A Needle in a Haystack

By: Bryan Gerber

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Throat hurts a bit? Take antibiotics. Stomach problems? Take antibiotics. Hurts to pee? Take antibiotics. It seems every burning or painful symptom can be cured by miracle drugs known as antibiotics, but what are these drugs?

These antibiotics are really metabolites (made by metabolism) that are organisms’ way of talking to one another. While some metabolites drive some organisms to die, others coordinate GROWTH (called quorum sensing molecules).

So what differs antibiotics from quorum sensing molecules? Ummmmm… Errrr….. we don’t know….

And that’s the problem! We do not know the natural uses of many of these metabolites. Scientists don’t know how many of these molecules work in living cells, they just do. In addition, there are other molecules we don’t even know about yet that may be useful.

So do we just keep studying the same organisms and pray that we observe some magical properties? We can always hire a herd of scientists to investigate a sea of random organisms looking for the one with the pearl inside. But I have to be honest; that’s not very scientific.

Dr. Shank from UNC Chapel Hill tackled this problem. And just like any high school student knows, the best way to listen in on thousands of subjects to see what is being said is to go to hubs of social media.

And for bacteria that’s just the soil around us!

In the screening procedure that Dr, Shank developed, a mixture of soil organisms are placed in a field of specially modified Bacillus subtilis. This particular organism was modified to fluoresce when any of its neighbors told it to change its growth pattern. In this way a talkative bacteria would light up like a target.

Why guess and check when you can just aim for the bullseye?

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Shank EA. Using coculture to detect chemically mediated interspecies interactions. JoVE (80):e50863. PMID: 24300024

One of these bacteria, such as the one shown on the right in the image above, could literally be picked up.

And by this I mean a steady handed individual can try to use a tiny toothpick and gently touch it to a fragile cell 1/300 the size of a pencil tip under a microscope magnifying the view 200 to 400 times that of your eye. Child’s play.

The procedure is nicely described below (with more of the technical aspects included):

Using Coculture to Detect Chemically Mediated Interspecies Interactions

Dr. Shank’s lab is currently investigating some of these bacteria and determining the molecules they are secreting. Understanding the role of these metabolites in normal ecological communities may help to explain why some antibiotic treatments go horribly wrong.

Who knows, maybe the days of bacterial infections in hospitals are over. Instead of pumping antibiotics into humans, we may be able to progress to more thorough treatments with multiple antibiotics. Or maybe new antibiotics may be found using this screening procedure.

Only time will tell.

Works Cited

Shank EA. Using coculture to detect chemically mediated interspecies interactions. JoVE (80):e50863. PMID: 24300024. DOI: 10.3791/50863

 

writing in the natural sciences