Detection And Analysis Of Frequent Bacteria And Fungus In The Skin Of The Patients With Eczematous Dermatitis

Objective: To investigate the colonization of bacteria and fungus in the lesion of the patients with eczematous dermatitis, to evaluate the relation between microorganism infection and eczematous dermatitis, and to provide the basis of the rational use of antimicrobial agents clinically.Methods: Samples of bacterial and fungus were obtained from the lesions, non-lesions of 90 patient and normal skin and were examined by culture and quantitative assessment of the density. SAgs production by 34 Staphylococcus aureus strain from skin of patients was investigated with reverse passive latex agglutination assay. Correlations of SAgs production with eczema area and severity index(EASI ), scores of six kinds of lesions and some serologic changes were analyzed. Identification of Malassezia spacies was taken by physio-biochemics approach.Results: The culturally positive rate of bacterial colonization was 67.78% on the skin lesions of eczematous dermatitis, and Staphylococcus aureus was overwhelmingly the dominant species accounting for 31.11%. The positive rate of Malassezia colonization was 47.78% on the skin lesions. Bacteria and fungus were also isolated from the non-lesions in these patient. However, there were statistical differences in the positive rate of the culture, the ratio and the colonization , that the positive rate of Staphylococcus aureus and Malassezia and the density of Staphylococcus aureus were much higher on the skin lesions than that on the non-lesions in eczematous dermatitis patient. Moreover, the amount of bacteria colonized, especially Staphylococcus aureus was markedly higher in the lesional skin with secondary infections than that without secondary infections.Among 34 Staphylococcus aureus strains, 14 strains produced SAgs with positive rate of 41.18%, 11 strains produced only one kind of SAg and3 strains produced at least two kinds of SAgs. In eczematous dermatitis patients, the severity of the disease was not associated with SAgs production, but Sag-producing patients had a higher fissure scores.The lesional skin of eczematous dermatitis had a higher rate of carrying Malassezia furfur and Malassezia globosa than others, which imply that Malassezia may have some relations with some eczematous dermatitis.Conclusion: The infection of Staphylococcus arueus and Malassezia may play an important role as an aggravating factor in pathogenesis of eczematous dermatitis. And early application of topical antibiotics is beneficial to the patient.