Overuse of antibiotics is not the only reason for organisms to develop resistance it is merely one factor. Many antibiotics work to either prevent the formation of a cell wall or block other key metabolic functions. Different classes of antibiotics will generally work on different types of bacteria.

Bacteria can gain resistance in at least two ways:

First, most antibiotics will not “kill” or prevent the growth of all its’ intended targets. Bacteria will have range of susceptibility. The goal is to reduce the numbers substantially so that the body’s’ own defenses can kill the remaining organisms. The remaining organisms, which either had greater resistance (genetic or mechanism development) or may have been in parts of the body in which the antibiotic was sub-therapeutic, survive. These bacteria multiply, with future generations, which have developed genetic resistance or develop mechanism to increase their chances of survival (slime, adherence factors).

The other way is for one type of bacteria, which has a natural resistance to a certain class of antibiotic, becoming infected with a bacterial phage (a virus that infects bacteria). The bacterial phage “latches” on the genetic material responsible for resistance to a particular class of antibiotics and infects the bacteria without that natural resistance and imparts the newly acquired genetic resistance factor to the new bacterial host. Subsequent generations of these altered bacteria will now also possess the antibiotic resistance.


Sorry if this is confusing or unclear, it is a lot easer to explain then to write.

Pete

Not hard to understand at all and I know that antibiotics are only part of the story. I wasn't suggesting otherwise. Even without antibiotics, some natural selection could render a group of pathogens completely resistant to a particular type of medication spontaneously (without ever having encountered it), although it's much more likely to happen non-spontaneously. <img src="/images/graemlins/smile.gif" alt="" />

I believe that, current research is looking into viral antibiotics meant to target very specific bacteria. Nanotech aims to do the same thing by affixing themselves either chemically or physically to bacterial receptors. The magic bullets may not be a theory too long...

Sorry if I gave the impression I was responding to your post specifically. It just happened to be the next in line.

The idea of directed or targeted drug delivery is very hot right now. We have an entire nanotechnology group looking at both treatment and detection, everything from infectious agents to cancerous cells. Although, I will reserve judgment for now as to their ultimate use or usefulness in clinical applications. I can remember when immuno-modulators like interleukins were going to be the magic bullet-cure all and while it is true, many have been useful; they still have their limitations.

Pete

No problem Pete... And your information was sound and obviously from an experienced professional.

I agree, genetic and nanotech are being looked at most carefully, and at some point their therapies will be integrated, but it's going to take time, lives, and money, and even then they may not be the miracles we are looking for. Every time a new whiz bang product comes out, we realize just how complex biology can be. <img src="/images/graemlins/smile.gif" alt="" />

Coastie,
I'm new here, but the wife came through for me when we discussed putting together our kit's......she had gone out on some errands, and on her way stopped at several Thrift Stores, (Salvation Army/Goodwill), types.
Next thing I know she's honking the horn, and I'm carrying in a large selection of Tin's in all manner of shapes and sizes! And all for less than a Dollar apiece!
Hope this help's some!

Krell

There is one other factor: Sex (in a way).

Bacteria can exchange genetic material with neighboring cells, often even across species lines. Can be proven like this:

Put, let's say, a strain of streptococcus on a growth medium. Let this strain be resistant to penicilin. Add another, radically different, bacterium (or even something that blurs the lines, like Anthrax).

After a few days, add large amounts of penicillin, wait 15 minutes, and examine under a microscope. You will find d lot of dead bacteria of the second species, but still, a large portion (sometimes nearly all of them) will have survived, which means they had a resistance against Penicillin, the only source of which were the streptococcus' genes.

Voila, bacterial sex <img src="/images/graemlins/wink.gif" alt="" />

Not quite, bacteria reproduce through binary fission, one cell becoming two and so forth. In general bacteria themselves are not able to naturally take on the genetic material of other bacterial organisms, since they do not recombine for reproduction. Where genetic material from one type of bacteria is introduced into another, is through bacterial phages, viruses that infect bacteria. Viruses reproduce by hijacking the host internal machinery; this includes reproduction of its genetic material as well as proteins for the construction of the various structural elements of the new virus. The virus then is either “shed”/released from the host cell’s membrane/cell wall or is released when the cell is lysed/”blown up”. The bacterial phage/virus can and does incorporate genetic material from the host cell (i.e. antibiotic resistance, pathogenic factors, etc.) and then passes it along to the next bacteria it infects.

Pete

Quote:
Do bacteria indulge in sex?: Bacteria don&#8217;t have sex in the traditional sense of the term. They multiply asexually. However, they can reproduce sexually using a technique known as plasmid (rings of DNA) migration. They wander around, bump into each other and &#8220;talk&#8221; to each other as to whether they want each other&#8217;s genetic material. With mutual consent plasmid(s) are exchanged through the cell membrane. Usually, this is done for survival to fight antibiotics and other toxins that are detrimental to them. Vegetative bacteria unite by a conjugation bridge through which all or part of a male genome migrates into the female cell. The gametic cells then separate. The ex-conjugant male goes on to multiply unaltered, surviving by virtue of its remaining DNA. The ex-conjugant female generates a mixed clone, some its own original copy (unaltered) and others modified slightly by virtue of the conjugal event, but still all are immortal.

from: http://www.chennaionline.com/science/BiotechCorner/14biotech.asp

You are absolutely correct that plasmid transfer is a major method of genetic material transfer in bacteria. I still object to the use of "sex" to describe the process, although I can see how one, in describing the process would use the term familiar to many readers. You may also want to check these web sites:

Bacterophages

Bacteria

Bacteria

Pete

A Wise Man said, the only stupid question, is the one that is not asked.......so here goes.......I have heard of using Tampon's for Tinder, but I also heard a reference earlier, as to using them in the FA Kit......can someone tell me Why?

Krell