Why are bacteries becoming resistant to antibiotics?

Question

Explain the process please. Not just that they`re becoming more used to the antibiotics.

Answer 1

I have just had two lectures on this exact topic. I assume you want biochemical process of resistance.

Before i can explain how they can become resistant, you need to know how antibiotics kill bacteria. Firstly the antibiotic ( Ab) needs to gain entry into the cell, the it needs to find its target, bind to it, then interfer with the target function. The target is usually the cell wall, the ribosome, nucleic acid synthesis and folate acid synthesis. Therefore there are several ways in which bacteria can become resistant.

The bacteria can stop the Ab entering the cell in the first place: gram negative cells have an extra layer around their cell wall which makes penetration harder. Also the Mycobacterium have a mycolic acid wall which is very waxy and near immposible to penetrate.

The bacteria can pump the drug out of the cell before it finds its targer.

The bacteria can change the Ab structure so it doesn't work: Some bacteria now produce kinase enzymes to alter the shape of streptogrammin Ab.

Finally the bacteria can change the target of the Ab.

The all of these can come about due to random mutations, the last one being by far the easiest for the bacteria to accomplish as a single point mutation can change the binding site of the Ab without affecting function.

I hope this goes someway to answer your question. If you like more detail feel free to e-mail me.

For the record, the nurse seems to think antibiotics can attack viruses - they can't.

Answer 2

Up until recently (like 20 years) doctors didn't always prescribed antibiotics to treat a person everytime she or he had symtoms that would warrent antibiotics. A lot of doctors would want the person to "sweat" it out or wait a couple of days to see how the symptoms were. Now, fast forward and people WANT antibiotics for everything from the common cold to ear aches. Antibiotics are widely used for everything listed and then some in some offices. Doctors that do not want to prescribe antibiotics make patients mad and they find ones that do. Thus that brings us to the viscious circle of creating the antibiotic resistant super viruses that can not be cured with anything and that in itself can and in most cases causes MRSA and that is even harder to cure because there isn't a antibiotic out there that can cure MRSA and its contagious. It isn't that our bodies are used to antibiotics, its viruses are more resistant because antibiotics are now a part of the virus.

Hope that helps!

Answer 3

Segregation.

All populations are destined to segregate , ( i.e differentiate) It starts by individuals being not exactly the same. And , selective forces may throw one way or the other ,, and the species "spread" (mechanical scatter?) allows some individuals to escape.

Scatter

Our immune system is only 10% accurate. This mathematical "scatter" allows it to cover the limits (max & min) of the pathogen's distribution. (Meaning that , pathogens like us ,, have individual differences.) The 90% " misses" makes sure that everything that looks nearly alike is collected __wholesale.

Plasmids

E. coli (gut bacteria) especially has been documented to plasmidise ,, wherein the "plasmids" seem to propose ways to survive the antibiotic on-slaught. Plasmids looks like viruses and are air-bourne and are infectious.
The plasmids infect the next generation of E. coli , but this " infection" makes it more prepared to survive the on-slaught.

Answer 4

Evolution.

The strong unaffected ones survive & breed, and the resulting ones inherit the resistance.

Survival of the fittest.

Answer 5

because of the abuse of antibiotics, bacteria are undergoing genetic mutation to develop new strains that are resistant to these antiobiotics.