- D3.536 - Staphylococcus aureus bacteria as a causative agent of upper respiratory tract allergies

Bacteria have been identified as a significant etiological factor in the development of allergic diseases of the upper respiratory tract, including allergic rhinitis, rhinosinusitis and adenoiditis. The allergenic properties of bacteria are determined by components of their cell wall (peptidoglycans, lipopolysaccharides), exotoxins and enzymes that can sensitize the body. The spectrum of microbiota in patients diagnosed with allergic rhinitis was assessed in the frontline region of the Kharkiv Oblast, Ukraine.

In the autumn-winter of 2025, 56 patients suffering from severe allergic rhinitis were examined with 32 of these being female and 24 male. The mean age of the patients was 51 years (±4.5 years).  Prior to this study, the patients had undergone medical history review and preliminary examinations, including a bacteriological examination of nasal swabs for Staphylococcus aureus (SA); levels of eosinophil cationic protein (ECP); and  allergy testing for inhalation allergens. All patients were tested for IgE antibodies to staphylococcal enterotoxin TSST (SE-IgE) using immunofluorescence methods. Patients generally experience a marked exacerbation of their condition during the autumn months, often manifesting  as rhinorrhea, cephalalgia, and cough. All patients had previously received therapy with intranasal corticosteroids.

The study yielded three distinct classifications based on colonization: The distribution was as follows: SA/SE (+/‒) 7.1%, SA/SE (‒/+) 39.2%, and SA/SE (+/+) 53.7%. The nasal colonization of SA and the sensitization  by SE-IgE were accompanied by a significant increase in eosinophil cationic protein, particularly in the SA/SE (+/+) group; patients within the SA/SE (+ /‒) group had ECP levels of 21.3 ± 1.32 ng/ml; in the SA/SE (‒/ +) group ECP levels were 33.4 ± 1.32 ng/ml; and in the SA/SE (+ / +) group ECP levels were54.3 ± 10.32 ng/ml.

In patients diagnosed with severe allergic rhinitis in the frontline region, a high prevalence of S. aureus colonization and sensitization to staphylococcal enterotoxin occurred, confirming the role of bacterial sensitization as a key trigger of eosinophilic inflammation and an aggravating factor in the clinical course of allergic disease. The determination of specific IgE to staphylococcal toxins allows a personalized approach to  patients who are resistant to standard treatment.