On April 12, 2018, the Journal of Antimicrobial Chemotherapy published * data from the international Survey of Antibiotic Resistance (SOAR), conducted in 2014–2016 in nine countries: Romania, Bulgaria, Croatia, Serbia, Russia, the Czech Republic, Greece, Slovakia, and Ukraine.

In 2002, the pharmaceutical company GSK initiated the Survey of Antibiotic Resistance (SOAR), an international study of antibiotic resistance in countries across the Middle East, Africa, Latin America, the Asia-Pacific region, and the CIS. Ukraine joined in 2011. Yuriy Feshchenko, professor, doctor of medical sciences, and director of the F. G. Yanovsky National Institute of Phthisiology and Pulmonology of the National Academy of Medical Sciences of Ukraine (Kyiv), became the project's national coordinator.

The SOAR study focuses on determining the susceptibility of key community-acquired respiratory tract infection pathogens , Streptococcus pneumoniae and Haemophilus influenzae, to antibacterial drugs. It is worth noting that lower respiratory tract infections, which cause 3.2 million deaths annually, are, according to the WHO, the third most common cause of death globally. Even in Europe, where infectious disease mortality rates are significantly lower than in other regions of the world, lower respiratory tract infections are the sixth leading cause of death.

The SOAR 2014–2016 study focused on monitoring resistance data in Eastern European countries: Romania, Bulgaria, Croatia, Serbia, Russia, the Czech Republic, Slovakia, Ukraine and Greece.

The aim of the study was to determine the susceptibility of 195 S. pneumoniae and 194 H. influenzae strains to antibacterial drugs. The strains were isolated from patients in Ukrainian centers (Diagnostic Center of the Medical Academy (Dnipro) and the National Institute of Phthisiology and Pulmonology (Kyiv) and Slovak (University Hospital in Nitra). The sensitivity of the isolated microorganisms to antibacterial drugs was studied using original molecules used to treat community-acquired respiratory tract infections (CA-RTI): penicillin, ampicillin, amoxicillin, amoxicillin / clavulanate, cefuroxime, cefaclor, ceftriaxone, erythromycin, azithromycin, clarithromycin, levofloxacin, moxifloxacin and trimethoprim / sulfamethoxazole.

The obtained data were analyzed according to three control points: Clinical and Laboratory Standards Institute (CLSI), European Committee on Antimicrobial Susceptibility Testing (EUCAST, Switzerland) and pharmacokinetics/pharmacodynamics (PK/PD).

The study results showed that 97% of S. pneumoniae strains isolated in Ukraine (n = 100) were susceptible to intravenous penicillin (according to CLSI breakpoints), 83% – to oral penicillin (according to CLSI and EUCAST). Moreover, all strains demonstrated susceptibility to levofloxacin and moxifloxacin. 98% were susceptible to ceftriaxone according to CLSI and PK/PD, with a decrease in the rate to 90% according to EUCAST. Susceptibility to low doses of amoxicillin and amoxicillin/clavulanate combination was 97% (CLSI, EUCAST); in the case of using high doses according to PK/PD criteria, susceptibility to amoxicillin remained at the same level, while susceptibility to amoxicillin/clavulanate increased to 99%. Susceptibility to oral cephalosporins and macrolides according to CLSI ranged from 83% for erythromycin to 89% for cefuroxime. Similar data were obtained according to the PK/PD and EUCAST breakpoints, with the exception of cefaclor, for which susceptibility was 28% according to PK/PD and 0% according to EUCAST. Susceptibility to trimethoprim/sulfamethoxazole was 75% according to all breakpoints.

In accordance with CLSI breakpoints, susceptibility of S. pneumoniae to antibacterial drugs was compared, including in different age groups. The only statistically significant difference was obtained regarding macrolides among strains isolated from children (n = 27, susceptibility to all three macrolides – 70.4%) and from adults (n = 65, susceptibility – 89.2%, P = 0.03), cefaclor: 70.4% of strains isolated from children and 90.8% from adults were sensitive to antimicrobial therapy using this drug (P = 0.02).

For comparison, the susceptibility of S. pneumoniae strains isolated in Slovakia was significantly lower than in Ukraine (n = 95). All strains were susceptible to fluoroquinolones, but susceptibility to penicillin, amoxicillin, amoxicillin/clavulanate combination, cefuroxime, and trimethoprim/sulfamethoxazole combination ranged from 61% to 64%, while only 44% of strains were susceptible to macrolides.

In Ukraine, susceptibility of H. influenzae to ceftriaxone, levofloxacin, and moxifloxacin was 100% according to all breakpoints. Susceptibility to the amoxicillin/clavulanate combination was also 100% according to CLSI breakpoints and, when using high doses, according to PK/PD criteria. However, since one strain was β-lactamase-negative ampicillin-resistant (BLNAR strain), the susceptibility rate according to CLSI breakpoints was reduced to 99%. Sensitivity according to PK/PD breakpoints (low doses) and EUCAST was 95.8%. Similarly, after adjustment for the BLNAR strain, susceptibility to cefuroxime was reduced from 97.9% to 96.9% according to CLSI breakpoints, and the sensitivity decreased further using other breakpoints: to 70.8% – PK/PD, to 0% – EUCAST. Susceptibility to cefaclor according to CLSI breakpoints was 87.5%, PK/PD – 0%. A similar gap was observed between the parameters of clarithromycin: 61.5% – CLSI; 2.1% – EUCAST; 0% – PK/PD. Susceptibility to the trimethoprim/sulfamethoxazole combination was 60.4% according to all breakpoints.

The disparity in study results between the two neighboring countries highlighted the need to monitor and publish national and regional data on antibiotic resistance and emphasized the importance of making decisions regarding antibacterial treatment for community-acquired lower respiratory tract infections based on local resistance data. As the scientists' observations confirm, antibiotic resistance levels can vary significantly not only between countries but also between healthcare facilities within a single country.**