Can a new compound help us fight antibiotic-resistant bacteria?
In recent years, scientists have been focusing on one of the world's most worrying problems, namely the fact that many bacterial strains have become antibiotic-resistant, and thus much more difficult — and sometimes impossible — to kill.
The Centers for Disease Control and Prevention (CDC) call this phenomenon "one of the biggest public health challenges of our time," explaining that, in the United States alone, over 2 million people become infected with antibiotic-resistant bacteria each year, and over 23,000 people die because of such infections.
For this reason, researchers all over the world have been looking for novel ways to address this crisis and kill off superbugs more effectively.
Now, a team of investigators from the University of Sheffield and the Rutherford Appleton Laboratory (RAL) in Didcot, both in the United Kingdom, have identified a new compound that, they say, can successfully target and fight some types of multidrug-resistant bacteria.
In their study — the findings of which appear in the journal ACS Nano — the researchers show that this new compound can be effective against antibiotic-resistant, gram-negative bacteria.
For categorization purposes, bacteriologists label bacteria as pertaining to two large classes: gram-positive and gram-negative bacteria.
Gram-positive bacteria include Staphylococci, Streptococci, and Pneumococci — bacteria that infect the skin, the blood, or the lungs.
Gram-negative bacteria include strands such as Escherichia coli, which is responsible for urinary tract infections, or Pseudomonas, hospital bacteria that often infect the blood or lungs.
A 'breakthrough' discovery
In the current study, the research team — led by Prof. Jim Thomas — focuses on the potential of a class of compounds called ruthenium(II) polypyridyl complexes, a name that scientists sometimes shorten to Ru(II) complexes.
These compounds, the researchers explain in their paper, have shown promise in anticancer therapy.
However, study co-author Kirsty Smitten, Ph.D., has now developed a Ru(II) derivative that is able to fight multidrug-resistant, gram-negative bacteria, particularly E. coli.
The researchers explain that they were easily able to test the new compound's effectiveness and follow its effect on bacteria because it gives off a specially devised white light.
"As the compound is luminescent, it glows when exposed to light. This means the uptake and effect on bacteria can be followed by the advanced microscope techniques available at RAL," Prof. Thomas explains.
The team also found that the new compound can make it more difficult for gram-negative bacteria to develop antibiotic resistance, which could also make it a candidate for targeted prevention efforts.
Prof. Thomas and colleagues call this discovery a breakthrough in research surrounding superbugs, and they believe that it could lead to more effective ways of challenging dangerous infections.
"This breakthrough could lead to vital new treatments to life-threatening superbugs and the growing risk posed by antimicrobial resistance."
Prof. Jim Thomas
However, the search does not stop here. At the moment, the research team notes, they only know that the new compound is effective against some strands of antibiotic-resistant bacteria, yet the investigators believe that it may be able to attack other bacterial strands as well.
This is a possibility that the investigators are hoping to confirm in the future.