The urease enzyme of Campylobacter pylori was studied and compared with that of a related spiral-shaped bacterium, St1, isolated from the rodent ileum. Both bacteria possessed constitutive urease enzymes with activities up to 20-70 times that of Proteusvulgaris. This activity was retained on SDS-polyacrylamide gels. Amajor catalytic subunit of mol. wt 300 000 was located for all (six) strains of C.pylori subjectedto SDS-PAGE whereas St1 had two active forms of mol. wts 140 000 and 150 000. Western-blot analysis indicated the presence of anti-urease antibodies in the sera of patients with C. pylori-associated gastritis. The response to C. pylori urease was not strain-specific but no cross-reactivity was detected between the C. pylori enzyme and that of St1. The very high urease activity of these bacteria is likely to be important in colonisation of the host. Possession of glutamate dehydrogenase activity by both organisms suggests that one role of the urease may be to assimilate the available urea nitrogen. Modification of the local environment to facilitate long-term colonisation is another possible function. Protection from acid is unlikely to be a primary role as the natural habitat of the organism St1 is the non-acid-secreting tissue of the small intestine.
BryantM. P.1974; Nutritional features and ecology of predominant anaerobic bacteria of the gastrointestinal tract. American Journal of Clinical Nutrition 27:1313–1319
ChengK. J.,
WallaceR. J.1979; The mechanism of passage of endogenous urea through the rumen wall and the role of ureolytic epithelial bacteria in the urea flux. British Journal of Nutrition 42:553–557
FitzgeraldO. F.,
MurphyP. M.1950; Studies on the physiological chemistry and clinical significance of urease and urea with special reference to the stomach. Irish Journal of Medical Science 292:97–159
HazellS. L.,
LeeA.,
BradyL.,
HennessyW.1986; Campylobacter pyloridis and gastritis: association with intercellular spaces and adaptation to an environment of mucus as important factors in colonization of the gastric epithelium. Journal of Infectious Diseases 153:658–663
HazellS. L.,
BorodyT. J.,
GalA.,
LeeA.1987; Campylobacter pyloridis gastritis I: Detection of urease as a marker of bacterial colonization and gastritis. American Journal of Gastroenterology 82:292–296
HespellR. B.,
SmithC. J.1983; Utilization of nitrogen sources by gastrointestinal tract bacteria. In
HentgesD. J.
(ed) Human intestinal microflora in health and disease Academic Press; New York: p 167
KaltwasserH. K.,
SchlegelH. G. S.1966; NADH-dependent coupled enzyme assay for urease and other ammonia-producing systems. Analytical Biochemistry 16:132–138
KleinerD.,
PhillipsS.,
FitzkeE.1981; Pathways and regulation aspects of nitrogen and ammonium assimilation and nitrogen-fixing bacteria. In
BotheH.,
TrebstA.
(eds) Biology of inorganic nitrogen and sulphur metabolism Springer; New York: pp 131–140
LeeA.,
PhillipsM.1978; Isolation and cultivation of spirochaetes and other spiral-shaped bacteria associated with the cecal mucosa of rats and mice. Applied and Environmental Microbiology 35:610–613
MusherD. M.,
GriffithD. P.,
YawnD.,
RossenR. D.1975; Role of urease in pyelonephritis resulting from urinary tract infection with Proteus. Journal of Infectious Diseases 131:177–181
PhillipsM. W.,
LeeA.1983; Isolation and characterization of a spiral bacterium from the crypts of rodent gastrointestinal tracts. Applied and Environmental Microbiology 45:675–683
SeniorB. W.,
BradfordN. C.,
SimpsonD. S.1980; The ureases of Proteus strains in relation to virulence for the urinary tract. Journal of Medical Microbiology 13:507–512
TowbinH.,
StaehelinT.,
GordonJ.1979; Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications. Proceedings of the National Academy of Sciences of the USA 76:4350–4354
VonKorffR. W.,
GlickD.1951; Role of urease in the gastric mucosa. II: In vitro studies with isotopic urea on frog mucosa. American Journal of Physiology 165:688–694
VonKorffR. W.,
FergusonD. J.,
GlickD.1951; Role of urease in the gastric mucosa. III. Plasma urea as source of ammonium ion in gastric juice of histamine-stimulated dog. American Journal of Physiology 165:695–700
WallaceR. J.,
ChengK. J.,
DinsdaleD.,
OrskovE. R.1979; An independent microbial flora of the epithelium and its role in the ecomicrobiology of the rumen. Nature 279:424–426
WilliamsS. E.,
TurnbergL. A.1980; Retardation of acid diffusion by pig gastric mucus: a potential role in mucosal protection. Gastroenterology 79:299–304
WilliamsS. E.,
TurnbergL. A.1981; Demonstration of a pH gradient across mucus adherent to rabbit gastric mucosa: evidence of a “mucus-bicarbonate” barrier. Gut 22:94–96
WoznyM. A.,
BryantM. P.,
HoldemanL. V.,
MooreW. E. C.1977; Urease assay and urease-producing species of anaerobes in the bovine rumen and human feces. Applied and Environmental Microbiology 33:1097–1104