Reciprocal Regulation between Fur and Two RyhB Homologs in / 生物医学与环境科学（英文）

Objective@#To investigate reciprocal regulation between Fur and two RyhB homologs in @*Methods@#Regulatory relationships were assessed by a combination of colony morphology assay, primer extension, electrophoretic mobility shift assay and DNase I footprinting.@*Results@#Fur bound to the promoter-proximal DNA regions of @*Conclusion@#Fur and the two RyhB homologs exert negative reciprocal regulation, and RyhB homologs have a positive regulatory effect on biofilm formation in

Epidemiologicai analysis of plague in Qinghai province from 2001 to 2010 / 中国地方病学杂志

Objective To explore the plague epidemical trend of nearly a 10 years data in Qinghai province to provide basis for making the prevention and control measures. Method The regional distribution and time distribution of animal and human plague, monitoring and plague foci of survey data in Qinghai from 2001 to 2010 were analyzed with Excel software 2003. Results In Qinghai province, a total of 167 strains of Yersinia pestis were isolated from infected animals and insects in 10 years. Yersinia pestis was mainly distributed in Wulan,Delinha, Geermu, and Tianjun, along the Qinghai-Xizang railway. Human plague was occurred every year from 2001 to 2010 except 2002, 2007, 2008, and 2010. In the 10 years, there were 37 plague cases and 16 of these cases died, the mortality was 43.24％. The plague cases were mainly distributed in Nangqian, Qumalai, Chenduo,Zhiduo, Xinghai, Tongde, Tianjun, Wulan and Qilian. And these cases were found mostly in the period from May to October, especially in the period from August to October. Major clinical type of the plague cases was lung-type (62.16％,23/37). Conclusions The plague epidemic situation in Qinghai province is still severe, animal plague occurred year after year, and human plague outbreaks occasionally. Monitoring and early warning in the key areas should be strengthened, and the comprehensive measures of plague prevention and control should be carried out to reduce the incidence and prevalence of plague.

Evaluation of immunization protection efficacy of plague subunit vaccine / 中华预防医学杂志

<p><b>OBJECTIVE</b>To evaluate the protective efficacy of plague subunit vaccine, BALB/c mice, guinea pigs and rabbits were used in this study.</p><p><b>METHODS</b>Groups of mice (10 per group), guinea pigs (14 per group) and rabbits (6 per group) were immunized with F1 + rV270 vaccine, EV76 vaccine and alum adjuvant by intramuscular route, respectively. Serum antibody titres of mice, guinea pigs and rabbits were determined by ELISA and the immunized animals were challenged with 10(6) CFU of Y. pestis strain 141 at the 8th week after the primary immunization.</p><p><b>RESULTS</b>The immunized mice, guinea pigs or rabbits with subunit vaccine developed anti-F1 IgG titre of 41 587.3 +/- 2.1, 11 543.7 +/- 2.1 or 522.4 +/- 22.4 and elicited statistical anti-F1 IgG titre difference among them (F = 17.58, P < 0.01). The immunized mice, guinea pigs or rabbits with subunit vaccine had anti-rV270 IgG titre of 15 748.7 +/- 1.6, 12.6 +/- 1.4 or 1648.0 +/- 5.0 and induced statistical anti-rV270 IgG titre difference among them (F value was 16.34, P < 0.01). There was significant anti-F1 IgG titre difference among mice, guinea pigs and rabbits immunized with EV76 vaccine that developed anti-F1 IgG titre of 913.4 +/- 4.5, 937.0 +/- 2.0 or 342.0 +/- 12.0 (F = 23.67, P < 0.01), whereas the immunized mice, guinea pigs and rabbits with EV76 vaccine developed anti-rV270 IgG titre of 12.0 +/- 1.0, 447.0 +/- 10.0, 40.0 +/- 11.0 and there was no anti-rV270 IgG titre difference between them (F = 2.20, P = 0.1314). The immunized mice with subunit vaccine developed significantly higher anti-F1 IgG titres than immunized guinea pigs and rabbits (q value was 30.57 and 19.04, respectively, P < 0.01), and there were no anti-F1 IgG titre differences between the immunized guinea pigs and rabbits (q = 0.04, P = 0.8485). The immunized mice with subunit vaccine developed significantly higher anti-rV270 IgG titres than immunized guinea pigs and rabbits (q value was 27.10 and 19.49, respectively, P < 0.01), and there were no anti-rV270 IgG titre differences between the immunized guinea pigs and rabbits with the subunit vaccine (q = 0.25, P = 0.6187). The immunized mice with EV76 elicited higher anti-F1 IgG titres than immunized guinea pigs and rabbits (q value was 40.67 and 29.10, respectively, P < 0.01), whereas there was no difference of F1 IgG titer between immunized guinea pigs and rabbits (q = 0.06, P = 0.8098). The immunized mice, guinea pigs and rabbits with subunit vaccine provided 100% (10/10), 86% (12/14) and 100% (5/5) protection against 10(6) CFU Y. pestis of challenge, respectively. The immunized mice, guinea pigs and rabbits with EV76 vaccine gave 100% (6/6), 93% (13/14) and 100% (6/6) protection against 10(6) CFU Y. pestis of challenge respectively.</p><p><b>CONCLUSION</b>BALB/c mice is the best small animal model for valuation of protective efficacy of plague subunit vaccine. The guinea pigs showed a high individual variation for this purpose. The rabbits can be used as an alternative model for evaluating plague subunit vaccine.</p>

Identification of 2 strains of suspected Yersinia pestis isolated from Marmot,,himalayana in Dege County,Sichuan Province / 中国地方病学杂志

Objective Throush identify biochemical characteristics and virulence factors of 2 strains suspected Yersinia pestis(Y.pestis)isolated from the dead Marmota himalayana(M.himalayana)to confirm the nature epidemic focus in Dege County,Sichuan Province.Methods Y.pestis was analyzed by specific staining and shape,culturing characteristics,splitting-test by bacteriophage,test of biochemical characteristics and glycolysis ability,virulence factors,virulence,nutritional requirement,plasmid,genetic test and genetic type. Results The tested strains were Gram staining bacilus.The main biochemical characteristics were Arabinose(+)、 Rhamnose(-),Maltose(+),Melibiose(-),Glycerol(+),Denitrification(+).The virulence factors with FI+.VW+, Pgm+,Pst I+;and with the common 6.0×106,45.0×106,65.0×106 plasmids,also with the virulence-relative plasmid gene.Both their absolutely lethal dose(LD100)in mice were 50 bacteria.The nutritional requirement appeared which were depended on Phenylalanine and Methionine.With the Genomovar 5 genotype characteristics of M.himalayana plague foci of Qinghai-Tibet plateau.The difference between tested strains and Yersinia pseudotubercuosis on the 3 different culture medium was obvious.The tested strains had a Y.pestis' specific 3a fragment,Pst I and FI-Ag,at 22 ℃,the strains could be split by bacteriophage completely.Conclusions According to the diagnostic criteria of plague in China,the 2 suspected strains isolated from Dege County,Sichuan Province ale confirmed as Y.pestis.both with powerful virulenceand with the characteristics of the Y.pestis of M.himahtyana in Qinghai-Tibet plateau plague natural focus.

Study on plague pathogeny in areas along Qinghai-Tibet Railroad in Qinghai from 2001-2006 / 中国地方病学杂志

Objective To study the features of Yersinia pestis(Y.pestis)in areas along Qinghai-Tibet Railroad in Qinghai Province.Methods To identify the biologic types and the molecular biological feathers of Y.pestis isolated from areas along Qinghai-Tibet Railroad in Qinghai from 2001-2006.Results All the tested Y.pestis was biologically of classical type and ecologically of Qinghai-Tibet plateau type.The Y.pestis had high virulence.The Y.pestis of 65×106 plasmids was distributed in the Tanggula area,the Y.pestis of 52×106plasmids,in Tianjun and Delingha areas.The Y.pestis srains carried 52 × 106 plasmids.except the two containing 65 X 106 plasmids in Wulan County.The genetic type of Y.pestis in Tanggula was type 5 and that in Zongwulong of Delingha,Saishike,Keke,Tongpu of Wulan was type 8 except 2 strains of Y.pestis isolated from woodchuck and the patients in Dananwan of Tongpu,Wulan County were type 15.Conclusion The Y.pestis in the area along Qinghai-Tibet Railroad in Qinghai belongs to Qinghai-Tibet plateau type with high virulence.