Antibiotic-resistance genes in viruses in fossilised 14th century human faecal sample

A discovery of viruses harbouring antibiotic-resistance genes in fossilised faecal samples dating from the 14th century could have implications not only for microbiologists but also for archaeologists, historians and anthropologists. The discovery was made by French researchers who studied samples from latrines from the period uncovered during an urban renewal project in the city of Namur in Belgium. The study is published ahead of print in the journal Applied and Environmental Microbiology.

The viruses found in the coprolites (fossilised faecal samples) are phages, i.e. viruses that infect bacteria rather than eukaryotes. These phages were examined by a mixture of “electron microscopy, high-throughput sequencing and suicide PCR approaches” according to corresponding author Christelle Desnues of Aix Marseille Université. The presence of the phages in the coprolites indicates that they would also have been present in the gastrointestinal tract. Many of the phage sequences identified were related to phages known in modern times to infect bacteria commonly identified in stools, including both harmless, helpful and pathogenic bacteria.

The findings revealed that the phages carried genes for antibiotic resistance, long before antibiotics were used therapeutically. The phages also carried toxin-resistance genes. Both antibiotics and toxins are commonly found in nature. The authors believe that these resistance genes would have protected gut bacteria. In this regard, they would have been essential in maintaining gut metabolism and health as the helpful bacteria inhabiting the gut and other body areas are important in human health. The results are consistent with other studies, for example of the human oral microbiome in skeletons of 1000 years old in which antibiotic-resistance genes were also found.

The phages in the coprolites differed taxonomically those within modern human faecal samples. However, Dr Desnues says that functionally their role has conserved. This adds weight to the hypothesis that the viral community in the human gastrointestinal tract play a fundamental role which has been conserved over centuries, despite dramatic changes in human diet and living conditions. The researchers are currently expanding their studies to fungi and parasites in the coprolites.

Sources:

Press release from American Society for Microbiology; available at http://www.eurekalert.org/pub_releases/2...022714.php [Accessed 28 February 2014].

APPELT, S., FANCELLO, L., LE BAILLY, M., RAOULT, D., DRANCOURT, M. and DESNUES, C., 2014. Viruses in a 14th-century coprolite. Appl. Environ. Microbiol. published ahead of print 7 February 2014 doi:10.1128/AEM.03242-13

WARINNER, C., RODRIGUES, J.F.M., VYAS, C., TRACHSEL, R., SHVED, N., GROSSMANN, J., RADINI, A., HANCOCK, Y., TITO, R.Y., FIDDYMENT, S., SPELLER, M., HENDY, J., CHARLTON, S., LUDER, H.U., SALAZAR-GARCÍA, D.C., EPPLER, E., SEILER, R., HANSEN, L.H., SAMANIEGO CASTRUITA, J.A., BARKOW-OESTERREICHER, S., TEOH, K.Y., KELSTRUP, C.D., OLSEN, J.V., NANNI, P., KAWAI, T., WILLERSLEV, E., VON MERING, C., LEWIS JR, C.M., COLLINS, M.J., GILBERT, M.T.P., RÜHLI, F. and CAPPELLINI, E., 2014. Pathogens and host immunity in the ancient human oral cavity. Nature Genetics 2014; doi:10.1038/ng.2906 (Advance online publication).