October 5, 2010
Under a very high magnification of 12000X, this colorized scanning electron micrograph (SEM) revealed the presence of a large grouping of Gram-negative Salmonella typhimurium bacteria that had been isolated from a pure culture. See PHIL 10982 for a black and white version of this image.
How do people catch Salmonella?
Salmonella live in the intestinal tracts of humans and other animals, including birds. Salmonella are usually transmitted to humans by eating foods contaminated with animal feces. Contaminated foods usually look and smell normal. Contaminated foods are often of animal origin, such as beef, poultry, milk, or eggs, but any food, including vegetables, may become contaminated. Thorough cooking kills Salmonella. Food may also become contaminated by the hands of an infected food handler who did not wash hands with soap after using the bathroom.
Salmonella may also be found in the feces of some pets, especially those with diarrhea, and people can become infected if they do not wash their hands after contact with pets or pet feces. Reptiles, such as turtles, lizards, and snakes, are particularly likely to harbor Salmonella. Many chicks and young birds carry Salmonella in their feces. People should always wash their hands immediately after handling a reptile or bird, even if the animal is healthy. Adults should also assure that children wash their hands after handling a reptile or bird, or after touching its environment.