Bacteria gain strength in space
Jeanne:
September 25th, 2007
Researchers have found that certain strains of bacteria can gain virulence in the weightless conditions associated with space flight. Scientists examined the effects of space flight on a strain of salmonella during the 2006 Atlantis mission. Space travel, they found, increased the likelihood that the bacteria would kill infected mice by 300%. This sharp increase in the rodents’ mortality rate was due in part to the fact that weightlessness appeared to cause the bacteria to undergo genetic mutations such that they became more dangerous.
The study was carried out by scientists at America’s National Academy of Sciences. The findings are particularly important given that the US space agency, NASA, is currently working on a project to land a manned craft on Mars in the not-too-distant future. The strain of salmonella investigated during the study, Salmonella typhimurium, is one of the most virulent forms of the deadly bacteria and is often very difficult to treat, even with antibiotics. Researchers have therefore emphasised the importance of maintaining good hygiene in the cramped conditions of a spacecraft. Commenting on the matter, Cheryl Nickerson, from the University of Arizona’s Center for Infectious Diseases and Vaccinology stated:
“Wherever humans go, microbes go; you can’t sterilise humans. Wherever we go, under the oceans or orbiting the Earth, the microbes go with us, and it’s important that we understand… how they’re going to change. These bugs can sense where they are by changes in their environment. The minute they sense a different environment, they change their genetic machinery so they can survive.”
Scientists hope that their research will bring them closer to developing a vaccine for the deadly disease. Genetic mutations in salmonella bacteria appear to have been controlled by a protein known as Hfq. The team hopes that drugs specifically designed to manipulate the protein could serve as a vaccine against salmonella. Treatments for salmonella are, at the moment, quite limited. Whilst mild cases of salmonella do not require specific medical attention, the condition can be fatal in certain instances. The disease is usually contracted through the consumption of contaminated food such as poultry, eggs and unprocessed milk. Symptoms include sudden nausea, abdominal cramps and bloody diarrhoea. Children and the elderly are particularly susceptible when it comes to contracting salmonella.