title: Molecular detection of virulence factors among food and clinical Enterococcus faecalis strains in South Brazil.
abstract: The present report aimed to perform a molecular epidemiological survey by investigating the presence of virulence factors in E. faecalis isolated from different human clinical (n = 57) and food samples (n = 55) in Porto Alegre, Brazil, collected from 2006 to 2009. In addition, the ability to form biofilm in vitro on polystyrene and the β-haemolytic and gelatinase activities were determined. Clinical strains presented a higher prevalence of aggregation substance (agg), enterococcal surface protein (esp) and cytolysin (cylA) genes when compared with food isolates. The esp gene was found only in clinical strains. On the other hand, the gelatinase (gelE) and adherence factor (ace) genes had similar prevalence among the strains, showing the widespread occurrence of these virulence factors among food and clinical E. faecalis strains in South Brazil. More than three virulence factor genes were detected in 77.2% and 18.2% of clinical and food strains, respectively. Gelatinase and β-haemolysin activities were not associated with the presence of gelE and cylA genes. The ability to produce biofilm was detected in 100% of clinical and 94.6% of food isolates, and clinical strains were more able to form biofilm than the food isolates (Student's t-test, p < 0.01). Results from the statistical analysis showed significant associations between strong biofilm formation and ace (p = 0.015) and gelE (p = 0.007) genes in clinical strains. In conclusion, our data indicate that E. faecalis strains isolated from clinical and food samples possess distinctive patterns of virulence factors, with a larger number of genes that encode virulence factors detected in clinical strains.
authors.affiliation: Programa de Pós-Graduação em Microbiologia Agrícola e do Ambiente Universidade Federal do Rio Grande do Sul Porto AlegreRS Brazil.
authors.forename: A W
authors.initials: AW
authors.lastname: Medeiros
authors.affiliation: Instituto de Ciências Básicas da Saúde Departamento de Microbiologia Universidade Federal do Rio Grande do Sul Porto AlegreRS Brazil.
authors.forename: R I
authors.initials: RI
authors.lastname: Pereira
authors.affiliation: Programa de Pós-Graduação em Microbiologia Agrícola e do Ambiente Universidade Federal do Rio Grande do Sul Porto AlegreRS Brazil.
authors.forename: D V
authors.initials: DV
authors.lastname: Oliveira
authors.affiliation: Programa de Pós-Graduação em Microbiologia Agrícola e do Ambiente Universidade Federal do Rio Grande do Sul Porto AlegreRS Brazil.
authors.forename: P D
authors.initials: PD
authors.lastname: Martins
authors.affiliation: Departamento de Ciências Básicas da Saúde Universidade Federal de Ciências da Saúde de Porto Alegre Porto AlegreRS Brazil.
authors.forename: P A
authors.initials: PA
authors.lastname: d'Azevedo
authors.affiliation: Programa de Pós-Graduação em Microbiologia Agrícola e do Ambiente Universidade Federal do Rio Grande do Sul Porto AlegreRS Brazil.
authors.forename: S
authors.initials: S
authors.lastname: Van der Sand
authors.affiliation: Instituto de Ciência e Tecnologia de Alimentos Universidade Federal do Rio Grande do Sul Porto AlegreRS Brazil.
authors.forename: J
authors.initials: J
authors.lastname: Frazzon
authors.affiliation: Programa de Pós-Graduação em Microbiologia Agrícola e do Ambiente Universidade Federal do Rio Grande do Sul Porto AlegreRS Brazil.
authors.forename: A P G
authors.initials: AP
authors.lastname: Frazzon
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D018441:Biofilms / Q000254:growth & development; D001938:Brazil; D013293:Enterococcus faecalis / Q000235:genetics* / Q000302:isolation & purification / Q000502:physiology; D005516:Food Microbiology; D018093:Gelatinases / Q000032:analysis; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology*; D006461:Hemolysis; D006801:Humans; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D037521:Virulence Factors; D018093:Gelatinases
keywords: biofilm formation; clinical enterococci; food enterococci; virulence determinants