A new study shows that humans transmitted Staphylococcus aureus bacteria to green monkeys. While there are many known cases of humans acquiring diseases from animals, transmissions from humans to monkeys are uncommon. The findings were just published in the journal Applied and Environmental Microbiology.
Researchers isolated strains of S.aureus bacteria from healthy green monkeys (Chlorocebus sabaeus) in The Gambia. They were able to isolate a total of 90 S.aureus bacterial strains. The team used a technique called high-throughput sequencing to determine how the strains were related to each other. From this information, the researchers were able to map out transmission events.
The results showed that green monkeys had acquired S.aureus bacteria from humans multiple times throughout history. Most of the isolated strains were part of the same clade and had been originally transmitted to monkeys 2,700 years ago. In addition, the team found two recent transmission events. One happened three decades ago while the other occurred just seven years ago. Interestingly, the bacteria lost genes in the transition to their new monkey hosts. According to the researchers, the genes were used to adapt to human host conditions and were no longer required.
The most recent transmissions from humans to monkeys may have occurred because green monkeys live near human developments. The monkeys in these areas are friendly and people often feed them. This allows S.aureus bacteria to easily jump hosts. While the team didn’t find any evidence of the reverse (bacteria transferring from monkeys to humans), the researchers caution that it may be possible as humans continue to come into contact with the wild monkeys.
As humans interact with wildlife, transmissions of bacteria between hosts may become more common. Limiting contact with wild animals will reduce the risk of disease for both humans and animals. Many of humanity’s deadliest diseases originated from animal hosts. Understanding the patterns of disease transmission is critical to avoid problems in the future.
Madikay Senghore et al. Whole-genome sequencing reveals transmission of Staphylococcus aureus from humans to green monkeys in The Gambia. Applied and Environmental Microbiology (2016).