Source tracing of the Yersinia pestis strains isolated from Heqing county, Yunnan province in 2017 / 中华流行病学杂志

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.

Yersinia Pestis: Un enigma filogenético

La PESTE o PLAGA ha sido una de las enfermedades más devastadoras en la historia del hombre y a pesar de los avances científicos actuales, no ha podido ser erradicada. Causada por la Yersinia pestis, produce cuadros clínicos de diversa severidad y alta mortalidad tales como las formas bubónica, septicémica, neumónica, cutánea y meníngea. Aunque se ha presentado en todos los continentes, no ha llegado a todos los países incluido el nuestro; sin embargo, ha afectado a países vecinos como Brasil, Perú y Ecuador. De los países desarrollados ha sido vitualmente eliminada, sin poder asegurar la erradicación del patógeno en sus reservorios naturales. La Yersinia es una enterobacteria que ha servido como modelo para estudiar las características de los gérmenes invasivos y como Yersinia pestis, ha desarrollado múltiples estrategias de virulencia que le han ayudado a mantenerse en un nivel constante en el ambiente, sin matar al huésped, mediante una PATOGENICIDAD BALANCEADA. Nuestro objetivo es el de revisar un mnicroorganismo enigmático e interesante en su contexto filogenético y de patogénesis en el hombre, sin entrar a describir las manifestaciones clínicas ni a discutir discutir diagnóstico y manejo

Immunochemical localization of the fraction-1 antigen, a virulence determinant of Yersinia pestis

The distribution of Yersina pestis Fraction-1 (F1) antigen was analyzed in cells grown at 28§C and 37§C. Fractionation of Y. pestis cells followed by analysis in SDS-polyacrylamide gel electrophoresis indicated that the mature form of the F1 antigen is localized in the extracellular matrix and in the cytoplasm. Localization of the F1 antigen was confirmed by immunoblots and a single peptide with a molecular weight of 17,000 daltons was recognized. Electron microscopy of Y. pestis cells labeled with colloidal gold-conjugated antibodies corroborated the extracellular matrix and cytoplasm dual location of the F1 antigen

Strain specific variation of outer membrane proteins of wild Yersinia pestis strains subjected to different growth temperatures

Three Yersinia pestis strains isolated from humans and one laboratory strain (EV76) were grown in rich media at 28§C and 37§C and their outer membrane protein composition compared by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-Page). Several proteins with molecular weights ranging from 34 kDa to 7 kDa were observed to change in relative abundance in samples grown at different temperatures. At least seven Y. pestis outer membrane proteins showed a temperature-dependent and strain-specific behaviour. Some differences between the outer membrane proteins of full-pathogenic wild isolates and the EV76 strain could aldso be detected and the relevance of this finding on the use of laboratory strains as a reference to the study of Y. pestis biological properties is discuted

Plasmid composition and virulence-associated factors of Yersinia pestis isolates from a plague outbreak at the Paraiba Stae, Brazil

Cepas patogênicas de Yersinia pestis foram coletadas durante um surto de peste no Estado da Paraíba em 1986. Os isolados de Y. pestis foram analisados quanto a presença de fatores associados à virulência e conteúdo plasmidial. Todas as linhagens analisadas foram proficientes na expressäo dos antígenos VW e fraçäo 1, além de possuírem capacidade de adsorçäo de pigmentos e produçäo de pesticina-fibronolisina-coagulase. Um perfil plasmidial semelhante composto por quatro plasmídeos com peso molecular de 60, 44, 14.9, e 6.4 MD foi encontrado em todas as linhagens. A clivagem do DNA plasmidial com a enzima de restriçäo EcoRI demonstrou o conteúdo plasmidial uniforme dos isolados de Y. pestis. Sete outras linhagens de Y. pestis, isoladas previamente no mesmo local mas em condiçäo endêmica, mostraram o mesmo perfil plasmidial. A falta de diferenças entre os isolados epidêmicos e endêmicos assim como o uso do perfil plasmidial na epidemiologia de Y. pestis é discutida