UC San Diego researchers confirm & expand Martin Henry Dawson’s insight from 90 years ago : bacteria communicate with each other

As reported in the journal CELL SYSTEM on April 27 2020, the team of Gurol Suel et al found that bacteria in bio films can retain memories of being shocked by strong light, down at the individual cell level.

Most bacteria prefer to live in biofilms (organized films of bacteria held together by a sticky gooey matrix) if they can.

Bacteria are incredibly small, invisibly small, but they hate to live alone - so they are often found, for example, living an organized life together literally in the trillions, in green slimy biofilms running for metres and metres in length in stream water and planted upon the rock surfaces in the streams.

Rub your tongue over your teeth - feel “wooly” ?  Well that’s a biofilm - time to brush !

And it is that same biofilm of mouth bacteria, now firmly planted inside damaged heart valves that killed most people who died from once deadly rheumatic fever : subacute bacterial endocarditis.

They were once so common and so awful they were known simply as RF and SBE.

It was Dawson’s other big research area that whipped these dreaded biofilms.

Dr Dawson was the first in history to use penicillin as it is used today : as a systemic internal antibiotic : he used it to try to cure and prevent RF and SBE - and succeeded !

But years early, Dawson first demonstrated that bacteria in biofilm engage in collective action, sending out chemical signals when they are ready to be “TRANSFORMED”, ready to receive a horizontal transfer of DNA from another sub-species of that same overall bacteria species.

The process they used is called Quorum Sensing , an extremely simple but also extremely elegant way to communicate : we have since learned that it is used, modified, by all living cells to organize themselves.

When the collective group of cells sense that the number of chemical molecules they are receiving is high enough (quite literally, a Quorum) they know that the transformation will succeed - enough cells will give off their DNA and enough cells will receive it, to successfully affect a transformation of the biofilm from one sub-species to another.

If fact, it was the discovery of Transformation that led to the realization that all living beings’ genetic information was stored in the lowly DNA, hitherto considered basically as mere simple packaging and not in the almighty and complicated proteins.

This is why I study and write about Dr Dawson, because his insights, now almost 100 years old, continue to have great relevance today....