Bifidobacterial occurrence in in cotton-top tamarin (Saguinus oedipus) and emperor tamarin (Saguinus imperator)

Unlike in humans, the diversity of bifidobacteria in the gut of non-human primates is poorly understood. In the present work, for the first time, the bifidobacterial population in cotton-top tamarin (Saguinus oedipus) and in emperor tamarin (Saguinus imperator) has been studied. The main objective of this study was the isolation and the identification of bifidobacterial strains from one adult subject of the cotton-top tamarin and from one adult subject of the emperor tamarin. The analysis of their bifidobacterial communities by molecular methods was assessed by culture dependent and culture independent techniques. Viable bifidobacteria ranging from 8 to 9.0 log10/g of faeces were found in both tamarins and sixty-three fructose-6-phosphate phosphoketolase positive strains were isolated and characterized. Rep PCR analysis with primer BOXA1R clustered these isolates in fifteen different groups. The 16S rRNA gene sequence analysis confirmed the presence of 15 different Clusters (nine Clusters for each tamarin) and six out of them were species previously described in other Callitrichidae (common marmoset): Bifidobacterium callithricos (Cluster V), Bifidobacterium stellenboshense (Cluster VIII), Bifidobacterium myosotis (Cluster X), Bifidobacterium biavatii (Cluster XII), Bifidobacterium tissieri (Cluster XIII) and Bifidobacterium catulorum (Cluster XIV). The remaining nine Clusters represent new species. Recently 4 clusters have been described as the novel species Bifidobacterium aerophilum (Cluster I), Bifidobacterium avesanii (Cluster II), Bifidobacterium ramosum (Cluster III) and Bifidobacterium callitrichidarum (Cluster XI). Clusters IV, VI, VII and IX are new species under description and Cluster XV is a new species under study. These new species show phenotypic similar features such as microaerophilic growth. Based on our results, bifidobacteria could be considered natural inhabitants of the gut of the cotton-top tamarin and emperor tamarin. An interesting finding is the high number of bifidobacterial clusters found in every single tamarin showing a high intra/inter-subjects diversity and similarity: this is in contrast with the few numbers of species (at maximum 4) usually found per human host. Interestingly, comparing data on studies of bifidobacterial distribution in New World Monkeys (common marmoset and tamarins), it can be observed that some bifidobacterial species were exclusively present in Common marmosets or tamarins, whereas other species were widely shared across all these Callitrichidae. Consequently, such complex and heterogeneous bifidobacterial communities seem to be composed of some bifidobacterial species more intimately close to their host (probably being genetically adapted to the host) and a core of species potentially shared across different host species, which reflect the co-evolution of these beneficial microorganisms with their host.