New antibiotics are hard and expensive to develop, so scientists are trying these alternatives

Including things such as water activated with reactive species, repurposing medicaments that are already used for other treatments, and attacking biofilms with metals

The need for new medicines urges more and more every day, especially as pathogens become resistance to current antibiotics. Creating new antibiotics that target systems already known is difficult due to the continuous evolution, and coming up with new targets requires gigantic efforts that evolve slowly.

From time to time, some new targets do get discovered -but from such discovery to actual antibiotics, there’s a long way ahead and millions to billions needed in investments:

In the last decades, many researchers and decision-makers began to approach the problem of antimicrobial resistance from different perspectives. A big chunk of current science is researching ways to kill pathogens with means that do not involve antibiotic molecules at all.

Here’s a summary of interesting examples, with pointers to specific cases from the recent scientific literature.

Drug repurposing

In general terms, drug repurposing is the process of finding new uses for existing drugs. The most interesting application consists in using a drug to treat a different disease or condition than it was originally intended for.

Rather than chasing or designing novel antibiotics from scratch, some computational researchers are searching massive libraries of molecules to identify whether current compounds might already have what it needs to target certain bacterial mechanisms, and thus kill the pathogens without having to invent or discover a new antibiotic. Sometimes, this research begins in silico, which is relatively cheap at the expense of inaccurate yet good enough to short-list candidate molecules for experimental studies. The experimental studies then end up providing information whether the drug can be repurposed from treating one problem to treating the pathogen in question.

This strategy is advantageous because it has faster development times and lower costs, as the safety of the drug has already been established, at least at certain concentrations. Besides, scientists already know how to obtain them in good amounts and know all their properties such as permeation, stability, etc.

For a deeper, expert-written review on drug repurposing to attack bacterial pathogens, see:

Plasma-activated water

Considered as a potential novel disinfectant is plasma-activated water, in which chemically unstable forms of oxygen and nitrogen develop. These stand in solution as radical reactive species. “Radical” in that they have unpaired electrons, thus are very reactive because electrons “want” to meet pairs.

Radicals are toxic, especially inside cells. And when bacteria are overloaded by radicals, they end up dying.

Recent research shows that plasma-activated water can be used in doses and ways safe enough for humans, but that can kill bacteria.

To know more about Plasma-activated water and its properties as disinfectant, check out these articles:

Metals targetting biofilms

Despite being single cells by nature, bacteria do band together and cooperate to avoid being affected by medications and antiseptics. One way they achieve this is by building biofilms, which are collections of bacteria living in a colony-like environment that they have created. Biofilms serve as a shield for the individual cells contained within. It is estimated that biofilms are responsible for about 80% of chronic human illnesses.

Gallium, a metallic element, prevents bacteria from absorbing iron, depriving the microorganisms of food over time. Due to this, one strategy being investigated to undermine biofilms is the use of medicines laced with gallium. Gallium compounds, according to recent research, can steeply stop bacteria from growing, even when they are protected inside biofilms. This allows then killing the bacteria with a dose of an antibiotic that is only one tenth of what is typically used.

For an example of peer-reviewed articles on using Gallium to treat bacterial biofilms, see Xia et al ACS Infect. Dis. 2021 (here).

Further reads

I started my investigation after reading this article, which I really didn’t like much so I tried to improve upon it -but it was a good starting point:

And if you like reading about modern research in biology…

Here are some other articles:

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