Email to a friend 
E. coli bacteria migrating between
humans, chimps in Ugandan park
Diana Yates,
Life Sciences Editor
217-333-5802; diya@illinois.edu
 |
Click
photo to enlarge |
Photo
courtesy Tony Goldberg |
| Tony
L. Goldberg, a professor of veterinary
pathobiology, with
anesthetized Red Colobus monkey in Kibale
National Park, Uganda. |
|
|
Released
2/22/07
CHAMPAIGN, Ill. —
Scientists from the University of Illinois at Champaign-Urbana have
found that people employed in chimpanzee-focused research and tourism
in a park in western Uganda are exchanging gastrointestinal bacteria – specifically Escherichia coli – with local chimpanzee
populations. And some of the E. coli strains migrating to chimps
are resistant to antibiotics used by humans in Uganda.
Their study will appear in the April 2007 issue of Biological Conservation
and is available now on the journal’s Web site.
Other studies have found bacterial exchanges between humans and non-human
primates – particularly in areas where the animals are known to
frequent garbage piles near human settlements. But this is the first
study to document the exchange of E. coli between humans and chimps
in a protected wildlife area. It is also the first to find antibiotic-resistant
strains in chimpanzees in Africa.
“Antibiotic resistance has traditionally been associated with
two factors: indiscriminate and over-prescription of antibiotics by
physicians in the developed world and the inclusion of antibiotics in
animal feed in the developed world,” said Tony L. Goldberg, a
professor of veterinary pathobiology and the principal investigator of the study. The new findings, Goldberg
said, show that over-the-counter sales of antibiotics for human consumption
can also have an impact on wildlife.
The research team, which included researchers from Makerere University
in Kampala, Uganda, and McGill University in Montreal, examined two
of 10 known communities of chimpanzees living in Kibale National Park,
Uganda. One of the two chimp groups has been the focus of two decades
of research by international teams of scientists. The other is regularly
visited by employees of a local tourism venture.
Goldberg’s team compared strains of E. coli in the chimps to those
of the Ugandans employed in research and tourism in the park.
The team also analyzed samples from people living in a village 5 kilometers
from the research site and 25 kilometers from the tourism station. People
in the village had no known contact with the chimps.
The team collected 250 E. coli isolates from 25 humans and 23 chimpanzees.
Of these, 89 unique genotypes (strains) of E. coli were found.
The E. coli strains from the chimps were more like those of the humans
working in the park than like humans living in the village.
“This expands our notion of the situations in which people and
chimps can exchange microbes,” Goldberg said. “Habitat overlap,
even without direct contact between people and primates, is sufficient
for the exchange to occur.”
The further finding that humans had transferred some antibiotic resistant
strains to chimps “was the smoking gun,” Goldberg said.
More than 81 percent of the humans and 4.4 percent of the chimps studied
were found to harbor at least one E. coli isolate that was clinically
resistant to an antibiotic. Antibiotics are used frequently in human
populations in this region of Uganda, Goldberg said, but antibiotics
have never been used in local wildlife, so the antibiotic-resistant
bacteria in chimps clearly originated in humans.
 |
Click
photo to enlarge |
Photo
courtesy Tony Goldberg |
| Veterinary
pathobiologist
Tony Goldberg collects water samples in the Kibale
National Park, Uganda. |
|
|
Goldberg said it
was not clear whether the exchange of bacteria was the result of
direct or indirect (environmental) association between the chimps
and humans working in the park. Both make use of local streams and
other environmental features.
Regardless of the route of transmission, it places both at risk, Goldberg
said.
“We’re as concerned about potential effects on human health
as on animal health,” he said.
He noted that the exchange of microbes between non-human primates and
humans is not new. Two deadly viruses, HIV and Ebola, are believed to
be linked to chimpanzees and other non-human primates. Human diseases
also pass to monkeys and apes, with equally dire consequences: Pneumonia,
respiratory disease, scabies and a polio-like virus have caused epidemic
mortality in chimpanzees in some African locales.
This study was funded by the Morris Animal Foundation.
Editor’s note: To reach Tony Goldberg,
call 217-265-0297; e-mail: tlgoldbe@illinois.edu.
