What bacteria are alpha-hemolytic?
Alpha-hemolytic Streptococcus species “Viridans group” streptococci, including species such as the Streptococcus mutans, mitis, and salivarius groups display alpha hemolysis.
What bacteria is Gram positive cocci in pairs?
Streptococci are gram-positive cocci that grow in pairs or chains. Most pathogenic streptococci are facultative anaerobes.
Which streptococci are alpha-hemolytic?
Streptococcus pneumoniae and a group of streptococci (Streptococcus viridans or viridans streptococci) found in oral flora display alpha hemolysis. Non-hemolytic (γ-hemolysis): If an organism does not induce any hemolysis on a blood agar plate, it is said to display gamma or no hemolysis.
What does Gram positive cocci in pairs mean?
“Gram positive cocci in clusters” may suggest Staphyloccocus species. “Gram positive cocci in pairs and chains” may suggest Streptococcus species or Enterococcus species. “Branching Gram positive rods, modified acid fast stain positive” may suggest Nocardia or Streptomyces species.
What is Alpha haemolytic?
Alpha-hemolysis (α-hemolysis) is a partial or “green” hemolysis associated with reduction of red cell hemoglobin. Alpha hemolysis is caused by hydrogen peroxide produced by the bacterium, oxidizing hemoglobin to green methemoglobin. It exhibit incomplete haemolysis with 1-2 mm wide.
What is cocci pairs?
Pairs of cocci are called diplococci; rows or chains of such cells are called streptococci; grapelike clusters of cells, staphylococci; packets of eight or more cells, sarcinae; and groups of four cells in a square arrangement, tetrads.
Is gram-positive cocci the same as MRSA?
MRSA bacteria usually show resistance to many antibiotics. Because MRSA is so antibiotic resistant (drug-resistant), it is termed a “superbug” by some investigators. This superbug is a variation of an already recognized human pathogen, S. aureus, gram-positive bacteria that occur in grape-like clusters termed cocci.
What is alpha-hemolytic?
Alpha-hemolysis (α-hemolysis) is a partial or “green” hemolysis associated with reduction of red cell hemoglobin. Alpha hemolysis is caused by hydrogen peroxide produced by the bacterium, oxidizing hemoglobin to green methemoglobin. Persistence of some unhaemolysed RBC’s can be seen microscopically.
What does alpha-hemolytic Streptococcus mean?
n. Streptococci that partially lyse red blood cells cultured on a blood agar medium, producing a green color around the cell colonies.
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