Staphylococcus aureus haemolysins: their use in strain typing.

By using a beta-lysin-producing test strain and anti-beta + delta lysins, the lysins of Staphylococcus aureus strains can easily be determined. The method was used for examination of the haemolysin production of 300 S. aureus strains isolated from human post mortem material and bovine mastitis. The results were cross-checked with those of three other typing tests, viz. phage typing, crystal-violet activity and lipase production. Strains isolated from human material produced most frequently alpha + delta, and less frequently delta or alpha lysins. The isolates belonged to phage groups I, II, III, were crystal violet negative and produced lipase. The bovine strains produced mostly beta + delta or alpha + beta + delta lysins, less frequently delta or beta lysins. The isolates belonged to phage group IV or were typable with phage 116 of phage group II. The majority of the strains was crystal-violet negative, lipase production was not characteristic.