Immunity Mechanisms in Experimental Salmonellosis

Salmonellae are generally believed to be facultative intracellular parasites capable of growing inside professional phagocytes, although this view has been questioned (Hsu, this volume). Some salmonellae have a broad host range and can affect many species (“salmonellae of animal origin”), whereas others are more restricted and cause disease in only one or a few hosts, such as S. typhi, the agent of human typhoid fever, which affects only humans. The latter tend to cause invasive disease (e.g. enteric fever), whereas human infections with “animal” salmonellae — which can be invasive in animals — can be localised to the gut (salmonella gastroenteritis).