Countering drug-resistant bacteria has been looked into for years ever since these types of pathogens burst on to the scene, with the Nobel Prize winner Alexander Fleming describing this type of microbe back in 1945 during his Nobel lecture.
To treat bacterial infections antibiotics are typically used, providing effective growth inhibition and elimination of the pathogen from the human system. However, natural variations in bacterial species, as well as the fact that they reproduce quickly and can transmit DNA within and between species, means that genetic information aiding antibiotic resistance quickly spreads in a population if left unchecked.
As a result of continued or unnecessary use of antibiotics, drug resistance has become one of the world’s pre-eminent conditions in the twenty first century, particularly in developed societies.
Around half a million people are treated for burns every year. Standard procedure would involve removing tissue and applying skin grafts to the area, as well as antibiotic creams or treatments, however seeing as drug-resistant strains are on the rise, medical specialist have had to look elsewhere to provide effective treatment.
That place was the food industry. Scientists at the Massachusetts General Hospital (MGH) Center for Engineering in Medicine looked into the use of electrical pulses to provide effective anti-bacterial treatment, a technique commonly use in the preservation of foods.
The paper was published in the scientific journal Technology, available in June.
Pulsed Electrical Fields (PEFs) have been around for a while, helping prevent spoilage by eliminating bacteria in our foods. It is thought the method behind this is the fact that these electrical pulses generate large holes in the membranes of the microbes, eliminating them from our potential dinner plate.
The researchers looked to use this theory with an eye on applying it to minimising wound infection, particularly burns.
In order to explore this idea, the MGH researchers applied a drug resistant strain of the bacteria A. baumannii to small third degree burns on the back of anaesthetised mice. The bacteria were labelled with florescent markers, allowing the scientist to see the progress of the bacteria using specialised equipment.
The bacteria were left in the tissue for forty minutes, with the researchers confirming their colonisation thanks to the aforementioned fluorescent markers. Two electrodes were placed each side of the burn, which, when electricity passed through, would create the electrical field pulse.
The mice underwent two forty-pulse treatments, spaced between five minute intervals. The mice were separated into two cohorts, the first receiving 250 Volts/mm whilst the other group received the double.
Using imaging techniques, the researchers noted a decrease in the number of bacteria in the wounds, with data ranging from an eight hundred fold decrease in the 250V/mm group to an astonishing ten thousand fold drop in bacteria levels.
Interestingly, the scientists noted that increasing the number of pulses per treatment, rather than the intensity of individual pulses, resulted in much greater bacterial reduction.
These results show dramatically improved bacterial disinfection compared to other technology, such as lasers, which are often absorbed or scattered within the wound meaning bacteria often persist, said Martin Yarmush, MD, PhD and senior author of the paper, speaking to the MGH press release.
“Pulsed electric fields are a previously unexplored technique that has the potential to provide a chemical-free way of disinfecting burns and other wound infections,” he added.
First author Alexander Golberg, PhD, of the MGH Center for Engineering in Medicine (MGH-CEM), commented on the wide ranging use of the technology: “Pulsed electrical field technology has the advantages of targeting numerous bacterial species and penetrating the full thickness of a wound.”
What other technology do you know of that scientists could look into with regards to the treatment of bacteria?