PLAGUE TODAY

6.2. PENICILLIN AND ANTIBIOTICS

THE PLAGUE IN CATALONIA

DESCRIPTION OF THE SYMPTOMS

HOW INFECTION OCCURS

INFECTION ROUTES

THE MICROSCOPE

MICROBES: BACTERIA

THE MARCH OF THE PLAGUE

MEDICINE IN THE MIDDLE AGES

MICROBIAL MEDICINE

THE SCIENTIFIC METHOD

FROM MAGIC TO MEDICINE


ANTIBIOTICS: MAGIC BULLETS

What are antibiotics? Antibiotics are any natural substances secreted by one microorganism to attack other microorganisms. An antibiotic is a chemical substance produced by microorganisms that has the capacity to stop the growth of bacteria and even destroy bacteria and other microorganisms . Antibiotics are chemicals that kill bacteria but not human cells. That is why they are called magic bullets. Bacterial microorganisms produce the antibiotics we take. Although many antibiotics are chemically synthesized today, antibiotic substances are still being harvested from microorganisms.
The significance of antibiotics is immeasurable considering their effectiveness against harmful bacteria.

ALEXANDER FLEMING AND PENICILLIN
In 1928 Alexander Fleming was examining a plate on which he was trying to grow Staphylococci. Fleming was a disorderly bacteriologist who left his cultures on the laboratory for weeks and had the habit of working with the window open. He observed a contaminant, a green mould, growing on the plate and all round the mould the colonies of Staphylococci had dissolved:
· The mould could be producing a toxic chemical.
· The mould could be producing a digestive substance.
The mould was called Penicillium notatum.
The substance it was producing was called penicillin.

HOW DO ANTIBIOTICS WORK?
Because bacteria are life forms, they do many chemical processes to stay alive. They must create their structural elements, digest and assimilate nutrients, replicate themselves as they multiply and protect themselves from hostile elements in their environment. Antibiotics obstruct these processes. Some can kill bacteria by interrupting a vital process; others slow them down or stop them from multiplying until your body's immune system can kill them. Each class of antibiotic -- penicillins, cephalosporins, and tetracyclines -- attacks a specific bacterial process. In turn, bacteria develop the ability to disable each class of antibiotic, usually by producing a chemical that inactivates it.

ANTIBIOTIC RESISTANCE
The first patient treated with penicillin was in 1941 thirteen years after Fleming discovery. The substance was produced from a living organism - it was hard to grow. Fleming was not a biochemist and the substance was very hard to purify. In 1943 penicillin was tried in a British war hospital in North Africa. It was in desperately short quantity. The urine from patients was collected and the penicillin extracted so that more people could be treated.
For decades, people across the Earth have conquered diseases with antibiotics. From World War II to the everyday battle against bacterial infections antibiotics have been used for their magic.
For years, doctors have been prescribing antibiotics as a cure for bacterial infections. As antibiotic use has increased, so has bacterial resistance to common antibiotics. Bacteria become antibiotic-resistant by mutating. If bacteria become resistant to antibiotics, what can we use to stop bacteria? Bacterial infections will be untreatable.