Table 2.

Biochemical characteristics of S. ficaria: comparison between human and environmental strains

Test% Positivity
Total (n = 42 strains)Human strains (n = 11 strains)Strains from environment (n = 31 strains)Pa
Catalase100100100
Cytochrome oxidase000
Nitrate reduction to nitrite69100520.01
Nitrate reduction to N2310480.01
H2S production000
Lipase000
Gelatinase5791450.01
DNase at 25°C436435NS
Urease000
Indole production000
Enzyme tests
 Arginine dihydrolase000
 Lysine decarboxylase000
 Ornithine decarboxylase000
 Tryptophan desaminase000
l-Aspartic acid arylamidase0b
Voges-Proskauer test719165NS
Phenol red acidification389480.03
Esculin hydrolysis100100100
Oxidation of:
 Glucose100100100
 Lactose675571NS
 Maltose100100100
 Mannitol100100100
 Xylose100100100
Acid from:
 Adonitol7955870.03
 Amygdalin959197NS
l-Arabinose868287NS
d-Arabitol9810097NS
l-Arabitol553661NS
 Cellobiose604565NS
 Galacturonate647361NS
 Glucose100100100
 Inositol6291520.03
 5-Ketogluconate100100100
 Maltose868287NS
 Mannitol959197NS
 Melibiose556452NS
 Palatinose4818580.03
 Raffinose959197NS
 Rhamnose290NS
 Sorbitol608252NS
 Sucrose939194NS
 Trehalose100100100
Glucose fermentation in the presence of:
 2,4,4′-Trichloro-2′-hydroxy-diphenylether (0.3 g/liter)6491550.04
 P-Coumaric (2 g/liter)100100100
Enzyme tests
 α-Galactosidase9310090NS
 β-Galactosidase7145810.03
 α-Glucosidase608252NS
 β-Glucosidase100100100
 β-Glucuronidase000
 α-Maltosidase4318520.05
N-Acetyl-β-glucosaminidase000
Utilization of:
 Acetamide000
 Citratec100100100
 Malonate000
Growth in the presence of polymyxin B (0.3 g/liter)000
  • a P values were determined by the χ2 test. NS, not significant.

  • b Doubtful for 12% of strains.

  • c A rate of positivity of 100% on Simmons citrate agar and also with Vitek GNI cards. This characteristic is very difficult to read when API 20E galleries are used (positive, 27%; negative, 19%; doubtful, 17%).