THE DETECTION AND ASSAY OF HYALURONIDASE BY MEANS OF MUCOID STREPTOCOCCI

Abstract

A method is presented by which hyaluronidase may be detected by observing its action on the colony characteristics of mucoid strains of Streptococcus pyogenes and certain strains of Streptococcus of Lancefield Group C growing on agar. This effect is due to destruction of the capsules of these organisms and is caused by hyaluronidase from all sources tried. Bacteria are tested for hyaluronidase production by streaking on seeded plates; fluids are tested by using assay cylinders or filter paper disks.The method is convenient and has the advantage of detecting small concentrations of the enzyme, to a limit of between 0.001 and 0.0001 turbidity reduction units per ml. The test may be elaborated to give a means of biological assay that may be used where there are substances in the medium or diluting fluid that interfere with assays by other methods.Provided the colonies do not autolyze during the 12 to 18 hr. required for the test, all mucoid S. pyogenes strains are suitable. However, among the Group C strains one was found with a capsule not destroyed by hyaluronidase, indicating a separate capsular type.In testing certain genera for hyaluronidase production, notably Streptococcus and Micrococcus, antibiotic activity may interfere with the test. These inhibitory strains are relatively infrequent.