311 research outputs found
Cholera and the Death of the Ancient Indus Civilization
The paper presents a hypothesis that the most probable cause of death of the ancient world Indus (Harappa) civilization was the epidemic of Asiatic cholera. A brief description of the Indus civilization that existed for two millennia (3300–1300 BC) is given. It is shown that the previously described factors for the decline of the thriving Indus civilization (climate change, shallowing of the Indus river and reduction in floods, catastrophic floods, drought, economic crisis, etc.) do not provide a consistent and comprehensive explanation of the causes of its death. Meanwhile, the natural environment and peculiarities of agriculture of the Indus civilization (annual floods affecting not only fields, but also sewage systems) created ideal conditions for the spread of water-borne cholera. The evolution of the Asiatic cholera agent is discussed. The results of paleogenomics study of this pathogen and their significance for the reconstruction of evolutionary events are briefly reviewed. The stages of evolution of Vibrio cholerae of the classical biovar are described, and possible mechanisms for the preservation of the pathogen during inter-epidemic period are considered. It is demonstrated that aside from cholera, other catastrophic, destructive epidemics are recorded in the history of mankind
Principles of Quantitative Morphometric Assessment of Cholera Vaccines Safety
Worked out is the algorithm of cholera vaccines quality based on application of the methods of quantitative registration of formalized parameters which characterize pathologic and adaptive processes in the intestine of the immunized laboratory animals. The following parameters were selected as formalized ones: quantity of interepithelial lymphocytes, morpho-functional condition of apudocytes and scyphiform cells. Morphometric parameters are presented as associations of indicators in the form of indices and coefficients in order to carry out interrelated assessment of separate parts of homeostasis. It was determined that in case the assessed parameters were in the limits identified in corresponding controls, adaptation condition of the organism and alterations described in histological assay were considered as benign and characterized safety or efficiency of tested cholera vaccines
Principles of Formation of Collection Funds of Microorganism Strains
The aim of the review was to consider the principles and criteria for the formation of funds of service microbiological collections and the specialized State collection of pathogenic bacteria (SCPB) at the RusRAPI “Microbe”. The rapid pace of characterization, study, and use of microbial diversity makes the development of criteria for the selection of microorganisms for permanent storage in collections particularly relevant. The number and format of these criteria are determined by the tasks the collection centers of different levels and specialization are facing. Service collections form their funds by depositing or acquiring type, reference, educational strains. In recent years, the practicability of expanding the range of strains, the deposition of which is desirable in service collections, has been recognized. These are strains characterized by phylogenetic, genomic, metabolic, ecological uniqueness; with a fully sequenced genome; known and emerging plant, animal and human pathogens that caused disease outbreaks; used in international research projects; having biotechnological and economic significance. The main task of the SCPB as a specialized state collection of pathogenic bacteria of groups I–II is to preserve strains characterizing the intraspecific diversity and populations of pathogens circulating in natural foci or in certain territories of the Russian Federation, isolated during epizootics, local or epidemic outbreaks. The selection criteria for strains for permanent storage are their ecological, phenotypic, and genetic peculiarities. The preservation of such a collection is important for future research using new technologies and tracking the evolution of pathogenic bacteria – causative agents of particularly dangerous infectious diseases
Paleogenomics of the Plague Agent and Prospects for Paleogenomic Studies in Russia
The review contains information on paleogenomic studies of the plague pathogen, Yersinia pestis, covering the prehistoric epoch, the periods of the first and second plague pandemics, epidemics and outbreaks of plague of the late XIX–XX centuries. We have summarized the data on the reconstruction of ancient Y. pestis genomes of the Late Neolithic, Bronze and Iron Ages, the Justinian Plague epidemic of the first plague pandemic, the Black Death epidemic and the subsequent epidemics of the second plague pandemic of the XIV–XVIII centuries, as well as on tracing the pathways of plague propagation waves in Eurasia and the course of plague agent evolution with the formation of a vector-borne transmission route with the help of arthropods. We present the results of our own research of Y. pestis genomes from the key sites of formation of etiological agents of the first and second plague pandemics in the Tien Shan Mountains, historical outbreaks in the Northern and North-Western Caspian sea region and other regions of Russia and adjoining countries in the late XIX–XX centuries. The paper discusses the areas of the Caucasus, Crimea, Northern Caspian, Siberia, and Tien Shan in the territory of Russia and neighboring states that are promising for national paleogenomic studies of plague
Historical and Modern Classifications of the Plague Agent
The review presents the data on domestic and foreign phenotypic classifications of Yersinia pestis strains developed in the XX century; genetic classifications of the XXI century; as well as on the genealogy of ancient strains of the plague microbe, reconstructed using paleogenomic technologies. Since the discovery of the plague agent in 1894, many classifications were created that corresponded to the level of development of microbiology at that time. The intraspecific classification schemes of the XX century were based on three principles: phenotypic differences between strains, features of the species composition of carriers, and geographical affiliation. With the development of molecular microbiology early on in the XXI century, a genetic nomenclature of the branches of the pathogen evolution was developed and a number of classifications based on the analysis of the population structure of Y. pestis were created. Through the prism of the genetic diversity of Y. pestis strains from natural plague foci in Russia, near and far abroad countries, an improved classification with a division into seven subspecies has been developed: pestis, tibetica, caucasica, qinghaica, angolica, central asiatica, ulegeica, which allocates the subspecies according to the phylogenetic principle and epidemic significance. With the advancements in paleomicrobiology, prehistoric lineages of evolution have been included in the genealogy of Y. pestis, which expand the data on the intraspecific diversity of the plague microbe
REGARDING THE RISKS OF OCCURRENCE OF EMERGENCY SITUATIONS IN THE SPHERE OF BIOLOGICAL SAFETY OF INTERNATIONAL CONCERN AND THEIR PREDICTORS
The paper presents the analysis of the current epidemiological situation from the viewpoint of identification of risks of emergency situation onset in the sphere of biological safety, which differs from the emergency situation of sanitary-epidemiological welfare in the character of after-effects that are comparable in the quality and the scale to the threats to national and international security. In reference to the parameters of emergency situation in the sphere of biological safety, epidemic of Ebola fever in West Africa countries (2013-2016) has been described. Biosafety emergency situation is most likely to be predicted in the following cases: occurrence of the flu pandemic of the novel subtype (International Health Regulations, 2005); intensification of unfavorable for public health tendencies against the background of Zika fever transmission; larde-scale failures in the provision of biological safety when working with pathogenic biological agents; foreseeable, hard to control consequences of onset and transmission of infectious diseases caused by microorganisms with synthetic genome; occurrence of epidemic events during international mass meetings; justified interpretation of emergency situation, applying IHR (2005), as an after-effect of violation of the Convention on the Prohibition of Biological and Toxin Weapons (CBTW) and the grounds for intervention into the internal affairs of offending countries with social-economic, geo-political aftermaths and damage to the national security
Analysis of the SXT Constin of Antibiotic-Sensitive <I>Vibrio cholerae </I>Strain of Non-O1/ Non-O139 Serogroup
In the genome of antibiotic-sensitive
Vibrio cholerae strain belonging to O50 serogroup, isolated in the territory of the Russian Federation in 1974, detected is the SXT conjugative trasposone – SXT constin. Analysis if its structure revealed that it does not contain genes of resistance to such antibiotics as streptomycin, sulfamethoxasole, trimethoprim, chloramphenicol, and kanamycin, being, probably, one of the predecessors of antibiotic-resistant SXT constins which spread out within the genomes of epidemic
Vibrio cholerae O139 strains in 1992
Evaluation of Potential Epizootiological Significance of Small Predatory Mammals in Ebola Virus Circulation in the Republic of Guinea
The aim of the work is evaluation of potential epizootiological significance of small predatory mammals in Ebola virus circulation in the Republic of Guinea. Registered has been coincidence of the areals of the common species of small predatory mammals of Viverridae family with distribution limits of epidemically significant Chiroptera species and Ebola virus in 1976-2014 in the countries of West, Central, East and South Africa. Substantiated are prospects of analysis of biological samples (blood, internal organs) from different representatives of predatory mammals ( Viverrida, Felidae, Canidae, Mustelidae, Herpestidae ) as well as from domestic dogs, for the purpose to detect natural Ebola fever foci. Pointed out is the necessity of targeted investigation of the mechanism of long-term preservation of Ebola virus in the environmental objects, first of all, in substrates of tree trunks hollows and grots, which are used as day-time shelters by different representatives of Chiroptera and Carnivora (families of Viverrida and Herpestidae)
Volcano–Plutonic Complex of the Tumrok Range (Eastern Kamchatka): An Example of the Ural-Alaskan Type Intrusion and Related Volcanic Series
Zoned plutons, composed of dunites, pyroxenites, and gabbroic rocks, have been referred to as the Ural-Alaskan type complexes (UA-complexes) and occur in numerous paleo-arc settings worldwide. Many of these complexes are source rocks for economic placers of platinum-group metals. Thus, it is important to understand how UA-complexes form and the origin and behavior of platinum-group elements (PGEs). It is widely assumed that the UA-complexes result from differentiation of supra-subduction high-Ca high-Mg sub-alkaline magmas. However, there is a lack of direct evidence for the existence and differentiation of such magmas, mainly because cases of UA-complexes being spatially and temporally linked to co-genetic volcanics are unknown. We studied an UA-complex from the Tumrok range (Eastern Kamchatka) where a dunite-clinopyroxenite-gabbro assemblage is spatially and temporary related to high-Ca volcanics (i.e., picrites and basalts). Based on the mineral and chemical composition of the rocks, mineral chemistry, and composition of melt inclusions hosted within rock-forming minerals, we conclude that the intrusive assemblage and the volcanics are co-genetic and share the same parental magma of ankaramitic composition. Furthermore, the compositions of the plutonic rocks are typical of UA-complexes worldwide. Finally, the rocks studied exhibit a full differentiation sequence from olivine-only liquidus in picrites and dunites to eutectic crystallization of diopside or hornblende, plagioclase, and K-Na feldspar in plagio-wehrlites and gabbroic rocks. All these results make the considered volcano–plutonic complex a promising case for petrological studies and modelling of UA-complex formation
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