Different protein expression profiles in cheese and clinical isolates of Enterococcus faecalis revealed by proteomic analysis

• Published in: Proteomics (Weinheim) Vol. 12; no. 3; pp. 431 - 447
• Main Authors: Pessione, Alessandro, Lamberti, Cristina, Cocolin, Luca, Campolongo, Simona, Grunau, Alexander, Giubergia, Sonia, Eberl, Leo, Riedel, Kathrin, Pessione, Enrica
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01-02-2012; WILEY‐VCH Verlag; Wiley-VCH; Wiley Subscription Services, Inc
• Subjects: 2-DE; Analytical, structural and metabolic biochemistry; Bacterial proteins; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Bacteriology; Biological and medical sciences; Cardiology. Vascular system; Cheese - microbiology; Electrophoresis, Gel, Two-Dimensional - methods; Endocardial and cardiac valvular diseases; Endocarditis; Enterococcus faecalis; Enterococcus faecalis - enzymology; Enterococcus faecalis - genetics; Enterococcus faecalis - pathogenicity; Food; fsr locus; Fundamental and applied biological sciences. Psychology; Gelatinases - genetics; Gelatinases - metabolism; Gene Expression Profiling; Gene Expression Regulation, Bacterial; Heart; Humans; Medical sciences; Microbiology; Miscellaneous; Moonlighting proteins; Proteases; Proteins; Serine Endopeptidases - genetics; Serine Endopeptidases - metabolism; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization - methods; Superoxide dismutase; Virulence Factors - genetics; Virulence Factors - metabolism; Enterococcus faecalis; Microbiology; Enzyme; Cardiovascular disease; Superoxide dismutase; 2-DE; Protein; Streptococcaceae; Peptidases; fsr locus; Proteases; Heart disease; Endocardial disease; Endocarditis; Proteomics; Bacteria; Hydrolases; Micrococcales; Oxidoreductases; Locus; Clinical isolate; Moonlighting proteins
• ISSN: 1615-9853; 1615-9861
• DOI: 10.1002/pmic.201100468

The use of Enterococcus faecalis in the food industry has come under dispute because of the pathogenic potential of some strains of this species. In this study, we have compared the secretome and whole‐cell proteome of one food isolate (E. faecalis DISAV 1022) and one clinical isolate (E. faecalis H1) by 2‐DE and iTRAQ analyses, respectively. Extracellular protein patterns differed significantly, with only seven proteins common to both strains. Notably, only the clinical isolate expressed various well‐characterized virulence factors such as the gelatinase coccolysin (GelE) and the extracellular serine proteinase V8 (SprE). Moreover, various other putative virulence factors, e.g. superoxide dismutase, choline‐ and chitin‐binding proteins and potential moonlighting proteins, have been detected exclusively in the secretome of the clinical isolate, but not in the food isolate. The iTRAQ analysis of whole‐cell proteins of the two strains highlighted a stronger expression of pathogenic traits such as an endocarditis‐specific antigen and an adhesion lipoprotein in the pathogenic strain E. faecalis H1. Subsequently, six food isolates (including E. faecalis DISAV 1022) and six clinical isolates (including E. faecalis H1) were tested for the presence of gelatinase and protease activity in the culture supernatants. Both enzymatic activities were found in the clinical as well as the food isolates which clearly indicates that protease expression is strain specific and not representative for pathogenic isolates. Genetic analyses revealed that not only the gelatinase and serine protease genes but also the regulatory fsr genes must be present to allow protease expression.