Type I and type IV pili of Xylella fastidiosa play different roles in twitching motility, biofilm formation, and cell-cell aggregation. Thirty twitching mutants were generated with an EZ::TN transposome system and type IV pilus-associated genes were identified, including fimT, pilX, pilY1, pilO, and pilR. Mutations in all resulted in a twitch-minus phenotype except that pilY1 mutant was twitchi...

Hair shaft disorders encompass a wide range of hair defects with or without fragility, which could be acquired inherited genetically. may localized generalized and are characterized by changes in color, structure, length, density. Pili torti, also called twisted hair, is clinical entity the flattened 180° along its axis. annulati described as striped showing alternate light dark bands. Trichorr...

The arsenate poisoning of R17 phage eclipse in Escherichia coli cultures grown in glycerol-containing medium has been found to be mediated by a dramatic loss in cell-associated F pili. Poisoning was very rapid and was nearly complete within 3 min at 37 C. The loss of pili was reflected by a 90% reduction in the ability of these cells to attach ribonucleic acid phage and by a reduction in the pi...

Neisseria gonorrheae bacteria are the causative agent of the second most common sexually transmitted infection in the world. The bacteria move on a surface by means of twitching motility. Their movement is mediated by multiple long and flexible filaments, called type IV pili, that extend from the cell body, attach to the surface, and retract, thus generating a pulling force. Moving cells also u...

PURPOSE To determine the relationship between pili annulati (PA) and acquired trichorrhexis nodosa (TN) seen in the same patient, considering the two main theories evoked by previous studies: greater stiffness of darker PA bands or associated cuticular damage. PROCEDURES Light microscopy of hair shafts from different regions of the patient's scalp. RESULTS TN was not superimposed to dark ba...

The extracellular matrix protects Escherichia coli from immune cells, oxidative stress, predation, and other environmental stresses. Production of the E. coli extracellular matrix is regulated by transcription factors that are tuned to environmental conditions. The biofilm master regulator protein CsgD upregulates curli and cellulose, the two major polymers in the extracellular matrix of uropat...

Amyloid fibers are filamentous proteinaceous structures commonly associated with mammalian neurodegenerative diseases. Nucleation is the rate-limiting step of amyloid propagation, and its nature remains poorly understood. Escherichia coli assembles functional amyloid fibers called curli on the cell surface using an evolved biogenesis machine. In vivo, amyloidogenesis of the major curli subunit ...

Multiple pilus types from a uropathogenic strain of Escherichia coli O6, strain 6260, were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), high-pressure liquid chromatography, binding assays, and erythrocyte adsorption. In addition, monoclonal antibodies were raised against purified pili of E. coli 6260 and used for immunological characterization. SDS-PAGE...

Escherichia coli produces proteinaceous surface structures called curli that are involved in adhesion and biofilm formation. CsgD is the transcriptional activator of curli genes. We show here that csgD expression is, in part, controlled post-transcriptionally by two redundant small RNAs (sRNAs), OmrA and OmrB. Their overexpression results in curli deficiency, in accordance with the inhibition o...

RydC pseudoknot aided by Hfq is a dynamic regulatory module. We report that RydC reduces expression of curli-specific gene D transcription factor required for adhesion and biofilm production in enterobacteria. During curli formation, csgD messenger RNA (mRNA) synthesis increases when endogenous levels of RydC are lacking. In Escherichia coli and Salmonella enterica, stimulation of RydC expressi...