Biologists have discovered a new type of Propionibacterium acnes – the bacterium that causes human acne by infecting skin pores and forming spots – which now exploits grapevines.
They named the new bacterium Propionibacterium acnes type Zappae after the Italian term zappa (means hoe) as well as a tribute to eclectic composer Frank Zappa, “who once wrote of ‘sand-blasted zits’ in one of his most famous satirical songs, ‘Jewish Princess,’ from his controversial ’79 ‘Sheik Yerbouti’ album,” said Dr Andrea Campisano and Dr Omar Rota-Stabelli from the Fondazione Edmund Mach’s Research and Innovation Center in Italy, co-authors of the paper published in the journal Molecular Biology and Evolution.
“This bacterium is so unconventional in its behavior, and its new habitat is so unexpected that we thought of Frank Zappa. Indeed, at the time we were discovering it, we were both playing a Zappa album in our cars,” they said.
Propionibacterium acnes type Zappae was first discovered by the scientists via a 16S rDNA gene-based microbiome analysis gathered from the stems of plants sampled from multiple sites throughout Northeast Italy.
The bacterium colonizes bark tissues, and the pith, where the bacterium can localize intracellularly. Thus, compared to being a bane to millions of teenage faces, Propionibacterium acnes type Zappae has adapted to an entirely new intracellular ecological niche in grapevines.
The team also investigated the evolutionary history of Propionibacterium acnes type Zappae by using two marker genes, recA and tly.
Remarkably, the findings support a human origin for the bacterium. The data also suggest a loss of function of recA, a protein essential for the repair of DNA, which means that the bacterium must rely on its grapevine host for survival.
Finally, the scientists estimate the emergence of Propionibacterium acnes type Zappae around 7,000 years ago, an age highly compatible with the first domestication of the grapevine and a time when human intensive practices, such as the grafting and pruning of vines, may have led to the transfer to its new host.
This is the first evidence ever of human to plant obligate transfer and gives new perspective of bacteria host transfer between humans and domesticated plants.
Andrea Campisano et al. Interkingdom transfer of the acne causing agent, Propionibacterium acnes, from human to grapevine. Mol Biol Evol, published online February 19, 2014; doi: 10.1093/molbev/msu075