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B6 M) Antibiotic Resistant Bacteria
B6 M) Antibiotic Resistant Bacteria
We looked at natural selection in an earlier section and I am just going to quickly rego over what natural selection is. Natural selection is where a mutation in the genetic information of an organism leads to variation in the population. Any advantageous mutation means that the organism is more suited to their environment and are therefore more likely to survive. If they are more likely to survive, they are more likely to reproduce and pass these advantageous genes/ characteristics onto future generations – this will result in these characteristics becoming more prolific (common) in the species. Any disadvantageous mutation means that an organism is less suited to their environment and are therefore less likely to survive. If they are less likely to survive, they are less likely to reproduce and pass these disadvantageous genes/ characteristics onto future generations – this will result in these characteristics becoming less prolific (common) in the species.
We are now going to have a look at how antibiotic resistant strains of bacteria come about. Antibiotics are drugs that either kill bacteria or inhibit the growth of bacteria. Bacteria evolve (change) very quickly because they reproduce at a fast rate; in ideal conditions, bacteria will double/ multiply every 20 minutes.
An antibiotic resistant strain of the bacteria comes about due to a random mutation in the DNA of the bacteria that makes the bacteria resistant to antibiotics. As this new strain of bacteria is resistant to antibiotics, it won’t be killed by the antibiotics and is therefore more likely to survive and reproduce, which passes the antibiotic resistant gene onto future generations. This results in more of the bacteria in the population being antibiotic resistant. The antibiotic resistant strain of the bacteria spreads easily through individuals as people are not immune to the new strain of the bacteria and there is no effective treatment (we cannot treat infected individuals with antibiotics because the strain is resistant to antibiotics). Antibiotic resistant bacteria are becoming more common and they are sometimes referred to as superbugs. An example of a superbug is MRSA – MRSA often spreads in hospitals and it can be fatal if an individual becomes infected with it.
We are now going to have a look at how antibiotic resistant strains of bacteria come about. Antibiotics are drugs that either kill bacteria or inhibit the growth of bacteria. Bacteria evolve (change) very quickly because they reproduce at a fast rate; in ideal conditions, bacteria will double/ multiply every 20 minutes.
An antibiotic resistant strain of the bacteria comes about due to a random mutation in the DNA of the bacteria that makes the bacteria resistant to antibiotics. As this new strain of bacteria is resistant to antibiotics, it won’t be killed by the antibiotics and is therefore more likely to survive and reproduce, which passes the antibiotic resistant gene onto future generations. This results in more of the bacteria in the population being antibiotic resistant. The antibiotic resistant strain of the bacteria spreads easily through individuals as people are not immune to the new strain of the bacteria and there is no effective treatment (we cannot treat infected individuals with antibiotics because the strain is resistant to antibiotics). Antibiotic resistant bacteria are becoming more common and they are sometimes referred to as superbugs. An example of a superbug is MRSA – MRSA often spreads in hospitals and it can be fatal if an individual becomes infected with it.
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Reducing the Development of Antibiotic Strains of Bacteria
More types of bacteria are becoming resistant to antibiotics, which is increasing the threat posed by antibiotic resistant bacteria. The increase in antibiotic resistant strains of bacteria can be attributed to the overprescribing and inappropriate use of antibiotics. This happens when doctors prescribe antibiotics for bacterial infections that would have cleared up without antibiotics or when doctors prescribe antibiotics for infections that antibiotics wouldn’t treat (antibiotics are only effective on bacterial infections – this means that it would be inappropriate to prescribe antibiotics for viral infections).
Drug companies can come up with new antibiotics that aim to kill these antibiotic resistant strains of bacteria. However, the development of new antibiotics is extremely expensive and slow as many tests and clinical trials need to take place. This means that the rate of increase in the number of new antibiotic resistant strains of bacteria will be faster than the rate of development of new antibiotics, which is quite worrying. Therefore, in addition to developing new antibiotics, we should also try to reduce new antibiotic resistant strains of bacteria developing in the first place. We can reduce the development of new antibiotic resistant strains of bacteria by doing the following:
More types of bacteria are becoming resistant to antibiotics, which is increasing the threat posed by antibiotic resistant bacteria. The increase in antibiotic resistant strains of bacteria can be attributed to the overprescribing and inappropriate use of antibiotics. This happens when doctors prescribe antibiotics for bacterial infections that would have cleared up without antibiotics or when doctors prescribe antibiotics for infections that antibiotics wouldn’t treat (antibiotics are only effective on bacterial infections – this means that it would be inappropriate to prescribe antibiotics for viral infections).
Drug companies can come up with new antibiotics that aim to kill these antibiotic resistant strains of bacteria. However, the development of new antibiotics is extremely expensive and slow as many tests and clinical trials need to take place. This means that the rate of increase in the number of new antibiotic resistant strains of bacteria will be faster than the rate of development of new antibiotics, which is quite worrying. Therefore, in addition to developing new antibiotics, we should also try to reduce new antibiotic resistant strains of bacteria developing in the first place. We can reduce the development of new antibiotic resistant strains of bacteria by doing the following:
- Doctors should not prescribe antibiotics inappropriately. You are only prescribed antibiotics in the UK if you really need them and overtime the NHS is trying to reduce the number of antibiotics that are prescribed. It is worth pointing out that the prescribing of antibiotics does not cause the bacteria to become resistant to antibiotics. Instead the presence of antibiotics creates a situation where antibiotic resistant strains of bacteria have a survival advantage, so reproduce and their numbers increase.
- Ensuring that patients take their full course of antibiotics even if they are tempted to stop taking them early because they are feeling better. By taking the whole course of antibiotics, we are ensuring that all of the bacteria are killed, and none survive to mutate and create antibiotic resistant strains.
- Reducing the number of antibiotics being given to farm animals. Currently, many farmers give their animals antibiotics to prevent them from becoming ill and for them to grow faster. This can lead to antibiotic resistant strains of bacteria developing in animals for the same reasons that have been discussed earlier. Some of these antibiotic resistant bacteria will be human pathogens, which means that they could spread to humans when we either prepare the food from the animals or when we consume them (meat and milk). Also, the antibiotics that the farm animals take will be excreted, which passes into the environment through faeces, urine and sewage. This can result in bacteria in water and land becoming resistant to antibiotics. Some of the antibiotic resistant strains of bacteria can then be passed onto humans. Some governments have passed laws that restrict the use of antibiotics in farming.
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