NOVELTY - Bacteriophage having specific bactericidal activity against Salmonella typhimurium, Salmonella gallinarum or Salmonella pullorum, belonging to the morphotype group B1 of the family Siphoviridae, comprising isometric capsid and long non-contractile tail, with a total genome size of 43 kbp and major structural protein size of 40 kDa, is new.    USE - The bacteriophage is useful: in the composition, which is used as an antibiotic, thus useful for the prevention or treatment of infectious diseases caused by at least one of S. typhimurium, S. gallinarum or S. pullorum, where the infectious disease caused by S. typhimurium is salmonellosis or Salmonella food poisoning, where the infectious disease caused by S. gallinarum is fowl typhoid and the infectious disease caused by S. Pullorum is Pullorum disease; and in animal feed, drinking water, sanitizer or cleaner (all claimed), where the bacteriophage is used as additive in animal feed, drinking water for livestock, in barn sanitizers and cleaners for meat products. The valuable food sanitizer comprising the bacteriophage prevents food-poisoning. The bacteriophage is useful: in food industry as a food sanitizer or food additive, for preventing salmonella infections; in livestock industry for the production of Salmonella free livestock; and in the sanitizer used in sewage disposal plants, poultry barns, slaughter houses, contaminated areas, and other production facilities. The cleaner comprising the bacteriophage as an active ingredient is applied to the contaminated skin, feathers, and other contaminated body parts of living animals, in order to remove Salmonella. The ability of bacteriophage in the prevention and treatment of S. typhimurium, S. gallinarum or S. pullorum was tested in chickens which were fed with feed supplemented with 107 pfu of bacteriophage (per g) and drinking water supplemented with 107 pfu of bacteriophage (per ml). The result showed that the protection rate of bacteriophage treated challenged group was found to be 80%, whereas the protection rate of non-treated challenged group was found to be 20%.    ADVANTAGE - The bacteriophage has acid-resistance in pH 2.5-9, heat-resistance in temperature 37-60 degrees C, dry-resistance at 60 degrees C for 120 minutes and it does not affect beneficial bacteria. The feed additive antibiotic comprising the bacteriophage is ecologically-friendly.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a composition comprising the bacteriophage as an active ingredient.