Comparison of recovery rates of various organisms from clinical hypertonic blood cultures by using various concentrations of sodium polyanethol sulfonate.

By using parallel culture techniques, the recovery rates of a wide spectrum of organisms encountered in hypertonic clinical blood cultures was determined from four different blood culture bottles. Each bottle was identical except for the amount of sodium polyanethol sulfonate (SPS) present. Flasks A, B, C, and D contained SPS in final concentrations of 0.025, 0.05, 0.075, and 0%, respectively. Of 144 patients found to have clinically relevant organisms in their blood cultures, 127 had positive A flasks, 144 had positive B flasks, 140 had positive C flasks, and 110 had positive D flasks. There was no significant difference in the time required to obtain organism recovery from the A, B, or C flasks; however, the time required to obtain organism recovery from the D flask was considerably longer, ranging up to 5 days in many cases. Of the various organisms recovered, 3 of 7 strains of anaerobic streptococci and 1 of 28 strains of Streptococcus pneumoniae appeared to be inhibited by SPS when the concentration was 0.075%. In no case was an organism recovered from either the A or D flask but not from the B flask, indicating that a concentration of 0.05% SPS in hypertonic media does not inhibit the growth of a wide spectrum of organisms in clinical blood cultures.