Abstract:Currently, the tree shrew has been widely used as an alternative laboratory animal in biomedical researches. Our previous study showed that Helicobacter spp. was the most distributed bacteria in gastro- intestinal of tree shrew, however, the species of this genus were still unknown. To find out the characteristics of Helicobacter spp. species carried in laboratory tree shrew, we performed the current study to provide useful information for future investigation. Seventy-two tree shrew fecal samples were collected, and processed for DNA extraction, nested PCR to amplify specific gene fragments with the genus specific primers. The species- specific primers including those for Helicobacter hepaticus, H. muridarum, H. bilis, H. rodentium, Flexispira rappini, H. suncus and H. typhlonius were used to amplify species-specific fragments from genus-positive samples. The samples negative for species-specific primers but positive for genus primer were sent for sequencing. BLAST and alignment methods were used to confirm their Helicobacter species. The results showed that eighteen feces were positive for Helicobacter, and the positive rate was 25%, among which eight strains were H. typhlonius, six were H. bilis, five were H. cinaedi, two were H. felis and one was H. macacae (Fig. 1). Four cases were mixed carrying both H. typhlonius and H. bilis. The carried Helicobacter genus and species had no statistical significance in tree shrew among different gender and age groups (P > 0.05) (Table 2). The highly carried rate of Helicobacter spp., mainly H. typhlonius, H. bilis and H. cinaedi, was found in laboratory tree shrew with different genders and ages.