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SPONTANEOUS α ‐TOXIN MUTANTS OF STAPHYLOCOCCUS AUREUS
Author(s) -
Dalen A. B.
Publication year - 1976
Publication title -
acta pathologica microbiologica scandinavica section b microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.909
H-Index - 88
eISSN - 1600-0463
pISSN - 0304-131X
DOI - 10.1111/j.1699-0463.1976.tb01949.x
Subject(s) - mutant , extracellular , toxin , agar plate , microbiology and biotechnology , staphylococcus aureus , fibrinolysin , hemolysin , agar , biochemistry , biology , bacteria , chemistry , enzyme , virulence , plasmin , genetics , gene
Prolonged cultivation of strain Wood 46 in fluid cultures resulted in a selection of mutants with low or no haemolytic activity. In one group of mutants, four out of five strains showed no production of α ‐toxin when examined by polyacrylamide gel electrophoresis and by double diffusion in agar. Two major extracellular proteins which have been identified by other methods as degradation products of α ‐toxin were also absent. The absence of α ‐toxin did not affect growth in fluid or solid media. Fibrinolysin was produced by these mutants but at a much lower rate than by the wild type. A second group of mutants was characterized by a slow rate of growth on rabbit blood agar and showed a heterogeneous extracellular protein pattern. These mutants had a high growth rate in fluid medium consisting of acid hydrolysed proteins. Production of fibrinolysin was absent or low in three out of four mutants in the second group. The slow growth and low production of α ‐haemolysin in rabbit blood agar probably was caused by deficient extracellular proteolytic activity of the mutants.