Related Experiment Video
Updated: May 6, 2026
A Co-culture Method to Investigate the Crosstalk Between X-ray Irradiated Caco-2 Cells and PBMC
Published on: January 30, 2018
In vitro interaction between Bacillus megaterium strains and Caco-2 cells
Ana C López1, Jessica Minnaard, Pablo F Pérez
1Bacteriology Unit, Phytopathology Research Center, Faculty of Agricultural and Forestry Sciences, National University of La Plata, La Plata, Argentina.
Abstract:
To further our understanding of the virulence potential of Bacillus megaterium strains, cell association and invasion assays were conducted in vitro by infecting human enterocytes (Caco-2 cells) with 53 strains of this bacterium isolated from honey. Two series of experiments were performed: (i) necrosis and cell detachment assays with the supernatants of bacterial culture filtrates from 16-h cultures and (ii) adhesion/invasion assays in which cultured enterocytes incubated with bacteria from 3-h cultures were resuspended in Dulbecco's modified Eagle's medium and chloramphenicol. The detachment of Caco-2 cells was evaluated by staining the cells with crystal violet. Necrosis was assessed by fluorescence microscopy of cells labeled with propidium iodide. Association (adhesion plus invasion) was determined by plate counts and invasion in an aminoglycoside protection assay. The results showed that spent culture supernatants detached and necrotized Caco-2 cells in a strain-dependent manner. Seven out of 53 B. megaterium filtered culture supernatants caused complete cell detachment. Suspensions of these same bacterial strains adhered and invaded enterocytes in 2-h infection experiments. To our knowledge, this is the first report on the interaction between B. megaterium and intestinal epithelial Caco-2 cells.
Insights
Bacillus megaterium strains from honey can damage human intestinal cells. Some strains adhere to and invade Caco-2 cells, indicating potential virulence factors.
Area of Science:
- Microbiology
- Cell Biology
- Gastroenterology
Background:
- Bacillus megaterium is a common bacterium found in various environments, including food sources like honey.
- Understanding the pathogenic potential of bacterial strains is crucial for public health and food safety.
- The interaction of B. megaterium with human intestinal cells has not been extensively studied.
Purpose of the Study:
- To investigate the virulence potential of Bacillus megaterium strains isolated from honey.
- To assess the ability of these strains to interact with human intestinal epithelial cells (Caco-2 cells) in vitro.
- To determine if B. megaterium can cause cell damage, detachment, adhesion, or invasion.
Main Methods:
- In vitro infection of Caco-2 cells with 53 B. megaterium strains from honey.
- Assays included cell detachment and necrosis using bacterial culture filtrates.
- Adhesion and invasion were evaluated using plate counts and an aminoglycoside protection assay.
Main Results:
- B. megaterium culture supernatants demonstrated strain-dependent Caco-2 cell detachment and necrosis.
- Seven out of 53 tested B. megaterium supernatants induced complete cell detachment.
- Bacterial strains associated with cell damage also adhered to and invaded Caco-2 cells.
Conclusions:
- Certain Bacillus megaterium strains isolated from honey possess virulence factors that can affect human intestinal epithelial cells.
- These findings highlight the importance of evaluating the pathogenic potential of B. megaterium, particularly strains from food sources.
- This study provides the first report on the interaction between B. megaterium and intestinal epithelial Caco-2 cells.
More Related Videos
10:52Enteric Bacterial Invasion Of Intestinal Epithelial Cells In Vitro Is Dramatically Enhanced Using a Vertical Diffusion Chamber Model
Published on: October 22, 2013
10:24Assessing the Viability of a Synthetic Bacterial Consortium on the In Vitro Gut Host-microbe Interface
Published on: July 4, 2018