The latest study and development of etiology,pathogenesis,diagnosis,differential diagnosis and cytogenetics are reviewed in this paper.

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.

Objective Tofacilitatetheradiologiststoinquireinformationrelatedtobreastdiseasesandimprovetheefficiencyand accuracyofsearchingdata.Methods Inthispaper,amultilevelstrategyhybridquestion-and-answermodelwasusedtodesignanautomatic question-and-answersysteminthefieldofbreastdiseasesimaging.Thefirstlayerofthismodelwasthequick matchingofquestion sentencesandFAQknowledgebase.Thesecondlayerwastoobtaintheanswersinthebasicknowledgebaseaccordingtothethresholdsetby processingthequestionsandcalculatingthesimilarityofthequestions.Thethirdlayerwastoacquiretheanswerparagraphfromthe webdocumentreturnedbythefull-textsearchengine.Results Thetestresultsshowedthattheaccuracyofthesystemansweracquisitionreached 85%.Thesystemcouldgivesatisfactoryanswerstotheproblemsexistingintheknowledgebase.Conclusion Theintelligentquestion answeringsystemforbreastdiseaseisconvenientandfast,anditisaneffectivetoolforradiologiststoinquiretheknowledgeofbreast diseases.

Objective To systematically evaluate the application value of next-generation sequencing technology in the etiological diagnosis of patients with sepsis.Methods Databases such as PubMed,Embase,Web of Science,The Cochrane Library,VIP,CNKI,WanFang Data Knowledge Service platform and SinoMed were searched from January 2018 to September 2022.The positive rate of sepsis detection,pathogen detection time,virus detection rate,28 days mortality rate and length of stay in intensive care unit(ICU)were com-pared between next-generation sequencing technology and traditional etiological detection method.Meta-analysis was performed using Review Manager 5.4.1 software,and funnel plot was pictured to analyze the publication bias of the included literatures.Results A total of 18 literatures were included.The results of Meta-analysis showed that the positive rate of next-generation sequencing group was 72.3％(1403/1941),which was significantly higher than that of the traditional etiological detection group[28.4％(556/1958),OR=7.03,95％CI:4.52-10.95,P＜0.01];the time of pathogen detection was significantly lower than that of traditional etiological detec-tion group(OR=-34.22,95％CI:-41.95--26.48,P＜0.01);the virus detection rate was significantly higher than that of tradi-tional etiological detection group(OR=57.82,95％CI:19.27-173.46,P＜0.01);the length of stay in ICU was significantly lower than that of traditional etiological detection group(WMD=-9.37,95％CI:-16.28--2.46,P＜0.01);there was no significant difference in 28 days mortality between the two groups(OR=0.43,95％CI:0.02-8.47,P=0.58).Conclusion Compared with tra-ditional etiological detection methods,next-generation sequencing technology can improve the positive rate of pathogen detection and vi-rus detection in sepsis patients,shorten the time of pathogen physical examination and the length of stay in ICU,and has higher applica-tion value for the diagnosis and treatment of sepsis.

OBJECTIVETo study the biological and genetic characteristics of 119 strains of Yersinia (Y.) pestis isolated from plague patients in Qinghai province, from 1958-2012.

METHODSBoth regular methods and different region(DFR)molecular typing techniques were used to study the epidemiological characteristics on 119 strains of Y. pesticin Qinghai during 1958-2012. Sources of Y. pestis from two outbreaks, in Nangqian county in 2004 and in Xinghai county in 2009,Qinghai province were also analyzed.

RESULTS105 strains of Y. pestis were identified as Qinghai-Tibet Plateau Ecotype while the other 6 strains as Qilian Mountains Ecotype. 84.03% (100/119) of the tested strains carried 4 virulence factors F1(+), Pst I(+), VW(+) and Pgm(+)). 97.30% (72/74) of the tested strains showed high virulence. Strains that carrying 52×10(6), 65×10(6), 92×10(6) plasmids were distributed in Hainan, Haibei, Haixi,Yushu,Guoluo, Huangnan and Huangyuan counties. Genomovar 5 and 8 were the main gene types that circling around Qinghai Lake. Genomovar 10 was found in strains of Y. pesticin Nangqian county while Genomovar 8 was found in the strains isolated from human plague patient during the epidemics in Xinghai county in Qinghai.

CONCLUSIONData from biological and genetic analyses on the epidemics of human plague in Nangqian county in 2004 and in Xinghai county in 2009 demonstrated that methods as DFR genotyping and virulence factors profiles, as well as plasmids profiles were powerful tools in confirming the human plague epidemics and sources of infection.

China ; epidemiology ; Genotype ; Humans ; Plague ; epidemiology ; microbiology ; Yersinia pestis ; genetics ; isolation & purification

OBJECTIVETo type Yersinia (Y.) pestis isolates under different regions (DFR) and to observe their geographical distributions in China.

METHODS23 DFRs primers and PMT1 (plasmid) primer were used to verify the DFR genomovars of Y. pestiss strains from 11 plague foci in China. A total of 3 044 Y. pestis isolates were involved for analysis on DFR profiles with the characteristics of geographical distribution.

RESULTS52 genomovars were verified in 3 044 Y. pestis strains in China in which 19 genomovars as major and 33 genomovars as minor genomovar. 21 new genomovars, namely genomovar 32 to genomovar 52 were described on the basis of 31 genomovars previously confirmed. Three new genomovars belonged to new major genomovars, namely Himalayan marmot natural plague foci of the Qinghai-Tibet plateau newly added genomovar 32 and genomovar 44 as major genomovars. Mongolian gerbil natural plague foci of Inner Mongolia plateau were newly added genomovar 50 as one of the major genomovars.

CONCLUSIONAmong 21 new genomovars, 3 were major genomovars, with Chinese Y. pestis DFR as the major genomovars which had obvious distribution characteristics.

China ; Genotype ; Geography ; Yersinia pestis ; classification ; genetics ; isolation & purification

OBJECTIVETo analyze the plasmid features and geographical distribution characteristics of Yersinia pestis of different plague foci in China.

METHODSA 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.

RESULTSA 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.

CONCLUSIONStrains 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.

Animals ; China ; Genotype ; Plague ; Plasmids ; Yersinia pestis