<prompt> Urease breath test is used to diagnose in which bacteria:StreptococciH. pyloriC. jejuniBacteroides  <response>: Ans. b H. pyloriRef: Bailey and Love 27th edition Page 1114 For H. pylori the best non invasive investigation to diagnose the presence - Serology ELISA The best investigation to diagnose eradication C13 and C14 urea breath test. Should be performed after - 4 weeks of therapy The best invasive investigation When Endoscopy is Done to diagnose: Rapid urease test The stain used for H. pylori: Giemsa or warthin starry stain Gram staining is not used The fecal antigen test also is quite sensitive and specific for active H. pylori infection and may prove more practical in confirming a cure of H. pylori. 