Surprise Discoveries in the Fight Against Superbugs

An Essay By Hannah D. // 6/8/2017

In the series of essays The Language of Bacteria, we discussed some ways that bacteria are able to fight against us. Specifically, we know that bacteria can protect themselves under coated biofilms, or they can pass around genes to make them unresponsive to antibiotics.

We also discovered new fields of research that are going into our next offensive strike on pathogenic bacteria. Scientists have made the revolutionary discovery that bacteria – a single-celled, nucleus-free, miniscule-by-plankton-standards creature – are capable of communicating with each other and even with us. This communication is key to their biofilm formation and pathogenicity.

There are other places, however, where scientists are looking to find solutions to the problems bacteria present us. Some of these have been quite surprising.

Take a group of scientists taking bacterial swabs off of seaweed samples. Many seaweeds are coated with bacterial biofilms, growing on the seaweeds like barnacles on a grey whale. Just off the Australian coast, however, scientists found a seaweed that did not have said biofilms. After testing for bacteria, they found that the surface of this seaweed was relatively clean.

The reason? A class of chemicals known as halogenated furanones. The seaweed produces a class of chemicals with a cyclic ketone group (an important functional group in organic chemistry) with halogens (iodine, bromine, fluorine, or chlorine) attached at certain places. Apparently, these chemicals are capable of preventing bacteria from building tough, thick biofilms on surfaces. Can this result in a crossover to human medicine? Time (and lots and lots of more research) will tell.

An even more astonishing source of possible new medical knowledge comes from a 1,000 year old Medieval text known as Bald’s Leechbook.

That is to say, a “Leechbook” was Ye Olde Speech for a doctor’s reference book, and this particular one was written by a fellow named Mr. Bald.

A truly inspired team of researchers made a discovery in Bald’s Leechbook when reading the text and idly searching for medieval treatments for what might be a bacterial infection. One expert was a linguist with a penchant for learning about epidemiology; the other was a biochemist whose hobby was historical reenactment (and medieval historical reenactment, at that).

Both were translating the text when they came upon a recipe for a treatment of a stye in the eye – something that may very well have been cause by a bacterial infection (an infection of Staphylococcus aureus. The recipe, which called for onions (or possible leeks; they made two batches, one with each, just to be sure), garlic, wine, and gall bladder bile from an ox, was left to sit for nine days and nine nights before they drizzled the liquid over S. aureus samples in the biochemist’s lab.

Much to their utter bewilderment, this stuff actually worked. They sent another batch to a lab that grew MRSA (the antibiotic resistant S. aureus), and found that it killed 90% of it.

This random medieval concoction was able to destroy 90% of a bacteria that is immune to even our harshest antibiotics. How?!

The researchers aren’t sure, but they theorize that it works by a mechanism totally different from that of antibiotics. Since bacteria have been exposed to antibiotics for quite a while now, genes for antibiotic resistance are rampant. Since they haven’t been exposed to whatever this is since the 12th century AD, genes for resisting it are lacking today. What if we could use this as a separate class of bacteria-killers, and rotate its use with antibiotics so that once one became ineffective, the new one could be rotated in again?

It’s possible. Once again, more research needs to be done, but what if? It would be a bit remarkable if our best chances at fighting bacteria came from both the cutting-edge research of bacterial communications . . . and a millennium-old Leechbook that included medical treatments for possession by evil spirits.

Sources:
Sifri, Costi D. (2008) “Quorum Sensing: Bacteria Talk Sense.” Oxford Journals, 47(8): 1070-1076. https://academic.oup.com/cid/article/47/8/1070/345306/Quorum-Sensing-Bac...

RadioLab podcast, including interview of the two women who discovered a MRSA treatment in Bald’s Leechbook: http://www.radiolab.org/story/best-medicine/