Actually, the over-use of anti-biotics has had a lot to do with anti-biotic resistent strains comming about. Given the rate at which bacterial cells can multiply and also how easy it is for them to mutate (there are certain "checks" in place in DNA replication in eukariotic cells, which doesn't take place in prokariotic gene replication) they are able to evolve more quickly. But the "aim" is towards survival, and the over-use of anti-biotics/improper use can result in them developing resistence.
A few matters to consider:
- Antibiotics work by hindering some biological process which is necessary to the continued survival of a bacterial cell. Viruses are not technically alive, and carry out no biological processes on their own, to be hindered. Viruses are essentially a strand of DNA, or RNA (with reverse transcriptionase) in the case of a retro-virus, which is surrounded by a protein coat. There is no cell membrane, no organelles, no matabolism, or other cell machinery involved in it's "survival". The protein coat, has a given recognition site, which can attach itself to a given site (a sort of 3-dimention "lock and key" sorta mechanism, where it "fits into" the right recognition site in a cell. There it can transfer it's DNA into the cell, and after inserting it's DNA, take the cell over, re-directing it's life processes to the creation of more viruses.
There's an important thing here, as anti-biotics do absolutely nothing in fighting off a viral infection, but can only fight off bacterial infections. Doctors are also more careful now, in prescribing anti-biotics.
- When people are prescribed a course of anti-biotics, but stop taking it when they start to feel better, it has only managed to kill off the the less resistent microbes first. To stop taking it pre-maturely is to allow the stronger microbes to re-produce and come back, with a strain that is more resistent. Reason they tell people to complete the dose, even if they do feel better in a few days (which if it's working as it should, they will). Feeling better in this case, doesn't mean all the disease causing bacteria are gone yet, however...
- Having a low dose of anti-biotics in our milk and what not is not exactly a good thing...
- One final matter. All microbes are not bad. Though some cause disease, there is also a certain amount of healthy intestinal floura in our gut, which we have formed a symbiotic relationship with. Antibiotics kill off all bacteria indiscriminitely, including the healthy bacteria in our gut.
Some of the things this intestinal floura does for us:
* Helps with digestion. For instance in the digestion of lactose (milk sugar), our bodies don't directly digest it, itself. The intestinal floura (lacto-bacilli organisms specifically) break the milk sugar down into something our bodies can use...
* Produces vitamin K, which is very much involved in our blood clotting ability, when we get cut. We don't need to necessarily supplement vitamin K in our diets however, because the healthy bacteria in our gut produce it for us.
* Gives us another layer of immunity. The healthy bacteria is able to deal with some of the disease killing bacteria/help kill it off for us. And unlike the anti-biotics we can injest, the bacteria in our gut is also capable of evolving "a new form of attack" if you will...
When one needs antibiotics for something, it isn't always a bad idea to follow the taking of anti-biotics with some aciphodopholis or something (one can get it by eating yogurt as well) to help replenish the "good type" of bacteria that resides in our gut, but not at the same time...
