DIAGNOSIS OF HELICOBACTER-PYLORI INFECTION IN A COLONY OF RHESUS-MONKEYS (MACACA-MULATTA)

Twenty-three young adult rhesus monkeys from China were evaluated for the presence of Helicobacter pylori. Gastric body and antral biopsy sa mples were tested for H. pylori by PCR analysis, culture, rapid urease testing, and histologic evaluation, Serologic testing to detect H. py lori immunoglobulin G (IgG) antibodies was performed by using a commer cially available human-based enzyme-linked immunosorbent assay (ELISA) test and an ELISA test which utilized homologous H. pylori antigens a nd an anti-rhesus IgG conjugate, PCR analysis with H. pylori-specific 26-kDa protein primers detected H. pylori in 21 of the 23 rhesus monke ys (91%), Culture testing identified the organism in 12 of the 23 anim als (52%), Rapid urease tests were positive for all animals, H. pylori was diagnosed by histological examination in 11 of 23 monkeys (48%), Of the 21 monkeys positive for H. pylori by PCR, only 3 (14%) had posi tive results by the commercial ELISA test, yielding a sensitivity of 1 4%, a specificity of 100%, and an accuracy of 22%, However, 19 of the 21 PCR-positive animals (90%) had positive results by the ELISA test w ith homologous rhesus H. pylori antigen and anti-monkey conjugate, wit h predicted index values greater than or equal to 0.7 considered posit ive and values between 0.5 and 0.7 considered equivocal, This test had a sensitivity of 90%, a specificity of 100%, and an accuracy of 91%, Therefore, the ELISA test with rhesus monkey origin components was mor e accurate for detecting infected animals than the human-based ELISA.