A molecular epidemiologist at Washington State University is working on a research project geared toward understanding how much of the presence and distribution of antibiotic resistance is ecological in nature, not just driven by the use of antibiotics.
The director-general of the World Health Organization earlier this year warned of “an end to modern medicine as we know it.” In the not-too-distant future, said Margaret Chan, “Things as common as strep throat or a child’s scratched knee could once again kill.”
The culprit: the growing ability of bacteria and other pathogens to fight drugs, a phenomenon known as antibiotic resistance. Chan singled out several underlying causes: counterfeit and substandard drugs, the use of antibiotics as growth promoters in livestock, a lack of new drugs in the pipeline and "gross misuse of these medicines.”
Doug Call wants to take an even larger view, looking at the ecological and socio-economic factors behind antibiotic resistance, from the genes of bacteria to the landscapes they live in to the pathways by which they travel through people and animals. A molecular epidemiologist in Washington State University’s (WSU) Paul G. Allen School for Global Animal Health, Call has received nearly $1.9 million from the National Science Foundation to conduct research in 30 villages across three ecological zones of the greater Serengeti ecosystem of Tanzania.
Call has chosen Tanzania in part because East Africa is a focus of the school, but also for the relatively self-contained interactions among its people and domestic and wild animals. In the United States, pathways between people and their food are much more distant and complicated to track, typifying the ease with which bacteria spread around the world via international travelers and global trade.
“We are one large cesspool of sharing flora,” Call says. Moreover, he says, bacterial resistance policies in the United States can target food sectors to control but, given the numerous means of bacterial transmission, they may not be particularly effective.
“The only way we can really get to that question is to better understand the extent to which this kind of mixing and transfer can occur,” he says. "That’s a lot of what we’re doing with this project – understanding how much of the presence and distribution of antibiotic resistance is ecological in nature, not just driven by the use of antibiotics.”
The three-part project will call on biological, medical and sociological sciences, with collaborators across WSU, Great Britain and Tanzania.
First, WSU anthropologists Robert and Marsha Quinlan will conduct a socioeconomic survey of villagers on issues that include veterinary care, antibiotic use, animal movements and trade, and water sources and treatment.
With more than a dozen transmissible diseases, “These guys have just about the worst of the worst possible diseases you can think of,” says Call.
Researchers also will collect bacteria through fecal samples, isolate E. coli, look at resistance to 15 drugs and do some genetic profiling to plot villagers’ movement across the landscape.
The third part of the research will be development of ecological models to explain the distribution of antibiotic resistance.
“Things are not just drug use,” Call says. "That dichotomy is false in my thinking about the world. It’s much more complex than that. We’re trying to capture an understanding of the ecological component to this problem because it’s going to better inform how we can improve our own policies in the United States, as much as in Tanzania.”
Additional funding for Call’s research is provided by Jan and Jack Creighton and the Caroline Engle professorship in Research on Infectious Diseases in the Department of Veterinary Microbiology & Pathology at Washington State University.
Learn more at the Washington State University Web site.