Anna K. Szkaradkiewicz

Bacillus oleronius and Demodex mite infestation in patients with chronic blepharitis

To better recognize the pathogenicity of ocular Demodex mites, we analysed Bacillus oleronius infection in patients with Demodex-related chronic blepharitis. The studies were conducted on 68 adult patients, in whom ophthalmological and parasitological tests permitted the distinction of a group of 38 patients with a diagnosis of Demodex-related chronic blepharitis (group 1, including a subgroup 1a with moderate blepharitis and a subgroup 1b with severe blepharitis) and a group of 30 healthy individuals (group 2). In every person studied six eyelashes were epilated from each eye and the number of Demodex per eyelash was scored. In parallel, bacterial culture and isolation allowed their phenotypic and molecular identification. The drug sensitivity of the isolates was tested using E-tests. Intensity of Demodex infestation showed no significant differences between subgroups 1a and 1b. From the epilated eyelashes 23 bacterial isolates were obtained, identified as being B. oleronius. All the studied strains were sensitive to ciprofloxacin, doxycycline and gentamicin. The Demodex mite represents an independent aetiopathogenetic factor in blepharitis. In parallel, the parasite may act as a carrier of B. oleronius bacteria, which most probably function as a co-pathogen in the development of severe forms of blepharitis.

Cytokine response in patients with chronic infections caused by Staphylococcus aureus strains and diversification of their Agr system classes

This study aimed to describe the levels of circulating cytokine levels produced by Th lymphocytes (IFN-γ, IL-4, IL-10, IL-17A), as well as the levels of cytokines produced by monocytes/macrophages (TNF-α, IL-1β, IL-12), in patients with chronic infections caused by Staphylococcus aureus strains, particularly in the context of the diversification of their Agr system classes. The studies were conducted on adult patients, including 50 patients with chronic suppurative dermatitis, 40 patients with chronic infections of the upper respiratory tract and 25 healthy individuals (control group). Blood serum cytokine levels were measured by enzyme-linked immunosorbent assay (ELISA). S. aureus was detected in cultures of suppurative dermal exudates or of pharyngeal smears. Classes of Agr systems in the S. aureus strains were identified using polymerase chain reaction (PCR). In both groups of patients, on average, levels of IFN-γ were doubled, while levels of IL-17A were increased by 2.5-fold, which, however, was not accompanied by increased levels of TNF-α or IL-12. The data indicate that the development of S. aureus infection among the studied patients was linked to an impoverished cytokine response of monocytes/macrophages, while that induced by the pathogen lymphocytes Th17/Th1 may be responsible for promotion of the chronic inflammatory response. In parallel, no quantitative or qualitative differences were disclosed between cytokine responses manifested by subgroups of patients infected with S. aureus strains belonging to class IV Agr, as compared to patients infected with strains of classes I to III Agr. Nevertheless, in the patients, strains belonging to class IV Agr prevailed, which points to the preferential relationship between the class and the pathogenicity of S. aureus.

Selected Factors of Innate Immunity in Healthy Individuals with S. aureus Nasal Carriage

Nasal carriage of Staphylococcus aureus represents a well-defined factor of risk involving community and hospital-acquired infections. Recently a significance of several host factors has been pointed out and, in particular, of immune determinants in nasal S. aureus colonization. Therefore, this study aimed at analysis of manifestation involving manifestation in the nasal secretions of important components of the host innate immunity – human beta-defensin-2 (HBD-2), lysozyme (Ly), and interferon-gamma (IFN-γ) in healthy individuals and in persons with persistent carriage of S. aureus. The studies were conducted in two groups of healthy volunteers, encompassing non-carriers (group 1) or persistent carriers of S. aureus (group 2). Elisa assays were employed to evaluate levels of HBD-2, Ly, and IFN-γ in nasal secretions of the examined donors. In S. aureus carriers a significant variability of HBD-2 levels was detected, corresponding to, respectively, the high (averaging at 1.46 ng/ml) and the low (averaging at 0.13 ng/ml) secretory response of the defensin. The level of Ly in S. aureus carriers averaged at 1.46 μg/ml and it manifested no significant difference as compared to that noted in non-carriers. In turn, concentrations of IFN-γ in nasal secretions in the group of carriers of S. aureus amounted on the average to 81.7 pg/ml and they were 1.3-fold higher that in the group of non-carriers. The obtained results allow to conclude that IFN-γ secretion by the nasal cavity-colonizing S. aureus remains quantitatively insufficient to eliminate the pathogen. Nevertheless, a significant increase in levels of this host factor may be important for restriction of the staphylococcal colonization and protection against development of an invasive infection. In turn, the role of HBD-2 and Ly in inactivation of the colonizing S. aureus remains doubtful.

Cytokine Response in Autovaccine-Treated Patients with Chronic Staphylococcus Aureus Infections

This study aims to describe the levels of circulating cytokines produced by Th lymphocytes (IFN-γ, IL-4, IL-10, IL-17A), as well as the levels of cytokines produced by monocytes/macrophages (TNF-α, IL-1β, IL-12), in patients with chronic Staphylococcus aureus infections before treatment and following completion of autovaccine treatment. The study was carried out on adult individuals, including 25 healthy subjects (group 1, control, not treated), 50 patients with chronic suppurative dermatitis (group 2) and 40 patients with chronic infections of the upper respiratory tract (group 3). Blood serum cytokine levels were measured by enzyme–linked immunosorbent assay (ELISA). S. aureus was detected in cultures of suppurative dermal exudates or of pharyngeal smears. For every individual patient an autovaccine was prepared, containing a suspension of inactivated S. aureus bacteria (1.5 × 108 bacteria/ml) isolated from the patient. The autovaccine was administered subcutaneously for a period exceeding 3 months, for a total of 18 injections. The average level of IFN-γ and IL-17 was 2–2.5 times higher in the infected patients. This was not accompanied by an increase in TNF-α or IL-12 levels. A treatment with autovaccine eradicated S. aureus infection in 42 (84%) patients of group 2 and in 14 (35%) patients of group 3. A significant increase (two-fold) in IL-17A was observed in treated patients. Also, following the treatment with autovaccine, all patients demonstrated a significant increase in the levels of IFN-γ, TNF-α and IL-12. These studies showed for the first time that efficiency of the autovaccine treatment in patients with chronic S. aureus infection depends on an adequate secretory response of TH17 cells.