This test is positive in
Test is quellung reaction quellung reaction: a small amount of growth is mixed with saline, antisera against the capsule polysaccharide, and methylene blue stain. After incubation at room temperature for 1 hour, the reaction is observed under the microscope.The organisms are outlined in light blue. A positive reaction shows clumping because of cross-linking of the antibodies and pneumococci. The halo effect around the pneumococci is apparent capsular swelling.Jawetz 7e pg 224
Streptococcus pyogenes
Streptococcus pneumoniae
Streptococcus mitis
Streptococcus agalactiae
Bacteriology