Grapes don't get acne, of course

An Italian team has discovered that Propionibacterium acnes, the ubiquitous human skin bacterium that causes acne, is also found within domesticated grapevines. The researchers say this is the first known inter-kingdom transfer of a bacterial symbiont, and that it likely happened during the Neolithic.

This specific variety of P. acnes is grape-adapted and an obligate endophyte: it can no longer live on human skin. It does the grapes no harm, and might be benefiting them in some way.

Though this is the first example of a human-to-plant pathogen transfer, the team thinks the same bacterium may live in other domesticated plants, and that other types of bacteria may also have transferred from humans to plants, Campisano said.