Scientists evolve huge hyperswarming pathogenic bacteria with multiple whipping flagella

What could go wrong?
August 19, 2013

Hyperswarming pathogenic bacteria multiple whipping flagella (credit: Dave van Ditmarsch et al./Cell Reports)

Memorial Sloan Kettering Cancer Center researchers have evolved hyperswarming pathogenic bacteria adorned with multiple whipping flagella — all the way down to the molecular level — and plan to unleash them in a laboratory.

That’s a good thing — or so say researchers in Cell Reports, a Cell Press publication (open access). The idea is to develop anti-biofilm therapies for use in people with cystic fibrosis or other conditions.

The researchers put Pseudomonas aeruginosa on special plates over a period of days. On those plates, bacteria that could spread out had an advantage in harvesting nutrients from the surface, and within a matter of days, some of those bacteria started hyperswarming. Oops.

“Keep calm, I’m a scientist.”

Investigation of the bacteria showed that P. aeruginosa gained its hyperswarming ability through a single point mutation in a flagellar synthesis regulator (FleN). As a result, the bacteria, which usually have one single flagellum, were locked into a multi-flagellated state. They became better at moving around to cover a surface, but much worse at forming densely packed, surface-attached biofilm communities. All told, the researchers saw this new ability independently arise 20 times.

Bacteria gone wild in petri dish (credit: Dave van Ditmarsch et al./Cell Reports)

The findings may be very important because biofilms are a major problem in clinical settings. Infectious biofilms are hard to remove and difficult to kill with antibiotics.

Drugs that target FleN or that otherwise make bacteria better at spreading out and worse at settling down could leave them more vulnerable to antibiotics and easier to get rid of.

There’s a grade B movie plot in there somewhere….