Vol 91, No 5 (2014)

Aim. Study species composition and factors of pathogenicity of staphylococci isolated from intestine biotope of children with HIV-infection. Materials and methods. 75 strains of staphylococci from HIV-positive and 45 strains from HIV-negative children were isolated and identified. Factors of specific adhesion, colonization potential, invasion factors and toxin-formation of staphylococci were studied. Results. In HIV-infected children Staphylococcus aureus, Staphylococcus xylosus, Staphylococcus epidermidis dominated. Quantitative level of S. aureus was 1.8x10 7 PFU/g. Adhesion, production of hemolysin, DNAse did not differ from the comparison group (p>0.05). Lipase activity in staphylococci from HIV-infected children was higher than in the control group (p<0.05). Conclusion. The data obtained reveal some mechanisms of development of endogenous infection in HIV-infected children

Aim. Comparative analysis of parameters of humoral and cell immunity in individuals vaccinated against tularemia. Materials and methods. Sera and blood samples of 258 immunized individuals were studied by indirect hemagglutination and leukocytolis with tularin reaction. Results. 73% of the examined individuals had both specific antibodies and positive values of cell immunity The presence of anti-tularemia immunity was registered in 26 of 30 individuals immunized 10 - 20 years ago. However in 76 individuals (26%) we have detected discrepancies of the results of the 2 methods that complicate the evaluation of specific immunity status. As such, the use of only 1 method characterizing either humoral or cell immunity does not give objective information. Conclusion. The use of 2 methods directed on detection of both specific antibodies and delayed-type hypersensitivity reaction is reasonable for the increase of validity of results of anti-tularemia immunity status evaluation. Only positive immunologic parameters of both tests confirm the presence of immunity against Francisella tularensis and the possibility of revaccination period delay.

Aim. Determine the frequency of antibodies to surface (anti-HBs) and core (anti-HBc) antigens of hepatitis B in population of St. Petersburg of various age for evaluation of protective herd immunity against hepatitis B virus (HB). Materials and methods. Blood sera of970 individuals (491 males, 479 females) of 10 age groups from 0 to 50 years and older were examined for the presence ofanti-HBs and anti-HBc IgG by enzyme immunoassay using commercial diagnostic test-systems. Results. In general anti-HBs at the level of 5 mIU/ml and above were detected in 603 of the examined individuals (62.2%). Anti-HBs at the level of10 mIU/ml and above were detected in 53.9%. The frequency of anti-HBs in protective titers in males and females in general turned out to be similar (52.6% and 55.2%, respectively). Juxtaposition of age-specific parameters of seroprotection and acute HB morbidity in St. Petersburg revealed an inverse correlation of medium strength (r=- 0.54). Conclusion. Results of the study confirm high effectiveness of

Aim. Study of antiviral activity of moraprenil phosphates (MPP) against herpes simplex type 1 virus (HSV1) in vitro and during experimental infection caused by HSV1 in mice. Materials and methods. Activity of MPP in vitro was tested by the ability to suppress formation of symplasts in VERO cells infected with HSV1, strain VR-3. A series of MPP that suppress virus-induced symplast-formation by 30 times was selected for in vivo experiments. Anti-viral activity of MPP in vivo was studied in HSV-1 infected mice after administration of either prophylaxis or therapy regimens. Results. MPP at the dose of 20 mcg/mice during s/c administration exhibited a pronounced prophylactic-therapeutic effect. Effectiveness of MPP during clinically evident herpes against the background of developing neurologic symptoms was demonstrated for the first time. Visual observation of the mice, that had received MPP as the first clinical symptoms of the disease appeared, has shown that against the background of preparation injection the clinical signs have ceased after 2 - 3 days and did not registered at least for the whole duration of the observation period (14 days). Conclusion. Active herpes infection is accompanied by the increase of FoxP3 expression in thymus was shown. Possible mechanisms of anti-viral effect of MPP are discussed.

Aim. Study the effect of Escherichia coli acellular metabolites of various phases of development on phagocytic activity of neutrophils against the background of pregnancy hormone effect - estriol (E3). Materials and methods. E. coli K12 (wt) metabolites were selected at the end of adaptation and logarithmic growth phases by filtration after cultivation at 37°C in LB broth. Neutrophils of heparinized venous blood of healthy non-pregnant women (follicular phase, n=8) were incubated for 1 hour with E3 at 2 ng/ml and 20 ng/ml, then 30 minutes with E. coli metabolites, LB medium or Hanks’ solution at 37°C. Phagocytic activity evaluation was carried out by inhibition ofbioluminescence of E. coli K12 TG1 lux+. Results. Exometabolites of logarithmic growth phase of E. coli culture inhibited neutrophil phagocytosis after 40 - 60 minutes of incubation in contrast to metabolites of adaptation phase compared with LB medium. Neutrophil cultivation after hormone treatment in LB medium that has the ability to stimulate neutrophil phagocytosis compared with Hanks’ solution did not alter their phagocytic activity. However inhibiting effect of E3 at 20 ng/ml on neutrophil phagocytosis compared with control was exhibited in Hanks’ solution (at 50 - 60 minutes) and after the effect of E. coli adaptation phase metabolites (at 40 - 60 minutes). Conclusion. E3 at the level extrapolated from its level at III trimester of pregnancy could facilitate the reduction of antimicrobial potential of neutrophils at the early stages of growth of pathogenic microorganisms.

Aim. Creation of a PCR test-system for determination of Actinobacteria class bacteria belonging to 2 genera that are the most widely represented among obligate anaerobic microbiota of human intestine: Bifidobacterium and Propionibacterium. Materials and methods. 8 strains of Bifidobacterium spp. and 6 strains of Propionibacterium genus were identified by morphologic, cultural and biochemical properties. Isolation of matrix DNA of the strains for PCR was carried out by «DNA-Express» kit (SPF «Lytech», Russia). Primers for determination of genus membership for obligate anaerobes were developed based on variability of 16S RNA gene by using «Lasergene 7.1» («DNASTAR, Inc.», USA) program. PCR screening of the isolated DNA was carried out based on «Syntol» LLC primers and reagents. Amplicon detection was carried out by agarose gel electrophoresis. Results. Multiplexing of 2 different primer pairs in a single probe at 68°C annealing temperature for 30 cycles showed the presence of non-specific amplicons that form in samples with bifidobacteria DNA-matrix. The increase of annealing temperature to 70°C and reduction ofthe number of PCR cycles to 25 resulted in the exclusion of formation of non-specific amplicons. Because the annealing temperature reached the level of values optimal for Taq-polymerase, a 2-phase PCR algorithm could be implemented. This solution allowed reducing the overall time of reaction to 45 minutes. Further increase of annealing temperature to 72°C and reduction of elongation phase up to 15 seconds at 30 PCR cycles did not result in a visible reduction of reaction effectiveness. Conclusion. A rapid system for identification of Bifidobacterium and Pronionibacterium genera using a system of 2-phase multiple PCR was developed. The system is part of a screening system for identification of major genera and species of cultured obligate anaerobic bacteria isolated from human intestine biotopes.

Aim. Study experimental production series of Staphylovac-2 by accumulation of specific IgG and safety. Materials and methods. Experimental production samples of staphylococci vaccines were studied by the accumulation of specific IgG in sera of immunized BALB/c line mice in EIA. Safety was evaluated in tests of acute and chronic toxicity including pathomorphologic and histologic, hematologic and biochemical studies, studies of the effect on central nervous system. Results. A statistically significant (2.6-3.0 times) increase of IgG levels in sera of immunized mice compared with control was noted. In the experiments studying acute and chronic toxicity the increase in body mass and mass of internal organs differed from data obtained from control animals at no observation periods. None of the studied methods of safety evaluation showed differences of the studied vaccine series from the control. Conclusion. The recommended dose for subcutaneous administration into human of 200 mcg is experimentally justified and could be the basis for carrying out clinical studies of staphylococci vaccines in humans.

Aim. Study the possibility of formation of induced resistance of purulent-septic infection (PSI) causative agents against disinfectants (DI) in bactericidal concentrations. Materials and methods. Daily exposure to bactericidal concentrations of preparations from the group of quaternary ammonium compounds (QAC) on Enterobacter cloacae strain that has incomplete sensitivity to the same disinfectants on the same test objects was carried out in experiments on test objects from wood and plastic. Exposure was carried out until the moment of transition from incomplete sensitivity to resistance. Results. E. cloacae strain that initially had incomplete sensitivity to various disinfectants of the QAC group in antibacterial concentrations according to manuals acquires resistance on test objects from wood and plastic after 2 - 12 exposures to the preparations. Conclusion. The data obtained give evidence that the resistance of PSI causative agents to disinfectants can take place not only under the influence of low concentrations of the preparations but also during use of disinfectants at bactericidal concentrations.

Epidemiologic aspects of ecology of foodborne infection causative agents that have taken root in contemporary technogenic loci created by humans in urbocenoses which include agrocomplexes of animal breeding, vegetable growing in open and closed ground are discussed. Soil and water sources with a wide transport network where microorganisms dwell in the environment under favorable for vital functions and growth conditions (humus deposits, temperature regimen, optimal pH, associations with hydrobionts, biofilm formation) are potent secondary reservoirs of infection causative agents. Some molecular-genetic mechanisms ofpolyhostality of Gram negative bacteria and listeria are examined.