Bacterial Deoxyribonuclease Production and Its Possible Influence on Mastitis Detection

Abstract

Various hemolytic streptococci, hemolytic staphylococci, and micrococci were tested for production of deoxyribonuclease (DNase). In general, beta-hemolytic pathogenic streptococci of human origin produced highest concentrations of DNase. However, some beta-hemolytic bovine strains were also highly productive. Alpha-hemolytic strains produced a maximum of 7.6 units/milliliter. None of the staphylococci or micrococci produced detectable DNase. The possibility of correlating DNase production with pathogenicity of the organism is suggested. Addition of DNase to milk abolished the California Mastitis Test (CMT) reaction only after leucocytes had been disrupted by the surface active agent. Possible effects of bacterial DNase production in milk on mastitis screening tests such as the CMT are discussed. © 1966, American Dairy Science Association. All rights reserved.