A note on the antiseptic properties of olive oil

Abstract

While studying the antiseptic properties of various benzyl compounds described elsewhere,¹ the authors examined a number of drugs which were insoluble in water, in order to test their bactericidal or antiseptic properties. Solutions of these drugs were made in various oils and the effects of the oily solutions were studied on staphylococcus pyogenes aureus. In this connection some interesting observations on the effect of the oils themselves were noted which were deemed worth while reporting in this place. In order to determine the antiseptic efficiency of the drugs in oil check or control experiments were made with the oils themselves by the following method.

Twenty-four hour broth cultures of staphylococcus pyogenes aureus were used for these tests, the cultures being filtered through glass wool before use to remove clumps of organism. 2 c.c. of the sterile oil to be tested was inoculated with one standard loopful of culture. Specimens for plating were removed at the end of 1 minute, 1 hour, 3 hours and 5 hours, each specimen being 0.1 c.c. drawn from the emulsion by means of a capillary pipette attached by a rubber stopper to a Tuberculin syringe. Dilutions in two parallel series were made in sterile 0.875 per cent. sodium chloride solution. Agar plates were made from these dilutions, and after 48 hours at 37.5 C°., the two parallel plates of the same dilution which showed the most suitable number of colonies for counting were selected, the colonies counted and the number of bacteria per c.c. estimated.

The following oils were examined; olive oil, cottonseed oil, liquid petrolatum or albolene (mineral oil), peach kernel oil and oil of sweet almonds. The results obtained are expressed in the subjoined table.