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Objective. To study the antimicrobial susceptibility profile of Moraxella catarrhalis isolates from different regions of Russia in 2010–2021. Materials and Methods. The study included 352 isolates of M. catarrhalis isolated in 11 cities of Russia (Volgograd, Irkutsk, Kazan, Kirov, Moscow, Murmansk, Perm, Seversk, Togliatti, Tomsk, and Ulan-Ude) in 2010–2021. Identification was done by MALDI-TOF mass spectrometry. Antimicrobial susceptibility testing was determined by broth microdilution method in accordance with the ISO 20776-1:2020. Interpretation of results was done in accordance with EUCAST guidelines (v.14.0). Results. Most of the isolates were isolated from respiratory specimens: 225 (63.9%) from sputum, 49 (13.9%) from nasal swabs, 41 (11.6%) from sinus aspirates, 17 (4.8%) from bronchoalveolar lavage, 8 (2.3%) from middle ear fluid, 6 (1.7%) from pharyngeal swabs, and 5 (1.4%) from conjunctival secretions. All tested isolates were susceptible to beta-lactams for which interpretive criteria have been established (amoxicillin-clavulanate, cefixime, ceftriaxone, cefuroxime). The susceptibility to clarithromycin and azithromycin was 99.7% and 100%, respectively. Ciprofloxacin, levofloxacin and moxifloxacin were active against 98.9%, 99.2% and 99.7% of isolates tested, respectively. Susceptibility to tetracycline was 99.7% and to trimethoprim-sulfamethoxazole was 99.4% (92% of isolates susceptible, 7.4% – susceptible at increased exposure). Conclusions. In the Russian Federation there is a favorable situation regarding the susceptibility of M. catarrhalis to antimicrobials. Amoxicillin-clavulanic acid, cefixime, ceftriaxone, azithromycin, clarithromycin, ciprofloxacin, levofloxacin, moxifloxacin and tetracycline retain high in vitro activity

One of the urgent problems of modern health care is the growing resistance of microorganisms to antibiotics, including carbapenems, which until recently were considered as the drugs of choice in the treatment of life-threatening infections. Enzymatic inactivation of antibiotics, including through the production of carbapenemase, is the main mechanism of resistance in Gram-negative bacteria. The treatment of these infections presents significant difficulties due to the extremely limited arsenal of effective drugs. Aztreonam is currently the first and only monocyclic beta-lactam antibiotic, monobactam, which is used in clinical practice for the treatment of infections caused by gram-negative bacteria. The data obtained in vitro and clinical observations are presented. These results justify the use of the drug in infections caused by a number of "problem" Gram-negative pathogens, including those resistant to carbapenems. Aztreonam has a high potential and should be used to treat patients with nosocomial infections – the focus of its use is Gram-negative bacteria-producers of metallo-beta-lactamases.

Objective. To evaluate antimicrobial resistance patterns of clinical Streptococcus pyogenes isolates from different regions of Russia during 2014–2017. Materials and Methods. A total of 792 clinical S. pyogenes isolates from 14 Russian cities were included in the study. Susceptibility testing was performed using reference broth microdilution method (ISO 207761:2006). Susceptibility testing results were interpreted using EUCAST v.10.0 breakpoints. Results. Penicillin G was active against all tested isolates with the MIC50–90 values of 0.016 mg/l and the highest MIC value of 0.25 mg/l. No resistance to linezolid, tedizolid and vancomycin were observed. Respiratory fluoroquinolones, moxifloxacin and levofloxacin, showed a high activity with the only 0.3% and 0.8% of resistant isolates, respectively. Almost all isolates (99.9%) were susceptible to trimethoprim/ sulfamethoxazole. The resistance rates to 14- and 15-membered macrolides varied from 12.1% to 17.2%. The only 2.4% of isolates were resistant to clindamycin. Resistance to chloramphenicol was 6.1%, to tetracycline – 17.2%. Conclusions. The comparison of this study results with the previously published Russian data on antimicrobial resistance of S. pyogenes shows there were no significant changes in the susceptibility of this pathogen over the past two decades, with the exception of macrolides. The growing resistance to 14and 15-membered macrolides raises a question on the further use of this antibiotic class for the empiric treatment of streptococcal infections in Russia.

Polymyxins are often the only agents that remain in vitro active against extensively resistant bacterial pathogens. However, the use of polymyxins is compromised by the number of unresolved issues, including the technical aspects of antimicrobial susceptibility testing, pharmacokinetic and pharmacodynamics parameters, optimal dosing regimens, and combined use with other antibiotics. All of the aspects of polymyxin use are discussed in detail in recently published «International consensus guidelines for the optimal use of the polymyxins», that was endorsed by the following professional societies: American College of Clinical Pharmacy (ACCP), European Society of Clinical Microbiology and Infectious Diseases (ESCMID), Infectious Diseases Society of America (IDSA), International Society for Antiinfective Pharmacology (ISAP), Society of Critical Care Medicine (SCCM), and Society of Infectious Diseases Pharmacists (SIDP).

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).

Objective. To evaluate antimicrobial resistance patterns of clinical Streptococcus pneumoniae isolates from different regions of Russia during 2014–2017. Materials and Methods. We included in the study 519 clinical S. pneumoniae isolates from 18 Russian cities. Susceptibility testing was performed by reference broth microdilution method (ISO 20776-1:2006). Susceptibility testing results were interpreted according to EUCAST v.9.0 breakpoints. Results. Using EUCAST non-meningeal interpretation criteria, 65.1% of isolates tested were susceptible (S) to penicillin; in addition 28.9% were in the category “susceptible, increased exposure” (I). S and I to ampicillin were 74.8% and 11.0% of isolates; to ceftriaxone – 79.0% and 15.6%, respectively. S to ertapenem and ceftaroline were 93.6% and 98.1% of isolates. Almost all isolates (99.6%) were S to respiratory fluoroquinolones (levofloxacin and moxifloxacin) and chloramphenicol (98.3%). All isolates were S to linezolid and vancomycin. Different 14-15-member macrolides were active against 67.8%–72.8% of isolates, activity of clindamycin was significantly higher (85.9%). Susceptibility rates to tetracycline and trimethoprim/sulfamethoxazole were 66.1% and 59.0%, respectively. Conclusions. There was a trend to decrease in susceptibility of S. pneumoniae in Russia to conventional β-lactams, macrolides and lincosamides. The most in vitro active antimicrobials are respiratory fluoroquinolones, linezolid, vancomycin, ceftaroline and chloramphenicol.

Objective. Objectives. To assess the rates of antibiotic resistance, production of acquired carbapenemases, genotypes and prevalence of «international high-risk clones» among nosocomial strains of Pseudomonas aeruginosa isolated in various regions of Russia within the «MARATHON 2015–2016» study. Materials and Methods. A total of 1006 non-duplicate nosocomial isolates of P. aeruginosa collected in 44 hospitals from 25 cities in Russia in 2015–2016 were studied. Species identification of isolates was performed by means of MALDI-TOF mass-spectrometry. Antimicrobial susceptibility was determined using broth microdilution method according to ISO 20776-1:2006 and interpreted using EUCAST MIC clinical breakpoints v.9.0. The presence of acquired carbapenemase genes of VIM, IMP, NDM, GES-2 and GES-5 groups was determined using real-time PCR. Genotyping of isolates was performed by analysis of selected single nucleotide polymorphisms in 7 chromosomal loci used for multi-locus sequence typing (MLST) of this species. Results. P. aeruginosa comprised of 17.4% of all bacterial pathogens isolated within the «MARATHON 2015–2016» study. The resistance rates to antibiotics were (in decreasing order of in vitro activity): 1.4% to colistin, 41.5% to aztreonam, 41.6% to ceftazidime/avibactam, 47.7% to amikacin, 51.5% to cefepime, 54.2% to tobramycin, 55.5% to meropenem, 56.3% to gentamicin, 56.8% to ceftazidime, 62.0% to piperacillin/tazobactam, 63.3% to ciprofloxacin, 65.2% to piperacillin, 67.5% to imipenem, and 97,6% to ticarcillin/clavulanic acid. Acquired carbapenemase genes were detected in 35% of the isolates including those for metallo-β-lactamases of VIM- (30.5%) and IMP-type (0.3%) and for GES-5-like serine carbapenemases. MBL producers were highly resistant to all antibiotics except for aztreonam (49%) and polymyxins (0%); GES-5-producers were resistant to most antibiotics except for aztreonam (4.8%), ceftazidime/avibactam (11.9%) and polymyxins (0%). The majority of carbapenemase producing strains belonged to the international “high-risk” CC235 (76.3%) and CC654 (21%) clones. All CC235 isolates revealed the presence of specific variant of the gene encoding secreted phospholipase A2, ExoU, which is a major virulence factor of P. aeruginosa. Conclusions. The results of this study indicate an increase in resistance rates to most antibiotics, including carbapenems, and in prevalence of carbapenemase production in nosocomial strains of P. aeruginosa. This can be largely attributed to the expansion of “high-risk” clones.

Objective. To assess rates of antimicrobial resistance and production of the clinically important acquired resistance mechanisms (extended spectrum beta-lactamases [ESBL] and carbapenemases) in nosocomial strains of Enterobacterales, and to determine genotypes and prevalence of “international high-risk clones” among carbapenemase-producing Klebsiella pneumoniae isolated in various Russian regions within the “MARATHON 2015–2016“ study. Materials and Methods. A total of 2786 non-duplicate nosocomial isolates of Enterobacterales, including 1316 isolates of K. pneumoniae and 837 isolates of Escherichia coli isolated in 49 hospitals from 25 cities in Russia in 2015–2016 were studied. Species identification of isolates was performed using MALDI-TOF mass-spectrometry. Broth microdilution method was used for susceptibility testing and phenotypic ESBL detection. The presence of acquired carbapenemase genes of VIM, IMP, NDM, KPC and OXA-48-groups was determined using real-time PCR. Genotyping of K. pneumoniae isolates was performed by multi-locus sequence typing (MLST) according to the Pasteur institute database and Diancourt et al. method. Results. A total of 48.2% of all bacterial pathogens isolated within the “MARATHON 2015–2016“ study comprised of Enterobacterales. The most common pathogens were K. pneumoniae (47.2%) and E. coli (30.0%). The majority of Enterobacterales isolates were resistant to oxyimino-β-lactam compounds: cefotaxime (78.4%), ceftazidime (67.2%), cefepime (68.4%) and aztreonam (71.5%). ESBL production was determined in 67.8% of isolates. Resistance to carbapenems (imipenem, meropenem and ertapenem) was observed in 6.9%, 6.5% and 23.6% of all Enterobacterales isolates, respectively. A total of 14.4% of Enterobacterales isolates carried the genes of class D carbapenemases OXA-48 (11.4%), class B carbapenemases NDM-1 (2.7%) and class A carbapenemases KPC (< 0.1%). Eight isolates (0.3%) of K. pneumoniae carried the genes of NDM- and OXA-48-like carbapenemases simultaneously and one isolate (< 0.1%) of Proteus mirabilis carried the genes of NDM and VIM metallo-β-lactamases. Most of the 57 genotyped carbapenemase-producing K. pneumoniae isolates belonged to the “international high-risk clones”: CG395 (45.6%), CG11 (12.3%), CG147 (10.5%) and CG307 (10.5%). The most active agents were ceftazidime/avibactam (3.5% of resistant isolates) and aztreonam/avibactam (MIC50 and MIC90 were 0.06 and 0.25 mg/L respectively). Colistin was the most active agent in vitro (18.6% of resistant isolates) among non-β-lactam antibiotics. The only 3.9% of E. coli isolates were resistant to tigecycline. The MIC50/MIC90 values of tigecycline for K. pneumoniae were 0.5 and 2 mg/L and did not exceed ECOFF value (≤ 2 mg/L). Conclusions. The results of this study showed an extremely high prevalence of resistance to most antibiotics, including carbapenems, and a variety of carbapenemase genes in nosocomial isolates of Enterobacterales. It makes a selection of empiric antibiotic treatment extremely difficult and warrants the need for regular resistance surveillance in every hospital.

Objective. Objectives. To assess the rates of antibiotic resistance and production of acquired carbapenemases in nosocomial strains of Acinetobacter spp., and to determine the genotypes and prevalence of “international high-risk clones” among nosocomial strains of Acinetobacter baumannii isolated in various regions of Russia within the “MARATHON 2015–2016” study. Materials and Methods. A total of 1005 non-duplicate nosocomial isolates of Acinetobacter spp., including 975 isolates of A. baumannii, collected in 44 hospitals from 25 cities in Russia in 2015– 2016 were studied. Species identification of isolates was performed by means of MALDI-TOF massspectrometry. Antimicrobial susceptibility was determined using broth microdilution method according to ISO 20776-1:2006 and interpreted using EUCAST MIC clinical breakpoints v.9.0. The presence of acquired carbapenemase genes of OXA-23, OXA-24/40, OXA-58, VIM, IMP, NDM, GES-2 and GES-5 groups was determined using real-time PCR. Genotyping of A. baumannii isolates was performed by analysis of selected single nucleotide polymorphisms in 10 chromosomal loci used for multi-locus sequence tying (MLST) of this species. Results. Acinetobacter spp. and A. baumannii comprised of 17.4% and 16.8% of all bacterial pathogens isolated within the “MARATHON 2015–2016” study. Resistance rates to carbapenems (imipenem and meropenem) were 77.4% and 77.1% of A. baumannii isolates, respectively. In 76.2% of A. baumannii isolates, the genes of acquired carbapenemases of molecular class D were detected, which belonged to the following groups: OXA-24/40 (57.5%), OXA-23 (18.4%) and OXA-58 (0.1%). Two isolates (0.2%) carried the genes of OXA-24/40- and OXA-23-like carbapenemases simultaneously. Most carbapenemaseproducing isolates belonged to the «international high-risk clones»: CC92/208OXF/CC2PAS (60.3%), CC944OXF/CC78PAS (25.4%) and CC109/231OXF/CC1PAS (11.6%). The vast majority of A. baumannii isolates exhibited resistance to ciprofloxacin (99.0%), amikacin (89.2%) and gentamicin (77.4%). The prevalence of resistance to tobramycin and trimethoprim/sulfamethoxazole was variable among strains of different genotypes. Colistin was the most active agent in vitro (0.9% of resistant isolates). Isolates of other Acinetobacter species were more susceptible to most antibiotics. However, two isolates of Acinetobacter ursingii and Acinetobacter baylyi carried the genes of NDM metallo-beta-lactamases. Conclusions. The results of this study indicate a very high prevalence of resistance to most antibiotics, including carbapenems, in nosocomial strains of Acinetobacter spp. This makes the selection of empiric antibiotic treatment extremely difficult and urges the need for regular local surveillance of resistance in every hospital.

An update on 2010 clinical practice guideline on Clostridium difficile infection (CDI) by the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA) was published in March 2018. This new version of guideline not only includes significant changes in the management of this infection and reflects the evolving controversy over best methods for diagnosis and threatment of CDI but has also incorporated recommendations for children. This document currently is the most complete and up to date source of information on CDI. In the present article we reviewed this new IDSA/SHEA guideline and compared it with existing European and Russian guidelines.

Wound healing and wound infection is not enough standardized in practice of surgeon. Existing recommendations on local antimicrobial agents do not contain references to specific products and do not explain their key features. The role of antiseptics and local forms of antibiotics in the treatment of wounds not completely defined, that gives the impression of an identical indications for their use. In reality topical formulations differ significantly in their chemical structure and mechanism of action. Recommendations for treatment of fresh and infected chronic wounds need to be adjusted, as many antiseptics and antibiotics have both positive and negative impact on the course of wound healing when applied topically

Daptomycin is the only clinically used member of a cyclic lipopeptides class of antibiotics. Daptomycin has rapid bactericidal activity against not only rapidly growing, but also against slow growing bacterial cells including those in biofilms. Spectrum of daptomycin’s activity includes almost all clinically important Gram(+) microorganisms. At the moment daptomycin is approved for two indications — complicated skin and skin structure infections, and bloodstream infections — bacteremia and right-sided endocarditis, caused by S. aureus. But at the same time there are a lot of clinical and experimental data showing that daptomycin could be an useful drug for the treatment of variety of other infections, such as bones and joints infections, febrile neutropenia, etc, especially those caused by multi-resistant strains.

The problem of genotypic variety of Acinetobacter baumannii isolated from patients with healthcare associated infections (HCAIs) are discussed. Carbapenemresistant strains, which are predominant in the study region, were shown to belong to the epidemic clonal line II and carry 1st class integron in their genome. Fraction of integron-positive isolates in HCAIs may be an indicator of nosocomial population of A. baumannii. The genes (gene cassettes) of integrons determine resistance to aminoglycosides, but not carbapenems.

Telavancin is a first marketed representative of semisinthetic lipoglycopeptides — new generation of glycopeptide antimicrobials. Telavancin is registered for the treatment of nosocomial pneumonia and skin and soft tissue infections caused by Gram(+) microorganisms, including multiresistant strains. Another perspective area of telavancin use — bloodstream infections, such as bacteremia and endocarditis. Telavancin is in vitro active against broad range of Gram(+) aerobic and anaerobic bacteria, including strains resistant to other antimicrobials: MRSA, MRSE, VISA, daptomycin non-susceptible strains of S. aureus, penicillin-resistant S. pneumoniae, ampicillin-resistant enterococci and enterococci with VanB phenotype of resistance to vancomycin. Talavancin is rapidly bactericidal due to its dual mechanism of action; it is active against intracellular bacterial cells and biofilmforming cells. Article reviews data of current in vitro and in vivo studies of telavancin, as well as clinical trials results.