MONITORING ANTIMICROBIAL RESISTANCE OF STREPTOCOCCUS PNEUMONIAE

Introduction. Streptococcus pneumoniae remains one of the leading pathogens causing respiratory infections worldwide, particularly in children, the elderly, and patients with chronic comorbidities. It is responsible for community-acquired pneumonia, otitis media, sinusitis, meningitis, and sepsis. The increasing resistance of pneumococcus to antibiotics is a major clinical problem that complicates empirical treatment. The COVID-19 pandemic further aggravated this issue due to widespread and often inappropriate antibiotic use. The aim of this study was to evaluate the role of S. pneumoniae in respiratory infections and analyze the antimicrobial resistance of its isolates in respiratory samples from hospitalized patients during 2018–2024. Methods. A retrospective analysis of respiratory specimens (nasopharyngeal swabs, tonsils, tracheal aspirates, and sputum) was conducted at the Poltava Regional Clinical Infectious Diseases Hospital. The susceptibility of the pneumococcal isolates was determined using the disk diffusion method according to EUCAST. The Antimicrobial Resistance Index (ARI) was calculated based on the frequency of resistant isolates and antibiotic consumption, following the methodology of the Ministry of Health of Ukraine. Results. The proportion of S. pneumoniae increased from 8.2% in 2018 to 10.1% in 2024, with a temporary decline during 2020-2021. Resistance to benzylpenicillin, erythromycin, and levofloxacin peaked in 2021 and subsequently decreased, while vancomycin and linezolid resistance remained low. Antibiotic consumption analysis revealed increased use of fluoroquinolones and carbapenems in 2024. The ARI rose progressively from 0.06 in 2022 to 0.17 in 2024, reflecting the accumulation of resistance. Conclusions. The growing share of S. pneumoniae among respiratory infections and its rising antimicrobial resistance highlight its clinical importance in the post-COVID-19 period. The observed increase in ARI underlines the need for prudent antibiotic use, strengthened resistance monitoring, and adaptation of empirical therapy to local resistance trends.