Save your friends: Bacteria sacrifice themselves for the good of the group
Antibiotic resistance attributed to protein produced by strong bacteria.
Thu, Sep 02 2010 at 8:29 PM
BETTER BACTERIA: Strong bacteria produce a protein to help protect weaker ones against antibiotics. (Photo: Adrian H Elcock/University of Iowa)
Antibiotic resistance is a hot topic among researchers today. Part of the problem was that researchers assumed a sort of "survival of the fittest" among bacterium. But according to stories in USA Today and Science Daily, it's more of a "sacrifice of the fittest" situation.
The USA Today article describes how the most antibiotic-resistant bacteria "sacrifice themselves so that their fellow bacteria have a better chance of survival." These resistant bacteria produce a protein that triggers a "protective mechanism" in other bacteria. Making this protein, called an indole, weakens the strong bacteria, but not before they've equipped their friends to survive the enemy — in this case, antibiotics.
Science Daily compares the indole to a steroid that helps the weak bacteria bulk up to better fight off the antibiotics.
The stories describe research conducted at Boston University, which counters previous assumptions that bacteria mutate to survive the onslaught of antibiotics. The old thinking was that the strong bacteria survived the drug because of mutations, but enough weak ones would die off to see relief in a patient. USA Today quotes researcher James Collins, saying that researchers were surprised "to find the weak strains not only surviving, but thriving," as a result of their altruistic bacteria friends.
These findings give insight about why bacterial resistance is so hard to combat. According to Science Daily, researchers now know that bacteria strains are complex, showing "dramatic differences ... within a single population, with some bacteria showing exceptional resistance and some almost none, not unlike cancer cells in humans."
Science Daily also explains that the findings indicate that bacteria can trick researchers. If we find a bacteria strain that seems weak initially, we now know it can go on to strengthen its troops for a stronger battle.