105 EVALUATION OF THE QUANTITY AND BIOFILM-FORMING ABILITY OF THE COLONIZED STAPHYLOCOCCUS AUREUS IN ATOPIC DERMATITIS PATIENTS

BackgroundAtopic dermatitis (AD) is an eczematous dermatitis usually presenting in childhood. A common complication in patients with AD is superimposed bacterial infections. Recent studies demonstrate that Staphylococcus species are capable of forming biofilms, which render these organisms markedly more resistant to antibiotics, antiseptics, and host immune responses. Since colonized AD skin lesions show evidence of immune dysregulation, pharmacophysiologic abnormalities, and disease persistence, we aim to investigate the presence of bacterial biofilms in children with AD.ObjectivesTo examine whether clinical isolates of S. aureus from atopic dermatitis lesions can form biofilms and that associated exotoxins made by S. aureus are contributing to the disease process.MethodsSpecimens for bacteriological examination were obtained from the lesions and nose of patients with AD using a cotton swab. The biofilm formation was quantitatively evaluated using optical density and cell quantification. The isolated bacteria were also amplified for coding regions of genes of interest by standard polymerase chain reactions (PCR). We also performed spa typing on all S. aureus isolates as an accurate screening technique to identify clonal populations.ResultsIn preliminary studies all isolated bacteria produced biofilm. Biofilm formation was not associated with the presence of Panton-Valentine leucocidin or the examined bacterial exotoxins (ETA, ETB, TSST-1, etc).ConclusionClinical isolates from AD skin lesions are able to produce biofilm. Future studies regarding the role of biofilms in immunopathology of AD are of paramount importance.