The Journal of Medical Microbiology, Vol 37, Issue 4 238-244, Copyright © 1992 by Society for General Microbiology
The production of a bactericidal monoglyceride in staphylococcal abscesses
H. D. Engler and F. A. Kapral
Department of Medical Microbiology and Immunology, Ohio State University, Columbus 43210.
The treatment of abscess homogenates with calcium ionophores stimulated the
production of a bactericidal lipid with properties indistinguishable from
those of a previously unidentified bactericidal lipid that had been
detected in staphylococcal abscesses. The lipid was identified as a
monoglyceride by thin layer chromatography. It resembled the unidentified
lipid in that it had a high specific activity, exhibited differential
activity, was inhibited by Staphylococcus aureus delta toxin, lecithin and
Ca++, and its activity was reduced by oxidation. Stimulation of
monoglyceride production by calcium ionophore requires the joint presence
of components from the sedimented and supernatant fractions of abscess
homogenates, and was not produced if boiled homogenate was used. The
addition of verapamil interfered with the production of monoglyceride in
homogenates treated with calcium ionophore. Monoglyceride was produced only
in abscess homogenates and not in homogenates of other normal tissues or
tissues taken from mice infected with S. aureus. Calcium ionophore could be
replaced by inositol triphosphate, suggesting that monoglyceride production
involved the release of calcium from intracellular stores. The
2-monoglyceride was the form originally produced in abscess homogenates,
but this spontaneously isomerized to the 1-monoglyceride. The fatty-acid
moiety of the monoglyceride consisted primarily of 16:0 and 16:1 fatty
acids.
