June 17, 2019
Overuse of antibiotics over the years has created a healthcare crisis that The Centre for Disease Control (CDC) call “one of the most urgent threats to the public’s health.” Antibiotic resistance is a growing public health crisis that contributes to much more serious illness, increased hospitalizations, increased mortality rates, longer recovery times and of course higher healthcare costs.
But there may be a new hero emerging in the fight against bacterial infections: ever heard of bacteriophages?
Antibiotic overuse is making antibiotics useless in the fight against bacteria. Along with over the over-prescribing of antibiotics to humans, the animal husbandry industry is also playing a huge role in breeding bacteria super bugs. Farmers regularly feed antibiotics to healthy animals to promote growth and prevent disease in animals that are forced to live in very tight quarters. In fact, the World Health Organization states that “in some countries, approximately 80% of total consumption of medically important antibiotics is in the animal sector, largely for growth promotion in healthy animals”.
Organisms are very adaptable and with extended exposure, bacteria adapt to ensure that they can exist in the face of antibiotics – voila, antibiotic resistant bacteria! The result is that bacteria come out much stronger and relatively immune to antibiotics –bacteria seem to be winning the fight.
Some bacteria grow resistant to the one antibiotic that is normally used to treat it. Some, called multi-resistant organisms, develop resistance to multiple antibiotics. And still others have become resistant to nearly all antibiotics, making them especially dangerous and capable of causing serious and wide-spread disease. These superbugs have the potential to trigger sepsis (also called blood poisoning) and become deadly. This leaves us with no effective weapons to fight a bacterial infection.
One extremely resistant bacterium called Clostridium difficile (c-diff) is a highly contagious infection that causes severe diarrhea, abdominal cramping, a rapid heart rate, fever, nausea, weight loss, and can progress to severe dehydration, kidney failure, and can certainly be fatal.
Like most bacterial infections, c-diff is especially dangerous for people with suppressed immune systems, those with chronic conditions, children, and the elderly. C-diff is so virulent that patients must be treated under isolation precautions in the hospital. It’s extraordinarily difficult to eradicate and C-diff can sometimes survive even the special deep cleaning protocols that hospitals use on c-diff rooms. This makes hospitals a potential location for transmission and also create a situation that is difficult to contain.
C-diff is just one type of bacteria that has been super-charged through antibiotic resistance. There are others and will be many more if we don’t find alternate ways to treat bacterial infections.
Bacteriophages are viruses that invade bacteria, and only bacteria. Recently, scientists have been able to genetically engineered phages to target and kill bacteria.
Bacteriophages (phages, for short) are unique in that they ONLY attack their target bacteria. Antibiotics, on the other hand, typically destroy bacteria more broadly - targeting the body’s beneficial bacteria as well as the disease-causing bacteria. That broad attack has helped increase antibiotic resistance.
This may be the first time you’ve heard of bacteriophages, but the idea is not new. In fact they were used very successfully to treat dysentery an cholera in the years before antibiotics were discovered. But further research was set aside when the success of penicillin led to other antibiotics. And antibiotics were a fantastic success in the medical world; that is, until over use and irresponsible use began to diminish their effectiveness.
Now, researchers are refocusing on bacteriophages and actively doing testing with people who are suffering with untreatable antibiotic-resistant bacterial infections. One example is highlighted in Nature Medicine, published research in May describing the use of bacteriophages to successfully treat a 15-year-old with a severe antibiotic-resistant infection after a lung transplant. The phages were specifically chosen to treat the type of bacteria that infected her. Her prognosis before treatment with phages was extremely poor, but the phage therapy successfully cleared up the infection without any long-term effects.
Bacteriophage treatment looks like a promising solution to our growing superbug crisis, but it is not without its own issues. Clean phages are difficult to produce, as the process leaves the phage surrounded by dead bacteria. If the dead bacteria are not carefully removed, they could trigger sepsis if given to a patient.
Another drawback is that phage treatment takes longer than other treatments, again because of the process. Phages are very selective, and each type only attacks very specific bacteria. To be an effective treatment, first the bacteria must be identified and then phages have to be identified that will kill that bacteria.
So while they don’t simply blast away at your body’s bacteria like antibiotics do, bacteriophages have to be tailored for specific uses. And that is both their strength and their Achilles heel.
Advances in science and technology since bacteriophages were first studied, over a hundred years ago, may be what was needed to elevate the potential to the next level. France and Eastern European countries have led the way in research, but as antibiotics become less effective, scientists around the world are taking notice and looking at alternate treatments. Phage therapy has been successful in experimental treatments and may just be our best hope against our antibiotic resistance bacteria superbug crisis.
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