RT Journal Article SR Electronic(1) A1 Vandamme, P. A1 Devriese, L. A. A1 Haesebrouck, F. A1 Kersters, K.YR 1999 T1 Streptococcus intestinalis Robinson et al. 1988 and Streptococcus alactolyticus Farrow et al. 1984 are phenotypically indistinguishable JF International Journal of Systematic and Evolutionary Microbiology, VO 49 IS 2 SP 737 OP 741 DO https://doi.org/10.1099/00207713-49-2-737 PB Microbiology Society, SN 1466-5034, AB The one-dimensional whole-cell protein patterns and a variety of biochemical characteristics of the type and reference strains of Streptococcus intestinalis and Streptococcus alactolyticus were studied. All the data revealed that strain of both species were indistinguishable. Reported differences in haemolytic activity and presence of Lancefield antigens were not reproduced. All strains were α-haemolytic. The S. intestinalis type strain possessed the group G antigen, but a second S. intestinalis reference strain and all of the S. alactolyticus strains possessed the group D antigen. All strains produced urease activity (albeit some after prolonged incubation), a characteristic considered important for S. intestinalis. Given the congruence between wholecell protein electrophoresis and percentage of DNA-DNA hybridization, these data suggest that Streptococcus intestinalis Robinson et al. 1988 is a junior synonym of Streptococcus alactolyticus Farrow et al. 1984., UL https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/00207713-49-2-737