Salmonella infection, or salmonellosis
Salmonella infection, or salmonellosis, is a bacterial disease of the intestinal tract. Salmonella is a group of bacteria that cause typhoid fever, food poisoning, gastroenteritis, enteric fever and other illnesses. People become infected mostly through contaminated water or foods, especially meat, poultry and eggs.
Salmonella infections are zoonotic and can be transferred between humans and nonhuman animals. Many infections are due to ingestion of contaminated food.
Salmonella is a gram-negative, rod-shaped bacilli that can cause diarrheal illness in humans. Put simply – Salmonella is a bacterium shaped like a rod with a cell wall composed of peptidoglycan.
Gram-negative is a term used in bacteriology for bacteria that lose the crystal violet stain and take the color of the red counterstain in Gram’s method of staining. Gram-negative bacteria usually have a cell wall composed of a thin layer of peptidoglycan. Bacilli is the plural of bacillus. Bacteria that have a rod-like shape are called bacilli.
Most people with salmonellosis develop diarrhea, fever, vomiting, and abdominal cramps 12 to 72 hours after infection. In most cases, the illness lasts four to seven days, and most people recover without treatment. In some cases, though, the diarrhea may be so severe, the patient becomes dangerously dehydrated and must be taken to a hospital. At the hospital, the patient may receive intravenous fluids to treat the dehydration, and may be given medications to provide symptomatic relief, such as fever reduction. In severe cases, the Salmonella infection may spread from the intestines to the blood stream, and then to other body sites, and can cause death, unless the person is treated promptly with antibiotics. The elderly, infants, and those with impaired immune systems are more likely to develop severe illness.
Researchers say they have paved the way toward an effective Salmonella vaccine by identifying eight antigenic molecules from human and mouse infections.