ANTIBIOTICS

Ten Candidates for Eradication

At the time of the American Civil War, 80 of 100 patients died after coming to a hospital for amputations, mostly from infections.

What the heck is an Antibiotic ?

Through a combination of skill and luck Alexander Fleming discovered penicillin which changed the world. He noticed that mold growing on some cultures that were left standing killed the bacteria around them.

Penicillin works by inactivating the enzyme that the bacteria use to make their cell walls. With holes in their cell walls the bacteria swell and lyse as they grow. (recall the egg demo) from cells alive

the structure of penicillin resembles that of the peptide that the bacteria need to crosslink to form their cell walls.

Creating leaks in a cell's membrane is another way of killing cells. Bacteria use hemolysin to put holes in our membranes.

images from Science magazine.

Gramacidin is an antibiotic that similarly puts holes in bacterial membranes making them leaky and thus killing the bacteria.


(figure from microbial underground)

By sharing genes bacteria are able to spread antibiotic resistance among themselves. The emergence of more and more resistant strains of bacteria is a serious threat to world health Therefore new drugs must continually be discovered. Animation.

 

Bacterial 'cheats' take advantage of cooperating bacteria. Bacteria cooperate durring an infection, but maybe this can be used against them.

 

F.D.A. Revising Guidelines on Antibiotics for Animals

 

 

CDC

BioTerrorism

Special Antrhrax issue Nature

can treat rats

Nature Focus