salmonella

Any of a very varied group of bacteria, genus Salmonella, that colonize the intestines of humans and some animals. Some strains cause typhoid and paratyphoid fevers, while others cause salmonella food poisoning, which is characterized by stomach pains, vomiting, diarrhoea, and headache. It can be fatal in elderly people, but others usually recover in a few days without antibiotics. Most cases are caused by contaminated animal products, especially poultry meat.

Human carriers of the disease may be well themselves but pass the bacteria on to others through unhygienic preparation of food. Domestic pets can also carry the bacteria while appearing healthy.

In 1996 an Australian biotechnology company produced a salmonella vaccine for use on cattle and poultry. It can be injected into eggs or given to day-old chicks in their drinking water. Cattle require a course of two injections, with annual boosters. The use of the vaccine in poultry has been approved by government authorities in Australia, and approval for its use in cattle is pending.

During 1995, salmonella was being used to develop a vaccine against plague by inserting a small section of the genetic code of the plague-causing bacillus Yersinia pestis into disabled S. typhi.