3. 2. 3 - Evolutionary race between pathogens and medicines Flashcards
Why do medicines we develop to destroy pathogens quickly become ineffective?
- due to mutation, adaptation and natural selection of pathogens
- pathogens are in an evolutionary race against us and medicine we create to treat the disease they cause
Pathogens = disease causing organism
What does it mean for a bacteria to become resistant?
The bacteria will not be affected by an antibiotic
What is the evolutionary race between medicine and pathogens?
- penicillin was discovered to treat bacterial pathogens
- penicillin didn’t kill all types of bacteria
- many bacteria had become resistant to penicillin within a year of the medicine being prescribed
- natural selection: those bacteria became prevalent and bacterial infections were no longer affected by penicillin
- produced a new antibiotic called methicillin
- then methicillin resistant bacteria soon spread through bacterial populations
Apply GENIE to bacteria becoming resistant
Genetic variation: some bacteria in the population include mutation
Environmental change: antibiotics taken —> environment changes
Natural selection: bacteria with the resistant mutation gene are more likely to survive (better at coping with the change)
Inheritance: these bacteria reproduce causing the new generation to inherit the advantageous resistant mutation allele
Evolution: if the environment remains unchanged —> natural selection will occur over and over again —> new species evolved with all the individuals having the better adapted variation
What are the factors that contribute to antibiotics being a problem in the future?
- antibiotics are too widely prescribed and used
- people do not complete courses of antibiotics —> makes it easier for resistance to develop
- some countries —> antibiotics are widely used in the food chain
- lack of hygiene encourages the spread of antibiotic resistant organisms
How can we overcome the problems of resistance?
- reduce the use of antibiotics
- better educate people so they understand they do not always need antibiotics
- reduce the use of antibiotics in farm animals
- DNA sequencing will help to identify bacteria and find new ways of targeting them with drugs