ADAPTATION OF THE [C-13]UREA BREATH TEST AS A NONINVASIVE METHOD FOR DETECTION OF HELICOBACTER PYLORI INFECTION IN SQUIRREL MONKEYS (SAIMIRI SPP)

摘要

The [C-13]urea breath test was adapted for use in squirrel monkeys (Saimiri spp.) for identification of experimentally induced infection with Helicobacter pylori, the bacterium causing gastric ulcer in humans. A canine anesthesia inhalation mask was modified with a volume-reducing insert allowing sufficient breath collection from these small primates within 30 sec. Fourteen milligrams of [C-13]urea per kilogram of body weight was adequate for clear distinction between experimentally infected and noninfected animals. Initial infection of five squirrel monkeys resulted in increased (CO2)-C-13 in breath within 3 days after inoculation with H. pylori. Additional inoculation with H. pylori superimposed on an existing gastric population caused a transient increase in breath (CO2)-C-13 values, which gradually declined over the following 15 days. Breath test results indicating H. pylori infection were confirmed by high [C-13] concentration in blood, by urease-positive culture, modified Steiner stain reaction, and Western blot analysis. This modified [C-13]urea breath test provides a rapid, reproducible, noninvasive method for screening small primates used as nonhuman models for the study of gastric infection with H. pylori.