scholarly journals The Pseudomonas aeruginosa Pathogenicity Island PAPI-1 Is Transferred via a Novel Type IV Pilus

2010 ◽  
Vol 192 (13) ◽  
pp. 3249-3258 ◽  
Author(s):  
Michelle Qiu Carter ◽  
Jianshun Chen ◽  
Stephen Lory
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Pathogenicity Island ◽  
Genomic Islands ◽  
Virulence Determinants ◽  
Type Iv Pilus ◽  
Conjugation System ◽  
Type Iv ◽  
Infection Models ◽  
Prepilin Peptidase ◽  
Plasmid R64

ABSTRACT Pseudomonas aeruginosa is a major cause of nosocomial infections, particularly in immunocompromised patients or in individuals with cystic fibrosis. The notable ability of P. aeruginosa to inhabit a broad range of environments, including humans, is in part due to its large and diverse genomic repertoire. The genomes of most strains contain a significant number of large and small genomic islands, including those carrying virulence determinants (pathogenicity islands). The pathogenicity island PAPI-1 of strain PA14 is a cluster of 115 genes, and some have been shown to be responsible for virulence phenotypes in a number of infection models. We have previously demonstrated that PAPI-1 can be transferred to other P. aeruginosa strains following excision from the chromosome of the donor. Here we show that PAPI-1 is transferred into recipient P. aeruginosa by a conjugative mechanism, via a type IV pilus, encoded in PAPI-1 by a 10-gene cluster which is closely related to the genes in the enterobacterial plasmid R64. We also demonstrate that the precursor of the major pilus subunit, PilS2, is processed by the chromosomally encoded prepillin peptidase PilD but not its paralog FppA. Our results suggest that the pathogenicity island PAPI-1 may have evolved by acquisition of a conjugation system but that because of its dependence on an essential chromosomal determinant, its transfer is restricted to P. aeruginosa or other species capable of providing a functional prepilin peptidase.

scholarly journals The organization of Helicobacter pylori cag-pathogenicity island (cagPAI) genes in multiracial population with histopathological changes of gastric mucosa

2019 ◽  
Author(s):  
Alfizah Hanafiah ◽  
Shaza Azlin Razak ◽  
Hui-min Neoh ◽  
Noraziah Mohamad Zin ◽  
Bruno S. Lopes
Keyword(s):  
Helicobacter Pylori ◽  
Gastric Mucosa ◽  
Pathogenicity Island ◽  
Type Iv Secretion ◽  
Virulence Determinants ◽  
Gastric Diseases ◽  
Cag Pathogenicity Island ◽  
Type Iv ◽  
Inflammatory Score ◽  
H Pylori

Abstract Background: Helicobacter pylori is a Gram-negative bacillus that colonises only the mucus layer of the human stomach and is implicated in gastric diseases. Virulent H. pylori harbouring cag-pathogenicity island (cagPAI) which encodes genes for type IV secretion system (T4SS) and CagA protein is one of the major virulence determinants involved in disease development. We examined the entire cagPAI genes in 95 H. pylori isolates from a multiracial population and examined the intactness of cagPAI region with histopathological scores of the gastric mucosa. Results: 95.8% of H. pylori isolates were cagPAI-positive with 23.2% having an intact cagPAI, whereas 72.6% had a partial/rearranged cagPAI. In our study, cag2 and cag4 were found to be significantly higher in H. pylori isolated from Malays, whereas cag4 was predominant in Chinese isolates. We also detected cag24 in significantly high proportion in isolates from the Malays and the Indians compared to the Chinese isolates. The intactness of cagPAI region showed an association with histopathological scores of the gastric mucosa. Significant association was observed between H. pylori harbouring partial cagPAI and higher density of H. pylori and neutrophil activity, whereas strains which lacked cagPAI was associated with higher inflammatory score. Conclusions: The screening of the entire cagPAI genes provides an accurate overview of the cagPAI organisation in H. pylori isolates in a multiracial population. The genotypes of H. pylori strains with various cagPAI rearrangement associated with patients’ ethnicities and histopathological scores might contribute to the pathogenesis of H. pylori infection in a multi-ethnic population.

scholarly journals Novel Class of Mutations of pilS Mutants, Encoding Plasmid R64 Type IV Prepilin: Interface of PilS-PilV Interactions

2007 ◽  
Vol 190 (4) ◽  
pp. 1202-1208 ◽  
Author(s):  
Eriko Shimoda ◽  
Tatsuya Muto ◽  
Takayuki Horiuchi ◽  
Nobuhisa Furuya ◽  
Teruya Komano
Keyword(s):  
Genetic Analysis ◽  
Type Iv Pili ◽  
Class I ◽  
Minor Components ◽  
Class Iii ◽  
Class V ◽  
Type Iv ◽  
Prepilin Peptidase ◽  
Class Iv ◽  
Plasmid R64

ABSTRACT The type IV pili of plasmid R64 belonging to the type IVB group are required only for liquid mating. They consist of the major and minor components PilS pilin and PilV adhesin, respectively. PilS pilin is first synthesized as a 22-kDa prepilin from the pilS gene and is then processed to a 19-kDa mature pilin by PilU prepilin peptidase. In a previous genetic analysis, we identified four classes of the pilS mutants (T. Horiuchi and T. Komano, J. Bacteriol. 180:4613-4620, 1998). The products of the class I pilS mutants were not processed by prepilin peptidase; the products of the class II mutants were not secreted; in the class III mutants type IV pili with reduced activities in liquid mating were produced; and in the class IV mutants type IV pili with normal activities were produced. Here, we describe a novel class, class V, of pilS mutants. Mutations in the pilS gene at Gly-56 or Tyr-57 produced type IV pili lacking PilV adhesin, which were inactive in liquid mating. Residues 56 and 57 of PilS pilin are suggested to function as an interface of PilS-PilV interactions.

scholarly journals FppA, a Novel Pseudomonas aeruginosa Prepilin Peptidase Involved in Assembly of Type IVb Pili

2006 ◽  
Vol 188 (13) ◽  
pp. 4851-4860 ◽  
Author(s):  
Sophie de Bentzmann ◽  
Marianne Aurouze ◽  
Geneviève Ball ◽  
Alain Filloux
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Cell Surface ◽  
Molecular Mechanisms ◽  
Type Iv Pili ◽  
Reading Frame ◽  
Type Iv ◽  
Bacterial Aggregation ◽  
Epithelial Cell Surface ◽  
Prepilin Peptidase ◽  
Pilus Assembly

ABSTRACT Several subclasses of type IV pili have been described according to the characteristics of the structural prepilin subunit. Whereas molecular mechanisms of type IVa pilus assembly have been well documented for Pseudomonas aeruginosa and involve the PilD prepilin peptidase, no type IVb pili have been described in this microorganism. One subclass of type IVb prepilins has been identified as the Flp prepilin subfamily. Long and bundled Flp pili involved in tight adherence have been identified in Actinobacillus actinomycetemcomitans, for which assembly was due to a dedicated machinery encoded by the tad-rcp locus. A similar flp-tad-rcp locus containing flp, tad, and rcp gene homologues was identified in the P. aeruginosa genome. The function of these genes has been investigated, which revealed their involvement in the formation of extracellular Flp appendages. We also identified a gene (designated by open reading frame PA4295) outside the flp-tad-rcp locus, that we named fppA, encoding a novel prepilin peptidase. This is the second enzyme of this kind found in P. aeruginosa; however, it appears to be truncated and is similar to the C-terminal domain of the previously characterized PilD peptidase. In this study, we show that FppA is responsible for the maturation of the Flp prepilin and belongs to the aspartic acid protease family. We also demonstrate that FppA is required for the assembly of cell surface appendages that we called Flp pili. Finally, we observed an Flp-dependent bacterial aggregation process on the epithelial cell surface and an increased biofilm phenotype linked to Flp pilus assembly.

scholarly journals The plasmid R64 thin pilus identified as a type IV pilus.

1997 ◽  
Vol 179 (11) ◽  
pp. 3594-3603 ◽  
Author(s):  
S R Kim ◽  
T Komano
Keyword(s):  
Type Iv Pilus ◽  
Type Iv ◽  
Plasmid R64

scholarly journals The Peptidoglycan-Binding Protein FimV Promotes Assembly of the Pseudomonas aeruginosa Type IV Pilus Secretin

2010 ◽  
Vol 193 (2) ◽  
pp. 540-550 ◽  
Author(s):  
H. Wehbi ◽  
E. Portillo ◽  
H. Harvey ◽  
A. E. Shimkoff ◽  
E. M. Scheurwater ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Binding Protein ◽  
Type Iv Pilus ◽  
Type Iv

scholarly journals The Basis for Natural Multiresistance to Phage in Pseudomonas aeruginosa

Antibiotics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 339 ◽  
Author(s):  
Christine Pourcel ◽  
Cédric Midoux ◽  
Gilles Vergnaud ◽  
Libera Latino
Keyword(s):  
Extracellular Matrix ◽  
Pseudomonas Aeruginosa ◽  
Phage Therapy ◽  
Genomic Islands ◽  
Closely Related Species ◽  
Clinical Strains ◽  
Type Iv ◽  
Insertion Elements ◽  
Resistant Strains

Pseudomonas aeruginosa is responsible for long-term infections and is particularly resistant to treatments when hiding inside the extracellular matrix or biofilms. Phage therapy might represent an alternative to antibiotic treatment, but up to 10% of clinical strains appear to resist multiple phages. We investigated the characteristics of P. aeruginosa clinical strains naturally resistant to phages and compared them to highly susceptible strains. The phage-resistant strains were defective in lipopolysaccharide (LPS) biosynthesis, were nonmotile and displayed an important degree of autolysis, releasing phages and pyocins. Complete genome sequencing of three resistant strains showed the existence of a large accessory genome made of multiple insertion elements, genomic islands, pyocins and prophages, including two phages performing lateral transduction. Mutations were found in genes responsible for the synthesis of LPS and/or type IV pilus, the major receptors for most phages. CRISPR-Cas systems appeared to be absent or inactive in phage-resistant strains, confirming that they do not play a role in the resistance to lytic phages but control the insertion of exogenous sequences. We show that, despite their apparent weakness, the multiphage-resistant strains described in this study displayed selective advantages through the possession of various functions, including weapons to eliminate other strains of the same or closely related species.

scholarly journals Characterization of Type IV Pilus Genes in Pseudomonas syringae pv. tomato DC3000

1998 ◽  
Vol 11 (11) ◽  
pp. 1048-1056 ◽  
Author(s):  
Elina Roine ◽  
Deanna M. Raineri ◽  
Martin Romantschuk ◽  
Mark Wilson ◽  
David N. Nunn
Keyword(s):  
Pseudomonas Syringae ◽  
Lytic Bacteriophage ◽  
Type Iv Pilus ◽  
Tomato Dc3000 ◽  
Plant Leaf ◽  
Type Iv ◽  
Pilus Biogenesis ◽  
Population Sizes ◽  
Pila Gene ◽  
Prepilin Peptidase

Many strains of Pseudomonas syringae produce retractile pili that act as receptors for lytic bacteriophage φ6. As these are also characteristics of type IV pili, it was postulated that P. syringae may possess genes for type IV pilus biogenesis. A cosmid clone bank of P. syringae pv. tomato DC3000 genomic DNA was used to complement a mutant of Pseudomonas aeruginosa defective in the PilD (XcpA) prepilin peptidase gene by selection for restoration of extracellular protein secretion, a function also known to require PilD. A cosmid able to complement this mutant was also able to complement mutations in the pilB and pilC genes, suggesting that, if the organization of these genes is similar to that of P. aeruginosa, the cosmid may contain the P. syringae pilA. This was confirmed by sequencing a region from this plasmid that was shown to hybridize at low stringency to the P. aeruginosa pilA gene. The deduced P. syringae PilA polypeptide possesses the characteristic properties of the type IV pilins. Heterologous expression of the P. syringae pilA in P. aeruginosa was also shown, conferring not only φ6 phage sensitivity to P. aeruginosa pilA mutants but also sensitivity to PO4, a lytic bacteriophage specific for the pilus of P. aeruginosa. This suggests that additional components might be present in the mature pilus of P. aeruginosa that are the true receptors for this phage. Chromosomal mutations in P. syringae pv. tomato DC3000 pilA and pilD genes were shown to abolish its sensitivity to bacteriophage φ6. To determine the importance of P. syringae pilus in plant leaf interactions, these mutations were tested under laboratory and field conditions. Although little effect was seen on pathogenicity, culturable leaf-associated population sizes of the pilA mutant were significantly different from those of the wild-type parent. In addition, the expression of the DC3000 pilA gene appears to contribute to the UV tolerance of P. syringae and may play a role in survival on the plant leaf surface.

A bacteriophage encoding a pathogenicity island, a type-IV pilus and a phage receptor in cholera bacteria

Nature ◽  
10.1038/20715 ◽  
1999 ◽  
Vol 399 (6734) ◽  
pp. 375-379 ◽  
Author(s):  
David K. R. Karaolis ◽  
Sita Somara ◽  
David R. Maneval ◽  
Judith A. Johnson ◽  
James B. Kaper
Keyword(s):  
Pathogenicity Island ◽  
Type Iv Pilus ◽  
Type Iv ◽  
Phage Receptor

scholarly journals Type II Protein Secretion in Pseudomonas aeruginosa: the Pseudopilus Is a Multifibrillar and Adhesive Structure

2003 ◽  
Vol 185 (9) ◽  
pp. 2749-2758 ◽  
Author(s):  
Éric Durand ◽  
Alain Bernadac ◽  
Geneviève Ball ◽  
Andrée Lazdunski ◽  
James N. Sturgis ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Bacterial Infections ◽  
Hydrolytic Enzymes ◽  
Macromolecular Complex ◽  
Type Ii Secretion ◽  
Type Ii ◽  
Secretion Systems ◽  
Type Iv Pilus ◽  
Type Iv ◽  
Type Iv Pilin

ABSTRACT The type II secretion pathway of Pseudomonas aeruginosa is involved in the extracellular release of various toxins and hydrolytic enzymes such as exotoxin A and elastase. This pathway requires the function of a macromolecular complex called the Xcp secreton. The Xcp secreton shares many features with the machinery involved in type IV pilus assembly. More specifically, it involves the function of five pilin-like proteins, the XcpT-X pseudopilins. We show that, upon overexpression, the XcpT pseudopilin can be assembled in a pilus, which we call a type II pseudopilus. Image analysis and filtering of electron micrographs indicated that these appendages are composed of individual fibrils assembled together in a bundle structure. Our observations thus revealed that XcpT has properties similar to those of type IV pilin subunits. Interestingly, the assembly of the type II pseudopilus is not exclusively dependent on the Xcp machinery but can be supported by other similar machineries, such as the Pil (type IV pilus) and Hxc (type II secretion) systems of P. aeruginosa. In addition, heterologous pseudopilins can be assembled by P. aeruginosa into a type II pseudopilus. Finally, we showed that assembly of the type II pseudopilus confers increased bacterial adhesive capabilities. These observations confirmed the ability of pseudopilins to form a pilus structure and raise questions with respect to their function in terms of secretion and adhesion, two crucial biological processes in the course of bacterial infections.

Sign in / Sign up

Export Citation Format

Share Document