An individual bacterium exposed to an antibiotic may develop a resistance to that antibiotic?

Question

I believe this is true but my friend says I am not.

Answer 1

Yep, But Very Unlikely, By Mutation.

Answer 2

no generally. What happens is taht in a colony of several million bacteria, which have slightly different genes (like humans) there may be one which by chance has a gene allwoing resistance to an antibiotic. Apply the antibiotic: all bugs die except the one with the gene, 20 mins later he divides; 20 minutes later these two divide; 20 mins later these 4 divide: within a day you have a million bacteria again: all of whom are resistant. That's how it workd generally. However you are theoretically correct: a bacterium could gain a plasmid (a ring of gene injected by another bacterium) and that palsmid could have the resistant gene on it. But this is practically most unlikely. So practically you are wrong: theoretically you are right.

Answer 3

Hey, I like that you're curious, and you're not just saying "Do my homework for me!" or "write this paragraph for my lab report for me!"

Generally, it's more the case that within a population there is variation. Take for instance resistance to novobiocin. Point mutations (changes in a single nucleotide) in a gene called gyrB at the right location confers resistance to this antibiotic. There are actually a couple locations in most bacteria that will do this. Point mutations happen like this all the time, at a certain basal rate. So within a population of cells, there may be one or two that have this mutation. Without novobiocin present, this actually slows them down - and in bacteria, speed of replication is everything. So they're selected against, but constantly re-arising at a low rate. Toss in some novobiocin and suddenly the balance switches - they can survive, while the rest cannot.

HOWEVER, there is some neat 'new' (uh... last decade, five years-ish?) research showing that when exposed to low concentrations (sub-lethal) of some antibiotics (perhaps many), an alternate polymerase is used that is not quite so fastidious about accurate copying of DNA sequence during replication. In plain english, it makes more mistakes - this means a higher mutation rate. Which means a higher chance of many things - cell death being one, but also resistance to that antibiotic will also increase in likelihood. Kinda close to the concept of directed mutations, but subtly different.

so ... you're right. Kind of. In order for this resistance to occur, replication of DNA must happen. Which means you're no longer talking about a single bacterium. You're talking about the 'offspring' of that bacterium. So. Your buddy is right. Sort of.

Answer 4

The statement is false.

An individual bacterium has the genes it has, and it won't change its genes to be able to resist an antibiotic. Either the bacterium can stand the antibiotic or it can't. One way or the other.

Answer 5

No, it's usually a single or select group of bacteria that are not affected by the antibiotic through random genetic mutations in the DNA. However, the antibiotic kills off the "normal" bacteria and the remaining "mutants" divide & flourish, all with the ability to withstand that particular antibiotic.

Answer 6

No. Individuals do not develop resistance. Resistance is caused by mutations in the bacterium's DNA. They don't develop resistance, they are "born" with it. However since bacteria pretty much clone themselves with asexual reproduction, all the resistant bacterium's "children" will also be resistant.

Answer 7

i think it's more, if a lot are exposed, there is one that is "resistant" but the resistant isn't necessarily helpful (except for when exposed to the antibiotic) many times it's more like a person born without arms walking into a place where everyone is handcuffed an dragged off to die- they live, because they can't be handcuffed, but it isn't really helpful... but yeah, it's a genetic trait, not an acquired trait, that's how all of a type of bacteria become resistant- you can't pass on acquired traits.

Answer 8

A population of variant bacteria exposed to a antibiotic will have some varieties survive the onslaught, thus fissioning into the next generation of resistant bacteria.

Answer 9

Ya know, if you want to become a biologist, you're going to have to study. You can't just ask a bunch of Yahoos all the time.

Answer 10

Unlikely, but possible, it is dependent on the sai tenet of the mycondrial; DNA which can be extracted.