All are true regarding Helicobacter pylori except:
Ans. is 'a' ie Less prevalent in developing countries (Ref. Harrison 17/e p 946 & 16/e, p 886 (15/e p 962 & 963))All the options can be easily understood as they have been frequently asked in previous year papers. Only option 'b' needs some explanation.Virulence factors in H. Pylori are-Vacuolating cytotoxin (Vac A)Group of genes termed the cag pathogenicity island (cag PAI)How do them because ulcers is not exactly known but their association with ulcers is firmly established. Lets see the evidences from Harrison - "Cytotoxic strains are more commonly associated from patients with peptic ulcer disease than from persons without ulcers""The cag PAI genes confer enhanced virulence on H. Pylori strains by inducing inflammatory cells to produce cytokines. Patients with peptic ulcers or gastric adenocarcinomas are more likely to have a cag A antibodies than patients without these conditions."
Less prevalent in developing countries
Toxicogenic strains usually causes ulcers
Urea breath test is positive
Gram negative organism
Peptic Ulcer and Related Disorders