Welcome to the Food Borne Disease Site. The sources of the foodborne illness pathogens are ubiquitous. Food and food products will always be contaminated with low levels of pathogens. At low levels, pathogenic microorganisms cause no problems. At illness thresholds, however, they can make people ill and cause death.

Tuesday, November 21, 2017

General characteristics of salmonella species

Salmonella grows in the temperature range of 2-47° C with rapid growth between 25 and 43° C. The minimum temperature for growth prevails at neutral pH and increases sharply with increasing acidity or alkalinity of the suspending medium.

The species are facultatively anaerobic, Gram-negative, straight, small (0.7-1.5 x 2. 0– 5. 0 μm) rods, which are usually motile with peritrichous flagella.

Salmonella species cause illness by means of infection, i.e. the organism grows and multiples in the host’s body and becomes established in or on the cells or tissue of the host.

Salmonella typhi
Salmonella multiply in the small intestine, colonizing and subsequently invading the intestinal tissues, producing an enterotoxin and causing an inflammatory reaction and diarrhea.

Cell envelope of Salmonella spp. consists of a complex lipopolysaccharide structure, which may function an an endotoxins. Once ingested, Salmonella viable cell are colonized in ileum and colon, by binding on the surface of epithelial cell an using type III secretion system to inject effector proteins directly into the host cell cytoplasm.
General characteristics of salmonella species
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