Bacteria in the Oral Environment. CHARACTERISTICS OF BACTERIA

1. Characteristics of bacteria

A. Description

1. Bacterium (plural, bacteria). Bacteria, protozoan organisms and can be seen only with a microscope (Fig. 6-1).

2. There are thousands of species of bacteria, most of which are harmless to humans.

a. Innocent bacterial species that are not harmful.

B. Pathogenic species of bacteria that can cause disease. Another term for pathogenic bacteria virulent bacteria. In the mouth, harmless and pathogenic bacteria live together in a symbiotic relationship.

3. Bacteria existed on earth longer than all other organisms and are still the most common type of cells.

4. Bacteria can be replicated quickly. This ability to divide lets you quickly populations of bacteria to quickly adapt to environmental changes.

B. structure of the cell membrane of bacteria. Strong protective layer is called the cell membrane covers almost all bacteria.

1. In the composition of cell membranes, is an important characteristic used in the definition and classification of bacteria.

2. Gram staining-laboratory method, which revealed differences in the chemical and physical properties of the bacterial cell membranes.

3. Depending on the permeability of the bacterial cell membranes, appear either purple or red under a microscope.

4. Gram staining shares of gram-positive bacteria (purple) and gram (red) cell membrane of bacteria types (Fig. 6-1).

a. Gram-positive bacteria (purple spots)

1) to have a single thick cell membranes

2) most of the bacteria associated with healthy periodontal Gram

3) preservation purple color when were stained with dyes, known as the crystal violet and so bacterial cell membranes show purple stain under the microscope

B. Gram-negative bacteria (red spots)

1) Have a double cell membranes

2) believed to play an important role in tissue destruction seen in periodontitis

3) not purple spot with crystal violet and therefore show a red spot under a microscope

4) remember that the membrane of gram-negative bacteria red spot, it may be useful to think of "red = inflammation" (as these bacteria are believed to play an important role in the inflammatory periodontal diseases) ..