特应性皮炎患儿皮损局部金黄色葡萄球菌外毒素检测

目的 了解特应性皮炎(AD)患儿皮损局部金黄色葡萄球菌(金葡菌)的带菌率及其分泌外毒素的情况,探讨金葡菌及其分泌的外毒素在AD发病中的作用.方法 AD皮损局部分离金葡菌,反向被动乳胶试验方法检测其外毒素表达,并与对照组进行统计学比较.结果 与对照组相比,AD患儿无论是皮损局部还是非皮损区金葡菌带菌率明显升高(P值均<0.01),且与疾病严重性呈正相关性(P<0.01).但AD皮损局部的金葡菌与对照组金葡菌相比,两者分泌外毒素的情况差异无显著性(P>0.05),并且皮损局部的金葡菌是否分泌外毒素与疾病严重性无直接相关性(P>0.05),但伴有血清总IgE水平升高的AD患儿,疾病相对较重(P<0.01).结论 AD患儿皮损区金葡菌带菌率为43.24%,其中47.46%分泌外毒素,以金葡菌肠毒素B(SEB)最常见.

Detection of Staphylococcus aureus-derived Exotoxins in Lesions of Childhood Atopic Dermatitis

Objectives To determine the prevalence of Staphylococcus aureus (S. Aureus) colonization and S. aureus-derived exotoxins in lesions of childhood atopic dermatitis (AD) and evaluate the role of S.aureus-derived exotoxins in the pathogenesis of childhood AD. Methods Specimens were taken from the skin lesions of 148 patients, non-lesional skin of 30 patients, and the skin of 250 controls for bacterial cultures. S. aureus-derived exotoxins were detected by reverse passive latex agglutination. Total IgE levels were determined with immunoradiometric assay. Results The prevalence of S. aureus colonization was significantly increased in both the lesional and non-lesional skin of patients with AD in comparison with the controls (P < 0.01). There was a positive correlation between the AD severity, as measured by SCORAD index, and S. aureus colonization (P < 0.01). There was no significant difference in the exotoxin-producing S. aureus isolated between the patients and controls. Moreover, the disease severity was not markedly different between patients with and without exotoxin-producing S. aureus (P > 0.05). However, patients with increased total IgE levels showed significantly high SCORAD indices (P < 0.01). Conclusions The results indicate that S. aureus could be isolated from 43.24% of AD lesions, in which 47.45% of the isolates could secret exotoxins, especially staphylococcal enterotoxin B.