Colonizing features of Staphylococcus aureus in early childhood atopic dermatitis and in mothers: A cross-sectional comparative study done at four kindergartens in Daegu, South Korea

Background: Colonization of Staphylococcus aureus is well known to be an aggravating factor for the flare-up of atopic dermatitis (AD), yet few studies have been done on its spread in families with childhood AD. Objective: To evaluate the characteristic features of skin-colonizing S aureus and to identify the source of S aureus in early childhood AD. Methods: Forty-four subjects with AD, 51 borderline (BD) subjects, and 36 normal controls (NC) aged 3-6 years and their mothers were recruited from four different kindergartens. After comparing the positive culture rate of S aureus in three different groups of children and their mothers, we determined if there is a possibility of intrafamilial transmission between the children with AD and their mothers using polymerase chain reaction and pulsed-field gel electrophoresis. Results: A high prevalence (72.7%) of S aureus colonization was found in the AD group compared with the BD and NC groups. However, the prevalence rate of S aureus in the mothers who had children with AD was not significantly higher than in the mothers from the BD and NC groups. Based on the pulsed-field gel electrophoresis results, the cutaneous re-colonization of S aureus in childhood AD appears to have been primarily originating from the patients' noses, and maternal origin does not appear to substantially contribute to S aureus transmission in early childhood AD. Conclusions: Since the cutaneous colonization of S aureus in early childhood AD predominantly originated from the patients' own noses, the maternal transmission route does not appear to contribute substantially to the colonization of S aureus in early childhood AD.