**4. Laboratory typing methods**

The determination of the relatedness of strains within a *Salmonella* serotype is a prerequisite for the identification of the sources of infection and for tracing the routes of *Salmonella*  dissemination in outbreaks. Since biochemical analysis did not further differentiate between the bacteria assigned to the same *S. enterica* subspecies, other phenotypic and molecular methods have been used (Riley, 2004).
