Properties

Pathogenesis

Clinical findings

Laboratory diagnosis

Treatment & Prevention

Curve, gram-negative rods.

Strongly urease-positive.

Infects only gastric-type mucosa.

Attaches to mucus-secreting cells of the gastric mucosa.

Production of large amounts of ammonia from urea by organism’s urease, coupled with an inflammatory response, leads to damage to mucosa.

Loss of protective mucus predisposes to gastritis & peptic ulcer.

Spread probably by person-to-person transmission.

Gastritis & peptic ulcer are characterized by recurrent pain in the upper abdomen, frequently accompanied by bleeding into the GI tract.

No bacteremia or disseminated disease occurs.

Most acute infections are inapparent.

After infection some patients develop symptoms for about 2 weeks:

- abdominal pain.

- nausea.

- bad breath.

- flatulence.

Definitive cause of:

- peptic ulceration.

- gastric carcinoma

Cultured from gastric biopsies taken through a fibre-optic endoscope; it grows micro-aerophilically at 37 degrees & colonies are very rapidly urease positive.

Urea breath test:

- ingestion of radioactive urea.

- in presence of organism, radiolabeld carbon dioxide is evolved & detected in breath.

Treatment of duodenal ulcers:

- amoxicillin + metronidazole.

- bismuth + metronidazole + tetracycline + omeprazole.

Prevention: careful disinfection of endoscopes needed to prevent nosocomial transmission.