In vitro interaction between Bacillus megaterium strains and Caco-2 cells

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.