Can antibiotics cause resistance in bacteria?

Answer 1

A simple way to explain it is:

When you have an infection and take antibiotics for it, the weaker bacteria are killed first, with the stronger ones surviving, or taking longer to destroy. So when you don't take the full round of antibiotics, the stronger bacteria are the ones left in your body, and they are the ones that will continue to multiply, resulting in a bacteria resistant to the antibiotic. This is why you should always take the full prescribed course of antibiotics.

Also, when antibiotics are prescribed, the body's natural defense system (the good bacteria) are destroyed along with the bad bacteria. This is why you should always eat yogurt with active cultures or drink buttermilk while on antibiotics - the active cultures put the "good" bacteria back in the body.

Answer 2

Bacteria reproduce rapidly - a new generation can be produced every 20 minutes by binary fission .

Antibiotics are used to treat bacterial infections : an antibiotic is a chemical that kills bacteria by preventing bacterial cell wall formation .

Mutations occur during reproduction , which produces some variation in the population of bacteria .

As individual bacteria with the most favourable features are most likely to survive and reproduce :

• A mutation might occur that enables a bacterium to resist being killed by antibiotic treatment , while the rest of the population is killed when treated .
• This bacterium would survive the treatment and breed , passing on the antibiotic - resistant gene to it's offspring . Future treatment of this population of bacteria using the same antibiotic would be ineffective as antibiotic - resistant strains of bacteria are created .

Answer 3

It certainly can. A plasmid (conjugative plasmid) that has a resistance gene on it, can transfer itself to another bacterial cell (called conjugation) or assist in the transfer of a non-conjugative plasmid that has a resistance gene to another cell (called mobilization). Whichever way it happens, once the plasmid is transfered to the new cell, this cell too may show signs of resistance to the particular antibiotic. This is one of the ways of the speard of resistance amongst bacteria. Peter M

Answer 4

Random mutations can occur in the genes of a bacterium so that they are less affected by antibiotics. This means that they can multiply and pass on their immunity. Also, if a patient doesn't finish their course of antibiotics, the bacteria are more likely to become resistant to them as not all of them will be killed.

Answer 5

plasmids have antibiotic resistance gene within them which protect them from that particular antibiotic.

for example - plasmid names pBR322 has 2 antibiotic resistance gene one for Tetracyclin and other for Amphyciline. The presence of these enable them to survive in medium that has these two antibiotics.

Answer 6

Not directly, a individual bacterial cell can not suddenly develop a resistance to an antibiotic but bacteria in general can develop resistant to particular antibiotics.

The mechanism for this development of resistance is natural selection/evolution, bacteria evolve to become resistant - in the presence of antibiotics the more resistant individuals are preferentially selected (they survive) and gradually the whole population is made of resistant individuals.

This happens because bacteria reproduce so fast.

Answer 7

Yes, R plasmid carries the information for antibiotic resistance. Examle Carbenecillin-resistant gene, tetracycline-resistance gene, and chloramphenicol-resistance gene.