TABLE 3.

Activities of general amidase, formamidase, and urease and presence of the amiE and amiF genes in different Helicobacter species

Strain	Urease activitya	Result for:
		General amidase		Formamidase
		AmiE-like activitya	amiE gene detectionb	AmiF-like activitya	amiF gene detectionb
H. pylori N6	9.98 ± 1.98	2.32 ± 1.28	+	0.76 ± 0.62	+
H. pylori 26695	3.17 ± 1.82	0.52 ± 0.35	+	2.7 ± 1.02	+
H. acinonychis	14.92 ± 1.59	0.08 ± 0.04	+	4.97 ± 3.52	+
H. felis	13.91 ± 1.59	<0.01	−	8.19 ± 4.36	+
H. mustelae	42.46 ± 11.67	<0.01	−	0.07 ± 0.02c	−
H. pametensis	<0.01	<0.01	−	<0.01	−
H. cinaedi	<0.01	<0.01	−	<0.01	−
H. bilis	4.79 ± 2.07	<0.01	−	<0.01	−
H. canis	<0.01	<0.01	−	<0.01	−
H. muridarum	1.11 ± 0.93	0.36 ± 0.17	+	0.04 ± 0.03c	−
H. hepaticus	20.68 ± 7.79	<0.01	−	<0.01	−
H. fennelliae	<0.01	<0.01	−	<0.01	−

^aResults are expressed as micromoles of substrate hydrolyzed per minute per milligram of protein ± standard deviation. The values shown are for the results of at least three independent experiments. The substrates used were urea for urease, acrylamide and acetamide for AmiE, and formamide for AmiF.

^bDetection was by Southern blot analysis with an amiE or amiF probe, as appropriate, except with H. hepaticus, for which genomic sequence data were available.

^cThis value is close to the limit of detection of formamidase activity.