Results from the Survey of Antibiotic Resistance (SOAR) 2018-21 in Ukraine: data based on CLSI, EUCAST (dose-specific) and pharmacokinetic/pharmacodynamic (PK/PD) breakpoints.

OBJECTIVES

To determine the antibiotic susceptibility of Streptococcus pneumoniae and Haemophilus influenzae from community-acquired respiratory tract infections (CA-RTIs) collected in 2018-21 from Ukraine.

METHODS

MICs were determined by CLSI broth microdilution test, and susceptibility data were interpreted using CLSI, EUCAST (dose-specific) and pharmacokinetic/pharmacodynamic (PK/PD) breakpoints.

RESULTS

S. pneumoniae (n = 64) and H. influenzae (n = 76) isolates were collected in 2018-21. Antibiotic susceptibility was 82.8% for pneumococci penicillin-susceptible by CLSI oral/EUCAST low-dose breakpoints and 98.4% by EUCAST high-dose/CLSI intravenous breakpoints. Fluoroquinolones were the most active (100% susceptible). CLSI susceptibility of 85.9%-96.9% was also observed for amoxicillin, amoxicillin/clavulanic acid and cephalosporins. Tetracycline and macrolide susceptibility was 73.4%-76.6%, and trimethoprim/sulfamethoxazole was 59.4%. EUCAST susceptibility was similar if high-dose regimens were chosen, although susceptibility to trimethoprim/sulfamethoxazole was 79.7%. Most H. influenzae isolates were β-lactamase negative (n = 72, 94.7%) with >94.7% susceptibility, except for trimethoprim/sulfamethoxazole (61.8% by CLSI/EUCAST low-dose, 68.4% by EUCAST high-dose). Susceptibility using EUCAST breakpoints was similar to CLSI, except cefuroxime (oral) with 0% of isolates susceptible versus 100% by CLSI. Cefaclor susceptibility was 11.8% using PK/PD breakpoints.

CONCLUSIONS

For H. influenzae, 100% susceptibility (CLSI) was observed to amoxicillin/clavulanic acid, macrolides, most cephalosporins and tetracycline. S. pneumoniae susceptibility was 100% to fluoroquinolones, 90.6%-96.9% to third-generation cephalosporins and 96.9% to amoxicillin and amoxicillin/clavulanic acid. This is consistent with previous resistance surveillance in Ukraine. Continued surveillance of antibiotic susceptibility is important for guiding empiric therapy of CA-RTIs.