T. Kanamoto et al., ISOLATION AND PROPERTIES OF BACTERIOLYTIC ENZYME-PRODUCING COCCI FROMTHE HUMAN MOUTH, FEMS microbiology letters, 144(2-3), 1996, pp. 135-140
One-hundred-and-one bacteriolytic enzyme-producing organisms were isol
ated from various sites of the mouth. All were non-hemolytic, Gram-pos
itive, and chain-forming cocci. Ninety-one strains, like the reference
strains of Streptococcus defectivus and S. adjacens, were dependent o
n pyridoxal for growth and produced a chromophore. The Rapid ID32 STRE
P system speciated these isolates as S. defectivus, S. adjacens or Gem
ella morbillorum. The remaining 10 bacteriolytic isolates were pyridox
al-independent and 8 belonged to S. intermedius. Some pyridoxal-indepe
ndent S. intermedius reference strains including ATCC27335(T) and all
group D Enterococcus strains tested were also bacteriolytic. Thus, bac
teriolytic enzyme production is common to nutritionally variant strept
ococci but not unique to S. defectivus and S. adjacens. The nutritiona
lly variant strains generally had arylamidases but not alkaline phosph
atase. The S. defectivus strains produced alpha- and beta-galactosidas
es (biotype 1) whereas the S. adjacens strains generally produced N-ac
etyl-beta-glucosaminidase and some had beta-glucuronidase but others d
id not (biotypes 2 and 3). The G. morbillorum strains had no detectabl
e activity of these glycosidases (biotype 4) but produced a chromophor
e and an arginine dihydrolase, exhibiting a physiological profile atyp
ical of the Gemella species. This indicates the possible presence of a
n additional phenotypic group or a new species among the nutritionally
variant streptococci.