Статья подготовлена при финансовой поддержке компании Пфайзер. В статье выражена позиция авторов, которая может отличаться от позиции компании Пфайзер.

Bacteriophage enzyme preparations exolysin and endolysin were studied. Exolysin (a phage-associated enzyme) was obtained from tail fraction and endolysin from phage-free cytoplasmic fraction of disintegrated Salmonella enteritidis cells. A new method for purification of these enzymes was developed, and their molecular masses were determined. The main catalytic properties of the studied enzymes (pH optimum and specificity to bacterial substrates) were found to be similar. Both enzymes lyse Escherichia coli cells like chicken egg lysozyme, but more efficiently lyse S. enteritidis cells and cannot lyse Micrococcus luteus, a good substrate for chicken egg lysozyme. Similar properties of exolysin and endolysin suggest that these enzymes are structurally similar or even identical.

The bacteriolytic activity of interleukin-2 and hen egg white lysozyme against 34 different species of microorganisms has been studied. It was found that 6 species of microorganisms are lysed in the presence of interleukin-2. All interleukin-2-sensitive microorganisms belong either to the Enterobacteriaceae, Bacillaceae, or the Lactobacillaceae family. It was also found that 12 species of microorganisms are lysed in the presence of lysozyme, and 16 species of microorganisms are lysed in the presence of sodium dodecyl sulfate (SDS). The bacteriolytic activity of interleukin-2 and lysozyme was studied at various pH values.

Objective. To evaluate antimicrobial resistance patterns of clinical Haemophilus influenzae isolates from different regions of Russia during 2014–2017. Materials and Methods. We included in the study 185 clinical H. influenzae isolates from 13 Russian cities. Susceptibility testing was performed by reference broth microdilution method (ISO 207761:2006). Susceptibility testing results were interpreted using EUCAST v. 10.0 breakpoints. Results. H. influenzae isolates were highly susceptible to all (96.8%-100%) β-lactams tested (amoxicillin/ clavulanate, cefixime, ceftaroline, ceftibuten, cefditoren, ertapenem) with the exception of ampicillin (15.1% isolates were resistant). Fluoroquinolones, – ciprofloxacin, levofloxacin, moxifloxacin were active against 95.7%, 94.6% and 97.9% of isolates, respectively. Chloramphenicol was active against 97.9% of isolates, tetracycline – against 98.4% of isolates. Activity of trimethoprim/sulfamethoxazole was low (69.2% of susceptible isolates). Conclusions. In general, we can state the favorable situation with the susceptibility of H. influenzae to antimicrobials in Russia. However, the increasing of resistance to aminopenicillins and emerging of quinolone-resistant strains could become a problem in the future. Study Results are deposited at on-line resource AMRmap (http://AMRmap.ru).

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