Salmonella – Overview

Salmonella is a rod-shaped, motile bacterium – nonmotile exceptions S. gallinarum and S. pullorum – nonsporeforming and Gram-negative. There is a widespread occurrence in animals, especially in poultry and swine. Environmental sources of the organism include water, soil, insects, factory surfaces, kitchen surfaces, animal feces, raw meats, raw poultry, and raw seafoods, to name only a few.

Nature of Acute Disease

S. typhi and the paratyphoid bacteria are normally caused septicemic and produce typhoid or typhoid-like fever in humans. Other forms of salmonellosis generally produce milder symptoms.

Nature of Disease

Acute symptoms: Nausea, vomiting, abdominal cramps, minal diarrhea, fever, and headache. Chronic consequences – arthritic symptoms may follow 3-4 weeks after onset of acute symptoms.

Onset time: 6-48 hours.

Infective dose: As few as 15-20 cells; depends upon age and health of host, and strain differences among the members of the genus.

Duration of symptoms: Acute symptoms may last for 1 to 2 days or may be prolonged, again depending on host factors, ingested dose, and strain characteristics.

Cause of disease

Penetration and passage of Salmonella organisms from gut lumen into epithelium of small intestine where inflammation occurs; there is evidence that an enterotoxin may be produced, perhaps within the enterocyte.