Sensibilization Spectrum in Preschool Children with Atopic Dermatitis

Background. Atopic dermatitis (AD) is an allergodermathosis that is widespread in children and adult populations. Sensibilization to food allergens prevails in children of early age, and to airborne allergens in older age. Impairments of skin barrier lead to increase in Staphylococcus aureus colonization and finally aggravate the course of AD and the sensibilization level.Objective. The aim of the study is to estimate the sensibilization spectrum in 3-6 years old children with AD and its correlation with severity.Methods. It was cross sectional study with two independent cohorts of 3-6 years old children with and without (healthy) AD. Estimation of sensibilization spectrum and revealing of correlation with disease severity were performed.Results. The study includes 106 children aged 4.4 ± 1.2 year (58.5% boys and 41.5% girls). Polysensibilization was revealed in 28.3% of children. According to our data: 3-6 years old children with AD most often had sensibilization to the cat epithelium (34.9%), cow's milk proteins (22.6%), Dermatophagoides pteronyssinus mite (16.0%). Sensibilization to enterotoxins of Staphylococcus aureus was revealed in 7.5% children. We have recorded weak positive correlation between the AD severity and the level of specific IgE to airborne and food allergens. There was no statistically significant correlation between the AD severity and the level of specific IgE to Staphylococcus aureus enterotoxins A and B. Conclusion. The most common sensibilization type among 3-6 years old children with AD was one to airborne allergens. Sensibilization to the cat epithelium prevails among airborne allergens, to the cow's milk proteins — among food allergens. The weak positive correlation between the AD severity and the level of specific IgE to airborne and food allergens was revealed. The weak negative correlation with the level of specific IgE to Staphylococcus aureus enterotoxins A and B was revealed, thus the data was statistically insignificant.

Molecular Detection of Staphylococcal Enterotoxins and mecA Genes Products in Selected Food Samples Collected from Different Areas in Khartoum State

Staphylococcal food poisoning is an intoxication that results from the consumption of improperly prepared or stored foods containing sufficient amounts of one or more preformed S. aureus enterotoxins. Nowadays, many researchers worldwide noted an emergence of resistant strains such as Staphylococci particularly for the antibiotic methicillin. Therefore, this study was aimed to determine the existence of Staphylococcus aureus and its enterotoxins, mecA genes, in selected food samples. A total of 400 selected food samples were collected from different areas in Khartoum State. The selected foods included cheese, meat products, fish, and raw milk. One hundred samples from each type of food were cultivated, and the resultant growth yielded 137 (34.25%) S. aureus, 126 (31.5%) bacteria other than S. aureus, and 137 (34.25%) yielded no growth. Eighty-four of the 137 S. aureus isolates were randomly selected and tested for the presence of mecA and enterotoxin genes. The oxacillin sensitivity test showed that 15 (11%) of 137 S. aureus isolates were oxacillin resistant. The PCR assay showed that the mecA gene was detected in 15 of 84 (17%) S. aureus isolates. Simultaneously, only 2 (2.385%) out of 84 S. aureus isolates showed an enterotoxin B gene product. There was a relatively moderate prevalence of methicillin-resistant Staphylococcus aureus with very low frequency of enterotoxin B gene in different kinds of selected food samples collected from Khartoum State. These findings elucidate the increased risk on public in Khartoum being affected by Staphylococcal food poisoning upon consumption of dairy or meat products prepared in unhygienic conditions that could lead to intoxication by Staphylococcus aureus enterotoxins.

Molecular screening of Staphylococcus aureus enterotoxins associated with samples of meat / Iraq

Staphylococcus aureus secreted many types of toxins accompanying Intestinal poisoning resulting from eating food contaminated with bacteria or their toxins. Five hundred meat samples were collected from local markets, including fresh, frozen, canned, sausage and hamburger to investigate their contamination with S.aureus and then determined their ability of these isolates to secrete enterotoxins by using polymerase chain reaction. The results showed that the ratio of isolated S.aureus is 30 (6%) and the percentage of encoding genes for toxins is 30(100%), 0(0%), 3(10), 0(0%),0(0%),3(10), 2(6.7), 1(3.3), 0(0%) and 3(10) to sea, seb, sec, sed, see, seg, see, sei, sej and sel respectively.The result shows the S.aureus isolated from contamination meat able to produce different type to enterotoxins sea, sec, seg, see, sei, and sel and present the sea toxin is the most prevalence type of staphylococcus enterotoxins.

Moulds and Staphylococcus aureus enterotoxins are relevant allergens to affect Type 2 inflammation and clinical outcomes in chronic rhinosinusitis patients

BackgroundSensitisation to moulds and Staphylococcus aureus enterotoxins (SEs) is associated with the pathophysiology of both asthma and chronic rhinosinusitis (CRS). The purpose of this study was to clarify the contribution of sensitisation to these allergens to Type 2 inflammation in the blood, nose and the lower airways, and clinical outcomes in CRS patients.MethodsWe prospectively enrolled 56 CRS patients who underwent endoscopic sinus surgery (ESS) (20 with comorbid asthma) and 28 healthy controls between October 2015 and December 2017. CRS patients were followed up for 12 months after surgery. Type 2 inflammation-related biomarkers were analysed using blood, resected tissue samples and sputum. 10 allergens including Alternaria, Aspergillus and SEs were measured. Type 2 inflammation-related biomarkers and clinical outcomes were compared in the stratification with the presence or absence of allergen sensitisation.ResultsSensitisation rate to moulds and SEs in asthmatic patients was increased when changing the cut-off value of specific IgE titre from 0.35 UA·mL−1 to 0.10 UA·mL−1 (1.7- and 4.5-fold, respectively). Moulds and SEs affected the prevalence of asthma and eosinophilic CRS by interacting with each other. All Type 2 inflammation-related biomarkers except for eosinophils in sinus tissue were significantly higher in patients with mould or SE (mould/SE) sensitisation (≥0.10 UA·mL−1) (n=19) than in those without (n=37) and healthy subjects (all p<0.05). Meanwhile, mould/SE sensitisation did not affect longitudinal changes in clinical outcomes after ESS. Changes in serum mould/SE-IgE levels after ESS remained unclear.ConclusionMould/SE sensitisation (≥0.10 UA·mL−1) may affect the development of Type 2 inflammation and clinical outcomes in CRS patients.