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Background. The ongoing pandemic of the novel coronavirus infection (COVID-19) draws attention to the significance of molecular and genetic monitoring of the SARS-CoV-2 spread among the population of the Russian Federation. The aim of the study was to analyze the dynamics of circulation of SARS-CoV-2 genetic variants in Russia.Materials and methods. The analysis of the circulation dynamics for SARS-CoV-2 genetic variants in Russia was carried out, covering the period from 28/12/2020 to 26/6/2022. The analysis included the data from Rospotrebnadzor Report No. 970 "Information about Infectious Diseases in Individuals with Suspected Novel Coronavirus Infection" and the Virus Genome Aggregator of Russia (VGARus). The presence of SARS-CoV-2 RNA was confirmed by the real-time reverse transcription polymerase chain reaction. The primer panels developed at the Central Research Institute of Epidemiology were used for amplification of genomic fragments and the subsequent sequencing.Results and discussion. Using the Russian VGARus platform developed by the Central Research Institute of Epidemiology, we received the data on mutational variability of SARS-CoV-2. By monitoring the circulation of SARS-CoV-2 genetic variants in Russia from 28/12/2020 to 26/6/2022, we found that Delta and Omicron genetic variants prevailed at different stages of the epidemic.Conclusion. The data of molecular and genetic studies are an essential component of epidemiological surveillance, being critically important for making executive decisions aimed at prevention of further spread of SARS-CoV-2 and laying the groundwork for creating new vaccines.

Aim: to assess the most important metabolic factors in centenarians and their impact on prognosis Materials and methods. It was a longitudinal study, including 64 centenarians (95 years and older), who live in Moscow. Complex geriatric assessment (FRAIL, IADL-C, MNA, GDS-15 and МOCA scores) and blood tests (HbA1c, cholesterol, LDL, HDL and TG) were performed. In 3 years we contacted patients’ relatives or social workers to find out about patients’ status. Results. Mean age of the patients was 98,3±1,9 years. We found out that 34,4% of the patients were frail. Cognitive impairments of different severity were presented in 84,4% of the patients. The median lipids values were as follows: cholesterol — 4,8 [4,2 ;5,8], TG — 0.97 [0,8; 1.2], HDL — 1.3 [4.2; 5,8), LDL — 3,1 [2,6; 3,7], HbA1c — 5,8 [5,6; 6,1]. In 59% of the patients HbA1c was below 6%; 33% had concentrations between 6% and 6,4%, and only in 8% we found HbA1c higher than 6,5%. No correlation was also found between HbA1c values and lipids profile. Comparing survivors and non-survivors groups we did not find any significant differences in total cholesterol, LDL, HDL and HbA1c (pConclusions. In centenarians usual prognostic factors such as HbA1c and lipids do not have any impact on prognosis but they influence functional status and QoL. Further investigations of metabolic status in super old persons are needed to personalize their lifestyle and treatment goals.

Non-proteinogenic neurotoxic amino acid β-N-methylamino-L-alanine (BMAA) is a bioactive molecule synthesized by various phytoplankton species, such as cyanobacteria, diatoms and dinoflagellates, and is known to be a causative agent of human neurodegeneration diseases. The ability of different microalgae to synthesize BMAA may be an indicator of the importance of this molecule in the interaction of phytoplankton organisms in nature. We were interested in the question: what kinds of mechanisms underline BMAA’s action on cyanobacterial cells under different nitrogen supply conditions. To answer this question we have performed molecular studies using a model cyanobacterial strain Nostoc (Anabaena) sp. PCC 7120. We have experimentally shown that the action of BMAA on nitrogen-fixing filamentous cyanobacteria changes nitrogen-carbon balance regulation, and differs under nitrogen starvation and in nitrogen-replete conditions. The primary main targets of BMAA’s action in cyanobacteria cells are, apparently, metabolic processes, such as nitrogen fixation, photosynthesis, carbon fixation and different biosynthetic processes, the regulation of which involves 2-oxyglutarate and glutamate. Our proteomic study has demonstrated that under BMAA-treatment the most significant difference lies in the expression change of a key nitrogen regulatory protein PII. This protein is downregulated in nitrogen-starving conditions and it is upregulated in nitrogen-replete conditions in the presence of BMAA. This could be the main reason behind a specific regulatory effect on heterocyst formation and heterocyst- and nitrogenase-related gene expression that this amino acid causes in Nostoc sp. PCC 7120. Due to the fact that all metabolic processes are interconnected and well balanced in cyanobacteria cells, the disturbance in nitrogen metabolism leads to changes in carbon metabolism and photosynthesis. This explains the severe changes of CO2 fixation proteins and photosystem reaction centre proteins that were found in our proteomics studies. BMAA addition leads to disorder in both amino acid synthesis and in purine synthesis, as well as disturbs DNA transcription and protein translation. Finally, many enzymes of oxidative stress, chaperones and SOS-response proteins are upregulated under such metabolic stress conditions. Therefore we can conclude that the disbalance in energy and metabolite amounts leads to severe intracellular stress that induces the upregulation of stress-activated proteins, such as: starvation-inducible DNA-binding protein, stress-response enzymes, proteases and SOS-response and DNA repair enzymes. It can be hypothesized that BMAA could be used by phytoplankton representatives (cyanobacteria, diatom, dinoflagelates) as a possible allelopatic tool to control cyanobacteria cell populations during their competition for nitrogen and other resources.

The constant increase of antibiotic-resistant strains of bacteria is caused by extensive uses of antibiotics in medicine and animal breeding. It was suggested that the gut microbiota serves as a reservoir for antibiotics resistance genes that can be carried from symbiotic bacteria to pathogenic ones, in particular, as a result of transduction. In the current study, we have searched for antibiotics resistance genes that are located inside prophages in human gut microbiota using PHASTER prophage predicting tool and CARD antibiotics resistance database. After analysing metagenomic assemblies of eight samples of antibiotic treated patients, lsaE, mdfA and cpxR/cpxA genes were identified inside prophages. The abovementioned genes confer resistance to antimicrobial peptides, pleuromutilin, lincomycins, streptogramins and multidrug resistance. Three (0.46%) of 659 putative prophages predicted in metagenomic assemblies contained antibiotics resistance genes in their sequences.Uvelichenie doli lekarstvenno-ustoĭchivykh shtammov bakteriĭ neposredstvenno sviazano s shirokim primeneniem antibiotikov v meditsine i zhivotnovodstve. Predpolagaetsia, chto mikroflora kishechnika sluzhit rezervuarom genov antibiotikorezistentnosti, kotorye mogut peredavat'sia ot simbioticheskikh bakteriĭ k patogennym mikroorganizmam, v tom chisle v rezul'tate fagovoĭ transduktsii. S ispol'zovaniem programmy predskazaniia profagov PHASTER i bazy dannykh genov antibiotikorezistentnosti CARD proveden poisk genov antibiotikorezistentnosti, nakhodiashchikhsia v sostave profagov, v mikrobnom soobshchestve kishechnika cheloveka. V rezul'tate analiza metagenomnykh sborok vos'mi obraztsov v sostave posledovatel'nosteĭ profagov byli obnaruzheny geny lsaE, mdfA i cpxR/cpxA, prisutstvie kotorykh obespechivaet ustoĭchivost' bakteriĭ k antimikrobnym peptidam, plevromutilinu, linkomitsinam, streptograminam gruppy A, a takzhe mnozhestvennuiu lekarstvennuiu ustoĭchivost'. Iz 659 predpolozhitel'nykh profagov, predskazannykh v metagenomnykh sborkakh, tri (0,46%) imeli v svoem sostave geny antibiotikorezistentnosti.

Prognostic express diagnosis of metabolic dysregulation was tested in highly qualified athletes engaged in various Olympic sports. The method is based on laser correlation spectroscopy (LCS) of biological fluids, which has widely been approved for use in medicine and evaluation of risks for natural and anthropogenic anomalies. Evaluating the risk for metabolic dysregulations with the relevant criteria will help to objectively estimate the efficiency of preventive actions in athletes.

Aim. To establish the specific features of the taxonomic and functional composition of the enteric microbiota in patients with alcoholic liver cirrhosis (LC). Subjects and methods. Metagenomic analysis was used to study the taxonomic composition and functional potential of the enteric microbiota in 20 patients with alcoholic LC. Total DNA was isolated from the patients’ fecal samples; thereafter full genome sequencing was carried out. The metagenomic analysis yielded the results of the relative taxonomic and functional abundance of microbial species in the test samples. These were comparatively analyzed with the previously published metagenomic datasets of healthy population cohorts in the Russian Federation, as well as in Denmark, China, and the USA. Results. In the majority of patients, the dominant part of the intestinal community represented bacterial species constituting the normal human intestinal flora. At the same time, abnormal gut microbiota composition, which was suggestive of marked dysbacteriosis, was identified in a number of patients. In addition, pooled analysis of the data could identify a number of species with a statistically significantly increase and decrease in the relative abundance as compared to the control groups. Thus, the enteric microbiota of the patients with alcoholic LC showed a high proportion of bacteria characteristic of the oral cavity. Analysis of the pooled metabolic potential of the microbiota in these patients demonstrated the higher abundance of enzyme genes involved in alcohol metabolism. Conclusion. In the patients with alcoholic LC, the microbiota composition changes identified in individual bacterial species may be associated with gastrointestinal comorbidities, such as chronic erosive gastritis, chronic pancreatitis, and gastric ulcer. The alterations occurring in alcoholic cirrhosis promote the penetration and generation of oral cavity-specific microorganisms in the human intestine. This may a potential biomarker for the diagnosis of liver diseases. The bacterial enzyme genes involved in alcohol metabolism have an increased abundance in patients with alcoholic LC and healthy volunteers from the Russian Federation.

Using the technology of DNA chips Infinium HumanMethylation 450 BeadChip it was analyzed quantitative DNA methylation status in 12 paired samples of prostate adenocarcinoma, and morphologically altered tissues. Analysis of differentially methylated regions of the genome showed an association with abnormal status for 21610 and 3852 hypomethylated hyper-methylated CpG sites. Dominance in the cancer genome hypermethylated sites and their predominant localization in the regulatory regions of genes indicate their possible role in the implementation of mechanisms of gene suppression in the pathogenesis of prostate cancer (PCa). For 14 genes studied were characterized array maximum values hypermethylation in promoter region (50% CpG sites) in combination with a high level of methylation differences between treatment groups (40%). Role of hypermethylation in some of them: AOX1, KLF8, ZNF154, TMEM106A in the pathogenesis of prostate cancer has been showed previously. Hypermethylation of genes ACSS3, TAC1, TUBA4B, ZSCAN12 not previously been shown for prostate cancer, but is characterized by the association with other cancers. In turn, the differences in the levels of methylation in genes GPRASP1, NKX2-6, ARX, CYBA, EPSTI1, RHCG been documented as a result of a number of genome-research oncology, but has not been studied in detail. To assess the diagnostic potential of epigenetic markers of prostate cancer there was carried out unbiased selection of individual CpG sites most reliably discriminate against tumor samples from a group of no tumor samples. In selected diagnostic model based on logistic regression included 9 CpG sites. Validation of the model was carried out on an independent dataset of methylation of 40 paired samples from the prostate cancer project Atlas of Cancer Genome (TCGA) analyzed on the same version of the DNA chip. Summarized rates of diagnostic informativeness of a model (specificity 95%, sensitivity of 97%, the area under the curve of the diagnostic test (ROC) - 0,96), obtained after validation, allow us to consider these CpG Sites as potential markers for molecular diagnosis of prostate cancer.

S. pneumoniae is a facultative human pathogen causing a wide range of infections including the life-threatening pneumoniae or meningitis. It colonizes nasopharynx as well as its closest phylogenetic relatives S. pseudopneumoniae and S. mitis. Both the latter, despite the considerable morphological and phenotypic similarity with the pneumococcus, are considerably less pathogenic for humans and cause infections mainly in the immunocompromized hosts. In this work, we compared the inhibitory effect of S. pneumoniae and its relatives on the growth of Moraxella catarrhalis strains using the culture-based antagonistic test. We observed that the inhibitory effect of S. mitis strains is kept when a hydrogen peroxide produced by cells is inactivated by catalase, and even when the live cells are killed in chloroform vapors, in contrast to the pneumococcus whose inhibiting ability disappeared when the cells die. It was suggested that this effect may be due to the production of bacterial antimicrobial peptides by S. mitis, so we examined the genomes of our strains for the presence of bacteriocin-like peptides encoding genes. We observed that a set of bacteriocin-like genes in the genome of S. mitis is greatly poorer in comparison with S. pneumoniae one; moreover, in one S. mitis strain we found no bacteriocin-like genes. It could mean that there are probably some additional opportunities of S. mitis to inhibit the growth of competing neighbors which are still have to be discovered. Electronic supplementary material The online version of this article (10.1186/s13568-017-0521-z) contains supplementary material, which is available to authorized users.

A high-molecular-weight plant polysaccharide belonging to the hexose glycoside (HG) class and composed of rhamnose (2–10%), arabinose (3–15%), glucose (10–67%), galactose (2–27%), xylose (0.1–3%), and mannose (0.1–5%) monosaccharides, as well as uronic acids (2–5%), had been isolated previously. It has high antiviral activity, as is proven by experimental models using hazardous and extremely dangerous viral infections such as herpes, cytomegalovirus, influenza, encephalitis, measles, rabies, and hepatitis C. The antiviral drug Panavir developed on its basis has an extremely low toxicity (LD50 = 3000) and is an antiviral and immunomodulatory agent. There has been no microscopic (instead of phenomenological) model of its biological or pharmacological activity because of a lack of knowledge about its physicochemical nature. In the present work, the results of a study on the physicochemical properties of the HG macromolecules which makes it possible to qualitatively explain the biological activity and pharmacological properties of Panavir are presented.

Accurate species-level identification of viridans group streptococci (VGS) is very important for understanding of their pathogenicity and virulence. However, an extremely high level of the similarity between VGS, especially Streptococcus pneumoniae, Streptococcus mitis, Streptococcus oralis and Streptococcus pseudopneumoniae, often results in misidentification of these organisms, so there is an urgent need of novel approaches to species identification. A set of 50 randomly selected clinical isolates of alpha-hemolytic streptococci from upper respiratory tract were characterized by the routine phenotypic methods (alpha-hemolysis, colony morphology, Gram stain and optochin susceptibility). Modern proteomic and genetic approaches - the direct bacterial profiling (DBP) by means of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) technique and multilocus sequence analysis (MLSA) scheme (http://viridans.emlsa.net/) - were applied for the accurate species identification. After that all isolates were stored at -70°C. Later they were re-inoculated, and a number of additional tests (bile solubility, latex agglutination by commercial "Slidex® pneumo-kit" and repeated optochin test) were performed. A considerable discrepancy was discovered in the results of the different approaches. Looking in the future, one could say that MLSA-like schemes based on the analysis of the nucleotide sequences of seven or more loci of the bacterial genome, appeared to be the most useful instrument in the VGS discrimination, in contrast to the numerous one-target identification schemes, which have been introduced into practice by now.

The review presents the current classification of antimicrobial peptides (AMP), which are the main component of innate immunity. The mechanism of their action and the molecular basis of the formation of resistance towards these peptides are described. Data on the use of AMP for the treatment of various infectious diseases, as well as the state of the art in genetic therapy using AMP, are given.

Methicillin-resistant Staphylococcus aureus (MRSA) is the causative agent of nosocomial infections observed worldwide. The goal of this work was to study the genetic variations in MRSA isolates recovered from Moscow clinics and compare various methods of molecular typing (multiplex PCR, SNP genotyping based on the determination of single-nucleotide polymorphisms). A total of 62 epidemiologically unrelated hospital-acquired MRSA isolates were studied. A previously described multiplex PCR assay was utilized for the molecular typing of staphylococcal cassette chromosome mec (SCCmec). SNP genotyping that targets the seven sequences in five housekeeping genes (arcC162, arcC210, aroE132, gmk123, tpi241, tpi243, and yqiL333) was employed. Primer extension was used to screen single nucleotide variants followed by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Multilocus sequence typing (MLST) was used as a reference assay. Most MRSA isolates (93.6%) were assigned to the clonal complex (CC) 8 disseminated worldwide. Three MRSA isolates (4.8%) proved to belong to CC1. The following correlation was established in this study between SCCmec cassette types and sequence types (STs): ST8-MRSA carried SCCmec type IV and ST239-MRSA carried type-III a SCCmec. Four SNP groups associated with certain SCCmec types were also identified. The developed SNP genotyping assay aided by MALDI-MS enables the rapid genotyping of S. aureus isolates according to their clonal types.

In this paper, we demonstrate that nickel nanoparticles are suitable and promising for forming multifunctional biopolymer structures and have advantages over other nanoplatforms. We found that aggregates of nickel nanoparticles form stable associates with fragments of single-stranded DNA (ss-DNA). The impact of the oligomer length, nucleotide composition, nature of the internucleotide bond, and association conditions on the structure and properties of the complexes was studied. The protein-nickel associates were studied for two recombinant histidine-tagged proteins, for which the isotherms of adsorption were obtained. Biopolymer molecules incorporated in associates do not degrade and can retain (completely or partially) their functionality. Therefore, they can be used for selection of aptamers with binding affinity for proteins. The results contribute to the development of new biopolymer-nickel nanostructures, which have potential as research and diagnostic tools in the fields of molecular nanoelectronics, biology, and medicine.

Antibiotic resistance markers were analyzed in C. trachomatis clinical isolates obtained after ineffective therapy of urogenital chlamydiasis with fluoroquinolones and macrolides. Heterotypical resistance to fluoroquinolones and macrolides was detected in all clinical isolates. No significant mutations in the target genes were detected. ispartof: Bulletin of Experimental Biology and Medicine vol:143 issue:6 pages:713-717 ispartof: location:United States status: published

Optochin-resistant pneumococci can be rarely caught in clinical microbiology laboratories because of the routine identification of all such strains as viridans group non-pneumococci. We were lucky to find four non-typeable Streptococcus pneumoniae clones demonstrating the different susceptibilities to optochin: one of them (Spn_13856) was resistant to optochin, while the other three (Spn_1719, Spn_27, and Spn_2298) were susceptible. Whole genome nucleotide sequences of these strains were compared to reveal the differences between the optochin-resistant and optochin-susceptible strains. Two adjacent genes coding maltose O-acetyltransferase and uridine phosphorylase which were presented in the genomes of all optochin-susceptible strains and missed in the optochin-resistant strain were revealed. Non-synonymous substitutions in 14 protein-coding genes were discovered, including the Ala49Ser mutation in the C-subunit of the F0 part of the ATP synthase rotor usually associated with pneumococcal optochin resistance. Modeling of a process of optochin interaction with the F0 part of the ATP synthase rotor indicates that the complex of optochin with "domain C" composed by wild-type C-subunits is more stable than the same complex composed of Ala49Ser mutant C-subunits.

A complex method for detection of genetic markers of N. gonorrhoeae resistance to penicillin was developed. Mutations in penA and ponA genes were detected by minisequencing reaction with subsequent detection of reaction products by MALDI-TOF mass spectrometry. This approach was tested on 31 clinical strains of N. gonorrhoeae with minimum inhibitory concentration of penicillin from 0.03 to 8 microg/ml and higher. Mutations in penA and ponA genes in moderately resistant strains were shown (minimum inhibitory concentration up to 0.5 microg/ml) and mutations in penA, ponA, and penB genes in resistant strains (minimum inhibitory concentration more than 1.0 microg/ml). beta-Lactamase genes were detected in 4 strains with high resistance (minimum inhibitory concentration 4-8 and more microg/ml). Correlation between microbiological resistance and presence of respective mutations in the studied locuses was detected.

To detect point mutations A2115C, A2143G/C, and A2143G in the 23S rRNA gene of Helicobacter pylori associated with resistance of the microorganism to clarithromycin, a new powerful way of analysis was used. This method involved the reaction of minisequencing followed by MALDI-TOF mass spectrometry of reaction products. In ten analyzed clarithromycin-resistant clinical isolates of H. pylori obtained in Russia, the resistance was found to be mediated only by mutation A2144G in the 23S rRNA gene.

Using multilocus sequence typing (MLST), 22 Helicobacter pylori isolates from Russia have been characterized. All of the Russian strains were assigned to a single population, hpEurope.

Complete sequences of omp1 gene encoding chlamydial main outer membrane protein were analyzed in 76 clinical strains of C. trachomatis. Thirty-four serovar-specific single-nucleo-tide polymorphisms were identified, 20 of them meet two criteria: unique position of the nucleotide and unique nucleotide substitution. Evaluation of serovar-specific single-nucleotide polymorphisms of omp1 gene can appreciably simplify and accelerate genetic diagnosis of C. trachomatis serovars.

A Mycoplasma hominis chromosomal fragment containing the full-length ftsZ gene was cloned and sequenced. Natural expression of this gene was demonstrated by reverse transcription–polymerase chain reaction (RT–PCR) with total RNA. TheM. hominis FtsZ protein was shown to differ substantially from its counterparts of two otherMycoplasma species, M. genitalium,and M. pneumoniae.The possibility of M. hominis ftsZ expression in Escherichia coliwas demonstrated with several bacterial strains. The M. hominis FtsZ protein was isolated from E. coli cells transformed with recombinant plasmids carrying the M. hominis ftsZ gene. Complementation between theE. coli and M. hominis FtsZ proteins was observed in transformants.

Genetic polymorphism of Russian population of N. gonorrhoeae was detected and a system for genotyping of its clinical strains was introduced into practice. Comparative analysis of the prevalence of N. gonorrhoeae genotypes in Russia and abroad was carried out. For adaptation of the methods of molecular typing of N. gonorrhoeae strains and its approbation on clinical strains isolated in Russia 41 clinical strains of N. gonorrhoeae were typed. The predominance of PIB serovar (83%) was demonstrated.

Of the 130 clinical isolates of Mycoplasma hominis from patients with nonspecific inflammatory diseases of the urogenital tract (UGT), approximately 10% contained the tet(M) gene after the course of treatment with tetracyclines. This gene was found in nine (25%) of the 36 Ureaplasma urealyticum clinical isolates. The nucleotide sequence of 13 tet(M) genes in TcR clinical isolates of M. hominis and five genes in U. urealyticum TcR clinical isolates was determined. A comparison of nucleotide sequences of eight tetM genes of different origin and tet(M) genes of Gardnerella vaginalis and M. hominis and U. urealyticum clinical isolates showed that the mosaic structure of the tet(M) gene is completely identical in 11 of 13 M. hominis TcR isolates but belongs to an unidentified allele different from those described earlier, Another new allelic variant of tet(M) was found in two isolates. In three of five TcR clinical isolates of U. urealyticum, a tet(M) gene, whose mosaic structure was identical to that of tet(M) reported previously for ureaplasmas, and also two new allelic variants, which have not been described so far, were found.

The effect of cocultivation of eukaryotic HeLa cells and Mycoplasma hominis mycoplasma on the resistance of the latter to fluoroquinolones (ciprofloxacin) was examined. It was shown that cocultivation of the M. homonisand HeLa cells during 24 h with subsequent addition of ciprofloxacin resulted in an increase of the micoplasma resistance to this antimicrobial agent. In the M. hominis cells cultivated in the presence of HeLa cells and the increasing concentration of ciprofloxacin mutations in the parC gene were observed only at low concentrations of the antimicrobial agent, while mutations in the gyrA gene were never detected. A gradual elevation of ciprofloxacin concentration up to 10 μg/ml resulted in the reversion of the parC mutations in mycoplasmas. Mycoplasma cells resistant to high flouroquinolone concentrations and isolated after cocultivation with the HeLa cells were characterized by the wild-type genotype in respect of the gyrA and parC genes. It was shown that infection of HeLa cells resulted in the appearance of genome rearrangements in M. hominis cells.

We studied the correlation between genetic transfer of tetM determinant in Tn916 conjugative transposon by urogenital mycoplasmas (Mycoplasma hominis and Ureaplasma urealyticum) and changes in the bacterial repertoire during treatment with a tetracycline antibiotic. Basic conditions favoring the nonspecific transfer of tetM determinant into mollicute cells are determined and the allele polymorphism of tetM determinant in clinical strains of M. hominis and U. urealyticum is evaluated. The structure of tetM gene in clinical mycoplasma and ureaplasma strains is characterized by a peculiar mosaic pattern and differs from all previously described alleles of this gene. The results suggest that tetracycline resistance in mollicutes is determined by mechanisms alternative to genetic transfer of tetM determinant.

Mollicutes are unique microorganisms characterized by a great extent for the reduction in genetic material, which retained the capability of independent division on acellular nutrient media. Phenotypically mycoplasmas differed from other bacteria by their small size and lack of a cell wall (mollis, soft; cutis, skin). High dependence on metabolism components utilized in the cultivation medium and high metabolic plasticity due to the absence of many genome regulatory elements make mycoplasmas perfect parasites for cells of the eukaryotic origin. The ability of these microorganisms to pass through host cells and their assumed participation in AIDS activation facilitate the study of mycoplasma pathogenesis. Another important feature of mycoplasmas, which is expressed during their interaction with a macroorganism, is their ability to escape from the immune response of a host due to surface antigen variation. These adaptation capacities of mycoplasmas ensuring their life in various biological niches, given a limited genome and the direct metabolic dependence on an environment, cannot be adequately explained at present. In this review, we attempted to collect and systematize data that contribute to our understanding of the important feature of mycoplasmas, genetic instability, which may underlie many of their adaptive responses.

Gene MDR1coding for P-glycoprotein belongs to a group of genes responsible for cell defense. The overexpression of this gene determines the resistance of tumor cells to a series of chemotherapeutic drugs known as multidrug resistance. Many chemotherapeuticals induce both the apoptosis and transcriptional activity of the MDR1gene in tumor cells. It is not known, however, how these two processes are associated with each other. In order to elucidate a possible link between them, we have studied the sphyngomyelinic pathway of signal transduction. This pathway is activated in response to various stress factors and includes the hydrolysis of sphyngomyelin of cytoplasmic membrane resulting in an accumulation of intracellular ceramide, which activates cascades of enzymatic reactions leading to various cell responses, including apoptosis. C2ceramide (N-acetyl-D-sphyngosine) and cytosar (1β-D-arabinosylcytosine, or ara C) were used to induce the sphyngomyelinic pathway. Their effects on human hemoblastosis cell lines (K562 and H9 cell lines) were examined. C2ceramide and ara C induced apoptosis in both cell lines over an 18-h incubation. C2ceramide also induced an increase in the expression of the gene MDR1in both cell lines, while ara C increased the activity of the gene MDR1only in H9 cells. The results obtained provide evidence for the contribution of ceramide-mediated signal pathway to the control of MDR1activity.

Recombinant plasmids containing the mellitin gene under the control of the lac and the tetM gene promoters were used for studying cytotoxic activity of mellitin in cells of mollicutes (mycoplasmas) and Escherichia coli. After transformation of Acholeplasma laidlawii andMycoplasma hominiscells with recombinant plasmid DNAs by electroporation, cell growth was suppressed. The expression of the mellitin gene in A. laidlawii andM. hominis cells was demonstrated using the reverse transcription polymerase chain reaction (RT–PCR). The possibility of using the mellitin gene in the recombinant vector as a potential antimycoplasmic gene-therapeutic agent with its selective expression in target cells is discussed.

Polymerase chain reaction was clinically used to diagnose chlamydial and mycoplasma infection in the cervix and male urethra. Examinations of 2260 patients with disorders of reproductive function detectedC. trachomatis, M. hominis, andU. urealyticum in 32.9, 9.7, and 25.7% of cases, respectively. A high incidence of mixed nongonococcal urogenital infections was observed, particularly in women. Seasonal fluctuations were shown in the detection rates of chlamydial and ureaplasmic infections.

A procedure for identifying chlamydia, mycoplasmas, and ureaplasmas by the polymerase chain reaction is described which uses a system of four primers complementary to fragments of the 16S RNA gene, one of which detects all three microorganisms and the other three are each specific for a particular organism. With this primer system, chlamydia, mycoplasmas, and ureaplasmas are detectable in a single reaction. The procedure may be used for routine diagnoses in diagnostic laboratories.

The proteasome is a high molecular protein complex whose purpose is specific protein degradation in eukaryotic cells. One of the proteasome functions is to produce peptides, which will then be presented on the outer cell membrane using main histocompatibility complex (MHC) molecules of the first or second class. There are definite reasons to believe that proteasome directly takes part in the specific degradation of myelin basic protein (MBP), which make up to 30% of all proteins in the myelin sheath of neuronal axons. The details of the proteasomal degradation of MBP are still unclear. In this work, the features of specific MBP degradation by proteasome were studied. It was demonstrated that MBP (non-ubiquitinated) is a good substrate for 20S and for the 26S proteasome. This is the first work on detecting the sites of MBP proteolysis by proteasome from brains of SJL/J/J and Balb/C mice's lines. Substantial differences in the degradation pattern of this neuroantigen were found, which could indicate the better presentation MBP parts on MHC molecules in the case of mice predisposed to the development of experimental autoimmune encephalomyelitis.

The spread of aminoglycoside resistance phenotype and respective genetic resistance determinants was evaluated in 243 Salmonella strains isolated within 1948-2010 and stored in the Culture Collection of the Russian State Research Institute for Control, Standardization and Certification of Veterinary Preparations (Moscow). The Salmonella strains showed resistance to streptomycin and gentamicin in 3.7% (n = 9) and 0.8% (n = 2) of the isolates respectively. Intermediate resistance to streptomycin was recorded in 9.9% (n = 24) of the isolates. To detect the genes responsible for the aminoglycoside resistance, primers for aadA1, aadA2, aadB, aphA1, aphA3, sat, strA, strB, aphA, aacC, rmtB, armA and rpsL genes amplification and sequencing were designed. The strains with lower susceptibility to streptomycin harbored aadA1, aadA2, strA, strB resistance genes encoding enzymes for aminoglicoside modification and rpsL mutant allele (K42N, G91D). Genetic mechanisms able to explain the gentamicin resistance development were not detected. Some strains carried genetic markers of streptomycine resistance but had no clinically sufficient resistance to it. In this regard, genetic testing is essential for prevention of drug resistance spreading due to horizontal transfer of genes in microbial population.

In the current study the isolation and identification of Physcomitrella patens (Hedw.) B.S.G. moss peptides are described. Physcomitrella patens moss is actively used in recent years as a model organism to study the biology of plants. Protoplasts, protonemata and gametophores of the moss are demonstrated for the first time to contain diverse small peptides. From gametophores was isolated and identified 58 peptides that are fragments of 14 proteins, and from protonemata - 49 peptides, fragments of 15 proteins. It was found that the protonemata and gametophores Ph. patens, which are the successive stages of development of this plant, significantly different from each other as a peptide composition and the spectrum of the precursor protein of identified peptides. Isolation of protoplasts of the enzymatic destruction of cell wall protonemata accompanied by massive degradation of intracellular proteins, many of whom are proteins of photosynthesis, which is a characteristic response of plants to stress the impact of environmental factors. A total of moss protoplasts were isolated and identified 323 peptides that are fragments of 79 proteins.

Time-of-flight MALDI mass spectrometry (MALDI-TOF-MS) profiling of blood serum of patients with Guillain-Barré syndrome (GBS, 36 samples), chronic inflammatory demyelinating polyneuropathy (CIDP, 24 samples) and practically healthy donors (HD) (35 samples) was carried out in order to identify potential biomarkers of autoimmune demyelinating polyneuropathies (ADP). To simplify the peptide-protein mixture of serum prior to MALDI-TOF-MS analysis samples were pre-fractionated on magnetic microparticles with a weak cation-exchange (MB-WCX) surface. Comparative analysis of mass spectrometric data using the classification algorithms (genetic and neural network-controlled) revealed a characteristic set of peaks, agreed change area with a high specificity and sensitivity of the differentiated mass spectrometry profiles of the blood serum of patients with DPNP and healthy donors (for GBS values of these characteristics reached 100 and 100, and for CIDP 94.1 and 100% respectively). Comparative analysis of mass spectrometric profiles of serum samples obtained from patients with GBS and CIDP, allowed to build a classification model to differentiate these diseases from each other, with a specificity of 88.9 and a sensitivity of 80%.

Two-dimensional electrophoresis and mass spectrometry detection were used to evaluate the range of proteins in rat brain after single treatment with ladasten (50 mg/kg). We identified 13 proteins with various levels of expression.

Sequential treatment of bisulfate-converted DNA was used to study methylation of promoter areas of SEPT9, HLTF, ALX4 and CDH1 genes. Methylation profiles were evaluated by comparing bioptical findings on colorectal cancer (n=55) and morphologically intact areas of the large bowel (n=71). Significant differences between groups were established for SEPT9, HLTF and ALX4 genes (por = 10(-9)) in evaluating medium-rate methylation of CpG. Diagnostic sensitivity (Se) peaked for SEPT9 (78 +/- 7%); specificity--(86 +/- 4%) (Sp). On site CpG (position "+14"), similar findings were reported: Se=81 +/- 6%, Sp=77 +/- 5%. Therefore, CpG(14)SEPT9 may be used as a separate marker. As a result of the use of HLTF as marker on all 23 sites, Se was 67 +/- 6% and Sp--87 +/- 3%; ALX4 diagnostic sensitivity--59 +/- 6%. Specificity level was similar to those of the other genes (88 +/- 3%). Despite the role of CDH1 gene in colorectal cancer, the group-to-group differences in methylation rates were minimal. Such values of Se and Sp as 54 +/- 6% and 67 +/- 5%, respectively, could not support methylation of the CDH1 promoter area for diagnostic purposes. Therefore, combined evaluation of SEPT9, HLTF and ALX4 genes offered more advantage as far as diagnosis is concerned. Hypermethylation in two of the three genes was assumed as a criterion for diagnosis. Under such conditions, diagnostic sensitivity was 81 +/- 7% (Sp=93 +/- 3%). With such high values, the criterion has a potential of being instrumental in working out diagnostic tests for colorectal cancer.

OBJECTIVES; Methicillin-resistant Staphylococcus aureus (MRSA) is a common pathogen of nosocomial infection. The goal of this work was to evaluate the clonality of hospital-acquired MRSA (HA-MRSA) circulating in Russian Federation and to compare different multiplex PCR techniques with SNP-based approach for MRSA typing.Epidemiologically unrelated MRSA isolates (n = 62) from Moscow hospitals were selected for typing. Genomic DNA from clinical isolates was purified using the DNA express kit (Lytech Ltd, Russia). Staphylococcus chromosomal cassette mec (SCCmec) typing was performed by PCR using the previously described methods. Seven loci from five housekeeping genes (arcC162, arcC210, aroE132, gmk123, tpi241, tpi243 and yqiL333) were used for SNP-typing. Detection of particular nucleotides in selected loci was carried out in the thermocyclic primer extension reaction, followed by mass spectrometry of the products. Standard MLST procedure was performed as reference method.The majority of the MRSA isolates (93.6%) belong to world-wide disseminated clonal complex (CC) 8. Three isolates (4.8%) belong to CC 1. All ST 239 isolates were found to carry SCCmec type III; ST 8 isolates, SCCmec type IV.Among Russian MRSA CC 8 isolates carrying SCCmec IV type are predominant. SNP-typing is powerful toll for studies of molecular epidemiology of MRSA.

The present study investigates epidemiological diversity and multidrug resistance spreading among Mycobacterium tuberculosis strains circulating in Moscow, Russian Federation. Among 115 M. tuberculosis strains selected randomly from the sputum of epidemiologically unrelated tuberculosis (TB) patients, multidrug-resistant (MDR) strains predominated. Mutations in the RRDR of the rpoB gene were detected in 64 (83.1%) of 77 rifampicin (RIF)-resistant strains. The Ser531→Leu substitution was prevalent among them (76.5%). Aberrations in the Ser315 codon of katG and/or in the inhA promoter region were found in 79 (84.0%) of 94 isoniazid (INH)-resistant strains. Strains belonging to the Beijing family prevailed. Seventy-one different patterns were identified using the 24-VNTR loci typing scheme. Three main 24-loci VNTR clusters included 34 strains which belonged to the Beijing family. The spoligotyping and 24-loci VNTR typing combination demonstrated maximal discriminatory power. Among the Beijing strains, the MDR phenotype was revealed more frequently than among the others. High genetic heterogeneity of the studied population was shown by the assessment of VNTR loci variability in the analyzed group and in the strains from other parts of Russia. Comparison of the 24-VNTR locus typing and spoligotyping data with revealed resistance-associated mutation allows us to make a suggestion that the active transmission of MDR strains and the independent appearance of drug resistance during chemotherapy occurred in the studied population simultaneously.

The frequence of mutations in the rifampicin resistant (RIF(r)) clones of microorganisms after adaption to ofloxacin and metronidazole was investigated to estimate the biological cost of H. pylori rifampicin (RIF) resistance. Mutations in rpoB gene responsible for RIF resistance of H. pylori were shown to have biological cost and be compensated by additional mutations in the microorganism genome. Comparison of the mutation frequency in the presence of metroniazole demonstrated that the acquired resistance to RIF resulted in changing of the adaptative capacity of the RIF(r) clones of H. pylori to metronidazole. Thus, a significant increase of the mutation frequency (700 times) in one of the RIF(r) clones and a broad spectrum of the mutations responsible for resistance to metronidazole vs. the H. pylori initial strain 26695 were observed. The findings could be evident of the fact that the adaptation to RIF changed the properties of the cell on one hand in such a way that its mutation capacity increased and that the target selection on the other hand revealed hypermutable cells, likely usual for the bacterial population.