22 June 2010

Razor-sharp teeth and venom: The bacteria love it

ResearchBlogging.orgA bite from a Komodo dragon would take you down. They have large teeth that are very sharp. And their salivary glands secrete venom.

For a long time, people sort of overlooked those two factors. The teeth were obvious, but the venom wasn’t. Instead, people suggested that one of the ways that the slow moving monitor lizards were able to take down large prey was because their mouths contained so many bacteria, that the bitten prey animal got infected, quite quickly, and went down from the bacteria.

The discovery of venom seemed to put the kibosh on that particular story – the prey die too fast for bacteria to be the cause of death. But it doesn’t change the fact that the mouths of Komodo dragons are loaded up with very nasty bacteria.

Bull and colleagues take a totally different approach to this question. Rather than asking what the bacteria do for the Komodo dragons, they ask what the Komodo dragons do for the bacteria.

They hypothesize that the way to view the relationship is using a disease model. Bacteria are spreading from dragon to dragon in an epidemic fashion. The bacteria spread from dragon to dragon by growing on the large kills that dragons make, which are often fed on by several different individuals. The dragons’ prey almost becomes an intermediate host; a means of spreading from dragon to dragon.

They are not suggesting that the bacteria are harming the Komodo dragons or causing them to become sick, which seems a bit of a strange bending of the word “disease,” but at least they warn us.

It’s an interesting way of looking at the problem. There’s no experimental evidence presented here that it allows you to make better predictions about the bacteria or the dragons, though.

Related post

The birth of dragons


Bull, J., Jessop, T., & Whiteley, M. (2010). Deathly Drool: Evolutionary and Ecological Basis of Septic Bacteria in Komodo Dragon Mouths PLoS ONE: 5(6): e11097. DOI: 10.1371/journal.pone.0011097

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