Isolation of bacteria other than Helicobacter pylori from stomachs of squirrel monkeys (Saimiri spp.) with gastritis.

Gastric biopsy specimens obtained from 12 squirrel monkeys (Saimiri spp.) were investigated by culture for the presence of bacteria. The stomachs of two monkeys with gastritis were colonized with gram-negative, urease-positive bacteria, identified as Ochrobactrum anthropi by the Vitek and API NFT methods (BioMérieux). A third monkey with gastritis was positive for Aeromonas salmonicida and Pseudomonas vesicularis (both urease-negative). No Helicobacter pylori was isolated from squirrel monkeys. Light microscopic and transmission electron microscopic examination revealed that the O. anthropi isolates were covered by extracellular material, indicating a capsule. Characterization of the O. anthropi urease revealed Michaelis-Menten constants (Km values) of 6.2 and 4.0 mM urea for the ureases of O. anthropi isolates S664 and S1835, respectively, and 3.7 for type strain 49188. Western blot analysis using H. pylori- and H. felis-specific antibodies detected shared antigenic epitopes between the ureases of H. pylori, H. felis, and O. anthropi. The apparent molecular mass of the urease enzymes of the O. anthropi isolates was determined on 6% nondenaturing gels to be approximately 82 kDa. Antimicrobial susceptibility tests, using the MicroScan method (Dade International), revealed multidrug resistance for the O. anthropi isolates with susceptibilities for the antibiotics amikacin, ciprofloxacin, gentamicin, cefoperazone, tobramycin, imipenem, and trimethoprim/sulfamethoxazole.