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.