Characteristics of Bacteria, Viruses, and Fungi Infectious diseases are diseases (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 could also be passed through air molecules. For example, the common cold and AIDS are infectious diseases, while diseases such as diabetes and gout are non-infectious diseases. Simple hygiene: Because many cold viruses are spread through contact with infected secretions, washing your hands frequently, carefully disposing of used tissues, and cleaning objects and surfaces can help reduce their spread. Bacteria: - They are very small living cells. - They are about 1/100 the size of cells in the body. - They make you sick by damaging cells and producing toxins. - Some can be useful if they are located on the right side of the body. Fungi: - Fungi can cause numerous plant and animal diseases: in humans, ringworm, athlete's foot and many more serious diseases are caused by fungi. - Because fungi are chemically and genetically more 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 1/100 the size of bacteria. - They make you sick by damaging your cells. - They replicate by invading the nucleus of a cell and using the DNA it contains to make many copies of itself. - The cell then bursts, releasing all the new viruses.- The... center of the card... wounds an existing wound. After carrying out experiments with the saliva of animals suffering from the disease, Pasteur concluded that the disease resides in the central nervous system of the body. When an extract of the spine of a rabid dog was injected into a healthy animal, rabies symptoms were produced. By studying the tissues of infected animals, rabbits, Pasteur managed 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 humans for the first time. He saved the life of a young man named JosephMeister who had been bitten by a rabid dog. Pasteur was invited to treat it with his new method. The treatment lasted 10 days and he eventually recovered and remained healthy. Since then thousands of people have been saved thanks to this treatment.