Kinetics of hemolysin production in bovine group B streptococci

Thirteen strains of group B streptococci etiologically related to bovine infections were investigated in order to observe the effects of non-hemoglobin iron and glucose on growth and hemolysin production; and to determine the necessity to stabilize the hemolysin with a carrier-stabilizer agent. Ferric citrate was diluted to give final concentrations of 1-11 micrograms/ml, added to iron-reduced (by CaCl2 precipitation) brain heart infusion media, inoculated and incubated at 37 degrees C. Parallel experiments were carried out with glucose. A variety of agents was employed to act as hemolysin stabilizers. Hemolysin production was detected by lysis of sheep erythrocytes. Both iron and glucose were crucial in concentrations 5-7 micrograms/ml and 0.5-1% respectively. Bovine serum albumin-starch mixture acted as an excellent stabilizer.