Role of bacterial proteases in pseudomonal and serratial keratitis

Matsumoto, Kousuke

doi:10.1515/bc.2004.131

Cited by 133 publications

(124 citation statements)

References 78 publications

Supporting

Mentioning

120

Contrasting

Unclassified

Order By: Relevance

“…These are extracellularly secreted enzymes, and their cleavage patterns with PAI-1 and plasminogen are different from those of Pla and PgtE. S. aureus and P. aeruginosa are severe pathogens which show multiple interactions with the human fibrinolytic system (2,6,34,39,61), and LasB is an acknowledged virulence factor in lung and skin infections. A functional difference with pathogenetic potential is that the aureolysin/LasB metalloproteinases cleave plasminogen at the amino-terminal region and at S441-V442, which results in miniplasminogen that is not enzymatically active but can be activated by tPA (2, 3), whereas Pla/PgtE cleave plasminogen at R561-V562, which generates active plasmin.…”

Section: Discussionmentioning

confidence: 99%

The Omptins ofYersinia pestisandSalmonella entericaCleave the Reactive Center Loop of Plasminogen Activator Inhibitor 1

et al. 2010

View full text Add to dashboard Cite

Plasminogen activator inhibitor 1 (PAI-1) is a serine protease inhibitor (serpin) and a key molecule that regulates fibrinolysis by inactivating human plasminogen activators. Here we show that two important human pathogens, the plague bacterium Yersinia pestis and the enteropathogen Salmonella enterica serovar Typhimurium, inactivate PAI-1 by cleaving the R346-M347 bait peptide bond in the reactive center loop. No cleavage of PAI-1 was detected with Yersinia pseudotuberculosis, an oral/fecal pathogen from which Y. pestis has evolved, or with Escherichia coli. The cleavage and inactivation of PAI-1 were mediated by the outer membrane proteases plasminogen activator Pla of Y. pestis and PgtE protease of S. enterica, which belong to the omptin family of transmembrane endopeptidases identified in Gram-negative bacteria. Cleavage of PAI-1 was also detected with the omptins Epo of Erwinia pyrifoliae and Kop of Klebsiella pneumoniae, which both belong to the same omptin subfamily as Pla and PgtE, whereas no cleavage of PAI-1 was detected with omptins of Shigella flexneri or E. coli or the Yersinia chromosomal omptins, which belong to other omptin subfamilies. The results reveal a novel serpinolytic mechanism by which enterobacterial species expressing omptins of the Pla subfamily bypass normal control of host proteolysis.Plasminogen activator inhibitor 1 (PAI-1) is a key regulator of the mammalian fibrinolytic/plasminogen system (29, 37). The fibrinolytic system comprises the serine protease zymogen plasminogen, urokinase-type plasminogen activator (uPA), tissue-type plasminogen activator (tPA), PAI-1, and plasmin inhibitor ␣ 2 -antiplasmin (␣ 2 AP) (for a review, see reference 52). Plasminogen is converted to plasmin, which is a broad-spectrum serine protease that dissolves fibrin in blood clots, degrades laminin of basement membranes, and activates matrix metalloproteinases that degrade collagens and gelatins in tissue barriers. Herewith, plasmin controls physiological processes such as fibrinolysis/coagulation, cell migration and invasion, and tumor metastasis (29, 37). PAI-1 maintains normal hemostasis by inhibiting the function of the plasminogen activators tPA and uPA, which are serine proteases and highly specific for cleavage of the plasminogen molecule. tPA binds to fibrin and is associated with plasmin-mediated breakdown of fibrin clots, whereas uPA has low affinity for fibrin and associates with cell surface proteolysis, cellular migration, and damage of tissue barriers (52).The mammalian fibrinolytic and coagulation systems are targeted by invasive bacterial pathogens during infection (reviewed in references 6, 11, 34, and 61). In bacterial sepsis, increased production of fibrin clots at a damaged endothelium results from enhanced thrombin-catalyzed fibrin generation and from an increased serum level of PAI-1. Coagulation can protect the host by activating immune systems or by physically restraining the bacteria (6,15,25,41). On the other hand, several invasive bacterial pathogens enhance fibrinolysis eithe...

show abstract

Section: Discussionmentioning

confidence: 99%

The Omptins ofYersinia pestisandSalmonella entericaCleave the Reactive Center Loop of Plasminogen Activator Inhibitor 1

et al. 2010

View full text Add to dashboard Cite

show abstract

“…Proteases, especially metalloproteases, contribute to virulence in pathogenic bacteria including P. aeruginosa, S. marcescens and B. thuringiensis [66][67][68] . In addition to degrading AMPs, proteases might be involved in the destruction of cells and tissues to facilitate colonization of the insect body 69 .…”

Section: Box 3 | Heritable Microorganismsmentioning

confidence: 99%

Bacterial strategies to overcome insect defences

2008

View full text Add to dashboard Cite

| Recent genetic and molecular analyses have revealed how several strategies enable bacteria to persist and overcome insect immune defences. Genetic and genomic tools that can be used with Drosophila melanogaster have enabled the characterization of the pathways that are used by insects to detect bacterial invaders and combat infection. Conservation of bacterial virulence factors and insect immune repertoires indicates that there are common strategies of host invasion and pathogen eradication. Long-term interactions of bacteria with insects might ensure efficient dissemination of pathogens to other hosts, including humans. R E V I E W S302 | APRIL 2008 | voLUME 6 www.nature.com/reviews/micro

show abstract

“…The elastase breaks down host proteins such as collagen, immunoglobulins, and complement proteins [6]. Alkaline protease is a an enzyme that cleaves various components, such as complement C1q and C3 [7], and prevents TLR5 activation through flagellin destruction [8].…”

mentioning

confidence: 99%

Molecular Detection of the VirulentExoUGenotype ofPseudomonas aeruginosaIsolated from Infected Surgical Incisions

Hassuna

2016

Surgical Infections

View full text Add to dashboard Cite

Background: Pseudomonas aeruginosa is one of the major pathogens responsible for hospital-acquired infections, which harbor a wide array of virulence factors. The main aim of this study was to determine the frequency of the virulent ExoU genotype in relation to the ExoS genotype among isolated P. aeruginosa from infected surgical incisions, followed by phylogenetic analysis. Methods: A total of 66 P. aeruginosa isolates were identified by cultural and biochemical characteristics. All isolates were tested for antimicrobial susceptibility against the following antimicrobial agents: imipenem, amikacin, gentamicin, amoxycillin, cefotaxime, cefepime, and levofloxacin. Molecular detection of the ExoS and ExoU as well as two other virulence genes was done by polymerase chain reaction (PCR). Sequencing of ExoU gene and phylogenetic analysis was performed.Results: Approximately 81% of the isolated P. aeruginosa were multi-drug resistant. The ExoS genotype was more prevalent (63%) among the isolates than the ExoU genotype (18%), with 9% of the isolates possessing both toxins. LasB and AprA were detected in 63.6% and 27.2% of the isolates, respectively. An association was observed between the number of virulence genes and the presence of multi-drug resistance. All the ExoU were multi-drug resistant (MDR), whereas 71% of the ExoS were MDR. Phylogenetic analysis of ExoU gene showed a 99% similarity with four different strains. Conclusion: Despite the greater frequency of the ExoS genotype, the presence of the virulent MDR ExoU genotype isolates from surgical site infections is an alarming sign requiring further intervention and investigations.

show abstract

Role of bacterial proteases in pseudomonal and serratial keratitis

Cited by 133 publications

References 78 publications

The Omptins ofYersinia pestisandSalmonella entericaCleave the Reactive Center Loop of Plasminogen Activator Inhibitor 1

The Omptins ofYersinia pestisandSalmonella entericaCleave the Reactive Center Loop of Plasminogen Activator Inhibitor 1

Bacterial strategies to overcome insect defences

Molecular Detection of the VirulentExoUGenotype ofPseudomonas aeruginosaIsolated from Infected Surgical Incisions

Contact Info

Product

Resources

About