Table 8.

Comparison of accuracy of identification systems forStreptococcaceae and similar organisms

Identification systemYear (reference)Group identifiedNo. of isolates tested% correct (% correct with additional tests, or to group level)Comments; (additional tests); problematic taxa
API 20Sb1982 (171)α-Hem.astreptococci19439.0 (56.5)Clinical isolates; (group level identification)
API 20S1982 (171)α-Hem. streptococci2020.0Reference strains
API 20S1985 (14)Group C streptococci850.0Equine isolates
API 20S1985 (67)Non-β-hem. streptococci53587.8Stock cultures; (additional tests required for viridans group)
API 20S1988 (183)Viridans group streptococci10950.0 (78.0)Clinical isolates, S. sanguis II
API 20S1991 (109)Viridans group streptococci10152.5Blood isolates
API 20S1995 (202)Enterococci36981.5Nosocomial isolates
API 20 Strepb1984 (185)Streptococci8471.4Bovine mastitis isolates
API Rapid Strepb1983 (199)Viridans group streptococci11981.0 (92.0)(Includes isolates with identification of <90%)
API Rapid Strep1984 (6)Streptococci20973.2Without additional tests
API Rapid Strep1984 (72)Streptococcaceae25170.5Isolates from humans
API Rapid Strep1984 (72)β-hem. streptococci7580.0Isolates from humans
API Rapid Strep1984 (72)Group D + aerococci7085.7Isolates from humans
API Rapid Strep1984 (72)S. pneumoniae+ viridans group streptococci10653.8Isolates from humans
API Rapid Strep1985 (14)Group C streptococci8594.1Equine isolates, 24-h incubation; (serology)
API Rapid Strep1986 (98)Streptococci27078.8Human and veterinary isolates; problems with group B and group C
API Rapid Strep1989 (236)Streptococci19988.4Isolates from bovine mastitis; S. bovis
API Rapid Strep1991 (103)Viridans group streptococci20374.0 (83.0)Reference and blood culture isolates
API Rapid Strep1991 (113)Streptococci14496.5Bovine isolates, 4-h incubation
BBL Minitekc1991 (103)Viridans group streptococci20365.0 (85.0)Reference and blood culture isolates
BBL Minitek1989 (237)Streptococci12734.6Isolates from bovine mastitis; S. bovis
MS GPd1990 (223)Enterococci10094.0Clinical isolates
MS Rapid GPd1991 (103)Viridans group streptococci20366.0 (77.0)Reference and blood culture isolates
MS Rapid GP1992 (203)Streptococci and enterococci26794.0Multicenter study
MS Rapid GP1992 (229)E. faecalis12100.0Clinical isolates
MS Rapid GP1995 (108a)Streptococci and enterococci7698.7 (100.0)Clinical isolates; (low probability)
MS Rapid GP1995 (182)Enterococcusspp.1788.2Direct identification of positive blood culture centrifuged pellets; identification available after 2 h
S. bovis1428.9
S. pneumoniae1361.5
Rapid ID 32 Strepb1991 (109)Viridans group streptococci10182.2Blood isolates
Rapid ID 32 Strep1992 (80)Streptococci plus enterococci and similar organisms43370.2 (95.3)Clinical and veterinary isolates; (agreement with additional tests)
RapID STRb1986 (7)Streptococci and enterococci26669.9Clinically significant culture isolates
β-hem. streptococci60100.0
Group D enterococci4893.7
Group D non-enterococci2373.9
S. pneumoniae2626.9 (88.5)(Optochin)
Viridans group streptococci10952.3 (72.5)(Optochin)
RapID STR1986 (252)Streptococci and enterococci24379.9 (93.8)Culture collection isolates of human origin; (serological testing, optochin)
β-hem. streptococci7587.0 (89.0)
Enterococci3990.0 (98.0)
Group D non-enterococci2090.0 (100.0)
S. pneumoniae1080.0 (100.0)
Viridans group streptococci8162.0 (93.0)
Aerococcusspp.988.9 (100.0)
RapID STR1988 (183)Viridans group streptococci10962.0 (80.0)Clinical isolates; S. intermedius
RapID STR1991 (103)Viridans group streptococci20350.0 (61.0)Reference and blood culture isolates
AMS GPIb1985 (67)Non-β-hem. streptococci50787.5Stock cultures; viridans group streptococci
Vitek GPIb1988 (183)Viridans group streptococci10972.0 (81.0)Clinical isolates
Vitek GPI1991 (34)E. faecalis116100.0Clinical isolates from tertiary-care hospitals
Vitek GPI1991 (34)Enterococci, not E. faecalis2461.9Clinical isolates from tertiary-care hospitals
Vitek GPI1991 (103)Viridans group streptococci20361.0 (82.0)Reference and blood culture isolates
Vitek GPI1991 (113)Streptococci14494.4Bovine isolates; 8-h incubation
Vitek GPI1995 (102)S. mutans16072.5Clinical oral isolates
Vitek GPI1995 (202)Enterococci369(95.3)(Motility, pigmentation)
Vitek GPI1992 (229)E. faecalis12100.0Clinical isolates
  • a α-hem., alpha-hemolytic; β-hem., beta-hemolytic.

  • b bioMérieux-Vitek Inc. Hazelwood Mo. and bioMérieux S. A., Marcy l’Etoile, France.

  • c BBL Becton Dickinson Microbiology System, Becton Dickinson & Co., Sparks, Md.

  • d Dade International Inc., West Sacramento, Calif.