conclusions our results indicated that the dissemination of pi-1 was widespread in s. pneumoniae isolates, although no pi-2 isolates were detected. furthermore, the frequency of rlra and rrgc of clinical isolates was significantly more than that of normal flora isolates. results the results confirmed the presence of rlra and rrgc genes in both clinical (n = 39) and normal flora (n = 26) isolate...

The pilus is an extracellular structural part that can be detected in some Streptococcus pneumoniae ( S. ) isolates (type I pili are found approximately 30% of strains, while type II 20%). It anchored to the cell wall by LPXTG-like motifs on peptidoglycan. Two kinds have been discovered, namely, pilus-1 and pilus-2. former encoded islet 1 (PI-1) a polymer formed protein subunits RrgA, RrgB RrgC...

Multiple pilus gene clusters have been identified in several gram-positive bacterial genomes sequenced to date, including the Actinomycetales, clostridia, streptococci, and corynebacteria. The genome of Corynebacterium diphtheriae contains three pilus gene clusters, two of which have been previously characterized. Here, we report the characterization of the third pilus encoded by the spaHIG clu...

Cell surface pili in gram-positive bacteria orchestrate the colonization of host tissues, evasion of immunity, and the development of biofilms. Recent work revealed that pilus assembly is a biphasic process wherein pilus polymerization is catalyzed by a pilus-specific sortase followed by cell wall anchoring of the pilus that is promoted by the housekeeping sortase. Here, we present molecular ge...

Different surface organelles contribute to specific interactions of a pathogen with host tissues or infectious partners. Multiple pilus gene clusters potentially encoding different surface structures have been identified in several gram-positive bacterial genomes sequenced to date, including actinomycetales, clostridia, corynebacteria, and streptococci. Corynebacterium diphtheriae has been show...

Recent data indicate that the human pathogen group B Streptococcus (GBS) produces pilus-like structures encoded in genomic islands with similar organization to pathogenicity islands. On the basis of the amino acid sequence of their protein components, 3 different types of pili have been identified in GBS, at least 1 of which is present in all isolates. We recently demonstrated that recombinant ...

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...

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...

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...