[Medical Q&A] Why do bacteria become resistant to antibiotics?

Planner: Chinese Medical Association

Reviewer: Zhao Jie, Chief Pharmacist Professor of the First Affiliated Hospital of Zhengzhou University

Bacterial resistance to antibiotics is a complex biological phenomenon involving multiple mechanisms.

Some bacteria can change the molecular structure of antibiotics, making the drugs inactive; some bacteria learn how to excrete antibiotics from the body, so that the antibiotics cannot reach an effective concentration inside the bacteria and cannot work; some bacteria can change some of their own structures, so that the antibiotics cannot work according to the original attack method. After exposure to antibiotics, sometimes one of the bacteria can survive because it has acquired a suitable way to resist antibiotics, so it begins to multiply and replace other killed bacteria, thus becoming the dominant population, which means that exposure to antibiotics forces bacteria to upgrade and evolve, making each surviving bacteria more likely to be resistant. What's more serious is that this resistance can sometimes spread between bacteria, allowing other bacteria to acquire this ability. Every time an antibiotic is taken, sensitive bacteria (bacteria that antibiotics can still attack) will be killed, but resistant bacteria will survive and grow and reproduce. If antibiotics are abused, resistant bacteria can develop. This is why repeated use of antibiotics increases the number of resistant bacteria. Resistant bacteria can cause diseases that were once treatable with antibiotics to become untreatable, and resistant bacteria are usually more difficult to eliminate. Only the rational use of antibiotics is the key to controlling the spread of bacterial resistance. Therefore, antibiotics should be used correctly under the guidance of a doctor, and the whole society should work together to create a good atmosphere of caring, supporting and participating in the rational use of antibiotics.