title: Heterogeneity of Staphylococcus aureus enterotoxin B as a function of growth stage: implications for surveillance of foods.
abstract: Staphylococcus aureus was grown in a fermentor under controlled conditions of pH, oxygenation, and temperature, while the higher-molecular-weight products of its growth were continuously removed across ultrafiltration membranes. These products were examined by single and double gel diffusion and immunoelectrophoresis against a variety of available anti-enterotoxin B antisera. All antisera examined were polyvalent for S. aureus antigens. However, two electrophoretically distinct proteins were the major reactants with the antisera. One of these was present in early- to mid-log-phase cultures. After mid-log growth was achieved, both were present but in continuously changing proportions. This observation was repeated with a variety of growth conditions and media. A significant part of the physicochemical heterogeneity of enterotoxin B observed over the past 20 years is thus correlated with the growth phase of the organism. Taken together, these facts are used to argue for a two-step rationale for the detection of food-borne staphylococcal disease: (i) screening for a presumptive hazard by analysis for any antigen, toxin, or enzyme of S. aureus in a foodstuff and (ii) confirmation of the hazard by identifying the presence of an enterotoxin using a combination of physicochemical and serological techniques.
mesh_terms: D000942:Antigens, Bacterial; D015478:Antigens, Heterophile; D004768:Enterotoxins / Q000096:biosynthesis; D005506:Food Contamination; D005516:Food Microbiology; D013211:Staphylococcus aureus / Q000254:growth & development / Q000276:immunology / Q000378:metabolism*
chemical_list: D000942:Antigens, Bacterial; D015478:Antigens, Heterophile; D004768:Enterotoxins