Behavior of Yersinia enterocolitica in Foods

Table 1

Biochemical tests used to biogroup Y. enterocolitica strains.

Test	Reaction for biotype^a
	1A	1B	2	3	4	5
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.