Table 3.

Key and differential biochemical characteristics of Helicobacter species colonizing either humans and/or animals

Characteristic	H. pylori	H. canis	H. cinaedi	H. felis	H. fennelliae	H. pullorum	H. westmeadii
Catalase activity	+	-	+	+	+	+	+
Urease activity	+	-	-	+	-	-	-
Oxidase activity	+	+	+	+	+	+	+
Alkaline phosphatase activity	+	+	-	+	+	-	+
γ-Glutamyl transpeptidase activity	+		-	+	-
H₂S production	-		-	-	-		-
Indoxyl acetate hydrolysis	-	+	-	-	+	-	-
Hippurate hydrolysis	-	-	-	-	-	-	+
Nitrate reduction	-	-	+	+	-	+	+
C₄ esterase	+		+		+		+
C₈ esterase lipase	+		+		+		+
Leucine arylamidase	+		-	+	-		+
Acid phosphatase	+		+		+		+
Naphthol-AS-B1-phosphohydrolase	+		+		+		+
DNase activity	+			+
G + C content (mol%)	35-37	48	37-38	43	37-38	34-35