Acne is caused when the sebaceous glands in the skin are unable to secrete an oily substance, called sebum, onto the surface of the skin. This is because the opening of the follicle is clogged from a mixture of skin cells and sebum. The opening of the follicle becomes plugged when the cells from the lining of the follicle are shed too quickly and clump together. Because Propionibacterium acnes (P. acnes) bacteria feed off sebum, they are then able to grow in the plugged follicle. Acne is caused by the inflammation that results from the chemicals and enzymes produced from the bacteria.
Salicylic acid, or ortho-hydroxybenzoic acid, is often used to treat acne by encouraging the sloughing of dead skin cells and, therefore, reestablishing a normal skincell replacement cycle. Whether or not salicylic acid directly kills P. acnes is currently debated. The first goal ofthis research was to determine if salicylic acid kills the bacteria. The second purpose of the research was to determine how the related meta and para isomers of salicylic acid affect P. acnes.
The method which produced the most useful data was the measurement of the bacterial growth by examining the change in turbidity of the samples. The results indicate that meta and para do inhibit growth and salicylic acid ( ortho) is the most effective at killing P. acnes.
Burch, Ireland, "An Investigation into the Effects of Structural Isomers of Salicylic Acid on Propionibacterium Acnes" (2004). Senior Research Projects. 38.