University of Pittsburgh Department of Biological Sciences Presents:
Friday Noon Seminar Series 2017-2018
Graduate Student: Travis Mavrich
Characterization and induction of human gut-associated Bifidobacterium prophages
The human gut microbiome is a complex and dynamic environment comprised of myriad microbial organisms, including Bifidobacterium. This bacterial genus is a member of the phylum Actinobacteria, is prominent in the human gut from birth, and plays positive roles in human health. Phages that infect gut-associated bifidobacterial hosts are predicted to be abundant, and their viral impact on bifidobacterial diversity may in turn affect the gut microbiome. However, few of these phages have been described. Here, we characterize three genetically distinct groups of phages integrated into several human gut-associated Bifidobacterium breve and Bifidobacterium longum strains. These prophages exhibit distant genetic relationships to isolated phages of other actinobacterial hosts. Although no infectious particles have been observed, we show that the phages are likely to be active in the gut and that some of them are competent for induction, replication, and virion assembly. Interestingly, some of them harbor a phase variation shufflon, Rin, which appears to promote inversion of receptor binding proteins to modulate host range specificity, similar to systems previously identified in coliphages. These bifidobacterial strains and phages exhibit dynamic evolutionary relationships, and they can be used in future studies to elucidate the role of Bifidobacterium in the gut microbiome.
Friday, March 17, 2018
A219B Langley Hall
12:00 PM Seminar