Live Cell Imaging of Clostridium difficile reveals Chemotaxis and Aerotaxis

Melissa Madril, Old Dominion University
Cody Scott, Old Dominion University
Erin Purcell, Old Dominion University
David Courson, Old Dominion University

Description/Abstract

Clostridium difficile is a Gram positive, motile, obligate anaerobe that infects and kills over 30,000 patients and costs the United States healthcare system $6.3B each year. The mucus lining the intestines is the host’s first line of defense against C. difficile; however, this bacteria possess flagella that may allow it to swim through the mucus and make contact with the underlying epithelial cells. Many motile bacteria utilize chemotaxis and/or aerotaxis to modulate flagellar motility and search for favorable environments to colonize. Our lab has been analyzing the behavior of C. difficile in varying nutrient and oxygen concentrations to identify environmental cues that regulate motility during infection. Using high resolution, real time, live cell imaging, we have visualized C. difficile motility in media with different concentrations of specific nutrients and dissolved oxygen. Our data shows that C. difficile responds to chemoattractants by adjusting its flagellar motility to limit dispersal away from high nutrient environments. Genetically different strains use distinct mechanisms to achieve the same end. Aerotaxis has not previously been demonstrated in C. difficile. Our data shows that higher levels of molecular oxygen promote motility via increased run velocity allowing cells to avoid oxygen poisoning. This information is important as it sheds light on how C. difficile avoids environmental stress and finds a colonization niche within the host.

 
Feb 3rd, 10:15 AM Feb 3rd, 11:15 AM

Live Cell Imaging of Clostridium difficile reveals Chemotaxis and Aerotaxis

Learning Commons @ Perry Library Conference Room 1311

Clostridium difficile is a Gram positive, motile, obligate anaerobe that infects and kills over 30,000 patients and costs the United States healthcare system $6.3B each year. The mucus lining the intestines is the host’s first line of defense against C. difficile; however, this bacteria possess flagella that may allow it to swim through the mucus and make contact with the underlying epithelial cells. Many motile bacteria utilize chemotaxis and/or aerotaxis to modulate flagellar motility and search for favorable environments to colonize. Our lab has been analyzing the behavior of C. difficile in varying nutrient and oxygen concentrations to identify environmental cues that regulate motility during infection. Using high resolution, real time, live cell imaging, we have visualized C. difficile motility in media with different concentrations of specific nutrients and dissolved oxygen. Our data shows that C. difficile responds to chemoattractants by adjusting its flagellar motility to limit dispersal away from high nutrient environments. Genetically different strains use distinct mechanisms to achieve the same end. Aerotaxis has not previously been demonstrated in C. difficile. Our data shows that higher levels of molecular oxygen promote motility via increased run velocity allowing cells to avoid oxygen poisoning. This information is important as it sheds light on how C. difficile avoids environmental stress and finds a colonization niche within the host.