Characterization of Actinobaculum spp. and related human pathogens by the API Coryne systema

CharacteristicReaction ofb:
Actinobaculum schaaliiActinobaculum massiliaeActinobaculum urinaleGardnerella vaginalisArcanobacterium bernardiaeArcanobacterium haemolyticumArcanobacterium pyogenesActinomyces turicensisVaribaculum cambriensis
β-Hemolysis on sheep blood agarwcwV++w
Nitrate reductionV
Pyrazinamidased+V (89)++
Pyrrolidonyl arylamidase+V (71)V (59)+
Alkaline phosphataseV (11)e+V (71)
β-Glucuronidase+V (18)+
β-GalactosidaseV (43)V (85)+V
α-Glucosidase++V (65)+V (87)+++
N-Acetyl-β-glucosaminidaseV (18)V (83)V (47)
Esculin hydrolysisV (11)e
Urease activity+
Gelatin hydrolysis+
Acid from:
    GlucoseV (56)f+++V (50)++++
    Ribose+++++V (83)++V
    XyloseV (44)f+++V
    SucroseV (44)+V (13)V (50)V (56)++
    Glycogen+V (53)+V (19)
  • a See Table 2 for additional information on the organisms.

  • b All species are catalase negative, facultative, anaerobic gram-positive rods. API Coryne system profiles for our nine isolates were compared with those in the manufacturer’s database for G. vaginalis and the Arcanobacterium spp. and those described in the reference concerned for A. massiliae (1 strain) (6), A. urinale (1 strain) (7), A. turicensis (43 strains) (14), and V. cambriensis (15 strains) (8). In the API Coryne system, the numerical code for A. turicensis is 0010000. This difference can be explained by the fact that Sabbe et al. read the carbohydrate fermentation reactions after 72 h, as acid production from glucose, ribose, and xylose is reported not to be recognized within 24 h for A. turicensis (4). Abbreviations and symbols: +, ≥90% of strains positive; −, ≤10% of strains negative; V, variable; w, weak. Values in parentheses are percentages of strains with a positive reaction.

  • c The isolates showed weak β-hemolysis, but only after 2 to 5 days. A. schaalii is described as nonhemolytic in the literature (n = 6) (9, 12).

  • d Reported as variable in the literature (n = 6) (9, 12).

  • e Reported as negative in the literature (n = 6) (9, 12).

  • f Reported as positive in the literature (n = 6) (9, 12).