Different strategies underlie the ecology of microbial invasions

Oct 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: New 3-D method improves the study of proteins

Related Stories

Bacteria connect to each other and exchange nutrients

Feb 23, 2015

It is well-known that bacteria can support each others' growth and exchange nutrients. Scientists at the Max Planck Institute for Chemical Ecology in Jena, Germany, and their colleagues at the universities ...

Scientists map protein in living bacterial cells

Sep 04, 2014

(Phys.org) —Scientists have for the first time mapped the atomic structure of a protein within a living cell. The technique, which peered into cells with an X-ray laser, could allow scientists to explore ...

The energetic origins of life

Jun 12, 2014

(Phys.org) —Imagination is perhaps the most powerful tool we have for creating the future. The same might be said when it comes to creating the past, especially as it pertains to origin of life. Under what ...

Symbiosis: enforced surrender?

May 20, 2014

Scientists from INRA and Lorraine University in France unraveled a key mechanism in the symbiosis between fungi and trees. During this mutually beneficial interaction, the fungus takes control of its host ...

Recommended for you

Single cells seen in unprecedented detail

1 hour ago

Researchers have developed a large-scale sequencing technique called Genome and Transcriptome Sequencing (G&T-seq) that reveals, simultaneously, the unique genome sequence of a single cell and the activity ...

Conifer study illustrates twists of evolution

1 hour ago

A new study offers not only a sweeping analysis of how pollination has evolved among conifers but also an illustration of how evolution—far from being a straight-ahead march of progress—sometimes allows ...

Bumblebees use nicotine to fight off parasites

1 hour ago

Researchers from Queen Mary University of London (QMUL) and Royal Holloway, University of London (RHUL), gave bumblebees the option to choose between a sugar solution with nicotine in it and one without. ...

New 3-D method improves the study of proteins

2 hours ago

Researchers have developed a new computational method called AGGRESCAN3D which will allow studying the 3D structure of folded globular proteins and substantially improve the prediction of any propensity for ...

User comments : 0

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.