Legionella pneumophila expresses pili of variable lengths, either long (0.8 to 1.5 microm) or short (0.1 to 0.6 microm), that can be observed by transmission electron microscopy. We have identified a gene in L. pneumophila with homology to the type IV pilin genes (pilEL). An insertion mutation was constructed in pilEL and introduced into the L. pneumophila wild-type strain by allelic exchange. ...

Previous studies have suggested that the Pseudomonas aeruginosa PAK pilus adhesin moiety resides in an epithelial cell-binding domain located in the C-terminal region of the PAK pilin structural protein. Synthetic peptides Ac17red (a synthetic peptide with a sequence identical to that of PAK pilin residues 128 to 144, with the Cys-129 and Cys-142 residues being in the reduced state) and Ac17ox ...

The endocarditis and biofilm-associated pilus (Ebp) operon is a component of the core genome of Enterococcus faecalis that has been shown to be important for biofilm formation, adherence to host fibrinogen, collagen and platelets, and in experimental endocarditis and urinary tract infection models. Here, we created single and double deletion mutants of the pilus subunits and sortases; next, by ...

Class 5 fimbriae of enterotoxigenic Escherichia coli (ETEC) comprise eight serologically discrete colonization factors that mediate small intestinal adhesion. Their differentiation has been attributed to the pressure imposed by host adaptive immunity. We sequenced the major pilin and minor adhesin subunit genes of a geographically diverse population of ETEC elaborating CFA/I (n = 31), CS17 (n =...

We give an unconditional proof of the André-Oort conjecture for arbitrary products of modular curves. We establish two generalizations. The first includes the Manin-Mumford conjecture for arbitrary products of elliptic curves defined over Q as well as Lang’s conjecture for torsion points in powers of the multiplicative group. The second includes the ManinMumford conjecture for abelian varieties...

We study the number N(n,An, X) of number fields of degree n whose Galois closure has Galois group An and whose discriminant is bounded by X. By a conjecture of Malle, we expect that N(n,An, X) ∼ Cn ·X 1 2 ·(logX)bn for constants bn and Cn. For 6 ≤ n ≤ 84393, the best known upper bound is N(n,An, X) � X n+2 4 ; this bound follows from Schmidt’s Theorem, which implies there are � X n+2 4 number f...

Pilin antigenic variation in Neisseria gonorrhoeae may result following intrachromosomal recombination between homologous pil genes. Despite extensive study, recA is the only previously characterized gene known to be involved in this process. In this study, the gonococcal recD gene, encoding one subunit of the putative RecBCD holoenzyme, was characterized and its role in pilin variation assesse...

El objetivo de este trabajo fue establecer la influencia que ejerce granulometría del lecho río, forma pila un puente y los parámetros hidrológicos en profundidad socavación, a partir modelo físico. Para el desarrollo experimental se empleó suelo granular proveniente río al le realizaron ensayos laboratorio para determinar distribución tamaño las partículas, empleando materiales cuya clasificac...