The inhibition of coagulase-negative staphylococci and Staphylococcus aureus of human or animal origin by most free fatty acids was similar, but coagulase-positive staphylococci were sensitive and coagulase-negative cultures were resistant to linolenic acid. Animal strains of S. aureus were more sensitive to linolenic acid than were human strains. These differences were reflected in the relative abilities of the three categories of strains to survive on human skin.
The antibacterial effects of 20 mg of linolenic acid were inactivated by 1 ml of serum in vitro. A test organism seeded on to skin also survived better if first suspended in serum. The mechanism of the interaction between serum and linolenic acid may be due to a detergent effect of the serum and could account for colonisation of diseased skin with S. aureus.
Cultures of S. aureus seeded on to human skin were rapidly killed after the skin has been covered with linolenic acid. The possibility of therapeutic use of linolenic acid as an antibacterial agent should be explored.
AlyR.,
MaibachH. I.,
MandelA.,
ShinefieldH. R.1976; Factors controlling the survival of Staphylococcus aureus on human skin.In Staphylococci and staphylococcal diseases. Proceedings of III International Symposium on Staphylococci and Staphylococcal InfectionsWarszawa 1975
JeljaszewiczJ.
Fisher Verlag; Stuttgart:941
FullerR.,
MooreJ. H.1967; The inhibition of the growth of Clostridium welchii by lipids isolated from the contents of the small intestine of the pig. J. gen. Microbiol 46:23
GutteridgeJ. M. C.,
LamportP.,
DormandyT. L.1976; The antibacterial effect of water-soluble compounds from autoxidising linolenic acid. J. med. Microbiol 9:105
HeczkoP. B.,
LuttickenR.,
HryniewiczW.,
NeugebauerM.,
PulvererG.1979; Susceptibility of Staphylococcus aureus and group A, B, C, and G streptococci to free fatty acids. J. clin. Microbiol 9:333
LaceyR. W.1968; Antibacterial action of human skin. In vivo effect of acetone, alcohol and soap on behaviour of Staphylococcus aureus. Br. J. exp. Path 49:209
LaceyR. W.,
LordV. L.,
GunasekeraH. K. W.,
LiebermanP. J., and LuxtonD. E. A.1980; Comparison of trimethoprim alone with trimethoprin-sulphamethoxazole in respiratory and urinary infections with particular reference to selection of trimethoprim resistance. Lancet1–1270