Animals ; Bacterial Proteins/metabolism* ; Gene Expression Regulation, Bacterial ; Plague ; Transcription Factors/genetics* ; Yersinia pestis/genetics*

The risk of plague epidemics and relapse of various types of plague foci persists in Inner Mongolia Autonomous Region. For Marmota sibirica plague foci, the animal plague has not been found but antibody has been detected positive. Nowadays, Marmota sibirica has been increasing in population and distribution in China. In bordering countries Mongolia and Russia, the animal plague has been continuously prevalent. For Spermophilus dauricus plague foci, the animal plague has been taken place now and then. Compared to the above foci, the animal plague is most prevalent in Meriones unguiculatus plague foci and frequently spread to humans. Due to higher strain virulence and historical disaster in Marmota sibirica plague foci and Spermophilus dauricus plague foci, plague prevention and control should be strengthened on these foci. In addition to routine surveillance, epidemic dynamics need to be further monitored in these two foci, in order to prevent their relapse and spread to humans.
Animals ; China/epidemiology* ; Epidemics ; Humans ; Plague/prevention & control* ; Prevalence ; Sciuridae ; Yersinia pestis

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
Bacterial Proteins/metabolism* ; Biofilms ; Gene Expression Regulation, Bacterial/physiology* ; Yersinia pestis/physiology*

Chinese tongue diagnosis was initially developed to quickly and efficiently diagnose and prescribe medicine, while at the same time allowing the doctor to have minimal contact with the patient. At the time of its compiling, the spread of Yersinia pestis, often causing septicaemia and gangrene of the extremities, may have discouraged doctors to come in direct contact with their patients and take the pulse. However, in recent decades, modern developments in the field of traditional Chinese medicine, as well as the spread of antibiotics in conjunction with the advancements of microbiology, have overshadowed the original purpose of this methodology. Nevertheless, the fast approaching post-antibiotic era and the development of artificial intelligence may hold new applications for tongue diagnosis. This article focuses on the historical development of what is the world's earliest tongue diagnosis monograph, and discusses the directions that such knowledge may be used in future clinical research.
China ; Diagnosis, Differential ; History, Ancient ; Humans ; Medicine in Literature ; history ; Plague ; diagnosis ; history ; microbiology ; therapy ; Tongue ; chemistry ; Yersinia pestis ; physiology

Objective: To understand the genotype of the Yersinia (Y.) pestis strains isolated from Heqing county, Yunnan province in 2017 and provide evidence for the prevention and control of plague in this area. Methods: Ten Y. pestis strains isolated from Heqing were typed by the detections of different region (DFR) and clustered regularly interspaced short palindromic repeats (CRISPRs) as well as multiple-locus variable-number tandem repeat analysis (MLVA). And the results were compared with those of the 93 Y. pestis strains from the adjacent plague foci of Heqing obtained from the established database for clustering analysis. Results: The results showed that Heqing strains had the same type of DFR (Genomovar 05) and CRISPRs (Cluster Ca7, Type 22) with isolates from the plague focus in Lijiang. Heqing strains and Lijiang strains were in the same cluster in MST and only VNTR loci N2117 and M23 of Heqing strains were different from that of Lijiang strains. Conclusion: The Y. pestis strains isolated from Heqing in 2017 were highly homogenous with the strains isolated from wild rodents in plague focus in Lijiang, and Heqing plague might be the result of further southward spread of Lijiang plague.
Animals ; China/epidemiology* ; Epidemiological Monitoring ; Genotype ; Minisatellite Repeats ; Molecular Typing ; Plague/microbiology* ; Rodentia/microbiology* ; Yersinia pestis/pathogenicity*

Recombinant Fl-V (rFl-V) fusion protein is the main ingredient of the current candidate vaccine against Yersinia pestis infection, which has been under investigation in clinical trial in USA. We investigated the soluble expression conditions of rF1-V in Escherichia coli BL21 (DE3) that we constructed before. After scale-up and optimization of fermentation processes, we got the optimized fermentation process parameters: the culture was induced at the middle exponential phase with 50 µmol/L of IPTG at 25 °C for 5 h. Soluble rFl-V protein was isolated to 99% purity by ammonium sulfate precipitation, ion exchange chromatography, hydrophobic chromatography and gel filter chromatography. The protein recovery was above 20%. Protein identity and primary structure were verified by mass spectrometry and Edman sequencing. Results of purity, quality and western blotting analysis indicated that the target protein is a consistent and properly folded product. Furthermore, the immunogenicity of various antigens formulated with aluminum hydroxide adjuvant was evaluated in mice. Serum antibody titers of 4 groups including 20 µg rFl, rV and rFl-V and 10 µg rFl+10 µg rV, were assayed by ELISA after 2 doses. The antibody titers of anti-Fl with 20 µg rFl-V were obviously higher than titers with other groups; meanwhile there were no significant difference of anti-V antibody titers among them. These findings confirm that rFl-V would be the active pharmaceutical ingredient of the plague subunit vaccine.
Adjuvants, Immunologic ; Animals ; Antibodies, Bacterial ; blood ; Antibody Formation ; Antigens, Bacterial ; immunology ; Blotting, Western ; Chromatography, Ion Exchange ; Enzyme-Linked Immunosorbent Assay ; Mice ; Plague ; prevention & control ; Plague Vaccine ; immunology ; Recombinant Fusion Proteins ; immunology ; Vaccines, Subunit ; immunology ; Yersinia pestis

OBJECTIVES: Plague remains a public health concern worldwide, particularly in old foci. Multiple epidemics of this disease have been recorded throughout the history of Iran. Despite the long-standing history of human plague in Iran, it remains difficult to obtain an accurate overview of the history and current status of plague in Iran. METHODS: In this review, available data and reports on cases and outbreaks of human plague in the past and present in Iran and in neighboring countries were collected, and information was compiled regarding when, where, and how many cases occurred. RESULTS: This paper considers the history of plague in Persia (the predecessor of today’s Iran) and has a brief review of plague in countries in the World Health Organization Eastern Mediterranean Region, including a range of countries in the Middle East and North Africa. CONCLUSIONS: Since Iran has experienced outbreaks of plague for several centuries, neighboring countries have reported the disease in recent years, the disease can be silent for decades, and the circulation of Yersinia pestis has been reported among rodents and dogs in western Iran, more attention should be paid to disease monitoring in areas with previously reported human cases and in high-risk regions with previous epizootic and enzootic activity.
Africa, Northern ; Animals ; Disease Outbreaks ; Dogs ; History of Medicine ; Humans ; Iran* ; Mediterranean Region ; Middle East ; Persia ; Plague* ; Public Health ; Rodentia ; World Health Organization ; Yersinia pestis

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.
Genotype ; Humans ; Polymerase Chain Reaction ; Virulence ; Yersinia pestis

OBJECTIVETo analyze the epidemiology data on plague in five counties in Zhejiang province and to evaluate the risk of plague in theses areas.

METHODSWe selected five monitoring stations as a risk assessment (Qingyuan county, Longquan city, Yiwu city, Wencheng county, and Ruian city) in Zhejiang province where the plague epidemic more serious in the history. At least one constant site and 1-4 variable sites where plague occurred in history were selected for monitoring. We collected the five counties (cities) surveillance data of indoor rat density, indoor Rattus flavipectus density, the Xenopsylla cheopis index of rat, the Xenopsylla cheopis index of Rattus flavipectus in 1995-2014. Isolation of Yersinia pestis was conducted among 171,201 liver samples and F1 antibody were detected among 228,775 serum samples. Risk matrix, Borda count method, and Delphi approach were conducted to assess risk of the plague of five counties (cities) in Zhejiang province.

RESULTSIndoor rat density in Qingyuan county, Longquan city, Yiwu city, Wencheng county, Ruian city was 1.58%-5.50%, 1.13%-9.76%, 0.56%-3.67%, 2.83%-16.08%, 7.16%-15.96%, respectively; Indoor Rattus flavipectus density of five counties (cities) was 0.08%-2.23%, 0-2.02%, 0-0.54%, 0.71%-5.58%, 0.55%-4.92%, respectively. The Xenopsylla cheopis index of rat in Qingyuan county and Wencheng county was 0.011-0.500 and 0.015-0.227, respectively; The Xenopsylla cheopis index of Rattus flavipectus of Qingyuan county and Wencheng county was 0.119-3.412 and 0.100-1.430, respectively; Ruian City and Yiwu city cannot collected Xenopsylla cheopis, Long quan city only collected the Xenopsylla cheopis index of rat in the five years. Yersinia pestis were not isolated in five counties (cities).There were 3 Apodemus agrarius samples positive of plague F1 antibody test, in Longquan city and Yiwu city in 2005. Borda count method to assess the Longquan city, Yiwu (Borda point were both 321) plague risk was higher than three other regions; Delphi approach to evaluation five counties (cities) belong to the plague had a lower risk areas, according to the level of risk score (Pf) Longquan city and Yiwu (Pf was 0.314, 0.292, respectively) plague risk were higher than three other regions (Pf were all 0.292).

CONCLUSIONThe main host and media were lower in five key plague surveillance counties (cities) of Zhejiang province; The result of Borda count method and Delphi approach for risk assessment indicated that endogenous plague recrudescence was at lower level, but Longquan city and Yiwu city risk were higher than other counties (cities).

Animals ; Cities ; Epidemics ; Epidemiological Monitoring ; Humans ; Murinae ; Plague ; Rats ; Risk Assessment ; Yersinia pestis

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