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Estimated rates of bad breath vary from 6% to 50% of the population. [1] Concern about bad breath is the third most common reason people seek dental care, after tooth decay and gum disease. [2] [3] It is believed to become more common as people age. [1] Bad breath is viewed as a social taboo and those affected may be stigmatized.
Halitosis (the medical term for bad breath) is usually caused by something in the mouth — whether it's leftover bits of food stuck in the teeth, a buildup of bacteria on the tongue or smoking ...
Hemolysis is the breakdown of red blood cells. The ability of bacterial colonies to induce hemolysis when grown on blood agar is used to classify certain microorganisms. This is particularly useful in classifying streptococcal species. A substance that causes hemolysis is called a hemolysin.
Hemolysins or haemolysins are lipids and proteins that cause lysis of red blood cells by disrupting the cell membrane.Although the lytic activity of some microbe-derived hemolysins on red blood cells may be of great importance for nutrient acquisition, many hemolysins produced by pathogens do not cause significant destruction of red blood cells during infection.
Alpha-hemolytic species cause oxidization of iron in hemoglobin molecules within red blood cells, giving it a greenish color on blood agar. Beta-hemolytic species cause complete rupture of red blood cells. On blood agar, this appears as wide areas clear of blood cells surrounding bacterial colonies. Gamma-hemolytic species cause no hemolysis. [11]
A red blood cell in a hypotonic solution, causing water to move into the cell A red blood cell in a hypertonic solution, causing water to move out of the cell. Hemolysis or haemolysis (/ h iː ˈ m ɒ l ɪ s ɪ s /), [1] also known by several other names, is the rupturing of red blood cells (erythrocytes) and the release of their contents into surrounding fluid (e.g. blood plasma).
H. influenzae will only grow on blood agar if other bacteria are present to release these factors from the red blood cells, forming 'satellite' colonies around these bacteria. For example, H. influenzae will grow in the hemolytic zone of Staphylococcus aureus on blood agar plates; the hemolysis of cells by S. aureus releases NAD which is needed ...
Agglutination(clumping) of red blood cells. This occurs in biology in two main examples: The clumping of cells such as bacteria or red blood cells in the presence of an antibody or complement. The antibody or other molecule binds multiple particles and joins them, creating a large complex.