A patient with a burning epigastric pain is admitted to the hospital, and a gastric biopsy is performed. The tissue is cultured on chocolate agar incubated in a microaerophilic environment at 98.6degF (37degC) for 5 to 7 days. On fifth day of incubation, colonies appear on the plate and curved, gram-negative, oxidase-positive rods are observed. Which of the following is the most likely identity of this organism?