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(right) γ-hemolysis (non-hemolytic, S. salivarius) 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.
In alpha-hemolysis, the blood is partially digested, causing the area around the colony to turn green. In beta-hemolysis, the organism digests the blood completely, leaving a clear area around each colony. [1]: 165–6 Organisms that do not produce hemolysis are referred to as gamma-hemolytic.
Alpha-hemolysin from uropathogenic E. coli produces extra-intestinal infections and can cause cystitis, pyelonephritis, and sepsis. Alpha-hemolysin from Staphylococcus aureus can cause severe diseases, such as pneumonia. Aerolysin from Aeromonas sobria infects the intestinal tract, but it might also cause sepsis and meningitis.
Species of streptococci are classified based on their hemolytic properties. [10] 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 ...
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).
Glucose-6-phosphate dehydrogenase deficiency is very common worldwide, and causes acute hemolytic anemia in the presence of simple infection, ingestion of fava beans, or reaction with certain medicines, antibiotics, antipyretics, and antimalarials. [3] Cell growth and proliferation are affected by G6PD. [20]
Most strains are gamma-hemolytic (non-hemolytic), but some also display alpha-hemolytic activity on sheep blood agar plates. Strep bovis is a non-enterococci. [citation needed] Biochemical Tests mannitol salt: negative bile esculin: negative MR/VP: positive/negative nutrient gelatin: negative starch: positive DNase: negative [citation needed]
Streptococcus mitis is a species of Gram-positive, mesophilic, alpha-hemolytic bacteria in the genus Streptococcus.These bacteria are facultative anaerobes, and made up of non-motile and non-sporing cocci (round cells) that are catalase negative.