14th century fossilized human feces contain antibiotic resistance genes

Researchers have discovered viruses containing genes for antibiotic resistance in a fossilized fecal sample from 14th century Belgium, long before antibiotics were used in medicine.

The viruses in the fecal sample are phages, which are viruses that infect bacteria, rather than infecting eukaryotic organisms such as animals, plants, and fungi.

Corresponding author Christelle Desnues of Aix Marseille Universite said that most of the viral sequences the researchers found in the ancient coprolite (fossil fecal sample) were related to viruses currently known to infect bacteria commonly found in stools (and hence, in the human gastrointestinal tract), including both bacteria that live harmlessly, and even helpfully in the human gut, and human pathogens.

Desnues said that the communities of phage within the coprolite were different, taxonomically, from communities seen within modern human fecal samples, but the functions they carry out appear to be conserved.

She said that their evidence demonstrates that bacteriophages represent an ancient reservoir of resistance genes and that this dates at least as far back as the Middle Ages.

The study has been published in the journal Applied and Environmental Microbiology.