Development of a Method for Determination of brucella suis Biovars Using Multilocus Real-time PCR

The aim of the study was to develop a methodological approach to determination of Brucella suis biovars through multilocus PCR with real-time registration of results.Materials and methods. We used 16 strains of B. suis of various biovars, B. neotomae and B. canis – 2 strains of each. Determination of the taxonomic affiliation of Brucella strains was carried out according to the Bruce-ladder, Suis-ladder, BRU-DIF protocols. The selection of primers and probes was performed using the software on the website www.genscript.com and the GeneRanner 6.5.52 program. Fragment sequencing according to Sanger was performed on a 3500 XL genetic analyzer in accordance with the manufacturer’s recommendations. Nucleotide sequence homology was assessed using the BLAST algorithm and the GenBank NCBI database.Results and discussion. An analysis of the structural organization of IncP and GI-3 genomic islands has been carried out in B. suis strains of various biovars. It has been established that in strains of B. suis II, IV biovars and B. canis, the terminal part of the BRA0368 gene, comprising 21 nucleotides (repeated in the BRA0367 gene) and the “TAA” stop codon, as well as almost the entire sequence of the BRA0367 gene were lost, owing to homologous recombination in the IncP genome island. A 21-nucleotide direct repeat and the “TGA” stop codon of the BRA0367 gene replaced the analogous region of the BRA0368 gene which resulted in the deletion the size of 185 bp. No differences have been noted in the structure of GI-3 in biovars. The evidence obtained made it possible to develop the approach (SuisDIF) for differentiating B. suis biovars, based on the amplification of genes located in the IncP and GI-3 genomic islands using real-time PCR. Its specificity was confirmed in the study of B. suis strains from the fund of the State Collection of Pathogenic Bacteria of the Russian Research Anti-Plague Institute “Microbe”. The conducted studies expand and supplement the data on the genetic heterogeneity of Brucella species and biovars. The proposed method for differentiating biovars of B. suis using multilocus PCR with real-time registration of results enhances the capacities for Brucella identification using molecular-genetic methods

MALDI-TOF Mass-Spectrometry Analysis of Plague Agent Strains

Objective of the study was to demonstrate practicability of data base creation, containing reference mass-spectra of agents of particularly dangerous infections, using MALDI-TOF mass-spectrometry, by the example of plague agent strains. Materials and methods. MALDI-TOF mass-spectrometry was deployed for the obtainment of mass-spectra of ribosomal proteins from the microorganisms under investigation with the help of mass-spectrometers - Microflex LT. Results and conclusions. Carried out was comparative analysis of the obtained mass-spectra of 10 Y. pestis strains and reference spectra of Y. tuberculosis , contained in commercial data base of MALDI Biotyper 3.1 (Bruker Daltonics, Germany). Developed data base was validated in the process of identification of plague microbe strains, isolated in the territory of natural plague foci of the Russian Federation. That data base provided for correct identification of Y. pestis strains up to a species

Management of Diagnostic Investigations at the Premises of Specialized Anti-Epidemic Team Mobile Complex at the Time of Running Mass Events

Laboratory support of epidemiological surveillance plays a significant role in the provision of sanitary-epidemiological welfare of the population at the time of preparations to and carrying out public events. Taking into consideration the increment of load upon the laboratory facilities of the Rospotrebnadzor institutions and general medical-and-prophylactic establishments, there emerges a need to deploy specialized anti-epidemic teams. By the example of management of the laboratory investigations in SAET mobile complex during XXVII World-wide Summer Universiade in Kazan, 2013 and G-20 Summit in Saint-Petersburg, 2013 formulated have been the basic principles of organization and algorithms of diagnostic work at the premises of laboratory facilities of SAET mobile unit deployed in order to provide for sanitary-epidemiological welfare of the population at the time of running public events

Anthropourgic Foci of Plague in Vietnam: Past and Present

The review contains the results of ecological-epizootiological and epidemiological investigations of plague in the territory of the Socialist Republic of Vietnam in 1989-2012. Studied has been the structure of epizootic triad - carrier-vector-pathogen. There is a low probability of plague foci occurrence in zones of tropical forests and savanna under the conditions of humid subequatorial climate. Main plague agent carrier on the Thai Nguyen Plateau is the synanthropic little rat, Rattus exulans . Specialized fleas species are absent on wild-living rats Rattus genus, as well as mice, and bandicoots, and the abundance of other species is small. It has been demonstrated that all the elements of the parasitic plague system are classified as introduced species. Thereupon it is inferred that plague foci in Vietnam are anthropourgic and are of anthropogenic origin solely. Plague cases in humans across the territory of the country were registered between 1898 and 2002. The most persistent ones functioned on the Thai Nguyen Plateau. Although epizootic activity of the foci in territory of the former endemic provinces has decreased, it is necessary to continue epizootiological monitoring further on in the modern period

DIAGNOSTIC POTENTIAL OF THE ERYTHROCYTIC IMMUNOGLOBULIN DIAGNOSTICUM FOR INDICATION AND IDENTIFICATION OF THE CAUSATIVE AGENTS OF PARTICULARLY DANGEROUS (DEEP) MYCOSES

Objective of the study was to assess analytical and diagnostic sensitivity and specificity of the “Reagent kit. Erythrocytic coccidioidomycosal and histoplasmosal immunoglobulin dry diagnosticum”, designed for identification of causative agents of coccidioidomycosis and histoplasmosis in isolated cultures of micromycetes, as well as in clinical and biological samples using indirect hemagglutination test.Materials and methods. The investigation included 264 positive samples (216 samples of micromycete suspensions, 48 samples of biological and clinical material) containing pathogens of histoplasmosis and coccidioidomycosis concentrated up to 3,12·106 and 1,56·106 cells/ml, respectively, and 128 negative samples containing heterologous microorganisms in concentrations equal to 5·106 cells/ml. The study was carried out using biological samples that were artificially contaminated with stated pathogens of particularly dangerous mycoses and samples, obtained from bioassay animals with experimental infection.Results and conclusions. It is established that diagnostic sensitivity of the reagent kit is not less than 99,0 %. The diagnostic specificity is not less than 98,0 %. Reproducibility of the results in all cases was 100 %. The results obtained testify to the prospect of introduction of the developed kit into the health care practice

System of Monitoring and Response to Public Health Emergencies of Sanitary-Epidemiological Character in the CIS Countries

The most important component of strengthening the potential for responding to biological threats both at the national and interstate levels is the formation of a unified system for monitoring and responding to emergencies (ES) of sanitary-epidemiological nature in the CIS territory.The aim of the work was to review the systems for monitoring and responding to emergencies of sanitary-epidemiological character in the CIS countries by the example of the Russian Federation, the Republic of Belarus, the Republic of Kazakhstan and the Kyrgyz Republic, to characterize the main areas of international cooperation on countering biological threats and coordinating international response measures in the CIS countries.Materials and methods. Information and analytical materials provided by organizations responsible for epidemiological surveillance and control in the CIS countries, Internet sources, and publications were used for the study.Results and discussion. The organization and functioning of the systems for monitoring and responding to emergencies in the CIS countries is a state function. It includes, as a rule, the national, regional (sub-national) and territorial (local) levels, which have horizontal and vertical connections. The legal framework is made up of documents of the legislative level. Interdepartmental interaction in response to emergencies is carried out both at the republican level and in administrative territories; the basis for interaction is the integrated planning of preventive and anti-epidemic measures and the functioning of the relevant organizational structures on an ongoing basis. Since 2015, with the support of the Government of the Russian Federation, programs have been implemented aimed at assisting partner countries in the implementation of the International Health Regulations (2005) in order to increase national response capacity and form a unified sanitaryepidemiological emergency response system in the CIS countries. The main areas of collaboration are strengthening the material and technical base and human resources of specialized institutions and scientific cooperation. As a result of the program implementation, a unified system for monitoring and prompt response to emergencies in the field of public health of sanitary-epidemiological nature has essentially been formed in the CIS countries to date, uniting more than 15 specialized institutions from 8 CIS countries

Management of the Investigation and Detection of Legionellosis Agent in the Environmental Samples during the Preparation and Holding of the XXII Winter Olympics and XI Paralympics in Sochi

Provided are the data on the management and carrying out of the laboratory control over the hot-water supply systems of the sports venues and accommodation areas for the presence of Legionella pneumophila during the XXII Olympics and XI Paralympics in Sochi, 2014. Inspected have been 105 facilities. The samples from 37 of them showed positive. L. pneumophila DNA concentration varies between 2.19·102 and 3.92·107 genome equivalents (g.e.)/l. By means of bacteriological investigation detected have been legionella colonies in the water supply systems of 16 facilities, at one of the items - the loading is over 1·104 colony-forming units/l. Performed has been comparative analysis of the results obtained using PCR assay and bacteriological test. Based on the genotyping of 7 isolated strains serogroup 1 and 2 strains of 2-14 serogroups it is concluded that L. pneumophila strains circulating in the resort town Sochi are genetically heterogeneous

Detection of Crimean-Congo Hemorrhagic Fever Virus Markers in Samples of Ixodes Ticks Collected in the Territory of the Republic of Guinea

Objective of the study. This work was carried out to identify markers (antigen and RNA) of CrimeanCongo hemorrhagic fever (CCHF) virus in samples from ticks, collected in all landscape-geographical areas of Guinea: Lower, Middle, Upper and Forest, to obtain up-to-date data on the distribution of the pathogen in the country.Materials and methods. Total of 4276 specimens of 8 species of ticks collected in 2016–2019 in the territory of the Republic of Guinea were studied, which were compiled into 1406 samples. Ectoparasites were collected from livestock animals, dogs, and small mammals. Viral antigen was detected using enzyme immunoassay (ELISA). The presence of RNA of the CCHF virus was determined by reverse transcription polymerase chain reaction (RT-PCR).Results and discussion. As a result of the studies, the antigen of the CCHF virus was detected in 21 samples (1.5 %), and RNA – in 37 (2.6 %). All samples, in which the viral antigen was detected, contained RNA of the CCHF virus. Positive results were obtained in samples from all geographical areas of the country. The main vectors and reservoirs of the pathogen in Guinea are ticks of the species Rh. sanguineus, Rh. geigyi, Rh. annulatus and Am. variegatum. The data obtained confirm the previously available information on the possibility of the pathogen circulation in this region and determine the need for further study of the spread of the CCHF virus in the territory of the Republic of Guinea

Experience in Using Mobile Laboratory for Monitoring and Diagnostics in the Socialist Republic of Vietnam

The aim was to present the experience of using mobile laboratory for monitoring and diagnostics (MLMD) during the epizootiological monitoring of the northern provinces of Vietnam. MLMD was transferred by Federal Service for Surveillance in the Sphere of Consumers Rights Protection and Human Welfare to the Socialist Republic of Vietnam as part of implementation of cooperation programs on combating infectious diseases. The use of MLMD made it possible to obtain new information on the circulation of pathogens of natural-focal infectious diseases on the territory of Vietnam. It also provided the necessary conditions for conducting research using methods of express diagnostics, bacteriological analysis, performing a full cycle of work – from the receipt of samples to the disinfection and destruction of infected material in compliance with the requirements of biological safety in the field. The effectiveness of using mobile laboratories in response to the emergencies of sanitary and epidemiological nature, both to strengthen stationary laboratory bases and to organize diagnostic studies in remote regions, has been shown. The use of MLMD for the diagnosis of COVID‑19 has been an effective component of countering the new coronavirus infection in Vietnam and significantly increased the volume of testing in the country