No abstract

The effect of cellular pathology and keratinization of skin and nasal cells upon binding of Staphylococcus aureus were examined. Adherence with epithelial cells obtained from either the skin or nasal mucosa of patients with atopic dermatitis was greater than that observed with normal cells (p less than 0.001); the difference in adherence between psoriatic and normal cells was not statistically significant. Tested nasal cells were microscopically differentiated into 4 general types based on stage or layer of keratinization: spinous, low granular, high granular, and keratin. The degree of adherence was related to the progress of keratinization. Data indicated the existence of 2 types of receptors for S. aureus on nasal cells: One, present upon both granular and fully keratinized cells, is not blocked by teichoic acid and appears responsible for the higher bacterial counts on atopic cells; the second is found on keratinized cells only and is susceptible to teichoic acid.

No abstract

Sphingosine and sphinganine, free sphingolipids of the stratum corneum, are, in vitro, strongly inhibitory for both bacteria and fungi. Whether or not they are suitable, indeed active, in vivo was examined: (i) on human volunteers, first as a preventative antiseptic against subsequently applied Staphylococcus aureus and Candida albicans, and second as a restorative antiseptic against the previously expanded normal skin flora; and (ii) on guinea-pigs as therapy for experimental C. albicans and Trichophyton mentagrophytes infections. In the antiseptic studies, which involved 200 micrograms/cm2 of sphinganine in ethanol (50 microliters of a 1.6% solution), up to three-log reductions in the population of target micro-organisms were obtained, compared with vehicle and untreated controls (P < 0.001). The daily application of sphingosine as 1.5% ethanol-petrolatum ointment was able to diminish inflammation slightly in dermatophyte-infected guinea-pigs (P = 0.02-0.05), although the animals remained culture positive over the 3-week sampling period. The candida infections, treated daily with 1.5% sphinganine in ethanol, showed no improvement in inflammation compared with controls, except for 2 days of the 2-week observation period (P = 0.01-0.03); however, by the fourth day of therapy the yeast was eliminated in 75% of animals. No gross toxicity was observed among animals or human volunteers. These experiments further support simple sphingolipids as important antimicrobial agents of the cutaneous barrier and point toward a new biochemical approach in treating infectious disease.