Researcher studies foodborne pathogen Salmonella in space
Researcher Cheryl Nickerson studies impact of fluid shear on Salmonella on International Space Station
Researcher Cheryl Nickerson took the foodborne pathogen Salmonella up to the International Space Station to study what might happen.
According to Arizona State University :
"During an earlier series of NASA space shuttle and ground-based experiments, Nickerson and her team made a startling discovery. Spaceflight culture increased the disease-causing potential (virulence) of the foodborne pathogen Salmonella , yet many of the genes known to be important for its virulence were not turned on and off as expected when this organism is grown on Earth. Understanding how this switching is regulated may be useful for designing targeted strategies to prevent infection."
After researchers brought the Salmonella into space and then back down again, it returned three to seven times stronger than Salmonella grown on the ground.
According to NASA :
“We think space travel tricks Salmonella into behaving as if it is in the human gut,” Nickerson says. “It’s a mechanical phenomenon having to do with ‘fluid shear.’”
When Salmonella move around, the pathogens can sense how strong the force of the fluid moving past them is. If the Salmonella are able to find a small nook in the intestine wall, however, the fluid shear goes away, which they can sense. In space, an article says , the Salmonella think they are safe because the fluid shear is so low.
Fluid shear has important functions to the cell, according to NASA:
"As it turns out, many of the genes activated by the low fluid shear environment of spaceflight are involved in transporting these ions in and out of the cells, so there could be a connection. Research on this ion effect is still ongoing, Nickerson says, but she speculates that it could eventually lead to new ways to use these ions to ward off Salmonella infections."
Later in 2013, Nickerson will go into space on the SpaceXDragon ship, bringing Salmonella with her to infect a nematode.
“Recognizing that the spaceflight environment imparts a unique signal capable of modifying Salmonella virulence, we will use this same principle in an effort to enhance the protective immune response of the recombinant attenuated Salmonella vaccine strain,” Nickerson says.