In his acceptance speech for the 1945 Nobel Prize for Physiology, Sir Alexander Fleming reflected on the discovery that made his mark on history – penicillin. He warned future generations: “It is not difficult to make microbes resistant to penicillin in the laboratory by exposing them to concentrations not sufficient to kill them, and the same thing has occasionally happened in the body. The time may come when penicillin can be bought by anyone in the shops.”
While it may have been perceived as an overcautious comment at the time, clinicians and patients alike now face a growing antimicrobial resistance.
Antimicrobial resistance is a classic example of evolutionary biology. When a few microbes survive a wave of antimicrobials, they are left to reproduce and build the next generation of invaders. As the new swarm of microbes inherits the protection of its parents, they become resistant to the initial regimen of antimicrobials. This presents a significant challenge in places where antimicrobials are prevalently used, such as hospitals. Thus, hospital-acquired infections can be more challenging to manage than infections acquired in the community.
For patients, the consequences of antimicrobial resistance can manifest in horrifying ways. As clinicians cycle through multiple rounds of antimicrobials to treat multi-drug resistant microbes, they are often left with fewer and often less desirable medications. Colistin, for example, is often used when there is simply nothing left in the antimicrobial arsenal. From kidney failure to brain toxicity, colistin is often a clinician’s Hail Mary attempt to fight an infection in a chronic hospitalized patient.
With antimicrobial exposure driving resistance, it is important that we reduce the amount of usage to its necessities. However, antimicrobial usage can serve commercial interests in unexpected ways. In the agricultural industry, antimicrobials are often incorporated as part of the feed for livestock to promote growth. In fact, colistin, the last-resort antimicrobial, was used for this purpose in China until 2017, when the government finally banned this practice.
Policy and good governance are necessary to control antimicrobial resistance. While regulatory controls of pharmaceuticals and clinical practice are stringent in many countries – for example, it is the standard in places like Canada that antimicrobials require a prescription for access – this is not always the case.
With antimicrobials under the stewardship of pharmacists, they are reserved for patients who actually need them. But in countries like India, antimicrobials can be purchased over the counter. This leads to a risk of unnecessary therapy, especially since there are misconceptions surrounding antimicrobial usage. In a 2015 WHO survey of about 10,000 people across 12 countries, 64 per cent said they believed antimicrobials can treat viral conditions like the common cold.
Prescribers also can also find themselves over-prescribing antimicrobials due to a plethora of reasons, including patients’ demands, inadequate training and fear of malpractice suits.
Left unchecked, the consequences will be deadly. A 2014 United Kingdom report predicted that antimicrobial resistance could lead to the loss of 10 million lives per year globally.
For patients, the consequences of antimicrobial resistance can manifest in horrifying ways.
A promising initiative has been the integration of antimicrobial stewardship teams at hospital sites. In Canada and the United States, there has been significant investment in creating teams of pharmacists and physicians dedicated to the optimization of antimicrobial usage. These teams work alongside infectious disease specialists to ensure that patients take the right antimicrobial, at the right dose, the right frequency and for the right duration. As a result, patients receive safer and more effective antimicrobial regimens while reducing the risk of resistance.
However, with growing resistance to existing antimicrobial agents, more work is needed on the innovation front. There is speculation that the development of polymer compounds may have the potential to replace the role of antimicrobials. This research is still far from complete, but it is the exploration of technologies like these that will pave the way to conquering this growing global threat.