ABSTRACT
Objective To screen the conservative,stable and specific DNA signature sequence in the plasmid of Yersinia pestis.Methods Specific validation trials and stability of the qualification test were carried out to 40 strains of Yersinia pestis,47 strains of non-Yersinia pestis of home and wild types of rodent in Yunnan,by using 32 DNA sequences derived from Yersinia pestis in the plasmid and conventional PCR technology,and Yersinia pestis vaccine strain EV76 as a positive control.Results Four pairs of relatively conservative,stable and specific DNA marker genes were screened:YPMT1.05c,YPMT1.03c,YPMT1.42 and YPMT1.04c.Conclusions The 4 pairs of Yersinia pestis DNA signature sequences can be used for rapid diagnosis of plague.
ABSTRACT
Objective To compare the difference of biochemical characteristics and virulent Pst Ⅰ of Yersinia pestis strains in traditional focuses of plague in Yunna Province and in the new focuses of plague in Yulong County. Methods The identification data of biochemical characteristics(Rhamnose, Glycerol, Maltose, L-Arabina and Melibiose fermentation) and virulence factor(Pst Ⅰ) from different focuses of plague in Yunna Province were Retrospectively collected by tube test followed by the analysis using statistics software SAS 8.0 by Fisher exact probability of disordered two-way R × C table χ2 test. Results Among 48 strains of Yersinia pestis from hantaan type plague focus, 1 strain fermented L-maltose, 48 strains fermented Glycerol. Among 165 strains of Yersinia pestis from the Soul type plague focus, 1 strain did not ferment L-maltose, only one of them fermented Glycerol. 1 strain from the Soul type plague focus was confirmed to have mutation, for the test of nitrate reduction reaction was negative. All 5 strains of Yersinia pestis from the new focuses of plague in Yulong County fermented L-maltose and Glycerol. The statistical result showed that the differences in L-maltose and Glycerol fermentation of Yersinia pestis from different natural focuses of plague in Yunnan Province were statistically siguificant (P < 0.01). The differences of other biochemical characteristics and Pst Ⅰ were not statistically significant (P > 0.01). Conclusions Biochemical characteristics of Yersinia pestis from the hantaan type plague focus and the Soul type plague focus in Yunnan province are overlapping. Biochemical characteristics of Yersinia pestis from the new focuses of plague in Yulong County are different from those tradition focuses of plague in Yunna Province but share similarities to those from Unquiculatus focuses in North Tibet.
ABSTRACT
Objective To find methods to isolate and purify plasminogen activator (Pla) from artificial culture of Yersinia pestis. Methods Ultrasonication and urea extracting combined by ammonium sulfate salting-out were tried to extract Pla. High performance liquid chromatography(HPLC) was used to purify Pla. The first step was ion exchange and the second was gel filtration, Preparative electrophoresis was used to purify Pla, too. The enzyme activity of the isolated or purificated Pla was detected. Results Both 50% - 60% saturated ammonium sulfate deposition of supernatant of plague bacilli ultrasonication and 0 - 10% saturated ammonium sulfate deposition of supernatant of plague bacilli powder soaked by urea had three bands(Mr about 31×103, 35×103 and 37×103) and lysis rings were 6.5 and 7.2 mm in diameter respectively when the enzyme activity was detected. Pla purified by HPLC was mainly composed of three bands(Mr about 31×103, 35×103 and 37×103), occupying more than 80% of total protein weight and lysis ring was 5.0 mm in diameter. Pla purified by preparative electrophoresis mainly consisted of three bands(Mr about 31×103, 35×103 and 37×103) with other proteins of low concentration nearby, no lysis ring was detected. Conclusions Pla is collected by the methods of ultrasonication and urea extracting. Priliminary purification of Pla can be achieved by HPLC and preparative electrophoresis.