Table 1: Biochemical tests used to biogroup Y. enterocolitica strains.

TestReaction for biotypea
1A1B2345

Lipase activity++
Salicin (acid production in 24 h)+
Esculin hydrolysis (24 h)+/−
Xylose (acid production)++++V
Trehalose (acid production)+++++
Indole production++V
Ornithine decarboxylase++++++
Voges-Proskauer Test++++++
Pyrazinamidase activity+
Sorbose (acid production)+++++
Inositol (acid production)++++++
Nitrate reduction+++++

aPositive, negative; /: delayed positive; V: variable.