Cultured typhoid bacteria. Close-up of typhoid bacteria (Salmonella typhi) colonies being cultured on a growth medium. S. typhi causes the disease typhoid, which is transmitted in food or water that is contaminated by faeces. This bacterium causes an acute fever, abdominal pain and diarrhoea or constipation. Severe cases can lead to intestinal bleeding and death. Antibiotic treatments and vaccines are available.