Antimicrobial Activity of Heparin

Abstract

Single clinical isolates of 8 spp. of microorganisms were incubated in solutions of heparin and brain heart infusion broth at various concentrations to determine the possible antibacterial effect of heparin. At heparin concentrations ranging from 12.5-400 U/ml, the effect on Escherichia coli, Pseudomonas aeruginosa, Candida albicans, Staphylococcus aureus and S. epidermidis varied with brain heart infusion broth concentrations of 1.2-10% and inocula of 102-106 colony-forming units [CFU]/ml; similar effects were not observed with Klebsiella pneumoniae, Enterobacter aerogenes and Citrobacter spp. The minimal inhibitory concentrations of heparin for 10 strains of each species were determined in 2.5% brain heart infusion broth with inocula of 104 CFU/ml. All 10 isolates of S. aureus and all 10 of S. epidermidis were inhibited by heparin concentrations of 125-500 U/ml. Three E. coli, 4 P. aeruginosa and 9 C. albicans strains were inhibited by .ltoreq. 500 U of heparin/ml. None of the K. pneumoniae, E. aerogenes, E. cloacae and Citrobacter spp. was inhibited by heparin at .ltoreq. 500 U/ml. Heparin inhibition of S. aureus in 2.5% brain heart infusion broth-500 U of heparin/ml could be quantitatively overcome by addition of Mg, Ca or Mg and Ca. These data suggest that the growth of microorganisms from heparin-containing material may be suppressed.