Escherichia coli serotype O157:H7 and Salmonella enterica cause severe diseases on animals and can transmit to humans. The abuse of antibiotics for husbandry or treating these pathogens leads to economic effects and the emergence of bacterial resistance on antibiotics.  Bacteriophages (or phages) are viruses which infect and kill specific kind of bacteria with high host specificity. The use of phages as antibacterial agents has been proposed. We screened and isolated phages from Japan and Vietnam against E. coli and Salmonella. We evaluated the characteristics and the lysis activities of these phages as bio-control measures. With the advance of Next Generation Sequencing, whole-genome sequences of phages were analyzed to determine taxonomy. The genome analysis was the critical step to identify lytic phages without any undesirable genes. The in vitro application showed the efficacy of suppressing the growth of bacteria. The use of single phage can cause lysis of several bacteria strains up to 7 h. Our study gives some information to screen phages for prophylactic and therapeutic applications in agriculture or food preservatives against E. coli and Salmonella.