Explain how antibiotic resistant bacteria can evolve.

Question

Explain how antibiotic resistant bacteria can evolve.

Answer 1

Antibiotics are often used improperly and is one of the causes of antibiotic resistant bacteria.  

Many people stop taking their prescribed antibiotics once they start feeling better.  It doesn't hurt the individual patient because their bacteria level has been reduced to a level that their body can tolerate etc.  What does happen is that the strongest of the bacteria are the ones that have survived and when they reproduce they pass this strength on to the next generation.   These bacteria infect someone else and if antibiotics are used improperly (not taking the full course) the same thing happens.  As this pattern continues, eventually the strongest of the strong bacteria are resistant to the antibiotic being used and something stronger needs to be used... and the cycle continues.

It is natural selection in action.

Edited to add:

Here is some good reading on a complex subject

http://textbookofbacteriology.net/resant...

Answer 2

Start with a colony of bacteria. In some individuals of the population, a mutation occurred that made those particular bacteria resistant to an antibiotic. When antibiotics are added to the bacteria's environment, the bacteria with the non-mutated gene will die, but the bacteria with the mutant gene will survive. This is a huge selective advantage - the individuals with the mutated gene will likely be the ones that reproduce successfully and increase in number within the population.

This fits all the criteria of natural selection. Was there a variation within individuals of a population? Yes, the mutated gene. Were some variations inherited by the offspring? Yes, the individuals with the mutated gene passed on that trait to their offspring. Were some individuals able to survive and reproduce better than other individuals? Yes, the non-mutated bacteria died while the mutated individuals survived. Was the differential survival and reproduction (Darwinian fitness) influenced by the heritable traits of individuals? Yes, since the non-mutated bacteria couldn't survive, their numbers in the population dropped while the mutated bacteria increased.

Putting it all together, the nature of the bacterial population as a whole will gradually change. What is evolution? The genetically based change in a population's traits over time. Did the bacterial population evolve? Yes.

Answer 3

Bacteria works under the idea that only the strong survive. In today's World, we're overrun by antibacterial soap, body wash, kitchen and bathroom cleaner, hand sanitizer, etc. All these things kill bacteria, yes, but the bacteria always comes back in larger, more powerful, more dangerous strength,which explains how it not only has evolved, but is evolving in a more alarming strength. Things LIke MRSA which is a strain of staph which is completely resistant to medicine, and results in the flesh literally rotting off the bone eventually resulting in death is what comes from this. I never use antibacterial anything if I can avoid it. Your body has it's own defenses made especially for warding off disease, without the help of antibacterial products.

Answer 4

Antibiotic Resistance evolves naturally because of natural selection through a random mutation. It becomes resistant to antibiotics-when an antibiotic is given some of the bacteria is killed but some still remains and this adapts to its environment and carries on flourishing