Abiotrophia defectiva was originally named Streptococcus defectivus [6].  Fastidious streptococci that grew as satellite colonies around other microorganisms or in complex media enriched with cysteine were originally described as nutritionally variant streptococci (NVS) by Frenkel and Hirsch [7].  Kawamura et al. recognized that S. defectivus and other NVS were not members of the genus Streptococcus  and created the genus Abiotrophia [1] 

Requires 10 mg/l pyrixoxal hydrochloride or 100 mg/l L-cysteine for growth [1]

Gram-positive cocci.  Nonmotile, nonsporulating, catalase negative, and oxidase negative.  Facultatively anaerobic with complex growth requirements.  Grows as satellite colonies adjacent to Staphylococcus epidermidis [1]. 

Abiotrophia defectiva is a common member of the human oral cavity, pharynx, intestine and urogenital tracts.  In a study examining the normal microflora of the oral cavity it was recovered from buccal, hard palate, tooth surface and subgingival sites [3].