一个疗程的抗菌治疗后出现持续性幽门螺旋杆菌感染——下一步该怎么办？

A 35-year-old Hispanic woman with no significant past medical history presents to the emergency department at midnight with a 3-month history of intermittent epigastric pain culminating in 3 episodes of coffee-ground emesis on the day of presentation. Her blood pressure is 90/60 mm Hg and her pulse is 95 beats per minute with evidence of postural orthostasis. Nasogastric lavage reveals coffee-ground material, which clears with a liter of saline. Her hematocrit is 32% before hydration. She is stabilized and resuscitated with intravenous fluids. Upper endoscopy reveals a 1-cm, clean-based, duodenal bulb ulcer. Gastric biopsies reveal a negative rapid urease test but histology reveals active ga