Q&A: What Makes Bacteria Antibiotic Resistant?

Have you ever wondered why your doctor emphasizes that you must finish your full dose of antibiotics? If you stop taking the drug too soon, the bacteria in your body may adapt to the antibiotic by acquiring chemical or physical changes. This adaptation, called antibiotic resistance, renders your prescription ineffective against the invasive agent. As antibiotic resistant bacteria spread, more people are affected by a disease with a now-futile treatment.

To understand how bacteria become resistant to antibiotics, we must first consider how these drugs work. Antibiotics kill bacteria by interfering with the bacterial cells’ important processes, including their growth and reproduction. An ideal antibiotic physically destroys the bacteria responsible for making you sick.

When a bacterium is no longer susceptible to the effects of an antibiotic, it is said to be resistant. Some bacteria develop intrinsic resistance, either by making their cell membranes less permeable to antibiotics or by pushing antibiotics out from within their cell bodies. Other bacteria produce enzymes to fight off antibiotics. Most bacteria develop resistance, however, due to genetic mutations that occur during their reproduction. A small error in reproduction can change a bacterium’s chemical and physical makeup so drastically that previously effective antibiotics no longer work.

The increase in antibiotic resistant bacteria poses a problem for global health, as it threatens humanity’s ability to combat disease. To prevent antibiotic resistance — to ensure that some bacteria will not survive to re-infect other cells — remember to take the complete dosage of your antibiotic, just as your doctor prescribed.

Cover image: To prevent antibiotic resistance, physicians must enforce that all patients take the full course of their prescriptions. Image courtesy of Readynutirion.