Methicillin-resistant Staphylococcus aureus from infected skin lesions present several virulence genes and are associated with the CC30 in Brazilian children with atopic dermatitis.

Atopic dermatitis (AD) is a chronic inflammatory skin disease and colonization by Staphylococcus aureus may affect up to 100% of these patients. Virulent and resistant isolates can worsen AD patient clinical condition and jeopardize the treatment. We aimed to detect virulence genes and to evaluate the biofilm production of S. aureus isolates from infected skin lesions of children with AD. Methicillin resistance was detected by phenotypic and molecular tests and the virulence genes were detected by PCR. Biofilm formation was assessed by bacterial growing on microtiter plates and later stained with safranin. Genotyping was performed by Pulsed-Field Gel Electrophoresis and Multilocus Sequence Typing. Among 106 AD patients, 55 (51.8%) had developed S. aureus cutaneous infections and 23 (41.6%) were methicillin-resistant (MRSA). All 55 isolates carried the fnbA, hla, icaA, sasG, and seu genes, and more than 70% presented cna, eap, ebpS, hlg, and pvl genes. Clonal complex (CC) 30 was the main lineage found (34.5%), especially among MRSA isolates (52.2%). The egc cluster and the bbp gene were significantly the most frequent in MRSA isolates and in USA1100/ST30/CC30 lineage. Most of the isolates (74.5%) were non-biofilm producers and many of them only started to produce it in the presence of fibrinogen. There was no significant association between S. aureus isolates features and the AD severity. This study demonstrated a high frequency of CC30 MRSA isolates presenting several virulence genes in infected skin lesions of AD children in Brazil, that may influence the severity of the disease and the treatments required.

Clinical oral profile of pediatric patients with atopic dermatitis: A cross-sectional study.

OBJECTIVES: This work aims to describe oral health conditions, eating habits, and oral hygiene in pediatric and adolescent patients with atopic dermatitis and correlate them with the severity of the Scoring Atopic Dermatitis (SCORAD). Also, we aim to estimate the effect of several variables on the diagnosis of dental caries in these patients. MATERIAL AND METHODS: A total of 92 children and adolescents with atopic dermatitis had their oral cavities examined. The effect of independent variables on the diagnosis of dental caries (outcome) was assessed using multiple binary logistic regression model. RESULTS: Mild patients presented higher score of decayed, missing, and filled teeth in permanent dentition than moderate patients (p = 0.040). In the multivariable regression final model, the covariates using inhaled corticoid (OR = 6.4; p = 0.003), type of teething [deciduous dentition (OR = 7.9; p = 0.027) and mixed dentition (OR = 10.5; p = 0.007)], and brushing quality [poor mechanical control (OR = 10.6; p < 0.0001)] demonstrated significant direct effect on the diagnosis of dental caries. CONCLUSIONS: Our findings suggest that the presence of dental biofilm, use of inhaled corticoid, and type of teething are related to the presence of caries in atopic dermatitis patients.