University of Wisconsin–Milwaukee

School of Freshwater Sciences

Biomarkers in Brazil

Amber Koskey, second-year School of Freshwater Sciences M.S. student,
traveled to Brazil last summer to use the bacterial source-tracking technology
developed by SFS Associate Professor Sandra McLellan to detect the presence
and source of human fecal bacteria in the river of two rural communities.
When she started grad school, Amber Koskey never thought she would be using a bike pump to hand-filter dozens of water samples, but field work in any setting – especially in a foreign country – sometimes demands innovative thinking. And, now that Koskey, a second-year School of Freshwater Sciences M.S. student, is a seasoned in situ scientist, she has found that innovation can also be used to protect her own health and safety while studying infectious diseases.

When Koskey’s research partner, Rafael Ponce-Terashima M.D. a fellow at Case Western Reserve University, was conducting research in eastern Brazil last year, he did most of the sampling in the Rio Jiquiriçá, in waders. The second time around, Ponce-Terashima and his new research partner took more precautions. “We were very diligent about sanitizing, wearing gloves and closed-toed shoes and we never went into the water,” Koskey says. They rigged up a sampling device from a pole, rope and Nalgene water bottle so that they could sample from shore. “It was very MacGuyverish,” she says. That contraption also had more practical purposes. “It definitely decreased our risk of getting shisto.”

Koskey’s research partner, Rafael Ponce-Terashima M.D. uses a hand-made
sampling device from a pole, rope and Nalgene water bottle so that they
could sample the river from shore.
“Shisto” is short for Schistosomiasis, a tropical parasite that is prevalent in tropical rivers contaminated by sewage – and rampant in the Jiquiriçá. The river runs through the two small communities in the Brazilian region of Ubaíra, where Koskey has been using the bacterial source-tracking technology developed by School of Freshwater Sciences Associate Professor Sandra McLellan to detect the presence and source of human fecal bacteria in the river.

The Schistosomiasis parasite is released into water sources through waste from infected humans and then incubates in freshwater snails (prevalent in the Rio Jiquiriçá) before spreading into waterways. The disease presents itself as a rash, or “swimmers itch” and can cause chronic health issues, including cardiovascular damage and gastrointestinal illnesses, if not treated.

Because many houses in the communities near the Jiquiriçá don't have septic systems, human waste is going directly into the river, creating a cycle of contamination. “These people walk through the water, bathe in the water, sometimes they use it for drinking water as needed because the water sources in the community aren’t the most reliable,” says Koskey. “They have the infrastructure to pipe water, but for various reasons, the system just fails and the people are left with no other option than to drink water from the river.”

Field work in any setting – especially in a foreign country – sometimes
demands innovative thinking. Pictured here is an incubator made by Koskey
and Ponce-Terashima.
The McLellan Lab has been using genetic markers to identify fecal indicator bacteria in Lake Michigan and in Milwaukee's Menomonee River and other local waterways. For their research in Brazil, Koskey and Ponce-Terashima have been using two biomarkers developed in the McLellan lab to pinpoint sewage outflows based on the presence of human bacteria in the river.

“We want to see if the markers are different between different cultures. In the United States, or even Milwaukee, we have a different gut microbiome than, say, a rural Brazilian.” She will study the possibility of developing site-specific bacterial tests for different geographic regions.

After attending XII International Course of Molecular Epidemiology in Emerging Infectious and Parasitic Diseases in Salvador Brazil in August, Koskey headed to her research site in Jenipapo and Volta do Rio. While Ponce-Terashima did most of the interpreting, Koskey learned enough Portuguese to help her interact with the locals. “Brazil is a very social culture,” she says. “We had to spend an entire day introducing ourselves to people in each of the communities and talking about what Rafael and I were doing. Mind you, this was all in Portuguese, so I am just standing there, smiling, saying ‘Hi my name is Amber. I am from the U.S. and helping Rafael with this project.’ This required a lot of patience, which I especially needed in hour-long meetings that were all in Portuguese.”

Koskey hopes her work with the communities will help prevent so many
illnesses caused by shisto. 
Koskey is also interested in researching the microbial community profiles of different animals to identify new indicators of waterborne pathogens. They could potentially be used to monitor the level and source of animal fecal contamination in the Rio Jiquiriçá and other water bodies in the region. The McLellan lab has been working on developing host specific markers for different organisms.

Reflecting on her work in Jenipapo and Volta do Rio, Koskey says that “It’s really neat to work with these communities and to help them in any way possible. Any opportunity for community education and outreach could prevent so many illnesses and potentially save lives,” she says. “Even if it's just talking to the little boy watching us and explaining to him why bathing in the water in this river caused him to get Shistosomisis months ago.”