Persistent little buggers

Ed Yong might be my favorite blogger. He’s cer­tainly the most pro­lific one I’m aware of (don’t sign up for his twitter feed if you don’t want to be inun­dated all day long — how do people keep up with that sort of thing?!). But more impor­tantly he’s enter­taining and good at what he does.

So imagine my excite­ment when I saw his byline on a mag­a­zine article about one of our very own fac­ulty in the most recent issue of New­Sci­en­tist. I’ve men­tioned Pro­fessor Kim Lewis a couple of times, but I don’t think I’ve talked specif­i­cally about his theory of “per­sister” cells.

Yong calls them “sleeper cells” in the article (of the same name) and does a good job explaining the theory, which attempts to explain how some bac­te­rial infec­tions per­sist after antibi­otic treatment.

One common and accepted mech­a­nism is antibi­otic resis­tance. Here indi­vidual bac­teria with muta­tions that make them resis­tant to the drug sur­vive while their un-​​mutated neigh­bors die. Over time, all that’s left are strong, antibi­otic resis­tant, mutated bacteria.

Bac­te­rial per­sis­tence, on the other hand, says that a small subset of bac­te­rial cells spe­cialize in sur­vival by “going to sleep” when con­di­tions are bad (ie., when an antibi­otic comes around).

In the last few years, Lewis and his team have begun to show that bac­te­rial per­sis­tence is respon­sible for dis­ease areas that were pre­vi­ously thought to depend on antibi­otic resis­tance. For example, Cystic Fibrosis patients often die from pneu­monia despite the fact that cul­tures of the incrim­i­nating bac­teria die when exposed to antibi­otics in the lab. In 2010 Lewis’ team showed that these patients actu­ally have sig­nif­i­cantly more per­sister cells than normal.

Yong’s article goes into a bit more detail about other researchers in the field who are attempting to find ways to kill off per­sister cells, for example by punching holes in their cell walls.

You’ll be able to access the full article online for a few days with a free account, but it will soon go behind the pay­wall and then I can’t do any­thing for you unless you want to drop by the office and read the paper copy (gasp!).