The Production of Staphylococcal Alpha-Hemolysin: The Rôle of Agar

The standardization of staphylococcal alpha-antitoxin, with special reference to anomalous haemolysins including delta-lysin

1. Evidence is submitted that an anomalous rabbit cell lysin reported by Minett (1936), α2-toxin and δ-haemolysin are identical. The last name is preferred.

2. Precautions are necessary to avoid interference by δ-haemolysin in titrations of α-toxin and α-antitoxin.

3. The existence of γ-haemolysin is confirmed; its wide distribution and possible confusion with α-toxin are noted. The name γ-toxin is thought more suitable than γ-hameolysin.

4. Multiple standard antisera are desirable for the detection of anomalous toxins. At least one should be of refined globulin.

5. Dilution and manipulation inactivate staphylococcal toxins and their effect needs consideiration in quantitative work. Infusion broth increases the stability of diluted α- and β-toxins.

Purification and properties of staphylococcal delta-hemolysin. I. Production of delta-hemolysin

Concentrated preparations of staphylococcal delta-hemolysin were obtained by growing selected hemolytic colonies from the 146P strain of Staphylococcus aureus on dialysis membranes laid over Brain Liver Heart agar plates at 37 C for 20 hr under 10% CO(2) and harvesting the growth from five such membranes in 1.0 ml of deionized distilled water. Incubation in a humid environment facilitated this harvesting procedure. Incubation longer than 40 hr or incubation under CO(2) higher than 10 to 20% gave lower yields of delta-lysin. Addition of a sugar, fermented by the organisms, resulted in lower yields of delta-hemolysin. Agar, although separated from the growing cells by the dialysis membrane, did potentiate delta-hemolysin production. Addition of 0.1% agar to the inoculum further enhanced this potentiation. delta-Hemolysin produced in broth or semisolid cultures was excessively diluted with the media. Dialysis membranes prevented this dilution and thus yielded concentrated preparations of delta-hemolysin.

Biological properties of alpha-toxin mutants of Staphylococcus aureus

McClatchy, J. K. (The University of Texas Southwestern Medical School, Dallas), and E. D. Rosenblum. Biological properties of alpha-toxin mutants of Staphylococcus aureus. J. Bacteriol. 92:575-579. 1966.-Twenty nonhemolytic mutants of Staphylococcus aureus were isolated after treatment of a hemolytic strain with ultraviolet light or nitrous acid. Thirteen strains isolated were completely lacking in the synthesis of alpha toxin or immunologically related proteins, presumably the result of a single mutational event. Although the strains were nonhemolytic on rabbit blood-agar plates, six of them retained the dermonecrotic and lethal activities usually associated with staphylococcal alpha toxin, as well as slight hemolytic activity for rabbit erythrocyte suspensions. The active mutants and one inactive mutant produced a protein that reacted immunologically with antibody to alpha toxin. Mutations which alter the alpha toxin molecule can effect the lethal, dermonecrotic, and hemolytic activities separately or in varying ratios.

Serologic studies of staphylococcal enterotoxin

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