The antiviral activity of the drug Kagocel®, which has a high safety profile and proven efficacy for the prevention and treatment of influenza and AVRI as an interferon inducer, was studied against a new pandemic strain of SARS-CoV-2 in vitro in Vero C1008 cell culture. The results of the study revealed that at the addition of the substance Kagocel® at the concentration of 5000 pg/ml into the cell culture 1 h before the virus infection and 1 h after, there was 100% inhibition of the cytopathic activity of the virus. It was also found that Kagocel® at the dose of 5000 pg/ml effectively suppressed the reproduction of the SARS-CoV-2 virus, vari­ant B, in Vero C1008 cell culture by 1.75 lg, the inhibition coefficient was 97.83 %.

Currently, the problem of nosocomial infections is of urgent concern. Pseudomonas aeruginosa is one of the key causative agents of this type of disease. The prospect of using bacteriophages in the prevention and control of infectious diseases is now being actively studied. The aim of the work is to study the effect of new bacteriophages on P.aeruginosa biofilm when used together with the antibiotic gentamicin. Cells of the laboratory reference strain P.aeruginosa PAO1 were grown in 96-well plates for a day, the resulting biofilms were treated with gentamicin in various concentrations, as well as bacteriophages AN14 and AN1. The degree of biofilm degradation was evaluated by staining the cells with crystal violet dye. The new lytic bacterio­phages AN14 (Siphoviridae family), AN1 (Myoviridae family) used in the study, showed pronounced antibiofilm activity on the first day of exposure to P.aeruginosa biofilm (p<0.001). The destructive effect of gentamicin on biofilms increased when the concentration of the antibiotic was increased in the range of 2—16 mg/ml. Addition of lytic bacteriophages AN14 and AN1 enhanced the effect of the antibiotic (p=0.05). Thus, the combined use of lytic bacteriophages and antibiotics led to a more effective eradication of biofilms than when used separately.

The effectiveness of 9 antibiotics against mono- and polymicrobial biofilms formed by Vibrio cholerae O1 strains was studied in vitro on fragments of chitinous exoskeleton of broad- fingered crayfish Astacus astacus in monoculture and together with oppor­tunistic bacteria Klebsiella spp. and non-O1/non-O139 V.cholerae. An increase in the antibiotic resistance of monomicrobial biofilms compared with planktonic bacteria was observed. Resistance of the polymicrobial biofilm bacteria to most antibacteri­al drugs corresponded to the resistance of the most stable strain in the monomicrobial biofilm. An increase in resistance to two and three drugs was observed in biofilms formed by classical toxigenic strains together with non-O1/non-O139 V.cholerae, while in biofilms formed together with Klebsiella spp. — to one antibacterial drug. Changes in antibiotic sensitivity during the interaction between bacteria in polymicrobial biofilm should be taken into account when developing tactics for prevention and treatment of infections.

Background. Current problems in the treatment of candidiasis include changes in the sensitivity of yeasts to antifungal agents, often used for the purpose of prevention, and changes in the spectrum of leading etiological agents.

Aim. Analysis of changes in the antimicotic effectiveness against Candida isolated from clinical and natural materials during 2014–2019 in Moscow.

Materials and methods. Antibiotic sensitivity of 186 isolates (75 clinical, 128 natural) of Candida species: C.albicans, C.parapsilosis, C.glabrata, C.krusei (Pichia kudriavzevii), C.intermedia, C.tropicalis, C.lusitaniae (Clavispora lusitaniae), C.guilliermondii (Meyerozyma guilliermondii), was determined by disc-diffusion method.

Results. The incidence among clinical isolates isolated in 2014: C.albicans (23.53%), C.tropicalis (20.59%), C.guilliermondii (20.58%), C.parapsilosis (17.65%), C.glabrata (17.65%); in 2019: C.parapsilosis (21.95%), C.albicans (17.07%), C.tropicalis (12.19%), C.guilliermondii (12.19%), C.krusei (9.76%), C.glabrata (9.76%), C.lusitaniae (9.76%), C.intermedia (7.32%). Incidence among natural isolates isolated in 2014: C.parapsilosis (29.17%), C.guilliermondii (25.0%), C.glabrata (16.67%), C.albicans (16.67%), C.tropicalis (12.5%); in 2016–2018: C.lusitaniae (14.94%), C.tropicalis (14.94%), C.glabrata (13.79%), C.intermedia (13.79%), C.parapsilosis (11.5%), C.guilliermondii (11.5%), C.krusei (10.34%), C.albicans (9.2%). 70.59% and 17.07% of clinical isolates demonstrated sensitivity to fluconazole in 2014 and 2019, respectively; 100% and 80.49% — to clotrimazole, 94.12% and 58.54% — to intraconazole, 97.06% and 73.17% — to nystatin, 100% and 75.61% — to amphotericin B. 70.83% of natural isolates isolated in 2014 were sensitive to all antimicotic agents. 26.44% were sensitive to fluconazole, 66.67% to clotrimazole, 43.68% to intraconazole, 48.28% to nystatin, 63.22% of the natural isolates isolated in 2016–2018 to amphotericin B.

Conclusion. During five years of observation, the antimicotic sensitivity decreased by 19.51–53.52% for clinical isolates of Candida genus and by 4.16–44.39% for natural isolates. It is possible that the spread of resistance among these yeasts is influenced by co-evolutionary processes occurring within the community of microorganisms under the influence of anthropogenic factors.

The article establishes the particularities of immune system dysfunction in the elderly during formation of a specific immune response to vaccination with a seasonal influenza vaccine depending on the level of seroconversion. The corrective effect of fucoidan — a sulfated polysaccharide extracted from brown algae Fucus evanescens — was shown in the formation of a spe­cific immune response, accompanied by an increase in the expression of the activation molecules CD69 and CD86 on mono­cytes, a decrease in the expression density of CD20 on B-lymphocytes, and an increase in the relative content of memory cells (CD4⁺CD45RO⁺-T-lymphocytes and cytotoxic CD8⁺CD45RO⁺-T-lymphocytes). Fucoidan extracted from the brown algae Fucus evanescens of the Sea of Okhotsk can be used to increase the effectiveness of seasonal influenza vacci­nation in the elderly.

Antibiotic resistance is one of the most relevant problems nowadays. The effectiveness of antibiotic therapy is determined, among other things, by the pharmacokinetic characteristics of the antibacterial drug. Therapeutic drug monitoring (TDM) is a modern way of overcoming the resistance of pathogens found in hospitals, which allows individualizing doses of the drug, especially in com­plex cases with increased pathogen resistance. The article describes two clinical cases of prescribing meropenem and conducting TDM, which made it possible to individualize the dosage of the antibacterial drug and provide adequate and effective therapy to patients. In the described clinical cases, the proposed dosing regimen of meropenem allowed achieving the target values of % T> MIC — more than 40%.

The aim of the work is to evaluate the diagnostic significance of the procalcitonin test (PCT) in the practice of a rheumatologist.

Material and methods. The study included 360 patients with various immuno-inflammatory rheumatic diseases (IIRD). Serum PCT concentration was determined by a quantitative electrochemiluminescent method on a Cobas E 411 analyzer (Roshe, Switzerland).

Results. The median (Me) level of PCT was 0.11 ng/ml [0.05; 0.16] in patients without infection (n=191). In patients with generalized infection (n=11), the Me level of PCT was 3.6 ng/ml [0.88; 11.3]. In cases of severe local infection (n=75), the Me level of PCT was 0.45 ng/ml [0.24; 1,2], while in case of mild local infection (n=83) — 0.12 ng/ml [0.05; 0.17]. ROC curve analysis showed that the diagnostic significance of determining PCT for generalized infection is very high, for severe local infection it is high, and for differentiation of generalized infection from local infection it is high.

Conclusion. PCT is a valuable diagnostic test that helps recognize generalized and severe local infections in patients with IIRD. However, when interpreting the values of PCT, the totality of data should be taken into account: specific rheumatic nosology, results of clinical laboratory, and instrumental examinations.

The review article includes summarized literature data on experimental evaluation of Francisella tularensis susceptibility to exist­ing antibiotics, and their effectiveness in treatment of tularemia in humans population. The data on ways to improve the effective­ness of some antibacterial drugs that show reduced activity in treatment of tularemia infection are presented. The range of studies aimed at creating modern and more effective antibiotics with new mechanisms of action is defined. A number of methods for mod­ifying variants of the already known groups of antibacterial drugs, as well as ways of prevention or limitation of antibiotic resist­ance formation in F.tularensis are described.

The Chikungunya virus (CHIKV) is an alphavirus transmitted to people by Aedes mosquitoes, usually Aedes aegypti and Aedes albopictus. The virus causes Chikungunya fever, a disease characterized by fever, nausea, headaches, rash, and persistent arthral­gia. Chikungunya fever may be associated with severe complications, including death. Since 2005, CHIKV has spread worldwide, leading to epidemics in Africa, Indian Ocean islands, Asia, and, most recently, in the Americas. Globally expanding pandemics with CHIKV rheumatic disorders and post-infectious complications are exacerbating public health problems. There is no specific vac­cine or drug to treat this viral infection. Analysis of the search for effective drugs in relation to CHIKV showed that, despite the diversity of research areas, as well as the use of modern advances in molecular biology, there are no etiotropic treatments or medic­inal immunobiological preparations (MIBPs) approved for use in practical medicine. However, new strategies for antiviral research are encouraging (inspire optimism?). Combined chemotherapy with interferons and antiviral agents is an appealing ther­apeutic strategy for providing increased antiviral activity and reducing drug concentrations.