Related Experiment Videos
Serotype-related HEp-2 cell interaction of Yersinia enterocolitica
Abstract:
The ability of human clinical isolates of Yersinia enterocolitica to interact with HEp-2 cells was found to vary considerably between the serotypes O:3, O:8, and O:9. Although all three serotypes adhered initially to the cell surface, regardless of incubation temperature of the bacterial inoculum or presence of the 40- to 48-megadalton virulence plasmid, the ability to localize intracellularly was not uniformly expressed. By using a combined light optical method based on differential interference contrast and UV incident light microscopy, we found that in serotype O:3, resistance to internalization was dependent upon prior growth at 37 degrees C and carriage of the virulence plasmid; in serotype O:9, this property was plasmid dependent but not temperature dependent; in serotype O:8, it was constitutive. The ability of serotype O:3 to resist internalization was correlated with the expression of plasmid-associated fibrillae on the bacterial surface. No relationship between fibrillation and HEp-2 cell interaction was apparent for serotype O:8 or O:9. Serotypes O:8 and O:9, unlike the O:3 strains studied, associated with HEp-2 cells in greater number after cultivation at 22 degrees C than after cultivation at 37 degrees C. We failed to establish a correlation between the expression of surface fibrillae and the ability to evoke guinea pig conjunctivitis.
Insights
Yersinia enterocolitica serotypes O:3, O:8, and O:9 exhibit varying interactions with HEp-2 cells. Intracellular localization depends on the serotype, virulence plasmid, and growth temperature, influencing bacterial pathogenesis.
Area of Science:
- Microbiology
- Cell Biology
- Pathogen-Host Interactions
Background:
- Yersinia enterocolitica is a significant human pathogen.
- Different serotypes of Yersinia enterocolitica display varied virulence factors.
- Understanding bacterial-host cell interactions is crucial for elucidating pathogenesis.
Purpose of the Study:
- To investigate the differential interaction of Yersinia enterocolitica serotypes O:3, O:8, and O:9 with HEp-2 cells.
- To determine the influence of the virulence plasmid and incubation temperature on bacterial internalization.
- To explore the role of bacterial surface fibrillae in host cell adhesion and internalization.
Main Methods:
- Utilized HEp-2 cells as a model for human epithelial cells.
- Employed differential interference contrast and UV incident light microscopy for high-resolution imaging.
- Assessed bacterial adherence and intracellular localization under varying conditions (temperature, plasmid presence).
Main Results:
- All serotypes adhered to HEp-2 cells, but intracellular localization varied significantly.
- Serotype O:3 resistance to internalization was linked to 37°C growth and the virulence plasmid, correlating with fibrillae expression.
- Serotype O:9 internalization was plasmid-dependent but not temperature-dependent, while O:8 showed constitutive resistance.
- Serotypes O:8 and O:9 showed higher association with HEp-2 cells at 22°C compared to 37°C.
Conclusions:
- The interaction of Yersinia enterocolitica with HEp-2 cells is serotype-specific and influenced by environmental factors and virulence determinants.
- Plasmid-associated fibrillae play a role in the internalization resistance of serotype O:3.
- Temperature-dependent adhesion patterns were observed for serotypes O:8 and O:9, suggesting distinct host-pathogen interaction mechanisms.