NUTRITIONAL REQUIREMENTS OF ENTEROTOXIGENIC STRAINS OF STAPHYLOCOCCUS AUREUS
Abstract
A 7-amino acid medium has been devised which permits good growth of S. aureus S-6 comparable to that obtained on an equivalent amount of complex medium. Further work is in progress to simplify this medium. Current findings show that when the amino acid, glutamic acid, serves as a carbon source in defined media, enterotoxin B is produced. The amount of toxin formed under these conditions is approximately 25 times greater than that when glucose serves as a carbon source. Substrates which supported growth but not toxin formation were ribose, glycerol, and pyruvate. Of the five-carbon sugars tested, only ribose supported growth whereas xylose and arabinose did not. The Kreb's cycle intermediates, succinate, citrate, acetate, oaxaloacetate, alpha-ketoglutarate, and malate did not support growth. A new method for the assay of enterotoxin has been developed which permits the detection of 0.06 micrograms of toxin. This is the microtiter hemagglutination inhibition method which is fast, accurate, repeatable, easy to read, and requires only micro-amounts of reactants. It has been adopted for routine use in our laboratory. Ether- extracted protein hydrolysate powder (PHP) still supported growth and toxin production when vitamins were added to the medium. In the absence of added vitamins, growth occurs but no toxin is produced.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1965
- Accession Number
- AD0624249
Entities
People
- Robert A. Mah
Organizations
- University of North Carolina at Chapel Hill