Understanding bacteria is necessary to prevent and treat diseases.
I. Some bacteria cause disease.
Some bacteria cause disease in plants and animals by disrupting the hose organism’s homeostasis, or the stability of its internal environment.
Bacteria cause illness in two ways:
Invading tissues and attacking cells
Ex: Tuberculosis
Making poisons or toxins that can be carried by blood to sites throughout the body.
Toxin: poison released by an organism.
Tuberculosis: bacteria multiplies in lungs, killings white blood cells that respond to invasion. The host responds to releasing enzymes that cause swelling, damaging the lungs.
II. Antibiotics are used to fight bacterial disease.
Colds and strep throat are treated differently because they are caused by different pathogens. Viruses cause colds, bacteria cause strep throat.
Antibiotics: chemicals that kill or slow down the growth of bacteria- work by stopping bacteria from making cell walls.
Produced by bacteria/fungi.
Used as medicine for humans and animals without damaging cells because animal cells don’t have cell walls. Viruses also lack cell wall, so antibiotics don’t work.
Overuse can completely wipe out the community of intestinal microbes, resulting in illness.
III. Bacteria can evolve resistance to antibiotics.
Inappropriate and incomplete use of antibiotics has produced a serious public health issue- multidrug-resistant bacteria.
Resistance occurs as a result of natural selection- as individuals who are more resistant are more likely to survive and reproduce. This has led to the evolution of multidrug resistant superbugs that are impossible to treat.
Bacteria can acquire genes for resistance through plasmid exchange.
Problem has arisen due to various factors:
Overuse: potential problem with antibiotics is that they may create a selective pressure that favors the very bacteria they are intended to destroy. Using antibiotics when bacteria are not causing illness may make some...