Microbiology Quality Control

Food contaminated by microorganisms (bacteria and yeasts), viruses, and protozoa can cause severe disease in humans. There are two categories of foodborne diseases.
  • First, food poisoning is caused by the presence of microbial toxins in food products, e.g. by Staphylococcus aureus, Clostridium perfringens (both produce enterotoxins which elicit enteric disease such as diarrhea), and Clostridium botulinum (botulism is the most severe type of food poisoning).
  • Second, the growth of microorganisms in the body after eating contaminated food, e.g. by Salmonella spp. (salmonellosis) and Campylobacter jejuni (high fever, abdominal cramps). Many human pathogens are transmitted by fecal contaminated water, the most important being Salmonella typhi (typhoid fever) and Vibrio cholerae (cholera).

Microbiological test procedures for the examination of foods and beverages have been standardized and regulated, but nearly every country has its own regulations. Most of the culture media, additives, dyes, and indicators, which Sigma-Aldrich offers, conform to norms like ISO. Product lines include:
  • Culture media and base ingredients
  • Chromogenic media for differentiation of microbes based on colony color
  • Test kits (biochemical, immunological, and molecular biological methods) for pathogen detection, identification, and confirmation
  • Vitroid certified reference microorganisms to test the performance of microbiological assays