable plastic bag is provided to maintain the CO2-enriched environment during incubation. The system may be inoculated and incubated at the site of specimen collection or used for specimen transport and growth of S. pyogenes.
• It has the advantage over other transport systems of obviating the necessity of transferring the specimen from the transport system to a culture plate.
• The base medium, modified Trypticase Soy Agar (TSA II), provides a combination of casein and soy peptones that supply organic nitrogen. The sodium chloride maintains osmotic equilibrium. Defibrinated sheep blood provides proper hemolytic reactions of streptococci. In addition, growth of Haemophilus hemolyticus, a nonpathogen whose hemolytic colonies are indistinguishable from those of beta-hemolytic streptococci, is inhibited. The incorporation of a unique combination of selective ingredients provides improved suppression of normal throat flora for improved recovery of S. pyogenes.
• Beta-hemolytic streptococci which show a zone of inhibition around a bacitracin (0.04 unit) disc may be presumptively identified as group A streptococci. In the JEMBEC system, a CO2-generating tablet is placed in a well within the plate and is activated by the moisture produced by the culture medium within the sealed plastic bag.
• The CO2 level generated is sufficient for the growth of S. pyogenes on the selective medium provided with the system.
• In addition to the plated medium, the JEMBEC System consists of resealable polyethylene bags and CO2-generating tablets (sodium bicarbonate and citric acid).

Application:

• Group A Selective Strep Agar with 5% Sheep Blood (ssA) is recommended as a primary selective plating medium for the isolation of group A streptococci (S. pyogenes) from throat cultures and other specimens in which the presence of S. pyogenes is suspected.
• Group B streptococci will also grow on this medium; most other streptococci, neisseriae, staphylococci and gramnegative bacteria are inhibited. The medium is designed for use in conjunction with Taxo A (bacitracin, 0.04 unit) discs for presumptive identification of S. pyogenes.