Abstract: The present invention relates to new contamination resistant artificial media for the routine cultivation of P. salmonis. In particular, it discloses first a liquid media based named Austral-SRS Broth that extensively require iron and sodium chloride; and, second, a blood-free agar media comprising tryptone soy with either ferric or ferrous salts (Austral-TSFe) agar or the use of hemoglobin (Austral-TSHem) as a source of iron in the agar. Also disclosed is a method for their preparation as well as their application in the development of antigens and low cost vaccines for protection against Piscirickettsiosis and the use of the medias for a kit that evaluate the antibiotic resistance appearance in different strain of P. salmonis isolated from the salmon industry.