We performed multilocus sequence typing of 64 North American Streptococcus suis serotype 2 porcine isolates. Strains were sequence type (ST) 28 (51%), ST25 (44%), and ST1 (5%). We identified nonrandom associations between STs and expression of the virulence markers suilysin (SLY), muramidase-relased protein (MRP), and extracellular factor (EF). Expression of pili encoded by the srtF and srtG pi...

Citrobacter rodentium is a murine pathogen that is now widely used as an in vivo model for gastrointestinal infections due to its similarities with human enteropathogens, such as the possession of a locus for enterocyte effacement (the LEE island). We studied the lrp gene of C. rodentium and found that it encodes a product highly similar to members of the Lrp (leucine-responsive regulatory prot...

Streptococcus pneumoniae pili contribute to adherence and virulence. The regulation of pilus-1 expression is bistable, thus piliated strains contain a variable proportion of pilus-1-non-expressing bacteria. We investigated whether such proportion changes during colonization. Pilus-1-expressing bacteria were quantified in nasopharyngeal washes and pharyngeal tissues from mice that received intra...

Many photosynthetic microorganisms have evolved the ability to sense light quality and/or quantity and can steer themselves into optimal conditions within the environment. Phototaxis and gliding motility in unicellular cyanobacteria require type IV pili, which are multifunctional cell surface appendages. Screens for cells exhibiting aberrant motility uncovered several non-motile mutants as well...

Type IV pilus (T4P) systems are complex molecular machines that polymerize major pilin proteins into thin filaments displayed on bacterial surfaces. Pilus functions require rapid extension and depolymerization of the pilus, powered by the assembly and retraction ATPases, respectively. A set of low abundance minor pilins influences pilus dynamics by unknown mechanisms. The Vibrio cholerae toxin-...

The apparent subunit sizes for pili of gonococci (Gc) have been visualized by using either Iodogen 125I-labeled whole Gc or immunoblotting with antipilus antiserum. These methods permitted definition of pilus subunit sizes for Gc of a given strain that had undergone changes either in piliation phenotype or in colonial opacity/protein II phenotype. The results indicate that pilus subunit size do...

Uropathogenic E. coli (UPEC), which cause urinary tract infections (UTI), utilize type 1 pili, a chaperone usher pathway (CUP) pilus, to cause UTI and colonize the gut. The pilus rod, comprised of repeating FimA subunits, provides a structural scaffold for displaying the tip adhesin, FimH. We solved the 4.2 Å resolution structure of the type 1 pilus rod using cryo-electron microscopy. Residues ...

Transport of DNA across bacterial membranes involves complex DNA uptake systems. In Gram-positive bacteria, the DNA uptake machinery shares fundamental similarities with type IV pili and type II secretion systems. Although dedicated pilus structures, such as type IV pili in Gram-negative bacteria, are necessary for efficient DNA uptake, the role of similar structures in Gram-positive bacteria i...