Virulence Factors of Pseudomonas aeruginosa

Döring, Gerd; Maier, M Liliana; Müller, Evelyn; Bibi, Zouhair; Tummler, B.; Kharazmi, Arsalan

doi:10.1159/000414341

Cited by 49 publications

(22 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…aeruginosa can produce a number of cell-associated and extracellular virulence factors which contribute to its pathogenesis (Doring et al, 1984(Doring et al, , 1985(Doring et al, , 1987Jaeger, 1994 ;Van Delden & Iglewski, 1998). The extracellular virulence factors include proteases (elastase, Staphylolytic protease and alkaline protease), pigments (pyocyanin, pyoverdine), haemolysins, exoenzyme S and exotoxin A (Pollack, 1984 ;Van Delden & Iglewski, 1998).…”

Section: Introductionmentioning

confidence: 99%

Pseudomonas aeruginosa mutations in lasI and rhlI quorum sensing systems result in milder chronic lung infection

et al. 2001

View full text Add to dashboard Cite

To understand the importance of quorum sensing in chronic Pseudomonas aeruginosa lung infection, the in vivo pathogenic effects of the wild-type P. aeruginosa PAO1 and its double mutant, PAO1 lasI rhlI, in which the signalgenerating parts of the quorum sensing systems are defective were compared. The rat model of P. aeruginosa lung infection was used in the present study. The rats were killed on days 3, 7, 14 and 28 after infection with the P. aeruginosa strains. The results showed that during the early stages of infection, the PAO1 double mutant induced a stronger serum antibody response, higher production of pulmonary interferon γ, and more powerful blood polymorphonuclear leukocyte (PMN) chemiluminescence compared to its wild-type counterpart. On days 14 and 28 post-infection, significantly milder lung pathology, a reduction in the number of mast cells present in the lung foci, a reduced number of lung bacteria, and minor serum IgG and IgG1 responses but increased lung interferon γ production were detected in the group infected with the PAO1 double mutant when compared with the PAO1-infected group. Delayed immune responses were observed in the PAO1-infected group and they might be associated with the production of virulence factors that are controlled by the quorum sensing systems. The conclusion of this study is that functional lasI and rhlI genes of P. aeruginosa PAO1 play a significant role during lung infection.

show abstract

Section: Introductionmentioning

confidence: 99%

Pseudomonas aeruginosa mutations in lasI and rhlI quorum sensing systems result in milder chronic lung infection

et al. 2001

View full text Add to dashboard Cite

show abstract

“…Its ecological diversity is probably related to its great metabolic versatility. Its pathogenic ability derives from the presence of several cell-associated and secreted virulence factors, such as elastase, exotoxin A, phospholipase, and alkaline protease, among others (8,26,47). P. aeruginosa uses a type III secretion system to directly deliver several effector proteins into the cytoplasm of the host cell, a key step in the cytotoxic and invasion processes (12,15,34,49).…”

mentioning

confidence: 99%

Structure of Pseudomonas aeruginosa Populations Analyzed by Single Nucleotide Polymorphism and Pulsed-Field Gel Electrophoresis Genotyping

et al. 2004

View full text Add to dashboard Cite

Pseudomonas aeruginosa has a wide ecological distribution that includes natural habitats and clinical settings. To analyze the population structure and distribution of P. aeruginosa, a collection of 111 isolates of diverse habitats and geographical origin, most of which contained a genome with a different SpeI macrorestriction profile, was typed by restriction fragment length polymorphism based on 14 single nucleotide polymorphisms (SNPs) located at seven conserved loci of the core genome (oriC, oprL, fliC, alkB2, citS, oprI, and ampC). The combination of these SNPs plus the type of fliC present (a or b) allowed the assignment of a genetic fingerprint to each strain, thus providing a simple tool for the discrimination of P. aeruginosa strains. Thirteen of the 91 identified SNP genotypes were found in two or more strains. In several cases, strains sharing their SNP genotype had different SpeI macrorestriction profiles. The highly virulent CHA strain shared its SNP genotype with other strains that had different SpeI genotypes and which had been isolated from nonclinical habitats. The reference strain PAO1 also shared its SNP genotype with other strains that had different SpeI genotypes. The P. aeruginosa chromosome contains a conserved core genome and variable amounts of accessory DNA segments (genomic islands and islets) that can be horizontally transferred among strains. The fact that some SNP genotypes were overrepresented in the P. aeruginosa population studied and that several strains sharing an SNP genotype had different SpeI macrorestriction profiles supports the idea that changes occur at a higher rate in the accessory DNA segments than in the conserved core genome.

show abstract

“…Antibodies against denatured elastase were raised in rabbits as described previously (22), and the immunoglobulin G (IgG) fraction was isolated from the immune sera by DEAE-cellulose chromatography (17 methionine (100 ,uCi/ml) in the presence of 0.15 mM EDTA. After 3 min, nonradioactive methionine was added to 100 ,ug/ml, and samples were removed at 0 (lanes 1 and 2), 1.25 (lanes 3 and 4), 2.5 (lanes 5 and 6), 5 (lanes 7 and 8), 10 (lanes 9 and 10), and 20 (lanes 11 and 12) min postchase. Cells were separated from the medium, and portions corresponding to a bacterial OD at 660 nm of 0.14 were immunoprecipitated with antielastase antibodies as described in the text.…”

mentioning

confidence: 99%

Synthesis, processing, and transport of Pseudomonas aeruginosa elastase

Kessler

Safrin

1988

J Bacteriol

View full text Add to dashboard Cite

Three cell-associated elastase precursors with approximate molecular weights of 60,000 (P), 56,000 (Pro I), and 36,000 (Pro II) were Safrin, J. Bacteriol. 170:1215-1219, 1988, forms a complex with an inactive periplasmic elastase precursor of about 36,000 molecular weight. Our results suggest that the elastase is made by the cells as a preproenzyme (P), containing a signal sequence of about 4,000 molecular weight and a "pro" sequence of about 20,000 molecular weight. Processing and export of the preproenzyme involve the formation of two periplasmic proenzyme species: proelastase I (56 kilodaltons [kDa]) and proelastase II (36 kDa). The former is short-lived, whereas proelastase II accumulates temporarily in the periplasm, most likely as a complex with the 20-kDa propeptide released from proelastase I upon conversion to proelastase II. The final step in elastase secretion seems to require both the proteolytic removal of a small peptide from proelastase II and dissociation of the latter from P20.Unlike most gram-negative bacteria, Pseudomonas aeruginosa secretes several proteins into the medium. Many of these proteins, including exotoxins A and S, the proteases elastase and alkaline proteinase, and phospholipase C, are toxic to humans and animals and are thought to enhance the virulence of the organism (5, 13,25,29,42). Although the properties of most Pseudomonas exoenzymes and the role that each of them may play in the pathogenesis of Pseudomonas infections have been studied in detail, relatively little is known about their synthesis and secretion. DNA sequencing of the structural genes of exotoxin A (10) and phospholipase C (34) indicated that like most exported proteins of other bacteria or higher organisms (for reviews, see references 2 and 35), both the exotoxin and the phospholipase are synthesized by the cells as larger precursors, each containing a typical amino-terminal leader sequence which is removed during the secretion process. Lory et al. (27) demonstrated that processing and secretion of the exotoxin precursor are both inhibited in the presence of ethanol, leading to accumulation of the precursor in the outer membrane. No exotoxin was found in the periplasm. These authors proposed that the exotoxin precursor is secreted cotranslationally and directly to the outer membrane via zones of adhesion between the inner and outer membranes. According to their model, the exotoxin precursor is proteolytically processed to the mature toxin upon release into the medium. Secretion of phospholipase C and of the elastase seems to follow a different route, since * Corresponding author. phospholipase activity (32) and an inactive elastase precursor (19,22) were demonstrated in the periplasmic fraction of P. aeruginosa cells. The inactive periplasmic elastase precursor is activated by controlled proteolysis (19,22), yet this precursor was reported to have the same molecular weight and the same N-terminal amino acid (alanine) as the extracellular elastase (7,8,19,24). Fecycz and Campbell (7) suggested that activati...

show abstract

Virulence Factors of Pseudomonas aeruginosa

Cited by 49 publications

References 0 publications

Pseudomonas aeruginosa mutations in lasI and rhlI quorum sensing systems result in milder chronic lung infection

Pseudomonas aeruginosa mutations in lasI and rhlI quorum sensing systems result in milder chronic lung infection

Structure of Pseudomonas aeruginosa Populations Analyzed by Single Nucleotide Polymorphism and Pulsed-Field Gel Electrophoresis Genotyping

Synthesis, processing, and transport of Pseudomonas aeruginosa elastase

Contact Info

Product

Resources

About