Beta hemolysis | definition of beta hemolysis by Medical dictionary
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complete or "true" hemolysis observed in blood agar cultures of various bacteria, especially hemolytic streptococci and staphylococci; virtually all the erythrocytes are destroyed in a relatively wide, regularly circumscribed, circular zone about the colony, thereby resulting in a clear "halo" of transparent agar; the zone of hemolysis is frequently much wider than the diameter of the colony; the degree of change varies with species of erythrocytes.
the development of a clear zone around a bacterial colony growing on blood agar, characteristic of certain pathogenic bacteria. Compare alpha hemolysis
References in periodicals archive
aureus, beta hemolysis and yellowish pigment were spotted in all the plates.
The washed fresh blood agar displayed partial beta hemolysis due to the combination of ATP levels and washing.
pseudoporcinus if it was a catalase-negative, gram-positive coccus; had positive agglutination results with group B PathoDx antiserum; and produced a wide zone of beta hemolysis on the blood agar--in contrast to the zone that is typically (though not always) narrower for GBS.
Stoner noted that the organism's distinctive beta hemolysis pattern and DNA sequencing can help avoid misidentification as GBS.