Antimicrobial resistance of Streptococcus spp. in different hospital units

Objective. To analyze antimicrobial susceptibility of representatives of the genus Streptococcus in different wards of a multidisciplinary hospital. Materials and Methods. Epidemiological observational descriptive continuous retrospective survey was conducted. Antimicrobial susceptibility data on 2916 streptococcal isolates obtained from the laboratory information system «ALISA» were analyzed for the period from 01.01.2017 to 31.12.2022. Antimicrobial susceptibility testing was performed using BD Phoenix M50, interpretation of susceptibility testing results was done in accordance with EUCAST recommendations. Statistical analysis was performed using Microsoft Excel 2010 and IBM SPSS Statistics22. Results. The following species of the genus Streptococcus were predominantly isolated: in the surgical infections ward – S. pyogenes (28.5%), S. agalactiae (22.0%), S. anginosus (16.5%); in the coloproctology ward – S. anginosus (41.7%), S. constellatus (16.0%), S. agalactiae (14.5%); in the surgical ward – S. anginosus (40.1%), S. constellatus (31.4%); in the intensive care ward – S. anginosus (21.8%), S. constellatus (11.3%), S. oralis (11.1%); in the gynecology ward – S. agalactiae (49.9%) and S. anginosus (31.3%). Significant proportion of S. agalactiae isolates were resistant to tetracycline and clindamycin in all wards. There was an increase in S. agalactiae resistance to erythromycin from 15.4% in 2019 to 38.3% in 2021 in the surgical infections ward, and from 16.7% to 38.5% – in the coloproctology ward. In addition, resistance to clindamycin increased from 24.2% in 2018 to 71.3% in 2020 to in surgical infections ward, from 13.6% to 70.7% in coloproctology ward, and from 20.0% to 90.3% in gynecology ward. In the intensive care unit, S. agalactiae and S. pyogenes were most frequently resistant to tetracycline (79.5% and 51.3%), erythromycin (32.8% and 31.7%) and trimethoprim-sulfamethoxazole (18.5% and 26.8%, respectively). S. pneumoniae showed the highest level of resistance to erythromycin (35.3%), clindamycin (29.3%) and trimethoprim-sulfamethoxazole (26,0%). Conclusions. In recent years, an increase in antimicrobial resistance has been identified in the most common streptococci. The antibiotic susceptibility of streptococci of the same species was found to be variable in different hospital wards. There was a tendency noted for increase in the occurrence of multiresistant strains of S. pyogenes and S. agalactiae in the intensive care and surgical infections ward.