Vol 88, No 2 (2011)

Aim. Determination of non-O1/non-O139 Vibri o cholerae toxin (CT) gene expression by using EIA, and biological effect of non-O1/non-O139 V.cholerae supernatant on cell cultures evaluation. M aterials and methods. 39 V.cholerae strains from various serological groups were studied. Hemolytic activity of strains was determined by using Greig test, and cholera toxin production — in GM1-EIA and in continuous cell lines by registering cytotonic, cytotoxic and proteolitic effect. Results. GM1-EIA method does not detect CT production in 29 museum strains of non-O1/non-O139 V.cholera e in vitro . CT was detected only in 1 non-O1/non-O139 V.cholerae strain supernatant with OD=0.577 that is substantially lower than in O1 V.cholerae strains (OD=2.176). In cell cultures non-O1/non-O139 V.cholerae supernatants diluted to 1:100 caused elongation only in single cells. Conclusion. Cytological model is a more sensitive technique to evaluate toxin producing abilities of non-O1/non-O139 V.cholerae strains and is appropriate for use.

Aim. Genetic and antigenic characterization of Neisseria meningitidis strains isolated during meningococcal infection outbreaks from individuals in contact with patients with generalized form of meningococcal infection. Materials and methods. Strains obtained in 2007—2009 in Moscow during examination of individuals that were in contact with patients during meningococcal infection outbreaks were analyzed. Multilocus sequence typing, genetic subtyping and typing of VR fragment (FetA) techniques were used. Results. Data regarding investigated strains were submitted to the database at http://pubmlst.org/ neisseria/. Previously undescribed sequence types were found in 12 strains, sequence-type could not be determined in 2 strains, 2 strains lacked VR fragment (FetA). Serogroup A meningococci had «P1.5-2,10: F3-5» antigenic profile and belonged to ST-75 and ST-3349 sequence-type, these data does not support the emergence of epidemically significant strains in the territory under surveillance. All typed serogroup C strains and 1 serogroup B strain are of «ST-41/44 complex/Lineage 3» clonal complex. Subtypes of serogroup C meningococci strains match subtypes of strains that cause generalized forms of infection, while serogroup B strains isolated from the carriers and strains isolated from the patients had different antigenic profiles. Ungrouppable strains had notably higher level of genetic and antigenic diversity: only 6 of 16 strains (37.5%) could be sequence-typed using earlier data, all these strains are of clonal complex «ST-53 complex» that consists mostly of strains isolated from the carriers. Conclusion. Ratio of meningococci population circulating in Moscow and subpopulation capable of causing generalized form of meningococcal infection (GFMI) is different for meningococci of various serogroups. Ungrouppable strains isolated from the carriers are highly different from strains causing GFMI.

Aim. Evaluation of immunobiological prop- erties of recombinant atoxic forms of the Pseudomonas aeruginosa exotoxin. Materials and methods. 3 recombinant atoxic forms of the P.aeruginosa exotoxin A were produced and studied: aTox1, consisting only of exotoxin A domain 1; aTox1,2, consisting of domain 1 and 2 ; and aTox1,2, Δ 3 , consisting of both domain 1 an d 2, and part of domain 3. Results. aTox1,2 and a T ox1,2, Δ 3 had distinctive antigenic properties. F ormulation s based on these recombinant pro- teins were immunogenic and protected animals from exotoxin A in experimental conditions. Conclusion. These results may be used to construct direct-action immunobiological formulations.

Aim. Comparison of α-fetoprotein (AFP) levels in blood sera samples of women in the early stages of pregnancy with positive or indeterminate results of anti-HCV. Materials and methods. Blood sera samples of women in the first trimester of pregnancy were analyzed by using microplate test systems for enzyme immunoassay (EIA) with complex and separate detection of antibodies against hepatitis C virus (HCV) antigens. Results. AFP levels were higher in women in the first trimester of pregnancy with anti-HCV than in women without anti-HCV. AFP levels in blood sera samples of pregnant women with indeterminate results of anti-HCV analysis were higher than in blood sera samples of pregnant women without anti-HCV. No differences in serum AFP levels were observed between anti-HCV positive samples and samples with indeterminate results of analysis. Conclusion. Increased AFP level in the first trimester of pregnancy was observed not only in women with HCV infection, but also in women with indeterminate results of anti-HCV analysis. The data suggest that these groups may have epidemiological similarity.

Aim. Evaluation of adhesive properties of mi- croorganisms colonizing rheumatoid arthritis and systemic lupus erythematosus patients. Materials and methods. Nose mucosa and urinal microflora from 62 rheumatoid patients (32 — rheumatoid arthritis and 30 — systemic lupus erythematosus patients) was studied. 57 opportunistic micro- organisms were isolated: including representatives of Staphylococcus , Escherichia, Klebsiella, Morganella, Enterobacter genera. Adhesive properties on erythrocyte model of microorganisms isolated in patients with rheumatoid disease, museum cultures and clinical strains were analyzed by using standard technique. Results. Bacteria isolated in rheumatoid disease patients were characterized by pronounced adhesive potential. Bacteria of Enterobacteriaceae family have shown significantly higher adhesive properties. Heterogeneity of adhesive properties levels, and genera and species adhesive potential of bacteria was determined. Conclusion. Microorganisms colonizing rheumatoid disease patients have a high adhesive potential that can increase the risk of patient infections.

Aim. To evaluate diagnostic value of lipopolysaccharide-binding protein (LBP) level in different infectious processes and dysbiosis. Materials and methods. Serum samples of patients with salmonellosis, urogenital chlamydiosis, community-acquired pneumonia, polypous rhinosinusitis, nd bacterial vaginosis were studied. Results. LBP level were lower in patients with salmonellosis compared to healthy persons and decreased with increasing severity of the disease. Higher levels of LBP were detected in patients with chlamydiosis. Direct correlation between LBP level and etiology and severity of community-acquired pneumonia was demonstrated. In patients with polypous sinusitis, LBP level correlated directly with duration of disease, and inversely — with duration of remission. Two fold increase of mean LBP blood concentration and its correlation with duration of dysbiosis in patients with bacterial vaginosis were revealed. Conclusion. Multidirectional modulation of antiendotoxin defense was observed in different pathological conditions.

Aim. The extent of environmental objects contamination by Legionella pneumophila in Nizhny Novgorod and Nizhny Novgorod region hospitals evaluation, and detection of potentially hazardous objects. Materials and methods. 433 swabs of environmental objects, and 43 hot water supply and pool water samples from various departments of 4 multi-disciplinary hospitals were studies. DNA from environmental samples was detected by using real time PCR. Results. L.pneumophila DNA was detected in 41 (9,47%) samples from environmental objects and in 2 (4,65%) samples from hot water supply. These bacteria were more frequently detected in environmental samples from physiotherapy departments. Repeated detection of legionellae from the same objects was registered. Conclusion. Circulation of legionellae in multidisciplinary hospitals was determined. Circulation high risk departments and risk objects — reservoirs of L.pneumophila in health care institutions were determined.

Aim. Analysis of LPS and LPS-binding protein (LBP) serum levels and prognostic value evaluation in cancer patients with sepsis. Materials and methods. Blood samples of 17 healthy donors and 46 cancer patients with sepsis were analyzed by using «Hycult biotechnology» kits (the Netherlands). Results. Serum LPS level in cancer patients with sepsis was increased significantly. A substantial decrease of LBP level was detected in blood samples of deceased patients. Conclusion. Dynamic increase of LPS serum level and decrease of LPS-binding protein serum level in cancer patients should be considered as an unfavo- rable factor for sepsis.

Aim. To study the optimal conditions for roller cultivation of cold-adapted reassortant vaccine strain of influenza virus A/17/Duck/ Potsdam/86/92 (H5N2) in MDCK and Vero cell cultures grown on nutrient medium based on soy and rice flour hydrolysates obtained using trypsin and bromeline. Materials and methods. Vaccine strain was cultivated on MDCK and Vero cells in rollers in the presence of plant proteases. Obtained culture samples of vaccine strains were lyophilized and their infectivity was assessed. Results. Cultivation of vaccine strain on MDCK and Vero cells grown in experimental media containing reduced quantity (2 and 3% respectively) of fetal calf serum («Gibco», USA) resulted in high titers of the virus in the presence of plant proteases (4 mcg/ml of papain and 20 mcg/ml bromeline). Conclusion. Use of plant enzymes and nutrient media based on enzymic plant hydrolysates, including those obtained with bromeline, for cultivation of vaccine strain on MDCK and Vero cell cultures in rollers could make the manufacturing process of live influenza vaccines safer and more cost effective.

Literature data on main immunobiological characteristics of 1 st generation plague vaccines as well as ways of development of new tools for specific prophylaxis of plague: recombinant live, chemical, antiidiotypic, and DNA vaccines are presented in the review. Their expected advantages and disadvantages, perspectives of development and practical use in system of antiepidemic mea- sures are assessed.

Application of main histocompatibility complex tetrames (MHC-tetramers) for antigen specific T-cells detection and analysis coupled with flow cytometry opened new opportunities for T-cell response analysis. MHC-multimers allow the de- tection of T-cells against viral, cancer and vaccine antigens with exceptional sensitivity and specificity. This approach has become the «gold standard» for quantative analysis of T-cell immune response. Certain aspects of analysis using MHC-tetramer are examined, and importance of this approach in T-cell response efficacy evaluation in anti-HIV vaccine trials as well as in HIV positive patients are discussed.