Salmonella typhi bacteria (magnified image under microscope)

What are salmonella - biological definition

Salmonella are non-sporulated and mobile Gram-negative bacteria belonging to the family. Enterobacteriaceae.


This genus of bacteria comes in three species: Salmonella typhi, Salmonella choleraesuis and Salmonella Enteridtis. The latter features over 1,400 variations.

With the exception of Salmonella typhi, which affects humans by causing typhoid fever, most are pathogenic to both humans and animals.

Major diseases caused

In humans, salmonella are responsible for different clinical conditions (diseases) such as typhoid and paratyphoid fever, salmonella gastroenteritis, localized infections, etc.

Broadcast sources

However, there are people who may suffer from asymptomatic infection or transient or chronic carriers, being responsible for the spread of the bacilli. The main sources of salmonella transmission are contaminated foods.