BROOKINGS – Heather Deter, a doctoral student in biology and microbiology, and Olena Boiko, a master’s student in geography, have been named recipients of South Dakota State University’s Joseph F. Nelson Graduate Scholarship. The award, which recognizes original scientific research, provides each student with $2,500 for tuition and expenses.

Deter, who completed her bachelor’s degree in microbiology at the University of Georgia, began studying how cells, known as persisters, gain resistance to antibiotics at Virginia Tech in 2016. She transferred to South Dakota State in 2017 when her research adviser, Nicholas Butzin, became an assistant professor in the SDSU Department of Biology and Microbiology.

“This award is an acknowledgement of the high-caliber research Heather is doing,” said Butzin, who is also a South Dakota Agricultural Experiment Station researcher. “She is not only enthusiastic and committed to her research but also mentors other students in my laboratory.”

Boiko, who earned her bachelor’s degree in chemical technology at the Kyiv Polytechnic Institute in Ukraine, is examining deforestation in the Ivory Coast. She is a graduate teaching assistant and coordinator of geography teaching assistants.

“This is recognition that what I am doing really matters,” said Boiko. “As I looked through the literature on the world’s tropical forests, I saw much more on Brazil and Southeast Asia than on West Africa. I want to bring this to people’s attention.”

Her research adviser, geography professor Darrell Napton, suggested that Boiko apply for the scholarship. “He’s always encouraging me to do more and become better – it is challenging but also rewarding. He really cares about his students.”

Napton said, “Olena is one of the most talented, insightful and productive students with whom I have worked. Her performance continually exceeds my expectations.”

Examining how cells gain antibiotic resistance

Persister cells are like sleeper cells – they are dormant while the patient is taking antibiotics, but when the antibiotics are gone, they start growing again.

“Antibiotic resistance happens because of a change in the DNA that subsequently alters the proteins the cell produces,” Deter explained. She has used several different approaches to understand how persistence happens.

In one study, Deter looked at how cells regulate the toxin-to-antitoxin ratio. “Toxin protein slows growth by affecting other systems – that slowed growth characterizes a persister cell,” she explained. “Antitoxins allow cells to grow normally, so in a normal cell, antitoxins need to be produced faster than the toxins.” Her analysis was published in the July 2017 issue of Toxins.

In addition, she is examining the role enzymes that break down proteins, known as proteases, play in cells developing persistence. “The cell has a limited number of processing resources. When many proteins wait in line to be processed, there is an increase in persistence,” said Deter, who is investigating three or four types of proteases.

“If we can figure out how to decrease the level of persistence, it will give us a good idea of what drug targets will affect persister cells,” Deter said. She plans on completing her doctorate in 2020 and then hopes to get a postdoctoral position.

Tracking deforestation in protected areas

Boiko examined Landsat satellite images to track changes in land use in the Mabi, Yaya, Songan and Tamin reserved forests of southeastern Ivory Coast. The Ivory Coast has one of the highest deforestation rates in Africa.

“The reserved forests are classified as protected areas,” she said. “Based on the definition in the forestry code, human activity is not permitted.” Boiko compared land use/cover in these reserved forests in 1986, 1999 and 2017.

“The dense forest coverage decreased substantially from 1986 to 2017,” she said. “There are clear discrepancies between what is on paper and on the landscape. The protective strategies are not working.” Though Boiko’s work focuses on only one small area, she said, “All across the Ivory Coast, I see the same patterns.”

The satellite images showed large forest areas converted into agricultural land, both for subsistence-level farming and plantations, to produce cash crops, which include coffee, cocoa, rubber and oil palm.

However, Boiko noted, “soil fertility is a problem.” After a couple of growing seasons, the land becomes less productive. To maintain or increase production, the farmers simply clear more land.

“Though we as geographers see maps as powerful tools, maps alone give little information about the drivers of change,” Boiko explained. To investigate what fuels these changes, she will examine environmental agency reports, United Nations documents and news articles.

 “I will synthesize change patterns and their drivers to draw conclusions, hopefully, as to why those protection strategies did not work and how we can do better in the future,” she said.

Boiko will finish her master’s degree this spring or summer and hopes to find a job working with geography or geographic information systems in the United States or Ukraine. “I want to see how things are done outside academia,” she said. However, she is still keeping her options open when it comes to doctoral work.