[THE EPIZOOTIC AND EPIDEMIC ACTIVITY OF NATURAL TULAREMIA FOCI OF DIFFERENT LANDSCAPE EPIDEMIOLOGICAL TYPES IN 2009-2014].

OBJECTIVE: to assess the present state of the natural tularemia foci of different landscape epidemiological types, by using individual focal areas as an example. MATERIALS AND METHODS: Epizootological monitoring and epidemiological analysis were conducted in the areas of natural tularemia foci of tundra (Wrangel Island), meadow-field (Central Federal District of the Russian Federation), flood-swamp (Arkhangelsk Region, Khanty-Mansi Autonomous District), and steppe (Mongolii) types. Small mammals (organs, blood), tularemia patients' sera, and environniental objects were examined. Molecular genetic and immune serological diagnostic assays were used. The incidence of tularemia in the past decade was analyzed using the maps for the epidemiological examinations of tularemia cases and medical reports. RESULTS: The natural foci of tularemia were established to continue to actively operate. There were 2913 cases of tularemia in the Russian Federation in 2001 to 2014. The flood-swamp natural foci, in which there were summer transmissive tularemia outbreaks, the largest of high occurred in Khanti-Mansiysk in 2013 when a total of 1005 people fell ill, are a special epidemic hazard. Analysis of the tularemia outbreaks suggests that there is a need for continuous epizootological monitoring of the areas of natural tularemia foci for the timely prediction and prevention of epidemic complications. It is noted that there is an unfounded reduction in the scope of preventive measures, and immunoprevention in particular, and a weaker control of the antitularemia immune status in the population residing in the area of active natural foci of tularemia.

[REAL TIME POLYMERASE CHAIN REACTION IN TULAREMIA LABORATORY DIAGNOSTICS].

AIM: Enhancement of tularemia laboratory diagnostics by F. tularensis DNA determination in blood sera of patients using real time polymerase chain reaction (RT-PCR). MATERIALS AND METHODS: 39 blood sera of patients obtained during transmissive epidemic outbreak of tularemia in Khanty-Mansiysk in 2013 were studied in agglutination reaction, passive hemagglutination, RT-PCR. Specific primers and fluorescent probes were used: ISFTu2F/R+ISFTu2P, Tu14GF/R+tul4-PR2. RESULTS: Advantages of using RT-PCR for early diagnostics of tularemia, when specific antibodies are not detected using traditional immunologic methods, were established. Use of a combination of primers and ISFTu2F/R+ISFTu2P probe allowed to detect F. tularensis DNA in 100% of sera, whereas Tul4G F/R+tul4-PR2 combination--92% of sera. The data were obtained when DNA was isolated from sera using "Proba Rapid" express method. Clinical-epidemiologic diagnosis oftularemia was confirmed by both immune-serologic and RT-PCR methods when sera were studied 3-4 weeks after the onset of the disease. CONCLUSION: RT-PCR with ISFTu2F/R primers and fluorescent probe ISFTu2P, having high sensitivity and specificity, allows to determine F. tularensis DNA in blood sera of patients at both the early stage and 3-4 weeks after the onset of the disease.

[Epizootic and epidemic manifestation of natural foci of tularemia in Moscow region (1965-2013)].

AIM: Detection of contemporary features of tularemia focimanifestations, determination of territories of high epidemic risk in various landscape zones and creation of a map of foci territories of Moscow Region for isolation of tularemia infectious agent cultures and registered human morbidity for justified planning of prophylaxis measures. MATERIALS AND METHODS: Report materials of epizootologic examinations of natural foci for 1965-2013, 156 maps of epidemiologic examination of cases of human infection with tularemia, results of studies of casting of predatory birds and dung of predatory mammals were used. Registered morbidity and isolation of tularemia infectious agent cultures from 1965 to date were applied to an electronic map of Moscow Region by sign method using modern. GIS-technologies (MapInfo 10.5 program). Electronic maps Ingit at 1:200,000 scale, as well as Google Earth program were used to search for base points. RESULTS: Analysis of morbidity has revealed structure change in human tularemia morbidity--an increase of the fraction of urban population and a decrease of the fraction of patients among rural inhabitants, unimmunized against this infection are mostly ill. The presence of DNA of tularemia causative agent in biological objects in the complex with serologic and bacteriological studies was shown to allow to detect flaccid epizootics even at low numbers of rodents. CONCLUSION: Cartographic reflection of registered morbidity and isolation of tularemia infectious agent cultures allowed to show territories with various degrees of epizootic activity and epidemic manifestation. Positive results of serologic and molecular-genetic studies of environmental objects gives evident on epizootic activity and constant risk of aggravation of epidemic situation for this infection.

[Evaluation of modern epizootic activity of natural tularemia foci in Voronezh region using immune-serological and molecular-genetic study of main carriers of the disease].

AIM: Improvement of monitoring and prognosis of epidemic manifestations of natural foci of tularemia on the territory of Voronezh region using immune-serological and molecular-genetic study of main carriers of the disease. MATERIALS AND METHODS: 539 small mammals captured during summer period of 2011 in 4 districts of North-Eastern part of Voronezh region were studied. Animal organs were studied by serologic (search for Francisella tularensis antigens) and molecular-biologic (detection of F. tularensis DNA) methods. Tularemia antigen was detected using passive hemagglutination reaction (PHAR) with erythrocytic tularemia immunoglobulin diagnosticum. Real-time polymerase chain reaction (RT-PCR) was applied for detection of tularemia causative agent DNA. RESULTS: Complex study revealed epizootic activity of natural foci of tularemia in the examined territory. F. tularensis antigen and/or DNA were detected in 82 objects (15.2%). Use of RT-PCR allowed to additionally detect samples with relatively low content of F. tularensis DNA substrate, when antigen was not detected in samples. High sensitivity and specificity of the RT-PCR was ensured by inclusion of specific probes (tu14-PR2 and ISFTu2P). CONCLUSION: The results obtained give evidence on functioning and epizootic activity of natural foci of tularemia in Voronezh region that requires constant monitoring of the territory and prophylaxis measures, first of all vaccination of risk groups by live tularemia vaccine.

[The molecular and genetic characterization of Francisella tularensis strains of different taxonomic status and virulence].

Typing of Francisella strains collection by means of PCR on the basis of tul4 and RDI genes was carried out. The identification of the species and subspecies of the 112 strains of Francisella tularensis was reashed. The PCR on DNA-targets loci of type IV pili genes: pilA, pilE2, pilE3, pilE4, pilE5, pilF, pilT, pilD and pilQ for differentiation of F. tularensis strains on virulence was carried out. It was demonstrated the possibility of differentiation of F. tularensis strains in PCR (primers A-B) on the basis of the revelation of the gene pilA in virulent strains of third subspecies F. tularensis and F. tularensis subsp. novicida. This gene pilA was not detected in the vaccine strain 15/10 and its variants, as well as in the most of avirulent F. tularensis subsp. holarctica strains. However, the fragment gene pilA was found in the attenuated strains F. tularensis subsp. tularensis and mediasiatica. It was not revealed any differences on other targets of pili genes between of F. tularensis strains, with the exception of the strain F. tularensis subsp. novicida Utah 112, which had not a fragment of the gene pilE2. The use of PCR to target the locus of the pilA gene allows to discriminate virulent F. tularensis subsp. holarctica strains from the vaccine 15/10, its variants and avirulent strains.

[Monitoring the natural foci of tularemia on Wrangel Island].

Long-term annual monitoring of the natural foci of tularemia was first made on Wrangel Island. The objects of the investigation were pellets of birds-myophages, blood samples from rodents, and excrements from carnivorous mammals. A total of 2626 biological samples were examined in the period 2002 to 2011. A serological test was ascertained to be the most effective method for the detection of tularemia epizooties; polymerase chain reaction should be used as an additional technique to examine blood samples, as well as rodent tubular bone debris taken from the pellets. Tularemia epizooties were registered in the populations of two species of lemmings every year, except in 2003. An intensive diffuse tularemia epizooty was first detected in this area, which emerged in 2019, peaked by spring 2011, and covered most of the island. The antigen of tularemia pathogen was identified in 43.46% of the samples under examination,which is a high quantitative indicator of the intensity of an epizootic process. The fact that positive samples are annually found in the same areas of the island suggests that the causative agent is steadily and long preserved in the parasitic system. The availability of stable and active natural tularemia foci on Wrangel Island calls for preventive measures, particularly vaccination of risk groups coming to the island to conduct researches.

[Peculiarities of the Brevundimonas diminuta Gl7ACA-Acylase quaternary structure formation and obtaining stable enzyme analogues].

The physicochemical and enzymatic properties of hybrid analogues of the Brevundimonas diminuta Gl7ACA-acylase (BrdGIA), containing the N-terminal chitin-binding domain of the bacterial chitinase (BrdG1A/NmChBD) or the C-terminal oligohistidine sequence (BrdGIA/H), were studied. An enhanced thermostability level of BrdG1A/NmChBD could suggest the stabilizing effect of the chitin-binding domain. An analysis of pH profiles of the enzymatic activity of recombinat BrdGIA analogues did not reveal significant differences: the catalytic activity of both variants changed slightly in the.interval ofpH values from 6.0 to 9.0 but drastically decreased at lower pH values. Both analogues demonstrated similar sensitivity towards denaturing agents: addition of 2.0 M ofguanidine chloride resulted in the complete inactivation of both enzymes. A scheme was developed for obtaining isolated recombinant alpha- and beta-subunits of BrdGLA. In vitro enzyme reconstructions indicated that the alpha-subunit was necessary for the formation of a correct spatial structure of the beta-subunit and for the formation of a functionally active enzyme.

[Detection of natural tularemia foci in Mongolia].

AIM: Study of the current spread of natural tularemia foci in Mongolia and its epizootic activity evaluation for consequent substantiation of the recommendations for prophylaxis of this disease. MATERIALS AND METHODS: Study of 1119 pellet specimens from predatory birds obtained in 6 aimag in Mongolia in 2008--2010 was performed. Tularemia antigen was detected by using antibody neutralization reaction (ANR) and passive hemagglutination reaction (PHR) with tularemia diagnosticums. Tularemia DNA was detected by PCR by using strain specific primers. Presence of plague antigen in PHR with plague immunoglobulin diagnosticum was also studied in all the samples. RESULTS: Epizootologic monitoring allowed the detection of natural tularemia foci in 5 of the 6 studied aimags in Mongolia. PHR was the most effective study method that allowed to detect tularemia antigen in the environmental objects in high quantities (up to 9.2% of positive samples) and high titers (up to 1:1600). PCR was less effective. Plague antigen was detected in 9 samples in 2010 for the first time, and in 3 cases together with tularemia antigen, which indicates a presence of combined natural foci of tularemia and plague in this territory. CONCLUSION: In the studied regions of Mongolia natural tularemia foci were detected, their epizootic activity was determined and recommendations for future study tactics of natural tularemia foci were given.

[Hantavirus infection in bank voles in the natural reservoir. Part 1. Characteristics of an infection process in bank voles]. / Khantavirusnaia infektsiia u ryzhikh polevok v prirodnom ochage. Soobshchenie 1. Osobennosti infektsionnogo protsessa v organizme polevok.

The specific features of hantavirus infection in naturally infected bank voles (Clethrionomys glareolus), the principal host of hantavirus of the serotype Puumala, were studied during long-term observation of individually marked animals in the active focus of hemorrhagic fever with renal syndrome (HFRS) in the south of Udmurtia. The infection time in the bank voles was defined by paired serum seroconversion tests. In the natural focus, hantavirus was shown to cause asymptomatic persistent infection in the bank voles with the body's peak accumulation of the virus and its environmental discharge within the first month of infection. In this period the animals present the greatest epidemic and epizootic hazards. Hantavirus infection has no negative impact on the viability of bank voles.

Dynamics of Puumala hantavirus infection in naturally infected bank voles (Clethrinomys glareolus).

Specific features of hantavirus infection in bank vole (Clethrionomys glareolus) were studied in the endemic area of hemorrhagic fever with renal syndrome (HFRS) in the foothills of the Ural mountains, using long-term observations on living animals by the capture-mark-recapture (CMR) method. The results demonstrated that the infection naturally circulating in the voles is chronic (lasting for up to 15 months) and asymptomatic, with a peak of Puumala virus accumulation and release from the organism during the first month after infection. It was shown that the bank vole population includes young animals with maternal immunity, which remain resistant to the Puumala virus infection for 3-3.5 months. The infection rate in voles depended on the age and sexual maturity of animals. The greatest proportion of seropositive animals was observed among overwintered males. Seroconversion in voles was more frequent during the period of high reproductive activity.

[The health-promoting tendency of systematic swimming exercises in preschool institutions]. / Ozdorovitel'naia napravlennost' sistematicheskikh zaniatii plavaniem v doshkol'nykh uchrezhdeniiakh. 1

Systematic swimming exercises in child preschool establishments increase toughening of children, resistance to unfavourable factors, and also favourably influence anthropometric indices. Besides, collective health indicators in such groups (health index, specific weight of children who get ill frequently, the presence of the antigen protective titre, mean duration of one case of a disease) were reliably better.

Identification of sulphur-organic compounds obtained by thermal treatment of the meat broths in the presence of alkyl-mercaptopropanol.

By means of GLC-analysis on columns with different polarity phases the composition of the sulphur-containing volatiles obtained by the thermal treatment of the industrial broths and alkyl-mercaptopropanol was studied using flame-photometric detector specific for sulphur. The identification of the sulphur-containing compounds was realized using both retention indices and GLC-MS. The comparison of the composition of sulphur-containing flavour components of the industrial broth with that of its product with alkyl-mercaptopropanol was carried out.