Salmonella enteritidis. Coloured Scanning Electron Micrograph (SEM) of the bacteria Salmonella enteritidis. They cause food poisoning in humans known as salmonellosis. These Gram-negative rod- shaped bacilli bacteria have hair-like flagellae used for motility. Salmonella enteritidis produces enterotoxins which act on the small intestine. Infection occurs when numbers of these bacteria are ingested through contaminated food, such as meat, milk and chicken eggs. Typical Salmonella food poisoning occurs with symptoms including vomiting, nausea, abdominal pain and diarrhoea. Infection is usually controllable with antibiotic drugs. Magnification: x6500 at 6x7cm size.