geneticist, demonstrated that antibacterial resistance arose spontaneously in bacterial cultures due to random genetic mutations, which occurs quickly in bacteria. The mutations were not a direct result of antibiotic exposure per se, but exposure to antibiotics allowed the mutated resistant bacteria to outcompete the bacteria susceptible to antibiotics. Antimicrobial resistance was an unavoidable consequence of the nature of microbes themselves. But several factors increased the speed of antimicrobial resistance. The quick development of several types of antibiotics within a brief period resulted in a general overuse in humans. In industrial farming, antibiotics were used prophylactically in livestock to increase growth rates and prevent illness. Early research seemed to demonstrate the potential for resistant bacteria to spread from livestock to humans, yet the use of clinically important antibiotics in agriculture persists. Since the 1970s, antibiotic research has stalled, and the pipeline of new antibiotics has gone dry, with very few in clinical trials. Why has antibiotic research stalled? Only 5 of the 20 pharmaceutical firms that participated in antibiotic exploration in the 1980s are still active in the field.4 Most large pharmaceutical companies have abandoned antibiotic discovery, and this responsibility has since been taken up by smaller firms, universities, start-ups, and biotechnology companies. But what is the reason for this shift? As death rates from cancer and heart disease rose and those from infectious diseases fell, there were slimmer economic margins for developing new antibiotics. The rate of discovery of new antibiotics slowed, and those few specialized drugs that were developed to overcome antimicrobial resistance were expensive to use. The latest antimicrobials are often only available in high-income countries, while low- and Resistant bacterial infections kill an estimated 1.27 million people every year across the globe. In 2018, about 1 million bacterial infections were reported in Canada, a quarter of which were resistant to first-line antibiotics. Antibiotics are a type of antimicrobial, which is a broader term that includes a variety of drugs that treat infections caused by microbes. Antibiotics are used to treats bacterial infections, while other antimicrobials are used to treat infections caused by viruses, fungi, and parasites. An antibiotic class is a group of antibiotics that share similar chemical structures and properties. Antibiotics can be categorized by chemical structure, mechanism of action, or spectrum of activity. First-line treatment for a given disease is the one that most prescribers will give to previously untreated patients, usually due to a combination of high effectiveness and low comparative risk. If that therapy is ineffective, prescribers will move on to a second-line treatment. What causes antimicrobial resistance? Microbes are living organisms that adapt over time. Like all living things, they replicate, survive, and spread as rapidly as possible. Microbes adjust to their surroundings and evolve to continue their existence. Waksman defined an antibiotic as “a compound made by a microbe to destroy other microbes.” Louis Pasteur, the French chemist and pharmacist who discovered the principles of vaccination, microbial fermentation, and his namesake pasteurization process, proposed that microbes could secrete material to kill other bacteria, back in the 19th century. Microbes co-exist in every environment on earth and compete for resources. Sometimes they create symbiotic relationships with other microbes. Other times, they seek to destroy each other using enzymes or chemicals. Scientists like Waksman found ways to use these compounds to the advantage of humans. Researchers sought to understand how resistance developed and whether antibiotics themselves played a role in their declining efficacy. In the years just after WWII, Milislav Demerec, a Croation-American 22 | 2025 | Issue 3 Issues and People
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