Influence of a phytosphingosine-containing chlorhexidine shampoo on superficial bacterial counts and bacterial adherence to canine keratinocytes

Abstract

Abstract Five healthy dogs and five dogs with atopic dermatitis were bathed weekly for four treatments with a shampoo containing chlorhexidine and phytosphingosine salicyloyl on one body side and shampoo vehicle on the other. Corneocytes were collected before the first and 1 and 5 days after the last treatment from both pinnae and left and right ventrolateral areas with four adhesive discs. With the first disc, surface bacteria were evaluated. The corneocyte layers on three other discs were covered with a bacterial suspension, incubated at 37 °C for 45 min, washed, and afterwards stained with methylene blue. Organisms were counted in a blinded fashion. There were no significant differences in bacterial numbers between placebo and treatment sites on nearly all time points, groups and areas. However, weekly shampooing with both chlorhexidine–phytosphingosine and shampoo vehicle reduced surface bacterial counts at nearly every site in every group. In contrary the count of adhered bacteria increased after treatment with both shampoos (chlorhexidine–phytosphingosine and shampoo vehicle) in almost all sites and groups.