Color enhanced negatively stained Salmonella typhimurium. Salmonella are a genus of bacteria belonging to the family enterobaacteriaceae. The are gram-negative, usually motile rods. Several of the more than 1,400 species are pathogenic, some causing mild gastroenteritis, other producing a severe and often fatal food poisoning. These bacteria are common in poultry and eggs as well as inadequately cooked beef and pork. TEM. Enhancement of 3E6768. Magnification: 5,000x at 2.25 film size.