title: Evaluation of a FRET-peptide substrate to predict virulence in Pseudomonas aeruginosa.
abstract: Pseudomonas aeruginosa produces a number of proteases that are associated with virulence and disease progression. A substrate able to detect P. aeruginosa-specific proteolytic activity could help to rapidly alert clinicians to the virulence potential of individual P. aeruginosa strains. For this purpose we designed a set of P. aeruginosa-specific fluorogenic substrates, comprising fluorescence resonance energy transfer (FRET)-labeled peptides, and evaluated their applicability to P. aeruginosa virulence in a range of clinical isolates. A FRET-peptide comprising three glycines (3xGly) was found to be specific for the detection of P. aeruginosa proteases. Further screening of 97 P. aeruginosa clinical isolates showed a wide variation in 3xGly cleavage activity. The absence of 3xGly degradation by a lasI knock out strain indicated that 3xGly cleavage by P. aeruginosa could be quorum sensing (QS)-related, a hypothesis strengthened by the observation of a strong correlation between 3xGly cleavage, LasA staphylolytic activity and pyocyanin production. Additionally, isolates able to cleave 3xGly were more susceptible to the QS inhibiting antibiotic azithromycin (AZM). In conclusion, we designed and evaluated a 3xGly substrate possibly useful as a simple tool to predict virulence and AZM susceptibility.
authors.affiliation: Department of Medical Microbiology and Infectious Diseases, Erasmus Medical Center, Rotterdam, The Netherlands ; Department of Oral Biochemistry, Academic Centre for Dentistry Amsterdam, University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands.
authors.forename: Wendy E
authors.initials: WE
authors.lastname: Kaman
authors.forename: Nora El
authors.initials: NE
authors.lastname: Arkoubi-El Arkoubi
authors.forename: Sanne
authors.initials: S
authors.lastname: Roffel
authors.forename: Hubert P
authors.initials: HP
authors.lastname: Endtz
authors.forename: Alex
authors.initials: A
authors.lastname: van Belkum
authors.forename: Floris J
authors.initials: FJ
authors.lastname: Bikker
authors.forename: John P
authors.initials: JP
authors.lastname: Hays
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D017963:Azithromycin / Q000494:pharmacology; D010450:Endopeptidases / Q000378:metabolism*; D031541:Fluorescence Resonance Energy Transfer; D008826:Microbial Sensitivity Tests; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*; D059748:Proteolysis; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000472:pathogenicity*; D011710:Pyocyanine / Q000378:metabolism; D053038:Quorum Sensing / Q000235:genetics; D013379:Substrate Specificity; D014774:Virulence / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D010455:Peptides; D017963:Azithromycin; D011710:Pyocyanine; D010450:Endopeptidases