Salmonella enterica serovar Typhimurium isolates recovered from cow Calves, lambs and human were tested for their virulence attributes uing Congo red binding test, ability to produce hemolysin, adherence assay and HEp2? cell invasion test. Moreover, antimicrobial drug sensitivity was determined. Using disc diffusion method and Genotypic characteristics including the presence of invA gene were studied using PCR. Six isolates were examined by PCR to determine the virulence invA gene which is responsible for invasion property of salmonella strains. The tested isolates were positive for invA gene sequence.