Anti-bacterial Nukes

Imagine an anti-bacterial nuclear warhead – a compound so volatile that bacteria cannot develop resistance to it, because once it is deployed, there aren’t any bacteria left to develop resistance.

Now imagine that the compound can be activated by light, which gives doctors and scientists the ability to pinpoint specific areas for detonation and to control its destructive radius.

Chemist Dr. Reza Ghiladi and his NC State colleagues have chemically modified a series of common photosensitizers – compounds currently in use to treat a variety of cancers – to produce a highly reactive form of oxygen when exposed to certain types of light. If the compound is in solution and bacteria take it up, exposure to light results in the total eradication of the bacteria. The idea is to reduce dangerous, antibiotic-resistant bacterial infections quickly and safely. But while the idea of putting bombs and humans together isn’t normally seen as having a positive effect on health, the properties of this compound may allow doctors to perform a surgical strike, rather than a carpet bombing, when trying to reduce infections from nasty actors like MRSA or Acinetobacter baumannii.

“Bacteria have much higher metabolic needs than regular cells, so in solution they will take up much more of the compound than any surrounding healthy cells, effectively turning them into Trojan horses,” Ghiladi says. “The light-activation also minimizes the damage to any healthy tissues, because the reaction is linked to very specific wavelengths of light, and that light will only be applied to affected areas.”

In laboratory tests, Ghiladi’s compound went up against bacterial nasties ranging from E. coli to TB to MRSA, and the kill rate after one application ranged from 95 percent for E. coli to 99.999 percent for the others. And these are on bacterial loads that are many times higher than anything a human would ever be exposed to.

“Typically what happens with antibiotic resistance is that the drug leaves just a few surviving bacteria after a treatment, and those bacteria are then able to produce ‘work-arounds,’ or resistance, to the drug. Our compound is lethal in its simplicity. We aren’t targeting a particular pathway into the bacteria, so it can’t develop resistance because the entire organism is wiped out.”

The practical applications for a compound like this one are numerous – it could be used to treat all sorts of things, from localized MRSA infections to surfaces in hospitals, providing round-the-clock anti-microbial protection. Ghiladi and his team are also planning to see if the compound is similarly effective as an anti-viral and anti-parasitic agent.