Antimicrobial susceptibility and association with serotypes of Streptococcus pneumoniae isolates in children with acute otitis media and acute sinusitis in Belarus

Abstract

Objective. To study antibiotic resistance and its association with serotypes of Streptococcus pneumoniaeisolated from hospitalized children with community­acquired ENT infections in Belarus during 2013­2016 and to analyze a potential for the use of different antibiotic classes in the treatment of those infections.Materials and methods. A total of 115 strains isolated from children with acute otitis media and 18 strains isolated from children with acute rhinosinusitis were tested. Antimicrobial susceptibility testing was performed by a broth microdilution method. Antimicrobial susceptibility testing results were interpreted according to the CLSI 2017 and EUCAST 2017 criteria.Results. Pneumococcal isolates obtained from the children with acute otitis media have the high rates (50­74%) of non­susceptibility to the majority of beta­lactams, 14­/15­/16­membered macrolides, lincosamides, tetracyclines, folate pathway inhibitors. Rates of non­susceptible to benzylpenicillin, amoxicillin, III­IV generation cephalosporins, and ertapenem isolates were 37­39%. All tested pneumococcal isolates were fully susceptible to fluoroquinolones, ansamycins, glycopeptides, and oxazolidinones. Wild­type strains were rare (13%). MDR and XDR strains were found in 71% and 38% of children, respectively, and belonged to vaccine serotypes, i.e. were fully covered by PCV13 and PPSV23, but partly covered by PCV10 (84% MDR and 80% XDR strains). Pneumococcal isolates from children with acute rhinosinusitis had lower antimicrobial resistance rates and incidence rates of MDR and XDR strains. It can be explained by different serotype distribution in different age­group patients with different types of infection. There were found associations between a patient's age <5 years, “pediatric” serotype, and risk for antibiotic resistant pneumococcal infection.