(a) a bacteriophage or a mutant thereof selected from a group consisting of bacteriophage strain EB1.11 deposited under number DSM 34393, bacteriophage strain EB1.25 deposited under number DSM 34394, bacteriophage strain EB1.27 deposited under number 34395, bacteriophage strain STA1.29 deposited under number DSM 343962 and bacteriophage strain MA2.74 deposited under number DSM 34397, wherein said strains were deposited at German Collection of Microorganisms on Sep. 28, 20221; and (b) a storage solution comprising a sodium salt, a calcium salt and a magnesium salt, wherein the magnesium salt is at least 5 times more than the calcium salt;

wherein the bacteriophage or the mutant thereof is capable of killing a Gram-positive bacterium comprising Staphylococcus aureus;

wherein the composition does not contain a TRIS buffer or a phosphate buffer;

wherein the composition is stable for at least about a year at 39.2-46.4° F. (4-8° C.); and

wherein the composition avoids coagulation of raw milk.