Quantitative CrAssphage real-time PCR assay derived from data of multiple geographically distant populations.

After its computational inference from human stool metagenomes, the CrAssphage has proven to be the most prevalent phage in the human gut, with presumably very wide geographic distribution. The currently available molecular assays do not sufficiently reflect the CrAssphage sequence variability. Here, we report a novel real-time PCR assay whose primers and probes are derived from data of multiple CrAssphage strains obtained from gut viral metagenomes of European, Asian, and African subjects. This assay can be useful in analyses of putative bacterial host co-occurence, and in association studies of non-infectious diseases where the phage may modify the content of gut bacteriomes.