The distribution of virulence genes, sefC, pefA and spvC, was investigated in 110 Salmonella Enteritidis phage type 4 strains by polymerase chain reaction. Their influence in the caecal colonization and invasion of liver and spleen of one-day-old chickens was studied. Eight isolates were negative for the spvC gene, three for the pefA gene and one, for the sefC gene. These results allowed grouping the strains into four genotypes. Presence of these genes did not influence bacteria invasion in the liver and spleen of the chickens ten days after infection, although the presence of more than one fimbrial gene can be related to caecal colonization.
Salmonella; virulence genes; colonization; invasion