Infectious dose
Encyclopedia
Infectious dose is the amount of pathogen (measured in number of microorganisms) required to cause an infection in the host.
Usually it varies according to the pathogenic agent and the consumer's age and overall health.
Usually it varies according to the pathogenic agent and the consumer's age and overall health.
Infectious doses for some known microorganisms
- Escherichia coliEscherichia coliEscherichia coli is a Gram-negative, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms . Most E. coli strains are harmless, but some serotypes can cause serious food poisoning in humans, and are occasionally responsible for product recalls...
: very large (106 - 108 of organisms) - SalmonellaSalmonellaSalmonella is a genus of rod-shaped, Gram-negative, non-spore-forming, predominantly motile enterobacteria with diameters around 0.7 to 1.5 µm, lengths from 2 to 5 µm, and flagella which grade in all directions . They are chemoorganotrophs, obtaining their energy from oxidation and reduction...
: quite large ( > 105 of organisms) - CholeraCholeraCholera is an infection of the small intestine that is caused by the bacterium Vibrio cholerae. The main symptoms are profuse watery diarrhea and vomiting. Transmission occurs primarily by drinking or eating water or food that has been contaminated by the diarrhea of an infected person or the feces...
: relatively large (104 - 106 of organisms) - Bacillus anthracisBacillus anthracisBacillus anthracis is the pathogen of the Anthrax acute disease. It is a Gram-positive, spore-forming, rod-shaped bacterium, with a width of 1-1.2µm and a length of 3-5µm. It can be grown in an ordinary nutrient medium under aerobic or anaerobic conditions.It is one of few bacteria known to...
: relatively large (104 spores) - Campylobacter jejuniCampylobacter jejuniCampylobacter jejuni is a species of curved, helical-shaped, non-spore forming, Gram-negative, microaerophilic bacteria commonly found in animal feces. It is one of the most common causes of human gastroenteritis in the world. Food poisoning caused by Campylobacter species can be severely...
: low (500 organisms) - ShigellaShigellaShigella is a genus of Gram-negative, nonspore forming, non-motile, rod-shaped bacteria closely related to Escherichia coli and Salmonella. The causative agent of human shigellosis, Shigella causes disease in primates, but not in other mammals. It is only naturally found in humans and apes. During...
: very low (10s of organisms) - C.parvum : very low (10 to 30 oocysts)
- Escherichia coli O157:H7Escherichia coli O157:H7Escherichia coli O157:H7 is an enterohemorrhagic strain of the bacterium Escherichia coli and a cause of foodborne illness. Infection often leads to hemorrhagic diarrhea, and occasionally to kidney failure, especially in young children and elderly persons...
: very low ( < 10 organisms) - Entamoeba coliEntamoeba coliEntamoeba coli is a non-pathogenic species of Entamoeba that frequently exists as a commensal parasite in the human gastrointestinal tract. Clinically, E...
: extremely low (from 1 cystCystA cyst is a closed sac, having a distinct membrane and division on the nearby tissue. It may contain air, fluids, or semi-solid material. A collection of pus is called an abscess, not a cyst. Once formed, a cyst could go away on its own or may have to be removed through surgery.- Locations :* Acne...
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