Bacteria are becoming resistant to antibiotics. Bacteria develop resistance through mutation. A bacteria can mutate and develop resistance by;
- Having an enzyme that breaks the antibiotic down
- Having a protein which pumps antibiotic out of the cell
- Mutating the structure of the bacterium so that the antibiotic no longer works This problem is very serious. Bacteria become resistant because;
- Bacteria mutate very easily. One in every million bacteria contains a mutation. That might sound like a small amount, but consider that one E coli bacterium can reproduce to form a colony of 2 million bacteria in two hours. Over weeks, months and years that’s a lot of mutations, some of which will be beneficial
- Bacteria reproduce very quickly (they divide every 20min) so a bacterium with a beneficial mutation will spread quickly
- Bacteria have the ability to pass copies of plasmids from one to another (conjugation). So a mutation in one bacterium can quickly be copied to others, even others in different
- The use of antibiotics speeds the rise of immunity. If a bacterial population is continually exposed to antibiotic all bacteria will die. As soon as a bacterium mutates the rest of the bacteria will be killed off by the latest dose of antibiotic; now the field is open for the mutated bacterium to grow without
- Humans have been reckless with use of antibiotics. They are often given to people who don’t need them (i.e. they have viral infections) or to people who don’t bother to complete the course of