Cross-contamination that leads to false positive results is a serious problem for laboratories using the PCR method. There are many ways to solve this problem, but none of them could be considered universal. Treatment with aerosols is the preferable method for decontamination of large areas of complex surfaces. The goal of this study was to determine effective aerosol compositions and regimens for the decontamination of nucleic acids on laboratory surfaces. The decontaminating activity of compounds that release active chlorine and active oxygen was studied using model surfaces contaminated with nucleic acids and bacteria. Effective modes of decontamination with aerosols were established by analysis of obtained experimental data. Differences between decontamination of nucleic acids and bacterial disinfection of the laboratory surfaces are shown.

We performed a comparative analysis of the phenotypic and genotypic characteristics of strains of the plague pathogen of phylogroups 2.MED4 and 2.MED1 of the medieval biovar of the main subspecies from epidemically active plague foci in the Caspian Sea region in the XX century. According to the results of the analysis, biochemical properties, nutritional requirements and plasmid profile of strains of phylogroups 2.MED4 and 2.MED1 of the medieval biovar of Y. pestis were determined. Genetic variability in the hemS, caf1M, and ssaJ genes associated with the virulence in strains of the 2.MED lineage was revealed. The data obtained on the phenotypic and genotypic characteristics of the medieval biovar of the plague microbe can be used in laboratory diagnostics of the plague microbe and will contribute to the study of genome changing in the process of microevolution of this highly virulent biovar.

Due to the prevalence and diversity of both symptoms and outcomes of COVID-19, the understanding of the factors that determine the risk of severe course of this disease and possible complications is of particular importance. In this review, we present the information on specifics of COVID-19 pathogenesis and give a theoretical justification for the factors that determine the course of this disease in patients of different age groups, patients with chronic pathology, and pregnant women. Particular attention is paid to the post-COVID syndrome.

Urinary tract infections (UTIs) are the leading cause of outpatient visits and nosocomial infections worldwide resulting in increased healthcare costs. Information about the disease-associated pathogens and their susceptibility profile is of paramount importance for choosing antimicrobials and containing the alarming rise in microorganisms’ drug resistance. This study aimed to investigate the prevalence of gram-negative and gram-positive uropathogens in hospitalized adult patients, considering their sensitivity profile. The study retrospectively analyzed 2099 urine samples received from December 2019 to May 2020. The isolates were identified by standard microbiological methods, and sensitivity testing was done following the Clinical and Laboratory Standards Institute (CLSI) guidelines (2019). Out of the 2099 samples tested, 212 were positive. The vast majority of samples (97.6%) was received from women. Escherichia coli (34.9%) was the most common gram-negative pathogen, while Enterococcus spp. (15.1%) prevailed among gram-positive organisms. Among gram-negative organisms, a high susceptibility was observed for aminoglycosides (amikacin, netilmicin), nitrofurantoin, and carbapenems, while a high resistance was found towards co-trimoxazole, fluoroquinolones, and cephalosporins. We confirmed that nitrofurantoin, a traditional oral drug, still demonstrates good activity against uropathogens. Thus, there is an urgent need to study uropathogens and their susceptibility patterns to control the inadvertent use of antimicrobials and the spread of multidrug-resistant strains.