Acne is the first bacteria found to have hopped from humans to plants

Humans aren't the only living things that play host to the bacteria that causes acne. A team of researchers believe that our ancestors passed the microbe to grapevines thousands of years ago, the first known bacterial transfer from human to crop.

In a letter published in the latest issue of Molecular Biology and Evolution, a team of researchers based at the Research and Innovation Center – Fondazione Edmund Mach in Italy announced that they had discovered Propionibacterium acnes, the pathogen that acne in humans, in the bark, xylem fibers, and pith tissue of Vitis vinifera L., the domestic grapevine. They believe that this represents a "unique example of horizontal interkingdom transfer of a human opportunistic pathogen...to a crop plant."

Does that mean that grapevines have to deal with pimples? No, grapevines haven't suffered negative effects from Propionibacterium acnes, and the researchers suggest that the pathogen may prove somehow beneficial to the plant as part of its microbiome. Based on genetic analyses, the researchers believe that the transfer of bacteria from humans to grapevines occurred relatively recently in the plant's history, likely during the Neolithic era when grapevines were domesticated.

The researchers classified this grapevine strain of Propionibacterium acnes as Propionibacterium acnes Type Zappa (P. zappa for short), after the late musician Frank Zappa—because an unusual discovery deserves an unusual namesake.

Photo by tribp.

Interkingdom transfer of the acne causing agent, Propionibacterium acnes, from human to grapevine [Molecular Biology and Evolution via LiveScience]