Antibiotics: How They Work, Antibiotic Resistance

Edited by Jamie (ScienceAid Editor), XanthousOfTheThirdQuadrant, Jen Moreau

How Antibiotics Work

Antibiotics work by being either bactericidal where they kill microorganisms; or by being bacteriostatic where they inhibit the growth of the microorganisms.

An example of a bactericidal antibiotic is Penicillin. This works by preventing the production of a substance that form the cell wall: peptidoglycan. This means the cell will continue to grow without dividing or developing new cell wall. Therefore, the wall gets weaker, and eventually ruptures (lysis).

Was this helpful? Yes | No | I need help

The action of Penicillin on bacterial cells

Other antibiotics work by inhibiting the protein synthesis or nucleic acid synthesis. Tetracycline is a bacteriostatic antibiotic that binds to ribosomes in bacteria, this means the cell cannot make proteins and therefore can't grow.

Was this helpful? Yes | No | I need help

When choosing antibiotics to treat diseases, it is important to think carefully. For instance, bacteria have a different type of ribosome (70S) to humans (80S), therefore they will only work to target the bacteria and not affect the patient.

Was this helpful? Yes | No | I need help

Narrow spectrum antibiotics target specific reaction in particular microorganisms; whereas broad spectrum antibiotics will have an effect on more general features so affect a wide range of pathogens.

Antibiotic Resistance

Antibiotic resistance arises as a result of natural selection. Since bacteria reproduce rapidly, resistance can arise quickly. Those antibiotics resistant will remain after treatment and can continue to divide.

Was this helpful? Yes | No | I need help

An example of antibiotic resistance can be seen with Penicillin, some bacteria can produce an enzyme called Penicillinase which breaks down Penicillin before it can take effect.

Other mechanisms of resistance include the evolution of a capsule that is resistant to antibiotic, and cell membranes becoming less permeable to antibiotic.

Bacteria can spread resistance genes between each other by bacterial conjugation where two cells join by their pilli and exchange plasmids which often contain genes for antibiotic resistance.

diagram of bacteria conjugation and exchange of plasmid via the Pillus

Antibiotic resistance is made much worse by the overuse of antibiotics in medical treatment. Some bacteria are resistant to most antibiotics (MRSA or mycobacterium-tuberculosis) meaning it is increasingly difficult to treat infection unless new antibiotics are developed.

Was this helpful? Yes | No | I need help

Questions and Answers

Do you know any good pubs in Rayleigh where I can get a pint and some food for under thiry quid?

I'm going there soon to meet up with some bloke and I just wondered if there was anywhere I could get a good pint and maybe a pie for a good price. The article is about antibiotics and not Essex pubs. I have tried: I haven't done anything, I just came on here and thought I might as well ask since you offered. I came here to read about antibiotics but I never decline the opportunity for help. I think it was caused by: I don't know the Rayleigh area well as I have only been a few times before and I am unable to go there myself at this moment.

Was this helpful? Yes | No | I need help

ScienceAid QnA. This section is not written yet. Want to join in? Click EDIT to write this answer.

Comments

ScienceAid welcomes all comments. If you do not want to be anonymous, register or log in. It is free.




Jamie
Featured Author
166 Articles Started
1,271 Article Edits
43,065 Points
Jamie is a featured author with ScienceAid. Jamie has achieved the level of "Captain" with 43,065 points. Jamie has started 166 articles (including this one) and has also made 1,271 article edits. 43,400 people have read Jamie's article contributions.
Jamie's Message Board
Jamie: Hi, my name is Jamie.
Jamie: Can I help you with your problem about "Antibiotics: How They Work, Antibiotic Resistance"?
 

Article Info

Categories : Micro

Recent edits by: XanthousOfTheThirdQuadrant, Jamie (ScienceAid Editor)

Share this Article:

Thanks to all authors for creating a page that has been read 992 times.

Do you have a question not answered in this article?
Click here to ask one of the writers of this article
x

Thank Our Volunteer Authors.

Would you like to give back to the community by fixing a spelling mistake? Yes | No