Detection of circulating HCV recombinant form RF1_2k/1b in blood serum of patients by real-time RT-PCR.

Globally, about 70 million people are infected with the hepatitis C virus (HCV), and about 400 thousand people die annually from chronic hepatitis C complications. The management of patients with chronic hepatitis C may require HCV genotyping, since the efficiency of some widely used antiviral drugs strongly depend on the viral genotype and/or subtype. The most prevalent HCV circulating recombinant form, RF1_2k/1b, is misclassified as genotype 2 by many commercial HCV genotyping kits, based on the RT-PCR analysis of the 5' untranslated region of the HCV genome. This leads to inappropriate patient treatment, since the accepted treatment schemes for HCV genotype 2 are ineffective for the RF1_2k/1b. Here we describe a method for detecting the RNA HCV RF1_2k/1b in blood samples by RT-PCR analysis of two regions in HCV genome (5'UTR and NS5b). The method was tested on 240 blood serum samples from HCV infected patients, in which HCV genotype was defined as 2 or mixed (2+1 or 2+3) by the two commercial genotyping kits "OT-Hepatogen-C genotype" ("DNA-Technology", Moscow) and "RealBest RNA HCV-1/2/3" ("Vector- Best ", Novosibirsk). 50 (20.8%) RF1_2k/1b cases were revealed, including three mixed infections: RF1_2k/1b + 1a, RF1_2k/1b + 3a, RF1_2k/1b + 1b. In all cases, the accuracy of HCV typing by the proposed method was confirmed by Sanger sequencing and phylogenetic analysis. The method is easy to implement into clinical practice and may be used in clinical settings equipped for RT-PCR analysis to correctly identify the recombinant variant RF1_2k/1b.

[The species variety of microflora in samples from urogenital tract of female patients of large network laboratory and its dependence of content of lactobaccilli].

The evaluation of content of DNA of lactobaccilli and particular types of aerobic anaerobic opportunistic bacteria in sampling of scrapes from urogenital tract offemale patients of the network laboratory INVITRO was implemented. The technique of polymerase chain reaction in real-time was implemented. It is demonstrated that decreasing of content of lactobaccilli in total bacterial mass isfollowed by increasing of occurrence, concentration and relative content of all types of opportunistic pathogens except ureaplasmna. These changes are expressed in different degree for different types of opportunistic pathogens. The increasing of varieties of types of microflora of urogenital tract under decreasing of content of lactobaccilli is noted.

[A single-tube real-time RT-PCR assay for the RNA detection and quantification of genetically diverse HIV Including rare non-M group of the HIV-1 and HIV-2].

The RT-PCR method with real-time fluorescence detection was used for development of φ prototype of diagnostic kit for reliable diagnosis of genetic variants of RNA of the HIV-1 of groups M, N, O, P and RNA of the HIV-2 in blood plasma and serum. The kit is stable against nucleotide defects, provides broad linear range of concentration of the HIV RNA, 100% analytical specificity and adequate analytical sensitivity: 42 ME/ml (HIV-1 of group M), 45 copies/ml (HIV-2), 92 copies/ml (HIV-1 of group O), 90 copies/ml (HIV-1 of group N). The kit provided successful detection and measurement of HIV RNA concentration in the samples of the international reference panel of the HIV-1 genotype. The results of the test correlate with results of commercial tests.

[DNA detection of pathogens transmitted by Ixodid ticks in blood of small mammals inhabiting the forest biotopes in Middle Irtysh Area (Omsk Region, West Siberia)].

Microtine rodents were captured in two disconnected sampling sites in Omsk region where Ixodes pesulrcatus and Ixodes trianguliceps are sympatric. In blood samples of rodents the DNA was revealed belonging to several ixodid-transmitted pathogens: Borrelia burgdorferi sensu lato (prevalence 20.0 and 6.0%, here and further values are given for the first and second site, respectively), Borrelia miyamotoi (8.3 and 2.0%), Anlaplasnma phagocytophilum (33.3 and 48.0%), Ehrlichia muris (30.0 and 2.0%) and Babesia microti (33.3 and 42.0%). Three genetic groups of A. phagocytophilhm based on 16S rRNA gene and groESL operon, as well as two genetic groups of B. microti, B. microti 'US'-type and B. microti 'Munich'-type, were detected.

[Microrna, evolution and cancer].

MicroRNAs are known as a posttranscriptional negative regulators of gene expression by binding to the 3'UTP of target mRNAs in cytoplasm. More than 1600 microRNAs expressed in human cells, are involved in the regulation of embryogenesis, differentiation, cell cycle, apoptosis, senescence, thus determining cell fate. Up to 60 % of protein coding genes are under their control. Various sets of microRNAs found in different human tissues under normal and pathological conditions, including cancer, suggest that miRNAs are involved in most cellular pathways. To date, there is no doubt that regulatory potential of the genome is largely determined by miRNAs. In our study, we performed a comparative phylogenetic analysis of the origin and evolution of the total set of 1048 miRNAs in the human genome and investigated the role of certain miRNAs in carcinogenesis of thyroid and mammary glands, as potential diagnostic and prognostic biomarkers of malignancy. Analysis of phylogenetic distribution of miRNAs in the human genome has shown four peaks of appearance of new miRNA genes in the evolution from Methazoa to H. sapiens. The highest amount of new miRNA genes appeared after divergence of H. s. from common ancestor with P. t. Expansion of transposable elements in genome was accompanied by the origin of new miRNA genes on the basis of their sequences. More than 14 % from 1600 miRNAs of human genome originated from mobile elements and still remain. Profiles of expression of 5 miRNAs, pertaining to oncomicroRNAs - miR-21, -221, -222, -155 and -205 - allow distinguishing ductal invasive carcinoma of mammary gland and thyroid papillary carcinoma. The data obtained suggest different ways and roles of participation of the same miRNAs in carcinogenesis of thyroid and mammary glands. So, these miRNAs and profiles of their expression might be used in the diagnosis and prognosis of cancer.

[The application of polymerase chain reaction in real-time operation mode to detect DNA of agents of human granulocytic anaplasmosis and monocytic erlychiosis].

The analysis was applied to detect DNA of agents of human granulocytic anaplasmosis and monocytic erlychiosis. The sampling included 109 ticks of Ixodes species from Novosibirsk oblast and Khabarovsk kray and blood samples of 111 mouse-like rodents from Omsk oblast. The used techniques included polymerase chain reaction in real-time operation mode with set of reagents "RealBest DNA Anaplasma phagocytophilum/Ehrlichia muris, ehrlichia chaffeensis" ("Vector-Best" Novosibirsk) and double round polymerase chain reaction. The DNA of A. phagocytophilum, agent of granulocytic anaplasmosis and/or DNA of E. muris, agent of monocytic erlychiosis was detected in 21 ticks and in blood samples of 52 voles. Both techniques were applied. The DNA of A. phagocytophilum was detected in samples of 2 voles and in 1 tick only after polymerase chain reaction in real-time operation mode was applied. It demonstrated that the set of reagents "RealBest DNA Anaplasma phagocytophilum/Ehrlichia muris, ehrlichia chaffeensis" permits to detect the DNA of isolates of A. phagocytophilum subsumed to different genetic groups. The set can be used for fast and effective detection of the DNA of agents of agents of human granulocytic anaplasmosis and monocytic erlychiosis in suspensions of analyzed ticks and blood samples.

[Development of an ultrasensitive mismatch tolerant PCR assay for the qualitative and quantitative determination of HIV-1 RNA].

A real-time fluorescent polymerase chain reaction was used to develop a RealBest HIV RNA kit that was clinically suitable for the detection of HIV-1 RNA and for the estimation of virus load in plasma and serum samples. Due to the selection of a highly conserved target region and to the experimental study of the impact of different primer-template and probe-template mismatches on RT-PCR with subsequent selection of the optimum oligonucleotide set, the developed assay can detect and measure the concentration of all subtypes of HIV-1, group M. The assay provides a high reproducibility and sensitivity and a wide dynamic range of virus loads (20 to 10 million IU/ml of plasma or serum).

[Hepatitis C virus genotyping using 5 nuclease real-time PCR and probes with oligodeoxyinosine linkers].

Hepatitis C virus (HCV) infection is a major cause of severe liver disease including liver cirrhosis and hepatocellular carcinoma. Genotyping became fundamental in the clinical assessment of patients with hepatitis C because the genotype of the hepatitis C virus determines the chance of therapeutic response and duration of treatment. We developed a new real-time PCR assay for genotyping of HCV with increased specificity due to a novel approach to dual-labeled probe design using oligodeoxyinosine linkers. The assay allows genotypes 1, 2, 3 to be distinguished and genotypes 4-6 with high specificity to be blocked. The analytical sensitivity (150 IU/ml) can be implemented. Of the 285 clinical samples genotyped using the developed assay, 45% were genotype 1; 6%, genotype 2; 49%, genotype 3. No discordant results with 5-UTR sequencing and commercial genotyping assays were obtained.

[Development of uncompetitive exogenous internal amplification control for real-time PCR based on UFA method].

An uncompetitive exogenous internal amplification control method (EIAC) was developed on the basis of short synthetic DNA segment, whose amplification can be detected in real time by UFA spectroscopy principle. The EIAC was shown to be useful as internal control in diagnostic test systems based on DNA or RNA detection by multiplex real-time PCR. It can be applied to assess the quality of extracted DNA or RNA, and also to detect and study the factors causing PCR inhibition and earlier plateau effect.

Determination of DNA polymerase and nuclease activities of DNA-dependent polymerases using fluorescence detection under real-time conditions.

A new method is proposed for estimation of polymerase activities using fluorescence detection during isothermal reaction. The method allows simultaneous determination of DNA-dependent DNA polymerase and 5'-3'-exonuclease activities using amplifiers supplied with an optical module for fluorescence detection under real-time conditions. Different primer-template combinations used as polymerase substrates were compared. Primer elongation (polymerase reaction) is detected by changes in SYBR Green I fluorescence upon binding to dsDNA during reaction; nuclease activities are detected by changes in fluorescence due to cleavage of the probe, containing the reporter fluorophore and fluorescence quencher, and hybridized in advance to the template single-stranded region. It was also shown that the method can be used for determination of relative activities of DNA polymerase preparations, estimation of temperature-time dissociation parameters of polymerase complexes with specific antibodies to its active center, and analysis of effects of inhibitors and activators of different nature on reaction rates of dsDNA polymerization and 5'-3'-exonuclease cleavage by polymerase. The method can be also used for estimation of endonuclease activities of DNA polymerases.