Living in the guts of worms are seemingly innocuous Photorhabdus luminescens bacteria that contribute to the worms' survival. Yet with a flip of a genetic switch, those same bacteria transform from harmless microbes into deadly insecticides.
How the photorhabdus bacteria and a single promoter inversion switches it from an upstanding community member in the gut microbiome to deadly killer in insect blood is the subject of a new study. The bacteria in question are bioluminescent insect pathogens. In their mutualistic state, they reside in the intestines of worms, growing slowly and performing other functions that aid nematode's survival, even contributing to reproduction.
Todd Ciche, assistant professor of microbiology and molecular genetics at Michigan State University, has seen variants like this emerge sometimes by chance resulting in drastically different properties, such as being lethal to the host or existing in a state of mutual harmony. Human guts are more complex and these interactions are harder to detect, the revelation certainly offers new insight that could lead to medical breakthroughs.
Jekyll and Hyde bacteria photorhabdus luminescens live and thrive in the guts of worms. Credit: Alex Martin
"Animal guts are similar to ours, in that they are both teeming with microbes," said Ciche, who worked with researchers from Harvard Medical School. "These bacteria and other microorganisms are different inside their hosts than isolated in a lab, and we're only beginning to learn how these alliances with microbes are established, how they function and how they evolve."
As the nematodes grow, the bacteria reveal their dark side. They flip a DNA switch and arm themselves by growing rapidly and producing deadly toxins. When the worms begin infesting insects, they release their bacterial insecticide.
"It's like fleas teaming up with the plague," Ciche said.
The question remains: What causes this dramatic transformation?
"If we can figure out why the DNA turns on and off to cause the switch between Jekyll and Hyde, we can better understand how bacteria enter stages of dormancy and antibiotic tolerance – processes critical to treating chronic infections," Ciche said.
Citation: Vishal S. Somvanshi, Rudolph E. Sloup, Jason M. Crawford, Alexander R. Martin, Anthony J. Heidt, Kwi-suk Kim, Jon Clardy, and Todd A. Ciche, 'A Single Promoter Inversion Switches Photorhabdus Between Pathogenic and Mutualistic States', Science 6 July 2012: 337 (6090), 88-93. DOI:10.1126/science.1216641
- PHYSICAL SCIENCES
- EARTH SCIENCES
- LIFE SCIENCES
- SOCIAL SCIENCES
Subscribe to the newsletter
Stay in touch with the scientific world!
Know Science And Want To Write?
- What Lies Beneath West Antarctica?
- Exodus 2100: Due To Climate Change
- Unified Mathematical Field Theory Talk
- How To Make Women's Tennis More Competitive
- Many Americans Putting Vision At Risk From Sun Damage
- Race And Racism 101 Lecture 1 Intro & Terminology
- Study Suggests Bipolar Disorder Has Genetic Links To Autism
- "Just adding another link. Spinning Brains..."
- "Okay, yes I hadn't thought about clear walled aquariums. That's a good example :). Maybe its easier..."
- " I tried to form a number system with Z6 and I got the same thing as with Z4 ! I too am unclear..."
- "Or maybe homosexuals are just more messed up than average to begin with. Nope, can't be. It's always..."
- "Perhaps it is time that large groups assign some type of weighting to authors to indicate their..."
- Bed Bugs May Have A Favorite Color
- NASA: Rising CO2 Will Help Food Crops
- NRDC Sues EPA Over Fracking – Has The Settlement Been Pre-Arranged?
- Vaccinate Pregnant Moms to Protect Babies from the Flu
- Pure Unstructured Structured Water – Because Some People Will Buy Anything
- Critical-Care Drug Shortages Continue, Despite FDA Action