January 31, 2024 - Antimicrobial resistance (AMR) has been a problem since the discovery of penicillin, and will continue to be a problem as long as there are infections that require treatment. It is a global issue that results in 4.95 million deaths per year, according to the World Health Organization. What is AMR and how can it be managed?
Antimicrobial resistance is the physiological adaptation of microorganisms to agents that would be toxic to them. A bacteria that makes people sick (known as a pathogen) learns to resist the medicinal effects of a medicine, or antibiotic. That new variation of the bacteria then spreads and results in the medicine no longer having an effect against an infection.
“AMR is a global issue,” says Dr. Mazen Saleh, Associate Professor, School of Natural Sciences at Laurentian University. “Normally when a person gets an infection, they get prescribed a specific antimicrobial, commonly known as antibiotic, although the two terms are not synonymous. If that microbe builds resistance by mutating, the option would be to prescribe a different antimicrobial to treat the infection. The problem lies therein. The antimicrobials become useless as the bacteria continues to mutate against one, two, sometimes three antimicrobials. We can get to a point where a pathogen is resistant to all of the antimicrobials available to us.”
This is something that scientists are already seeing happen with tuberculosis. There are multidrug-resistant (MDR) and extensively drug-resistant (XDR) forms, which is when “the pathogen is resistant to multiple structurally unrelated antimicrobials, including first and second line antimicrobials. The major concern in this case is when the pathogen becomes resistant to all the antimicrobials we have at our disposal and these infections can no longer be treated with traditional medications,” says Dr. Saleh.
While chemical antimicrobials like sulfa drugs and penicillin have been used to treat infection since the time of the second World War, naturally occurring non-chemical antimicrobials, called phages or bacterial viruses, and antimicrobial peptides (AMPs) are newer treatments. Phages and peptides behave the same way as chemical-based antimicrobials, in that they attack the bacteria but rather than being created in a lab, they are abundant in nature and they target the pathogen more specifically.
“Phages and peptides can be useful when multidrug-resistance or extensive drug-resistance occurs,” says Dr. Saleh. “With the increasing resistance to antibiotics globally, peptides and phages are receiving renewed interest by scientists. Still, phages and peptides have their downsides and are not the perfect replacement for what is currently the most ideal treatment for bacterial infections, antibiotics.”
“The most pressing potential outcome if we don’t take action against antimicrobial resistance is the spread of lethal pathogens. The risk of spread of antimicrobial resistance can not be overstated,” says Dr. Saleh. “At that point, we would not have any other options. In general, bacteria becomes resistant to every new drug that we develop, but we can slow down the spread of resistance.”
Slowing down the spread of antimicrobial resistance happens in a few ways.
According to Dr. Saleh, patients and physicians alike have a responsibility when it comes to taking antimicrobials. “Physicians are cautious when prescribing antibiotics to ensure that a bacterial infection is the cause of the ailment. Likewise, patients should not expect antibiotics to resolve any infection, particularly self-resolving mild viral infections that cause the common cold. Additionally, Dr. Saleh cautions, “Patients should always complete the course of an antibiotic that has been prescribed to them. Don’t stop taking it when symptoms stop or after a few days. Complete the course.”
Dr. Saleh also says that the way that leftover antibiotics are disposed of is of critical importance. “Dispose of leftover medication by bringing it into a pharmacy. If these antibiotics end up in the environment, like water ways and landfills, they can encourage resistance. Similarly, if antibiotics are left in the cabinet, it increases the potential of people taking the medication later to self-medicate or self-treat an illness which also contributes to antimicrobial resistance within the population.”
With the cold and flu season in full-effect, Dr. Saleh emphasizes that considering these cautions around the use of antibiotics will support global efforts in slowing antimicrobial resistance.