Toxigenic Corynebacterium diphtheriae strains cause diphtheria in humans. The toxigenic C. diphtheriae isolate NCTC13129 produces three distinct heterotrimeric pili that contain SpaA, SpaD, and SpaH, making up the shaft structure. The SpaA pili are known to mediate bacterial adherence to pharyngeal epithelial cells. However, to date little is known about the expression of different pili in vari...

The effects of rifampin and streptolydigin, inhibitors of ribonucleic acid (RNA) synthesis, on the production of F pili by Escherichia coli were studied by electron microscopy. The inhibition of RNA synthesis reduces the number of new pili produced by depiliated cells, but does not affect their length or the number of pili present at the time of inhibition or the retraction of pili. We suggest ...

We have purified pili from isogenic opacity colony variants that were derived from 14 gonococcal strains. Pili purified from opaque colonies of one strain usually differed from pili purified from transparent colonies of the same strain. In 10 of the 14 strains examined, the apparent subunit molecular weight of pilin isolated from the opaque variants was larger than that seen with pilin obtained...

Type I pili are proteinaceous tethers that mediate bacterial adhesion of uropathogenic Escherichia coli to surfaces and are thought to help bacteria resist drag forces imparted by fluid flow via uncoiling of their quaternary structure. Uncoiling and recoiling have been observed in force spectroscopy experiments, but it is not clear if and how this process occurs under fluid flow. Here we develo...

The in situ stimulation of Fe(III) oxide reduction in the subsurface stimulates the growth of Geobacter spp. and the precipitation of U(VI) from groundwater. As with Fe(III) oxide reduction, the reduction of uranium by Geobacter spp. requires the expression of their conductive pili. The pili bind the soluble uranium and catalyse its extracellular reductive precipitation along the pili filaments...

A variety of bacterial pathogens use nanoscale protein fibers called type IV pili to mediate cell adhesion, a primary step leading to infection. Currently, how these nanofibers respond to mechanical stimuli and how this response is used to control adhesion is poorly understood. Here, we use atomic force microscopy techniques to quantify the forces guiding the adhesion of Pseudomonas aeruginosa ...

Escherichia coli with mannose-resistant (MR) pili, in contrast to those with mannose-sensitive (MS) pili, did not adhere to rat peritoneal macrophages and human polymorphonuclear granulocytes, as measured by use of radioactive bacteria and by the chemiluminescence response induced by the cell contact. With some MS-piliated E. coli strains, unpiliated bacteria, obtained by growth at a pilus-rest...

CooD, the minor subunit of CS1 pili of enterotoxigenic Escherichia coli, is essential for the assembly of stable, functional pili. We previously proposed that CooD is a rate-limiting initiator of CS1 pilus assembly and predicted that the level of CooD expression should therefore determine the number of CS1 pili assembled on the cell surface. In this study, we confirm that CooD is required for t...

Pili from enterotoxigenic Escherichia coli pathogenic for humans have been isolated by adsorption to the surface of erythrocytes followed by thermal elution. The pili are composed of two protein subunits with molecular weights of 13,100 and 12,500 as determined by sodium dodecyl sulfate-gel electrophoresis. These pili also bind to human buccal cells under temperature conditions (37 degrees C) w...

It is critical for bacteria to recognize surface contact and initiate physiological changes required for surface-associated lifestyles. Ubiquitous microbial appendages called pili are involved in sensing surfaces and facilitating downstream behaviors, but the mechanism by which pili mediate surface sensing has been unclear. We visualized Caulobacter crescentus pili undergoing dynamic cycles of ...