Features of Bacteria, Viruses and Fungi

Features of Bacteria, Viruses and Fungi

Infectious diseases are diseases or illnesses (caused by bacteria or

viruses) that can be transmitted from person to person or from

organism to organism by touch or the exchange of blood or saliva and

also could be passed through air molecules. For instance, the common

cold and AID's are infectious diseases, whereas illnesses such as

diabetes and gout are non-infectious diseases.

Simple Hygiene:

Because many cold viruses are spread by contact with infected

secretions, frequently washing the hands, carefully disposing of used

tissues, and cleaning items and surfaces can help to reduce their

spread.

Bacteria:

- They are very small living cells.

- They are about 1/100th the size of body cells.

- They make you ill by damaging your cells and producing toxins.

- Some can be useful if they are in the right part of the body.

Fungi:

-Fungi can cause a number of plant and animal diseases: in humans,

ringworm, athlete's foot, and several more serious diseases are caused

by fungi.

- Because fungi are more chemically and genetically similar to animals

than other organisms, this makes fungal diseases very difficult to

treat.

- Some fungi provide numerous drugs (such as penicillin and other

antibiotics).

Viruses:

- Viruses are not cells, they are much smaller.

- They are about 1/100th of the size of bacteria.

- They make you feel ill by damaging your cells.

- They replicate themselves by invading the nucleus of a cell and

using the DNA it contains to produce many copies of itself.

- The cell then burst, releasing all the new viruses.

- The...

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...ering an existing wound. After

experimenting with the saliva of animals suffering from the disease,

Pasteur concluded that the disease rests in the central nervous system

of the body. When an extract from the spinal column of an rabid dog

was injected into healthy animal's symptoms of rabies were produced.

By studying the tissues of infected animals- rabbits, Pasteur was able

to produce an attenuated form of the virus. This could be used for

inoculation.

On July 6 1885, Pasteur tested his pioneering rabies vaccine on man

for the first time. He saved the life of a young man called Joseph

Meister who had been bitten by a rabid dog. Pasteur was urged to treat

him with his new method. The treatment lasted 10 days and at the end

he recovered and remained healthy. Since then thousands have been

saved by this treatment.