Related Experiment Video
Updated: Sep 13, 2026
Invasion of Human Cells by a Bacterial Pathogen
Published on: March 21, 2011
Enterococcus faecalis: specific and non-specific interactions with human polymorphonuclear leukocytes
C A Guzmàn1, C Pruzzo, L Calegari
1Institute of Microbiology, University of Genoa, Italy.
Abstract:
In previous studies we have demonstrated that the ability of Enterococcus faecalis to adhere to and to be internalized in human urinary tract epithelial cells, Girardi Heart cells and human polymorphonuclear leukocytes (PMNs), was dependent on whether the strain had been isolated from urinary tract infections (UTI) or endocarditis (EN) respectively. These properties were further modified by growth of the organism in human serum. In the present report, using competition assays we show that adhesins containing a D-glucose moiety play a role in mediating the interactions between human PMNs and E. faecalis strains isolated from UTI and grown in brain-heart infusion broth (BHIB). On the other hand, adhesins containing both D-glucose and D-galactose moieties were involved in the interactions between PMNs and serum grown UTI isolates or EN isolates grown in either BHIB or human serum. Moreover, the impairment in the association between both UTI and EN strains after growth in serum appears to be at least partially related to a decrease in enterococcal surface hydrophobicity.
Insights
Enterococcus faecalis interactions with human cells depend on infection source and growth conditions. Adhesins with specific sugars mediate these interactions, with serum growth impacting bacterial surface properties.
Area of Science:
- Microbiology
- Immunology
- Cell Biology
Background:
- Enterococcus faecalis exhibits varied adherence and internalization in human cells based on isolation source (UTI vs. endocarditis).
- Bacterial growth in human serum modifies these interaction properties.
Purpose of the Study:
- To investigate the role of specific adhesins in mediating interactions between E. faecalis and human polymorphonuclear leukocytes (PMNs).
- To understand how growth in serum affects E. faecalis interactions with PMNs.
Main Methods:
- Competition assays were employed to identify mediating adhesins.
- E. faecalis strains from urinary tract infections (UTI) and endocarditis (EN) were cultured in brain-heart infusion broth (BHIB) and human serum.
- Bacterial surface hydrophobicity was assessed.
Main Results:
- Adhesins with D-glucose mediated interactions between PMNs and serum-grown UTI isolates.
- Adhesins with D-glucose and D-galactose were involved in interactions with serum-grown UTI isolates or EN isolates.
- Serum growth reduced enterococcal surface hydrophobicity, impairing bacterial association with PMNs.
Conclusions:
- Specific sugar moieties on E. faecalis adhesins dictate interactions with human PMNs.
- Serum-induced changes in bacterial surface hydrophobicity influence E. faecalis-PMN interactions.
Related Concept Videos
01:31Defense Against Bacterial Pathogens
Phagocytes
Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol...
01:20Determinants of Bacterial Pathogenicity and Virulence
01:25Clinical Significance of Antibiotic Resistance