CsrA-Mediated Translational Activation of the mRNA Enhances HmsD-Dependent C-di-GMP-Enabled Biofilm Production in Yersinia pestis.

The plague bacterium, Yersinia pestis, forms a biofilm-mediated blockage in the flea foregut that enhances its transmission by fleabite. Biofilm formation is positively controlled by cyclic di-GMP (c-di-GMP), which is synthesized by the diguanylate cyclases (DGC), HmsD and HmsT. While HmsD primarily promotes biofilm-mediated blockage of fleas, HmsT plays a more minor role in this process.

A novel subtype of sporadic Creutzfeldt-Jakob disease with PRNP codon 129MM genotype and PrP plaques.

The presence of amyloid kuru plaques is a pathological hallmark of sporadic Creutzfeldt-Jakob disease (sCJD) of the MV2K subtype. Recently, PrP plaques (p) have been described in the white matter of a small group of CJD (p-CJD) cases with the 129MM genotype and carrying resPrP type 1 (T1). Despite the different histopathological phenotype, the gel mobility and molecular features of p-CJD resPrP T1 mimic those of sCJDMM1, the most common human prion disease.

CsrA Enhances Cyclic-di-GMP Biosynthesis and Yersinia pestis Biofilm Blockage of the Flea Foregut by Alleviating Hfq-Dependent Repression of the mRNA.

Plague-causing Yersinia pestis is transmitted through regurgitation when it forms a biofilm-mediated blockage in the foregut of its flea vector. This biofilm is composed of an extracellular polysaccharide substance (EPS) produced when cyclic-di-GMP (c-di-GMP) levels are elevated. The Y.

Co-infection Assay to Determine Yersinia pestis Competitive Fitness in Fleas.

Co-infection refers to the simultaneous infection of a host by multiple pathogenic organisms. Experimental co-infection studies using a mutant and its isogenic wild type have proven to be profoundly sensitive to analysis of pathogen factor mutation-associated fitness effects in in vivo models of infectious disease. Here we discuss the use of such co-infection experiments in studying the interaction between Yersinia pestis and its flea vector to more sensitively determine the critical bacterial determinants for Y.