Naked Science Forum

Life Sciences => Physiology & Medicine => Topic started by: artistic on 05/08/2006 06:34:21

Title: Penicillium and Penicillin
Post by: artistic on 05/08/2006 06:34:21
Help! Need help on project on Penicillium and Penicillin! WOuld appreciate it!

•What is Penicillium
•Where can you find it(Both)
•What is Penicillin
•How was this substamce discovered
•Other relevant info

Thx!
Title: Re: Penicillium and Penicillin
Post by: Mjhavok on 05/08/2006 08:47:10
Penicillium is a fungus commonly known as bread mold.
Penicillin or Penicillins are antibiotics that I think are produced by the fungus.
The discovery of it is down in history as Alexander Fleming although I think some others noted the antibacterial effects of it.
Alot of bacteria are now resistant to penicillin and its derivatives. MRSA etc.
Title: Re: Penicillium and Penicillin
Post by: iko on 05/08/2006 13:56:25
In 1928 Alexander Fleming discovered accidentally that a mould (Penicillium notatum) contaminating left over cultures of bacteria was actually inhibiting bacterial growth. He got published his observation in a scientific journal and almost forgot about it.
Later on two pathologists in London, Florey and Chain, managed after months of hard work and no money (IIWorld War 1939)to grow a little amount of penicillium using large culture containers (fermentators).  Purified penicillin could cure lethal bacterial infection in mice/rats.
Those basic experiments led to further development of penicillin producing techniques and to extraordinary results in human bacterial infections.
After several years the scientist and the two pathologists got the Nobel Prize for Medicine.

http://www.molbio.princeton.edu/courses/mb427/2001/projects/02/antibiotics.htm

PostScriptum: but only A.Fleming will be remembered in History.
(When you find something, publish first...and forget about the rest of the hard work!)
Title: Re: Penicillium and Penicillin
Post by: another_someone on 11/08/2006 00:40:25
Since the mould, and thus the actual antibacterial chemical, is a long established natural product and not something totally artificial – why then is resistance to it so new – or is it?  Has penicillin resistance always been there, just we haven't noticed it until recently?



George
Title: Re: Penicillium and Penicillin
Post by: iko on 11/08/2006 08:26:13
Antibiotic resistance in bacteria develops by spontaneous mutations and natural selection.
Furthermore some bacteria have the amazing capability to exchange informations (DNA) with other bugs, including antibiotic resistance genes...naughty beasts!
I'll look for some picture for you in the big www.basket, hold on.
iko

www.paratekpharm.com

That's a website, you have to find AB resistance+pictures yourself
(Damn...I couldn't manage to copy just a picture into the message!)
Title: Re: Penicillium and Penicillin
Post by: iko on 11/08/2006 09:51:19
Yes, penicillin has always been produced by that mould to keep the other bugs away, but resistence developed after we purified it and challanged with billions of bacteria in thousands of humans. Bacteria living in humans did not have many chances to meet penicillin before.
Did I get your point correctly?
And it works the same way with all the other antibiotics.
iko
Title: Re: Penicillium and Penicillin
Post by: another_someone on 11/08/2006 12:45:16
quote:
Originally posted by iko

Yes, penicillin has always been produced by that mould to keep the other bugs away, but resistence developed after we purified it and challanged with billions of bacteria in thousands of humans. Bacteria living in humans did not have many chances to meet penicillin before.
Did I get your point correctly?
And it works the same way with all the other antibiotics.
iko



To an extent, yes; but many disease causing bacteria are either generally around in the environment, or at least common in the environment of the mouth, throat, and intestines; and in each of these cases, they must have at least occasionally been in contact with bread mould in the past.

Diseases that are purely blood born (e.g. the bacteria that causes bubonic plague), may well not have had much past exposure the bread mould, then I don't hear very much about  bubonic plague developing penicillin resistance.  MRSA (the most commonly heard of disease that is developing antibacterial resistance) is caused by a bacteria that lives on the human skin, and so would easily have infrequent natural contact with bread mould.



George
Title: Re: Penicillium and Penicillin
Post by: Mjhavok on 11/08/2006 13:07:55
Y. pestis (the bacterium responsible for the bubonic plague) is highly susceptible to several antibiotics, mainly streptomycin and chloramphenicol. Second-tier aetiotropic drugs include tetracycline-group preparations; the latter are often used together with streptomycin due to synergistic effects.

It should be noted that strains resistant to one or two agents specified above have been isolated.

Bacteria replicate fast and in no time there are millions and then billions of them. This means that they have a greater chance of developing some form of restistant to a certain antibiotic because of mutations in replication. I think resistance to penicillin was noticed in the 1960s. Unsure though.

Steven
Title: Re: Penicillium and Penicillin
Post by: iko on 11/08/2006 15:03:20
quote:
MRSA (the most commonly heard of disease that is developing antibacterial resistance) is caused by a bacteria that lives on the human skin, and so would easily have infrequent natural contact with bread mould.


Antibiotic Resistant bacteria are "created" by mutations/selection on skin, gut and respiratory tract of patients that have to take antibiotics for a long time to survive their ailments.
It is not surprising that the most dangerous bugs are found in hospitals.
bye
iko
Title: Re: Penicillium and Penicillin
Post by: iko on 12/08/2006 08:30:46
Our "artistic" young fellow disappeared in a cloud of dust.
Can these few data satisfy his curiosity and complete his project?
- What is the mechanism of action of penicillin?
- What is the mechanism of bacterial resistance to p.?
- How to counteract resistance?
- How toxic is penicillin compared to other antibiotics?
iko
Title: Re: Penicillium and Penicillin
Post by: artistic on 12/08/2006 17:48:09
Thanks alot guys anyways I didn't need it so complex but thx alot!