Etiology and antibiotic resistance of the microflora of the upper respiratory tract in children who sought outpatient care

The aim of the study was to identify the main microorganisms colonizing the mucous membrane of the nasal cavity and pharynx in children of different age groups, and their antibiotic sensitivity. Materials and methods : 311 children aged 0 to 17 years who applied for outpatient care of St. Petersburg State Medical Establishment «City Polyclinic No. 63» for the period from March to December 2023 were examined. 511 samples were examined — 241 from the nasal mucosa and 270 from the pharyngeal mucosa. Antibiotic sensitivity has been determined. The frequency of colonization in children who sought outpatient care for upper respiratory tract infections ( n = 186) and for other reasons ( n = 103) was calculated. Results. Clinically significant microorganisms were isolated from 176 (61.3% ± 2.87) children: S. aureus 30.0 ± 2.7, S. pyogenes 19.9 ± 2.3, M. cataralis 11.1 ± 1.9, S. pneumoniae 8.4 ± 1.6, H. influenzae 5.6 ± 1.3, others 3.8 ± 1.1. 41 (14.3%). The risk group for colonization of S. aureus are boys RR = 1.47 (95% CI: 1.02—2.12) p = 0.02. The risk group for colonization of M. cataralis and S. pneumoniae are children from 0 to 9 years old: RR = 9.45 (95% CI: 2.29—38.93); p (Fisher) = 0.00002 and RR = 4.9 (95% CI: 1.49—16.06); p (Fisher) = 0.0018, respectively. 59.8% of S. aureus strains were resistant to benzylppenicillin, 14% to roxithromycin and clindamycin, 13% to azithromycin and erythromycin, 18.7% of H. influenzae strains to ampicillin and amoxicillin, 87.5% of S. pneumoniae strains had intermediate resistance to cefaclor, 90.8% of S. aureus strains to clarithromycin. 99% of S. aureus strains, 98.4% of S. pyogenes and 97.4% of S. pneumoniae had intermediate resistance to levofloxacin.