Gram positive cocci,

0.6-1.4 µm

that occur in irregular grape-like clusters and,

less often, single and in pairs, tetrads, and in short chains.

INFECTION: low numbers of colony-forming units (less than 105 cfu/ml) are often present

Facultative anaerobic

BA: can be intesely yellow at first isolation

Large; entire, very glossy, smooth, opaque, butyrous, convex, non hemolytic; usually white but colonies can be yellow or orange

McConkey: growth (not always)

BBAØ: growth

James Versalovic et al.(2011) Manual of Clinical Microbiology 10th Edition