A recent study conducted by MRC Unit The Gambia “Whole-genome sequencing reveals transmission of Staphylococcus aureus from humans to green monkeys in The Gambia”, published in American Society For Microbiology shows that pathogens can also jump the species barrier to move from humans to animals. The new research, shows that green monkeys in The Gambia acquired Staphylococcus aureus from humans.
In The Gambia, increasing urbanisation and tourism have meant that wild green monkeys have become habituated to humans resulting in increased opportunities for inter -host transmission of potential pathogens. “Although wild, these monkeys are very acclimated to humans, who often feed them peanuts,” explained co-author Martin Antonio, PhD, Unit Molecular Biologist & Principal Investigator, Vaccines and Immunity Theme, Medical Research Council Unit The Gambia who led the work.

According to the author Madikay Senghore, PhD student, “this study is a fine example of interdisciplinary synergies leading to cutting edge research that has enhanced our understanding of the dynamics of human pathogens in closely related primates.”

In the study, experts isolated strains of S. aureus from the noses of healthy monkeys in The Gambia and compared the monkey strains with strains isolated from humans in similar locations. “We used a technique known as high-throughput sequencing to gain an exquisitely detailed view of the relationships between the various strains,” said study co-author Mark Pallen, MD, Ph.D., Professor of Microbial Genomics, Warwick Medical School, the University of Warwick, Coventry, UK. “The results showed that monkeys had acquired S. aureus strains from humans on multiple occasions,” he added.

Most of the S. aureus found in monkeys were part of a clade, a group with common ancestors, which appeared to have resulted from a human-to-monkey transmission event that occurred 2,700 years ago. Research findings shows two of the most recent human-to-monkey transmission events appear to have taken place around three decades ago, and roughly seven years ago, respectively. These events appear to be the result of human encroachment into the monkeys’ natural habitat, and probably resulted from transfer of human bacteria from hands to food that was then fed to monkeys. The investigators found no evidence of transmission of S. aureus from monkeys to humans. However, as the two species come into ever-closer contact, there might be an increased risk of additional inter -species exchanges of potential pathogens.

Acknowledgements: The Department of Parks & Wildlife Management, Ministry of Forestry & the Environment, The Gambia and MRC Unit The Gambia staff

Authors: Madikay Senghore, Sion C Bayliss, Brenda A Kwambana-Adams, Ebenezer Foster-Nyarko ,Jainaba Manneh, Michel Dione, Henry Badji, Chinelo Ebruke, Emma L Doughty, Harry A Thorpe, Anna J Jasinska, Christopher A Schmitt, Jennifer D Cramer, Trudy R Turner, George Weinstock, Nelson B Freimer, Mark J Pallen, Edward J Feil, Martin Antonio.