Different strategies underlie the ecology of microbial invasions

October 23, 2006

Infectious disease can play a key role in mediating the outcome of competition between rival groups, as seen in the effects of disease-bearing conquistadors in the New World--or, on a much smaller ecological scale, the ability of bacteria to spread their viruses to competing bacteria.

In a new study, researchers have compared two different general ways in which bacteria compete with one another, and they have found that each strategy seems to be particularly effective under different ecological circumstances--for example, depending on whether the bacteria are rare invaders or abundant residents. The findings, reported by a group of researchers including Sam P. Brown of the University of Texas at Austin, Cambridge University, and University of Montpellier II, and François Taddei of University of Paris, appear in the October 24th issue of Current Biology.

Bacteria are not always so fortunate as to grow alone in their environment, and they often face competition from other lineages. One widespread solution is to kill these competitors.

In the new work, the researchers explored the relative value to both invading and defensive bacteria of two distinct microbial mechanisms of killing competitors: through the release of chemicals (for example, antibiotics or bacteriocins) and through the release of parasites (for example, bacterial viruses, known as phages). Focusing on the second mechanism in an experimental setting, the researchers showed that even though some of the invading bacteria can be killed by their own phage parasites, upon their death they release a burst of infectious parasites that can kill competitor bacteria.

Unlike chemical killing, released parasites trigger an epidemic among susceptible competitors, which become factories producing more parasites. Amplification therefore makes phage carriers able to successfully compete with phage-susceptible bacteria even faster when the carriers are rare, whereas chemical killers can only win in a well-mixed environment when chemical carriers are sufficiently abundant. The findings show that the release of chemical toxins is superior as a resident strategy to repel invasions, whereas the release of parasites is superior as a strategy of invasion.

Citation: Brown et al.: "Ecology of Microbial Invasions: Amplification Allows Virus Carriers to Invade More Rapidly When Rare." Publishing in Current Biology 16, 2048–2052, October 24, 2006 DOI 10.1016/j.cub.2006.08.089

Source: Cell Press

Explore further: Promising results for two genetic weapons against malaria

Related Stories

Promising results for two genetic weapons against malaria

September 28, 2017

Two new papers by researchers at the Johns Hopkins Bloomberg School of Public Health's Malaria Research Institute report successes for highly promising strategies against malaria, a disease that still kills more than 400,000 ...

Microbial murder mystery solved

November 8, 2017

Immune cells called "killer cells" target bacteria invading the body's cells, but how do they do this so effectively? Bacteria can quickly evolve resistance against antibiotics, yet it seems they have not so readily been ...

Recommended for you

Stellar nursery blooms into view

December 13, 2017

The OmegaCAM camera on ESO's VLT Survey Telescope has captured this glittering view of the stellar nursery called Sharpless 29. Many astronomical phenomena can be seen in this giant image, including cosmic dust and gas clouds ...

Mosquito sex protein could provide key to controlling disease

December 13, 2017

If you thought the sex lives of humans were complicated, consider the case of the female Aedes aegypti mosquito, bringer of Zika, dengue, and yellow fever: She mates but once, in seconds and on the wing, with one lucky male; ...

Faster, more accurate cancer detection using nanoparticles

December 12, 2017

Using light-emitting nanoparticles, Rutgers University-New Brunswick scientists have invented a highly effective method to detect tiny tumors and track their spread, potentially leading to earlier cancer detection and more ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.