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Objective To understand the relationship between habitat choice of Himalaya marmot and vegetation elements such as vegetation coverage,grassland type,vegetation type and so on by using geographic information technology in Qinghai.Methods Himalayan marmot field survey data from Qinghai Provincial Institute for Endemic Disease Control and Prevention and vegetation coverage,grassland type and other remote sensing and geographic information data was processed for spatial overlay using ArcGIS tool.The vegetation characteristic information of the location of Himalayan marmot was searched and analyzed statistically,and then the initial quantitative analysis of Himalayan marmot on the selection of habitat vegetation conditions was made.Results After screening,84 samples of Himalayan marmot were retained.The mean of vegetation coverage was 0.708 5,the range was 0.313 3-1.000 0.Totally 54.76％ (46/84) of the Himalayan marmot samples was in the vegetation coverage of 0.70 to 1.00.Among the nine grassland types,the alpine meadows accounted for 39.78％ of total area of Qinghai,with 59 Himalayan marmot sample points distributed,which accounting for 70.24％ (59/84).Himalayan marmot mainly feed on some of the roots of grassland plants,including Poa pratensis,Alpine Kobresia,Potentilla,Polygonum viviparum,Kobresia cordata,Oxytropis,Aster and other miscellaneous grass.Conclusions Vegetation conditions is one of the important factors of Himalayan marmot in habitat selection.Quantitative analysis of the relationship between Himalayan marmot spatial distribution and vegetation factors by using geographic information technology,can deepen the understanding of marmot habitat selection,and provide a basis for grassland plague surveillance and control.
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We have evaluated the plague epidemic situation in the Three Rivers Source Region,Qinghai Province in recent 20 years to provide the basis for revising the plague prevention countermeasures.We have analyzed the time distribution and the plague epidemic situation between animals and human beings during twenty years in the Three Rivers Source Region,Qinghai Province by describing epidemiology.The animal plague in the natural source of Marmot plague was extremely serious in the Three Rivers Source Region during the past 20 years.It mainly distributes in Yushu State and Tanggula County,Germu City and the serious season ran through the whole period of marmot camp ground activities and the peak was between June and August.Human plague epidemic took place between May and October each year and reached its peak between July and September.The peak covered about 41.67％ at most.It mainly endemic distributes in Nangqian and Xinghai Country.During the past 20 years,we have totally found 14 human plague epidemics in the Three Rivers Source Region,among which 48 cases took place and there were deaths of 17 cases.The fatality rate was 35.42％.The lung type was the majority among 48 cases,which startde with the glandular type.During the past 20 years the plague epidemic has been active and the animal plague epidemic broke out continuously in the Three Rivers Source Region,Qinghai Province.The variety of animals and insects infected the plague epidemic was increasing.The human plague epidemics is most serious with high fatality rate,but it is on the decline as a whole.
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Plague was classified as a natural focus disease,occurred in remote areas of tratfic block in the past.But with the development of society and economy,plague of long distance transmission risk is growing in the source regions and densely populated areas.In order to effectively prevent and control the spread of plague outbreaks are occurring,and long distance transmission spread in Qinghai Province,and adhere to the implementation of the long-distance transmission of plague prevention and control strategies,avoid threats and reduced long distance spread of plague.
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Application of the PCR-derived technology in gene identification and genotypes of different ecotype Yersinia pestis to make the high-throughput experimental results can reflect the epidemic history and compare the diversity in genome, pathogenicity, so that results from these experiments provide an important basis for clinical diagnosis, treatment and origin. But the experiment should be considered typing ability, practicality, budget and other experimental factors or conditions, because each PCR-derivative technology has advantages and disadvantages.
Subject(s)
Humans , Genotype , Polymerase Chain Reaction , Virulence , Yersinia pestisABSTRACT
<p><b>OBJECTIVE</b>To analyze the plasmid features and geographical distribution characteristics of Yersinia pestis of different plague foci in China.</p><p><b>METHODS</b>A total of 2 213 Yersinia pestis strains were colected from 11 Chinese plague foci separated during 1943 to 2012, and plasmid DNA according to alkali cracking method, and measured the relative molecular mass (Mr) of plasmid DNA based on the standard plasmid contrast method, then analyzed the plasmid profiles by agar gel electrophoresis.</p><p><b>RESULTS</b>A total of 2 213 strains had 16 kinds of plasmids with different Mr, including 4×10(6), 6×10(6), 7×10(6), 13×10(6), 16×10(6), 20×10(6), 22×10(6), 23×10(6), 27×10(6), 30×10(6), 36×10(6), 45×10(6), 52×10(6), 65×10(6), 72×10(6) and 90×10(6). Plasmid were classified into 26 kinds of plasmid profiles. A total of 2 213 Yersinia pestis strains contained 4 large plasmids, 52×10(6), 65×10(6), 72×10(6) and 90×10(6), whose ratio was 22.10% (589/2 213), 75.60% (1 672/2 213), 0.17% (4/2 213), 2.12% (47/2 213), respectively. Among which, strains with plasmid 52×10(6), 65×10(6), 90×10(6) distributed in Qinghai-Tibet plateau Himalayan Marmot natural plague foci, strains with 72×10(6) plasmid only distributed in Inner Mongolia Meriones unguiculatus natural plague foci and Junggar Basin R. opimus natural plague foci, and 65×10(6) plasmid distributed in all the other foci.</p><p><b>CONCLUSION</b>Strains in Chinese 11 plague foci contained 4 kinds of large plasmid, the Mr respectively were 52×10(6), 65×10(6), 72×10(6), 90×10(6), which were classified into 26 kinds of plasmid profiles with other plasmid. These plasmid profiles distributed in relatively independent epidemic focus.</p>
Subject(s)
Animals , China , Genotype , Plague , Plasmids , Yersinia pestisABSTRACT
<p><b>OBJECTIVE</b>To analyze the results of etiology and serology of plague among human and infected animals in Qinghai province from 2001 to 2010.</p><p><b>METHODS</b>Thirty-seven cases of human infected with plague, 53 541 different animal samples, 5 685 sets of vector insects flea and 49 039 different animal serum samples were obtained between 2001 and 2010. A total of 7 811 samples of serum from healthy farmers and herdsmen in 14 counties in Qinghai from 2005 to 2007 were collected. Yersinia pestis (Y. pestis) were detected in visceral and secretions from human, infected animals and vector insects, respectively. Plague antigen was detected by reverse indirect hemagglutination assay (RIHA) in those samples. Indirect hemagglutination assay (IHA) was used to test plague FI antibody in serum of human and infected animals.</p><p><b>RESULTS</b>37 human plague cases were confirmed, 21 strains of plague Y. pestis were isolated from human cases and 14 positive were detected out. 133 of 7 811 samples of human serum were IHA positive, with the positive rate at 1.7%. A total of 146 strains of plague were isolated from infected animals and vector insects, 99 out of which were from infected animals, with a ratio of Marmota himalayan at 72.7% (72/99) and the other 47 were from vector insects, with a ratio of callopsylla solaris at 68.1% (32/47). The number of IHA and PIHA positive were 300 and 10, respectively. A total of 3 animals and 3 insects species were identified as new epidemic hosts for plague. The natural plague focus of Microtus fuscus was discovered and confirmed and coexisted with natural focus of Marmota himalayan in Chengduo county, Yushu prefecture. The epidemic situation of plague is distributed mainly in Haixi, Yushu and Hainan prefectures.</p><p><b>CONCLUSION</b>From 2001 to 2010, animal infected with plague was detected in successive years and human plague was very common in Qinghai. New infected animals and vector insects species and new epidemic areas were confirmed, hence the trend of plague prevalence for humans and animals is very active in Qinghai province.</p>
Subject(s)
Animals , Humans , Antibodies, Bacterial , Blood , China , Epidemiology , Disease Vectors , Insect Vectors , Microbiology , Plague , Epidemiology , Yersinia pestis , ClassificationABSTRACT
Objective To purify native F1 antigen from E pestis EV76 strain and determine its ef-ficacy against Y. pestis. Methods A new purification method was developed by the substitution of physical disruption ( glass beads) for organic solvent ( acetone and toluene) one, followed by a combination of ammo-nium sulfate fractionation and SephacrylS-200HR column filtration chromatography. Groups of mice were im-munized with F1 antigen adsorbed to 25% aluminum hydroxide in PBS by intramuscular route. The immu-nized animals were challenged subeutaneously(s, c. ) with 104 CFU of Y. pestis strain 141 at 18 weeks after the primary immunization. Results There was no IgG titre difference between two groups of mice with one-dose immunization, whereas in the two-dose immunization groups, the group F1-40 μg induced a statistically higher antibody titre than the group F1-20 μg. Complete protection was observed for animals immunized with purified F1 antigen by s.c. route. In contrast, the control mice immunized with aluminum hydroxide suc-cumbed to a same dose of Y. pestis 141 challenge. Conclusion This purification strategy is a simple and ef-fective, and can be operated in a large scale. Native F1 antigen extracted from Y. pestis EV76 is highly im-munagenic, and can be used as a key antigen component to develop sub-unit vaccine of plague.