Open AccessNew Insights into the Enterococcus faecium and Streptococcus gallolyticus subsp. gallolyticus Host Interaction Mechanisms
Author(s) -
Ana María Sánchez-Díaz,
Beatriz Romero-Hernández,
Elisa Conde-Moreno,
Young-Keun Kwak,
Javier Zamora,
Patricia Colque-Navarro,
R. Möllby,
Patricia Ruíz-Garbajosa,
Rafael Cantón,
Laura GarcíaBermejo,
Rosa del Campo
Publication year - 2016
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0159159
Subject(s) - enterococcus faecium , microbiology and biotechnology , biology , enterococcus , streptococcus , biofilm , bacteria , genetics , antibiotics
Enterococcus faecium and Streptococcus gallolyticus subsp. gallolyticus ( S . gallolyticus ) were classically clustered into the Lancefield Group D streptococci and despite their taxonomic reclassification still share a similar genetic content and environment. Both species are considered as opportunistic pathogens. E . faecium is often associated with nosocomial bacteraemia, and S . gallolyticus is sporadically found in endocarditis of colorectal cancer patients. In both cases, the source of infection is commonly endogenous with a translocation process that launches through the intestinal barrier. To get new insights into the pathological processes preceding infection development of both organisms, we used an in vitro model with Caco-2 cells to study and compare the adhesion, invasion and translocation inherent abilities of 6 E . faecium and 4 S . gallolyticus well-characterized isolates. Additionally, biofilm formation on polystyrene, collagen I and IV was also explored. Overall results showed that E . faecium translocated more efficiently than S . gallolyticus , inducing a destabilization of the intestinal monolayer. Isolates Efm106, Efm121 and Efm113 ( p < .001 compared to Ef222) exhibited the higher translocation ability and were able to adhere 2–3 times higher than S . gallolyticus isolates. Both species preferred the collagen IV coated surfaces to form biofilm but the S . gallolyticus structures were more compact ( p = .01). These results may support a relationship between biofilm formation and vegetation establishment in S . gallolyticus endocarditis, whereas the high translocation ability of E . faecium high-risk clones might partially explain the increasing number of bacteraemia.