Relevance. Infections caused by methicillin-resistant strains of Staphylococcus aureus are an urgent problem of hospital epidemiology, and control measures involve the development of new antimicrobials. Probiotics based on bacterial strains isolated fro natural habitats are considered promising means of combating MRSA.Aims. To test the possibility of using the Bacillus safensis 440-1 strain isolated from Antarctic soil. as an antibacterial agent for the treatment of experimental staphylococcal infection.Purpose of the study – check the possibility of using the Bacillus safensis 440-1 strain, isolated from Antarctic soil, as a topical antibacterial agent for the treatment of experimental staphylococcal infection.Material and methods. The potential virulence of Bacillus safensis strain 440-1 was studied on a mouse peritonitis model, and its activity against the methicillin-resistant Staphylococcus aureus SA776 test strain was studied on a localized wound infection model.Results and discussion. Our study demonstrated the safety of the tested strain due intraperitoneal use. We found that the use of the studied strain reduces the staphylococci amount in wounds from the third day from the start of the study to the end of the observation period, without aggravating the course of the infection.Conclusion. Bacillus safensis strain is a promising potential probiotic and it can be used as a part of complex antiseptic or disinfectant after additional studies aimed at developing an optimal mode of its use.

Severe course of COVID-19 in inpatients can be caused by a number of reasons, including viral and bacterial superinfections. Empirical use of antibiotics, as well as poor infectious control stimulate the emergence and spread of multidrug-resistant bacteria. Klebsiella pneumoniae is the most common carbapenemase-producing bacterial pathogen causing nosocomial infections. These strains became significantly widespread during the COVID-19 pandemic. Objective. To analyze phenotypic and genetic characteristics of K. pneumoniae strains as the dominant bacterial pathogen in severe COVID-19 patients in the intensive care unit. Patients and methods. This study included 38 COVID-19 patients (including 6 patients with severe disease) treated in the intensive care units of Moscow and Saint Petersburg hospitals for infectious diseases between July 2020 and December 2020. All patients signed an informed consent to participate in the study; patient data was anonymized. The following samples were collected: sputum, bronchoalveolar lavage, and nasopharyngeal swabs. We performed bacteriological identification of isolated bacterial strains, drug susceptibility testing, and whole genome sequencing of K. pneumoniae strains. Results. The majority of K. pneumoniae strains isolated from patients with severe COVID-19 contained clusters of aerobactin and enterobacterin genes. However, some of them (strains 90 and 124) also contained clusters of yersiniabactin genes. These genes are associated with high virulence and ability to form biofilms. The isolated strains belonged to four sequence types (ST874, ST395, ST147, ST15) that are characterized by high virulence and antibiotic resistance. These K. pneumoniae strains can be considered as one of the major causes of severe and lethal COVID-19. Conclusion. Our findings suggest that the detection rate of K. pneumoniae in COVID-19 patients increased from 30% to 70% during the pandemic. Phenotypic tests demonstrated that more than 80% of the strains were resistant to most antibiotics used in patients with complicated COVID-19. The combination of gypervirulence and antibiotic resistance is crucial for nosocomial transmission of these strains and their effect on the disease outcome. The emergence of hyper-resistant pathogens necessitates regular epidemiological monitoring and robust infection control in Russian hospitals, especially in intensive care units. Key words: COVID-19, severe disease, Klebsiella pneumoniae, genome sequencing, carbapenemases, hypervirulence, antibiotic resistance

Assisted reproductive technologies (ART) are one of the most effective ways in fighting infertility, but their effectiveness is influenced by various factors. Our study focuses on examining importance of risk factors underlying ART failure related to altered microbiome pattern in the female reproductive system. The case-control study was based on conducting a laboratory examination of 129 infertile couples applied to the Department of Assisted Reproductive Technologies due to failure of in vitro fertilization (IVF), whereas control group consisted of females with successful progressive pregnancy after ART. Chlamydia, herpes virus and cytomegalovirus were assessed by using PCR and ELISA, whereas culture method was used to detect Trichomonas vaginalis in vaginal swabs and ejaculate applying Trichomonas Modified CPLM Medium (HiMedia, India) followed by microscopy. In addition, the qualitative and quantitative composition of the vaginal biocenosis was studied with multiplex RT-PCR by using Femoflor-16 kit (DNA-technologies, Russia). Serological tests were based on measuring IgG and IgA antibodies against Chlamydia trachomatis in ELISA (diagnostic kits purchased from Vektor Best, Russia; NovaTec, Germany; ImmunoComb, Israel) as well as antibodies against immediate early HSV-1/2 proteins (BioService, Russia) and immediate early HHV-5 proteins (Vector Best, Russia). C. trachomatis and herpesvirus DNA was measured by using PCR diagnostic kits Amplisens (Interlabservice, Russia). It was found that sexually transmitted infection agents were highly prevalent in infertile couples applying to the hospital for IVF. Significant factors for non-pregnancy were vaginal dysmicrobiocenosis (OR = 7.5 (95% CI 1.04—54.1), p = 0.02) and detected T. vaginalis (OR = 2.6 (95% CI 1.12—6.4), p = 0.01). Dysbiosis of the reproductive system, including those occurring due to trichomonas infection is associated with lowered ART effectiveness. It is evident to timely detect urogenital infections and dysbiosis while preparing infertile couples for IVF cycles.

Relevance. Miscarriage is one of the most common obstetric pathologies that determine the spontaneous death of the fetus. The role of changes in the microbiome of various biotopes is considered as a risk factor of this disease.Aim of the research is to assess the microbiocenoses structure of the reproductive system and the intestine associated with the development of spontaneous miscarriages in early pregnancy.Materials and methods. A case-control study was conducted and organized. The group of «cases» included 23 women with spontaneous miscarriage at 5–14 weeks of pregnancy and the control group included 23 women with normal pregnancies Based on the data of metagenomic sequencing of V3–V4 regions of the 16S rRNA gene, a comparative assessment of the structure of the vaginal and intestinal microbiome in these groups was carried out.Results. As a result of the study, a number of taxonomic groups of microorganisms in the vagina and intestines associated with miscarriage. It was found that the decrease in the proportion of Lactobacillus spp. in the structure of the vaginal microbiome, less than 90% of the total number of identified taxa is associated with this pathology (OR = 5.28 (95% CI = 1.2-23.2)). The gut microbiocenoses of women with spontaneous miscarriage are characterized by less taxonomic diversity than the gut microbiome of women with advanced pregnancy. At the same time, some representatives of the intestinal microbiome (Akkermansia sp., Faecalibacterium sp., Bifidobacterium sp., Methanobrevibacter sp., Lactococcus sp.) predominate in women with a normal pregnancy.Conclusion. The study demonstrated a significant role of changes in microbiocinosis of the reproductive tract and intestines in miscarriage. There is a potentially protective function of lactobacilli. The obtained data substantiates the need for active use of molecular genetic methods focused on the assessing the structure of the vaginal and intestinal microbiota in assessing the risks of reproductive failures.

Aim. Comprehensive epidemiological assessment of factors affecting the effectiveness of the infertility treatment in medical organizations of St. Petersburg. Materials and Methods. The effectiveness of assisted reproductive technology programs in St. Petersburg reproductive centers was evaluated by analyzing the respective database for infertility treatment in 2013-2017. We retrospectively examined 843 patient records that were submitted to one of the St. Petersburg reproductive centers in 2014-2017 with the following survey and in-depth clinical examination of 129 couples before in vitro fertilisation. Results. Risk factors of infertility included vaginal dysbiosis (OR = 7.5 (95% CI 1.04-54.1)), Trichomonas vaginalis infection (OR= 2.6 (95% CI 1.12 - 6.4)), and smoking (OR = 2.6 (95% CI 1.0 - 6.5)). Conclusion. Optimised screening of couples before in vitro fertilisation may increase the effectiveness of assisted reproductive technology programs. Stimulation of the population's commitment to a healthy lifestyle including non-smoking policy should be one of the main directions to prevent infertility.

Дана характеристика факторов персистенции хламидий и их значения в формировании мужской репродуктивной патологии. Рассмотрены диагностические подходы по установлению урогенитальной хламидийной инфекции у мужчин с учетом формирования аберрантных форм патогена. Предложен комплексный лечебный подход с применением антибиотиков, индукторов интерферона и препаратов заместительной интерферонотерапии для лечения мужчин с персистирующей хламидийной инфекцией и бесплодием. Ключевые слова: факторы персистенции хламидий, репродуктивные нарушения у мужчин, интерферонотерапия

Serratia marcescens is a frequent cause of health care-associated infections and has led to multiple outbreaks. Here, we report the draft genome of a multidrug-resistant S. marcescens strain 189 which was isolated in 2012 as a predominant clone in a neonatal hospital in Kemerovo.

Aim. To give epidemiological assessment of potential risk factors for prevalence of antibiotic resistant strains of upper airways and ENT-organs infectious pathogens in children. Materials and methods. The study included children (165 persons) aged 1 to 17years, who asked for ambulatory-polyclinic medical care in connection with upper airways and ENT-organs diseases and formed the group of “cases” (75 persons) - patients, colonized by Streptococcus spp. and Staphylococcus aureus strains with antibiotic resistance not less than one of three classes (beta-lactams, macrolides, lincosamides) and the control group (90 persons) - patients without the facts of colonization by antibiotic-resistant strains of the studied microorganisms. During doctor’s reception, parents of all patients were surveyed. Results. According to the results of a survey carried out, there was estimated connection of 18 potential risk factors with carriage of antibiotic-resistant strains. Pneumococcal vaccination in the investigated population was a factor, rendering preventive effect on the colonization rate of antibiotic-resistant strains Streptococcus spp. and Staphylococcus aureus ( OR = 0,40 [95 %DI 0,19-0,86]). At the same time, no ties between colonization by antibiotic-resistant microorganisms and risk factors, connected with previous use of antibiotics, especially without doctor’s administration, was noted. Conclusions. Vaccination with pneumococcal vaccines in the studied population is a factor, controlling prevalence of resistance to antimicrobial drugs