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The article presents analysis of activities concerning organization of pre-analytic stage of monitoring of HIV resistance to anti- retrovirus preparations on territories of the Privolzhskiy Federal Okrug. The medical records of patients receiving anti-retrovirus therapy and appointment cards to detect drug resistance of HIV from territorial centers of prevention and control of AIDS and infectious diseases are analyzed. The results of testing of specialists of service of prevention of AIDS/HIV with questionnaire "Characteristics of pre-analytical stage under implementation of molecular genetic and immunologic analyses" developed in the Privolzhskiy okrug center of prevention and control ofAIDS and samples of bio-tests obtained during coming-outs in regions of okrug were included into analysis too. The failures in implementation of pre-analytical stage were established. Hence, the subsequent decreasing of informativeness of analyses or inexpediency or even impossibility of application of testing of AIDS drug resistance. The recommendations are proposed concerning main directions of work to enhance pre-analytical stage of analysis of AIDS resistance to anti-retrovirus preparations.

Aim: Genotyping of noroviruses that had circulated in the territory of Nizhny Novgorod during 6 epidemic seasons (2006 - 2012), detection of dominating genovariants and analysis of their change., Materials and Methods: Feces samples from children hospitalized in an intestinal infection department of one of the infectious disease hospitals of Nizhny Novgorod served as material for the study. Noroviruses were detected by reverse transcription polymerase chain reaction. Genotypes and gene variants were determined by analysis of nucleotide sequences of viral genome regions coding capsid protein and RNA-dependent RNA-polymerase., Results: During examination of 6589 children with an acute intestinal infection between July 2006 and June 2012 noroviruses were detected in 17.55% of cases. Nucleotide sequences of capsid and/or polymerase gene regions were determined for 114 norovirus isolates. Genotyping has shown that noroviruses of 8 various genotypes had circulated in the territory of Nizhny Novgorod--GII.1, GII.2, GII.3, GII.4, GII.6, GII.7, GII. 12, GII.13 with the domination of GII.4 noroviruses for the whole observation period. A dynamic of change of epidemic variants of genotype GII.4 noroviruses that had been accompanied by an increase of frequency of detection of norovirus in children hospitalized with acute intestinal infection similar to global was established. A short-term circulation of GII.4 2006b-NN 2008 norovirus subvariant in spring of 2008 and spread of genotype GII.12 norovirus during 2009, 2010 epidemic season were also shown., Conclusion: The data obtained give evidence to the necessity of norovirus circulation monitoring with the aim of early detection of novel virus variants that may determine an increase of norovirus infection morbidity.

Prevalence of the primary drug resistance mutations and resistance developed in patients receiving highly active antiretroviral therapies in the HIV-infected persons in the Privolzhsky federal district was studied. It was demonstrated that among the ART-naive HIV-positive patients there were no mutations leading to the development of resistance. A high level of the resistance to lamivudin, nevirapin, efavirenz was revealed among the persons receiving the antiretroviral therapy. As a whole, the frequency of mutations of resistance to nucleoside reverse transcriptase inhibitors (23.8%) and nonnucleoside reverse transcriptase inhibitors (26.9%) was much higher than to protease inhibitors (1.2%).

A total of 5230 specimens from children with gastroenteritis collected in Nizhny Novgorod in 2006-2010 were screened for human parechoviruses (HPeV). HPeV were observed every year with mean frequency of 6.16%. The majority of HpeV (65.83%) was detected in children younger than 3 years. The typing of 71 detected HPeV with the use of partial sequencing of the VP3-VP1 region revealed the presence of HPeV1 (91.55%), HpeV6 (5.63%), HPeV3 (3.08%), HPeV4 (1.54%). HPeV1B was predominant among HPeV1, HPeV1A was identified rarely. Six stains of HPEV1 formed separate phylogenetic cluster, had sequence gomology with HPEV1A or HPeV1B not more than 88% and could be characterized as members of a separate genotype HPeV1.

Aim: Genotyping ofastroviruses isolated from children with acute enteric infection (AEI) on the territory of Nizhny Novgorod in 2006 - 2011., Materials and Methods: Samples of feces from children hospitalized in intestine infection department of a Nizhny Novgorod infectious diseases hospitals served as study material. Astroviruses were detected by reverse transcription polymerase chain reaction method. Astrovirus genotypes were determined based on phylogenetic analysis of nucleotide sequence of genome fragment coding capsid protein., Results: During examination of 5759 children with AEI from July 2006 to June 2011 astroviruses were detected in 2.6% of cases, and in 2010 - 2011 the frequency of astrovirus detection (5.19%) was significantly higher than in the previous epidemic seasons and the average based on the whole observation period. Genotyping of the detected astroviruses showed that genotype 1, 2, 3, 4, 5 astroviruses circulated on the territory of Nizhny Novgorod with predomination ofgenotype 1. Genotype 1 astroviruses are presented by genetic lineages 1a, 1b, 1d with predomination of lineage la. From the start of 2010 all the detected isolates from genetic lineage la belonged to a single new sublineage - 1a-2010. The second by quantity of detected isolates were genotype 5 astroviruses identified for the first time in Nizhny Novgorod in July 2010. Genotype 2, 3 and 4 astroviruses were detected in isolated cases., Conclusion: Activation of astrovirus circulation in the population of Nizhny Novgorod that was shown by a significant increase of frequency of their detection in children with AEI in 2010 - 2011 epidemic season with the highest probability was caused by appearance of genotype 5 astroviruses, that had not previously been detected in this territory and other territories of Russian Federation.

In 2009 echovirus 9 caused a higher seasonal incidence of enterovirus infection (EVI) and its several outbreaks in a number of regions of Russia. Analysis of the partial VP1 coding region differentiated 4 phylogenetic lineages of echoviruses 9 variants identified in patients with aseptic meningitis and EVI in 2007-2009. One variant of echovirus 9 was most commonly encountered in 2009. Echoviruses 9 identified in different areas, which had a high (98.2-100%) homology of nucleotide sequences of the partial VP1 coding region, varied in the amino acid sequences within the B-C loop.

A prospective longitudinal controlled investigation of 189 patients with secondary diffuse peritonitis was performed. A correlation between the levelof interleuikin-6 of peritoneal exudate, the severity of the patients' state, the number of complications and outcome of the course of the disease was established. The maximal number of complications and unfavorable outcomes falls on the peak value ofinterleuikin-6.

The genes regulating resistance to potassium tellurite were cloned from plasmid pS221 with a broad host range. The studied DNA fragment encodes for the synthesis of two polypeptides with molecular mass of 38 and 43 kD. Metal tellurium crystals were localized in the periplasm of Pseudomonas aeruginosa ML4262 (pBS221) cells by electron microscopy. Results of colony hybridization permit us to propose that the cloned genes of potassium tellurite resistance have sites of homology with plasmids RP4(IncP), R27 (IncH), pBS38, pBS79, and R931(IncP-2).

Modern data on prevalence, structural and functional organization of the tetracycline resistance determinants in bacteria are reviewed. The three mechanisms of the antibiotic resistance are the tetracycline efflux, the ribosomal protection and the antibiotic modification. The problems of evolution of tetracycline resistance genes are discussed.

The colony hybridization and tetracycline accumulation techniques made possible to demonstrate the majority of the 29 bacteria of Pseudomonas genera to harbour the plasmids carrying tet determinants belonging to classes A-C, while one strain contained a plasmid carrying tet determinant of class B. For the first time the determinants of classes D and E were found on R plasmids in Pseudomonas aeruginosa. The determinant of G class was identified on two plasmids identical to pBS221 plasmid described previously.

Plasmid pBS221 was physically mapped for restriction endonucleases EcoRI, BamHI, BglII, HindIII. The regions essential for the plasmid existence and participating in replication (oriV trfA*) and mobilization (mob) were cloned. The tet determinant and oriV trfA* regions were localized on the physical map of the plasmid. A DNA sequence homologous to genes of Tn501 mer operon was detected in this plasmid. The studies on homology of plasmids RP4 (IncP alpha), R751 (IncP beta) and pBS221 plasmid suggest that the latter belongs to the IncP beta subgroup.

Tetracycline-resistance determinant of the plasmid pBS221 isolated from a Pseudomonas aeruginosa strain has been cloned on pUC19 vector plasmid. The determinant is expressed under aerobic and anaerobic conditions coding for two proteins: a 36 Kd protein conferring antibiotic resistance and 27 Kd repressor protein. The determinant is not homologous to tet-determinants of the known classes as shown by blot hybridization experiments. The determinant represents a new class--G. Determinants of the new class are widespread among Serratia marcescens strains.