Although ubiquitous, the processes by which bacteria colonize surfaces remain poorly understood. Here we report results for the influence of the wall shear stress on the early-stage adhesion of Pseudomonas aeruginosa PA14 on glass and polydimethylsiloxane surfaces. We use image analysis to measure the residence time of each adhering bacterium under flow. Our main finding is that, on either surf...

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...

Colonization of the human stomach by Helicobacter pylori is an important risk factor for development of gastric cancer. The H. pylori cag pathogenicity island (cag PAI) encodes components of a type IV secretion system (T4SS) that translocates the bacterial oncoprotein CagA into gastric epithelial cells, and CagL is a specialized component of the cag T4SS that binds the host receptor α5β1 integr...

Type IV pili play an important role in bacterial adhesion, motility, and biofilm formation. Here we present high-resolution atomic force microscopy (AFM) images of type IV pili from Pseudomonas aeruginosa bacteria. An individual pilus ranges in length from 0.5 to 7 microm and has a diameter from 4 to 6 nm, although often, pili bundles in which the individual filaments differed in both length an...

Bacterial surface colonizers are subject to a variety of physical stresses. During the colonization of human epithelia such as on the skin or the intestinal mucosa, bacteria mainly have to withstand the mechanical stress of being removed by fluid flow, scraping, or epithelial turnover. To that end, they express a series of molecules to establish firm attachment to the epithelial surface, such a...

Type IV pili (Tfp) are widespread filamentous bacterial organelles that mediate multiple virulence-related phenotypes. They are composed mainly of pilin subunits, which are processed before filament assembly by dedicated prepilin peptidases. Other proteins processed by these peptidases, whose molecular nature and mode of action remain enigmatic, play critical roles in Tfp biology. We have perfo...

The invasion of intestinal epithelial cells by the Crohn disease-associated adherent-invasive Escherichia coli (AIEC) strain LF82 depends on surface appendages, such as type 1 pili and flagella. The absence of flagella in the AIEC strain LF82 results in a concomitant loss of type 1 pili. Here, we show that flagellar regulators, transcriptional activator FlhD(2)C(2), and sigma factor FliA are in...

Strains of Neisseria meningitidis elaborate one of two classes of pili. Meningococcal class I pili have many features in common with pili produced by N. gonorrhoeae, including the ability to bind monoclonal antibody SM1 and a common gene and protein structure consisting of conserved, semivariable, and hypervariable regions. Class II pili are SM1 nonreactive and display smaller subunit molecular...

Macarbomycin (MM) preferentially kills Escherichia coli carrying episomes derepressed for sex pili formation (drd episomes). Using MM, we have isolated various types of mutants from both F-lac.tet and R100-1 episomes and have classified them into two types by sex pili formation. Among 26 mutants, 20 could not produce pili and had lost both the ability for conjugal transmission and sensitivity t...