Related Experiment Videos
Alpha-actinin accumulation in epithelial cells infected with attaching and effacing gastrointestinal pathogens
A Ismaili1, D J Philpott, M T Dytoc
1Division of Gastroenterology, Hospital for Sick Children, Toronto, Ontario, Canada.
Abstract:
Fluorescent F-actin staining utilizing phalloidin, a highly toxic mushroom poison, is used as an indirect test to detect attaching and effacing (AE) bacteria. A study was done to determine if accumulation of alpha-actinin in infected tissue culture cells is a consistent feature and whether it corresponds with the AE response. Rearrangement of alpha-actinin was detected using immunofluorescence microscopy by incubation of infected cells with a murine monoclonal anti-alpha-actinin antibody. Foci of alpha-actinin-specific fluorescence corresponding to areas of bacterial adhesion were detected by transmission electron microscopy in HEp-2 and gastric KATO-III cells infected with only those bacterial strains that formed AE lesions. Therefore, this study shows that alpha-actinin accumulation is a consistent, specific manifestation of the AE phenotype and forms the basis for the development of a safe alternative test for detecting AE bacteria.
Insights
Alpha-actinin accumulation is a consistent marker for attaching and effacing (AE) bacteria. This finding offers a safer alternative to phalloidin-based detection methods for AE bacterial infections.
Area of Science:
- Microbiology
- Cell Biology
- Bacterial Pathogenesis
Background:
- Attaching and effacing (AE) bacteria are detected using fluorescent F-actin staining with phalloidin.
- Phalloidin is a toxic mushroom poison, necessitating safer detection methods.
Purpose of the Study:
- To investigate alpha-actinin accumulation as a consistent indicator of AE bacterial infections.
- To determine if alpha-actinin rearrangement correlates with the AE response.
Main Methods:
- Immunofluorescence microscopy was used to detect alpha-actinin rearrangement in infected cells.
- Murine monoclonal anti-alpha-actinin antibody was employed for detection.
- Transmission electron microscopy confirmed alpha-actinin foci at bacterial adhesion sites.
Main Results:
- Alpha-actinin accumulation was observed specifically in HEp-2 and KATO-III cells infected with AE bacterial strains.
- Foci of alpha-actinin fluorescence corresponded precisely with bacterial adhesion points.
- The observed alpha-actinin rearrangement was consistent across tested AE bacterial strains.
Conclusions:
- Alpha-actinin accumulation is a reliable and specific marker for the AE phenotype.
- This finding provides a basis for developing a safer alternative test for AE bacteria detection.