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(FTC International Consulting)
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Food Microbiology
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Escherischia Coli (E.Coli) |
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E. coli is a gram negative organism, which commonly inhabits the intestine and serves to prevent harmful bacteria from causing illness. A select few strains of E. coli ( enterotoxic, enteropathogenic, enterohaemolytic and enteroinvasive) are virulent forms which can cause severe disease and death. the organism can be resistant to lower pH environments, is readily destroyed by heat. The infective dose is not known for certain but is believed to be as low as 10 organism (for H1:0157)
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Listeria Monocytogenes (L. monocytogenes) |
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Listeria is a gram positive motile organism that is also commonly found in the intestinal tract. It is quite a hardy organism, resistant to heat, freezing and environmental extremes. The organism can cause a range of disease, including gastrointestinal, meningial, encephalitis, scepticemia and stillbirth. Fewer than 1000 organisms may be needed to cause disease |
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| Staphylococcus aureus (S. aureus) | ||||||||||||||||||
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Staph aureus is a gram positive rod which can produce a heat stabile toxin. The organism, found on the skin and in the nasal passages, is readily transmitted to foods where it can flourish. Generally, people that have been intoxicated with staph toxin will exhibit nausea, vomiting and retching. Headaches, muscle cramping and transient blood pressure changes may occur but more rarely. |
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| Clostridium botulinum (C. botulinum) | ||||||||||||||||||
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Known to produce the most toxic poison known to man, this organism, a facultative anaerobic gram positive rod, will produce its toxins only strictly anaerobic conditions. The organism forms heat resistant spores, which can only be destroyed by a combination of pressure and heat (121 Celsius @ 15 psi). It is commonly associated with improper canning and pickling techniques, but has also been found in vacuum packaged meats. The toxin, a potent neurotoxin acts on the central nervous system. The infective dose is a few nanograms. Several serotypes of C. botulinum exist (serotypes A,BC,D,E,F,G), of which A,B,E and F are implicated in human botulism.
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| Clostridium perfringens | ||||||||||||||||||
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This organism is an obligate anaerobic gram positive spore forming rod. The organism produces a toxin which is responsible for human poisonings. A common organism in soil. Generally associated with foods that have been improperly stored or not cooled sufficiently. Toxins are generally formed in the intestine. Inoculation levels are high, generally in the 100,000,000 organisms range. |
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| Bacillus cereus (B. cereus) | ||||||||||||||||||
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B.cereus is a facultative aerobic spore former which produces two types of toxins. The two types of intoxication exhibit different symptoms, one causes vomiting (emetic), the other diarrhea. The toxin is highly heat stable. Organisms must be ingested to cause intoxication. Generally high levels of ingestion are required (100,000 organisms) |
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| Salmonella spp. | ||||||||||||||||||
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Various types of Salmonella species exist, all gram negative rods, many of which exhibit the ability to cause serious illness. S.typhi produces typhoid fever and septicemia, as does S. paratyphi. S. typhermurium produces Salmonellosis. With infective doses as low as 15 - 20 organisms, this organism can cause serious gastrointestinal illness, along with headaches and possible chronic arthritic conditions. The organism is generally associated with improperly cooked meats, poultry and seafood (chicken being a very common host), but also with improperly processed or stored processed foods, cocoa, chocolate, eggs and other products.
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| Shigella spp. | ||||||||||||||||||
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A gram negative non spore forming rod, this organism is extremely virulent and is generally transmitted through the fecal oral route. It is responsible for bacterial dysentery, causing bloody diarrhea. Most common causes of contamination are through fecal contamination of water and through fecal-oral transmission routes (unsanitary handling of foods)
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| Hepatitis A | ||||||||||||||||||
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Hepatitis A is of the family of rotaviruses. Infections are generally caused by transmission of the virus through contaminated water, salads, fruit and vegetables. Infectious doses are not known but expected to be as low as 10 viruses. The virus cause malaise, anorexia, abdominal discomfort and jaundice. |
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| Hepatitis E | ||||||||||||||||||
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Clinically indistinguishable from Hepatitis A thiis of the family of rotaviruses. Infections are generally caused by transmission of the virus through contaminated oral - fecal transmission routes, as well as direct contact. |
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| Standard (Aerobic) Plate Count | ||||||||||||||||||
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This is a measure of the total number of aerobic organisms found in a sample. Generally expressed as cfu/g or cfu/ml (colony forming units per gram or per ml), it can be a measure of the cleanliness of a food sample. Cultured products, such as cheese and yogurt will have very high standard plate counts, but these are organisms that are grown on purpose, and thus not necessarily a measure of the cleanliness of the product. In order to determine whether a food is safe to eat, more tests must be conducted |
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| Coliforms | ||||||||||||||||||
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Coliforms are a classification of bacteria, to which E.coli species belong. Others included in this group and Enterobacter, Klebsiella and Citrobacter species. Presence of these organisms MAY indicate fecal contamination. |
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| Faecal Coliforms | ||||||||||||||||||
| The faecal coliforms are a classification of coliforms that are commonly found in fecal matter.Presence of these organisms probably indicates fecal contamination. | ||||||||||||||||||
