Superantigen gene profile of Staphylococcus aureus colonizing Egyptian pediatric patients with atopic dermatitis: relationship to disease severity and multi-drug resistance

Background: Eczematous skin of atopic dermatitis [AD] is highly susceptible to infection and colonization by Staphylococcus aureus and the superantigen toxins can worsen the condition

Objectives: To assess the colonization of Egyptian pediatric AD patients with S. aureus and to characterize the superantigen gene profile of isolates in relation to severity and to presence of multiple drug resistant [MDR] strains

Methodology: The study included 53 AD pediatric patients and 45 controls. Severity of AD was assessed by scoring atopic dermatitis [SCORAD] index. Swabs were collected to isolate S. aureus. Isolates were subjected to multiplex PCR reactions for detection of six superantigen genes and to antimicrobial susceptibility tests by disc diffusion method

Results: Colonization with S. aureus was significantly higher [P < 0.0001] in AD children compared to controls and was significantly associated [P= 0.001] with severity. Superantigen genes were detected in 30.1% of isolates. The most prevalent genes were sea [64.5%], seb [32.3%], sec [6.5%] and tsst-1 [3.2%]. Multidrug resistance was found in 63.1% of strains. Severity of AD was significantly higher with strains harboring superantigen genes [P=0.04] and with MDR strains [P=0.0002]. Among methicillin resistant S. aureus [MRSA], seb was the most prevalent superantigen gene [37.5%], while sea was most prevalent in methicillin-susceptible S. aureus [MSSA] [20%], MDR [23.1%] and non MDR isolates [13.2%]

Conclusion: Superantigen genes and multidrug resistance are common in S. aureus colonizing AD patients and are associated with severity. More attention should be paid at performing antimicrobial susceptibility testing before antibiotic therapy

Association of IL-13 [-1055 C/T] and CYP1A1 [MspI] gene polymorphisms with chronic obstructive pulmonary disease in Egyptian patients in relation to disease severity

Background: Chronic obstructive pulmonary disease [COPD] is one of the most important causes of morbidity and mortality worldwide, characterized by persistent and progressive airflow limitations. The etiology seems to be an interaction between genetic and environmental factors

Objectives: In this study, we aimed to identify the possible association of IL-13 [-1055 C/T] and CYP1A1 [MspI] gene polymorphisms with COPD in Egyptian patients and their relation to the severity of the disease

Methodology: Our study included 200 participants [100 COPD patients and 100 controls]. Pulmonary function tests were performed for patients, DNA extraction was done and the polymorphisms were analyzed using polymerase chain reaction- restriction fragment length polymorphism [PCR-RFLP] for serum samples from all participants

Results: IL- 13 -1055 C/T polymorphism was significantly associated with COPD; CT and TT genotypes [P=0.01, 0.03 respectively] compared to CC genotype, with a significant association of the T allele with the disease [P=0.003], while CYP1A1 MspI polymorphism showed no significantly different distribution between patients and controls [P=0.11and 0.068 for CT and CC respectively], while, a significant association between the C [m2] allele and COPD was found [P=0.04]. IL-13 -1055 T allele and CYP1A1 MspI C [m2] allele were found to be significantly associated with more severe cases of COPD when compared to the less severe ones [P= 0.03 and 0.02, respectively]

Conclusions: IL-13 -1055 C/T polymorphism is associated with COPD, and the presence of IL-13 T allele and CYP1A1 MspI C [m2] allele are risk factors for developing more severe COPD