title: Incongruence between the cps type 2 genotype and host-related phenotypes of an Enterococcus faecalis food isolate.
abstract: Enterococcus faecalis is a nosocomial opportunistic pathogen, but is also found in fermented food products where it plays a fundamental role in the fermentation process. Previously, we have described the non-starter E. faecalis cheese isolate QA29b as harboring virulence genes and proven to be virulent in Galleria mellonella virulence model. In this study, we further characterized this food strain concerning traits relevant for the host-pathogen relationship. QA29b was found to belong to sequence type (ST) 72, a common ST among food isolates, and thus we consider it as a good representative of food E. faecalis strains. It demonstrated high ability to form biofilms, to adhere to epithelial cells and was readily eliminated by J774.A1 macrophage cells. Despite carrying the cps locus associated with the capsular polysaccharide CPS 2 type, cps genes were not expressed, likely due to an IS6770 inserted in the cpsC-cpsK promoter region. This work constitutes the first study of traits important for interaction, colonization and infection in the host performed on a good representative of E. faecalis food isolates. Reported results stress the need for a reliable serotyping assay of E. faecalis, as cps genotyping may not be reliable. Overall, QA29b characterization shows that despite its virulence potential in an insect model, this food strain is readily eliminated by mammalian macrophages. Thus, fine tuned approaches combining cellular and mammalian models are needed to address and elucidate the multifactorial aspect of virulence potential associated with food isolates.
authors: ITQB, UNL, Apartado 127, 2781-901 Oeiras, Portugal.
authors: Frédéric Bustos
authors: FB
authors: Gaspar
authors: Natalia
authors: N
authors: Montero
authors: Elodie
authors: E
authors: Akary
authors: Neuza
authors: N
authors: Teixeira
authors: Renata
authors: R
authors: Matos
authors: Bruno
authors: B
authors: Gonzalez-Zorn
authors: Maria Teresa
authors: MT
authors: Barreto Crespo
authors: Pascale
authors: P
authors: Serror
authors: Maria de Fátima
authors: Mde F
authors: Silva Lopes
mesh_terms: D000818:Animals; D018441:Biofilms / Q000254:growth & development; D002611:Cheese / Q000382:microbiology; D003428:Cross Infection / Q000235:genetics; D013293:Enterococcus faecalis / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity*; D005838:Genotype; D008264:Macrophages; D008322:Mammals; D010641:Phenotype; D011135:Polysaccharides, Bacterial / Q000235:genetics*; D011401:Promoter Regions, Genetic; D012703:Serotyping; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics
chemical_list: D011135:Polysaccharides, Bacterial; D037521:Virulence Factors