Faculty-Student Research Team's Groundbreaking Work Highlighted in mSphere
Published on 16 July 2019
Amy J. Reese, Ph.D, associate professor of microbiology at St. Louis College of Pharmacy, and her team of faculty-student researchers are celebrating the recent publication of their fungus-related research in mSphere, an open-access, peer-reviewed journal of the American Society for Microbiology (ASM). The article, titled “Cell Envelope Integrity and Capsule Characterization of Rhodotorula mucilaginosa Strains from Clinical and Environmental Sources,” highlights a breakthrough in understanding a disease-causing fungus that thrives in hospitals and is difficult to treat.
Reese’s research team included Jeramia Ory, Ph.D., associate professor of biochemistry, Johnathan Yockey, Pharm.D. ‘19, Luke Andres, Pharm.D. ’19, and P3 student Moleigh Carson.
Reese has personally spent 10 years researching the structure of the disease-causing fungus, Rhodotorula mucilaginosa (R. mucilaginosa), and developing ways to diagnose it in patients. She is interested in disease-causing fungi because, although they can be very deadly, they are not widely understood.
“First and foremost, doctors need to be more aware of the presence of disease-causing fungi and their capabilities,” said Reese. “Then, the fungus must be correctly identified in order to be treated, and we also have to understand its structure in order to develop and use effective antifungal medications.”
Reese’s team began by working to unravel the mystery of why R. mucilaginosa resists antifungal medications used to treat similar fungi. They discovered that the fungus has a two-layer coating around its cell membrane, including a cell wall and a sugar capsule, which protects it from both the environment and a patient’s immune system. Fungal cell walls are particularly strong because they include chitin, the same sugar coating found in exoskeletons. While the capsule of R. mucilaginosa was previously noted in literature, there had been very little research on it.
The next step was to determine if the fungus’ structure varied when it came from a clinical setting, such as a hospital, as opposed to a natural environment. The team gathered and analyzed eight strains of the fungus from environmental sources and eight strains that originated in clinical settings. Using India ink staining, they discovered that the clinical strains had a larger capsule, suggesting that the process of passing through a person’s immune system actually strengthened the organism.
“Patients with cancer, AIDS and auto-immune disorders are most at risk for fungal infections because they spend lots of time in hospitals getting treatment,” Reese explained. “R. mucilaginosa is especially dangerous because it grows well on plastic, including catheter tubes, which increases the potential of exposure to hospital patients.”
Once the team understood the fungus’ structure and adaptability, they were able to create an antibody with the ability to attach itself to the fungus to “label” it. This antibody appears fluorescent under certain lighting, which could help scientists correctly identify it in a patient’s blood.
Throughout the research process, Reese’s students played an integral role. Carson used India ink to make images of the fungus in order to understand its construction, while Yockey tested the fungus’ adaptability to different conditions, and Andres worked on the antibody cell-tagging side of the research.
In June, Reese, Ory and Yockey presented their published findings at ASM’s MICROBE 2019 meeting in San Francisco.
“I like bringing students into the lab because it keeps me motivated, and I want to create experiences where the student learns to be the expert and feels like they’ve really made a difference,” Reese stated. “I’m very proud of the insights and innovations that my students have brought to this project, and we’re thrilled to be able to have the opportunity to share our findings with the readers of mSphere and the public at-large.”
Financial support for the study came from the College’s Research and Scholarly Committee (RSAC), which provided Reese with three Faculty Research Incentive Fund (FRIF) grants to conduct her work.
In the coming months, Reese’s team will continue to study the structure of R. mucilaginosa, while also further examining its environmental and hospital strains and conducting further experiments with anti-fungal agents.
The full abstract of the team’s findings can be found in the May/June 2019 issue of mSphere. To learn more about research at the College, visit stlcop.edu/research.