26th April 2011 Bacteria in Space

In a fascinating article [1], Ed Yong explains how experiments in space are providing insight into disease on Earth. It's well worth a read.

Extreme Conditions

In extreme conditions, we can learn much about how bacteria functions. In hot undersea vents, studying bacterium led to the discovery of an enzyme which could create pieces of DNA at high temperature.  This enzyme gave rise to the polymerase chain reaction which is used to multiply DNA in the lab.[2]

For many years it was believed that bacteria could not live in the harsh conditions of the stomach but, against much disbelief and scorn, two Australians, Barry Marshall and Robin Warren, showed that Helicobacter pylori bacterium is a major factor in stomach ulcers.[5]

Bacteria in Space

Scientists led by Cheryl Nickerson have found that salmonella bacteria are far more virulent in microgravity (almost zero gravity) than they are on earth. They clump together more easily, which forms a biofilm which is more prone to cause disease. It is thought that this clumping is triggered easier by the reduced force of the liquid over the bacteria, which would usually indicate to the bacteria that they have reached the calmer regions of the body where they are adapted to reproduce.[ 1, page 3]

The mechanism which controls the changes in salmonella is a protein called Hfq. This switched genes on and off. If something to target Hfg could be found, it could lead to a weapon against not only salmonella but other bacteria too.

Weakened Immune Systems

In space, astronauts' immune systems are weakened since the white blood cells do not activate properly. Putting this together with the stronger bacteria and lack of medical facilities and care, it adds up to a hazardous situation for those travelling in space.

Update: Rosie Redfield (University of British Columbia) has some doubts as to the rigor of the paper the article is based on.[10]

Sources

1. Wired Magazine: Space Medicines Final Frontier
2. Wikipedia: Micro-g Environment
3. Wikipedia: Polymerase Chain Reaction
4. Wikipedia: Hfq Protein
5. Wikipedia.: Timeline of peptic ulcer disease and Helicobacter pylori
6. Wikipedia: Barry Marshall 
7. Wikipedia: Robin Warren
8. Wikipedia: Helicobacter pylori
9. Sciencemuseum: Spacebacteria
10. Rosie Redfield: Do bacteria become superbugs in space?