zebrafishCredit: iStock

A Wayne State University School of Medicine student and two recent graduates working on a collaborative project in the laboratories of Associate Professors of Ophthalmology, Visual and Anatomical Sciences Ashok Kumar, PhD, and Ryan Thummel, PhD, have discovered that zebrafish don’t contract endophthalmitis.

The eye infection can cause blindness within hours if not diagnosed and treated quickly.

Matthew Rolain, Frank Mei, MD ’19 and Xiao Yi Zhou, MD ’17, contributed to the study, “Zebrafish are Resistant to Staphylococcus aureus Endophthalmitis,” published in Pathogens, a peer-reviewed journal in the field of microbiology and immunology.

The study showed that while humans require only 10 to 100 ‘bugs’ to cause endophthalmitis, and mice require 5,000 before infection, in the freshwater fish, even 250,000 bacteria won’t cause the eye infection. The finding indicates that zebrafish eyes are incredibly resistant to such eye infections and possess strong host defense mechanisms.

Dr. Thummel and others in the field have shown that humans and fish share similarities in eye structure and immune responses. Studying why fish, but not human eyes, are resistant, may help identify protective pathways and molecules that could be translated to humans.

“Traditionally, we have used a mouse model to study the pathobiology of these infections. In recent years, zebrafish have emerged as an important model organism in biomedical research, providing insight into the pathogenic mechanisms of infectious diseases. We sought to determine their susceptibility with the ocular bacterial infection,” Dr. Kumar said. “I contacted my colleague Dr. Thummel and discussed the idea, and the project took off with participation of three medical students who completed the task collectively.”

Dr. Kumar’s laboratory focuses on understanding the pathobiology of ocular infections, especially those affecting the retina, such as endophthalmitis. The infection most often occurs due to surgical complications or eye trauma.


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“Apart from conducting research, I truly enjoyed mentoring these medical students,” Dr. Kumar said. “I hope they continue develop scientific acumen as they transition to their respective residency programs.”

Matthew Rolain will graduate from the School of Medicine in 2020.

“Working with Dr. Kumar and Dr. Thummel was an awesome experience,” he said. “They gave me great guidance and were always very supportive, regardless of the outcome of our experiments. It was nice being able to learn about the research process while working on such an interesting and potentially impactful project. Hopefully the scientific community will be able to build on our results to better help future patients.”

Dr. Mei is now a resident in his transitional year in Chicago before starting a two-year ophthalmology program at the University of Texas Southwestern Medical School in Dallas.

“Individually, Drs. Kumar and Thummel were well respected in their separate expertise. However, the unification of their talents into a singular project created a collaborative environment where the strengths of both labs meshed, launching and dramatically expediting this project to completion in a very short timeframe. Bridging the gap between Scott Hall and the Kresge Eye Institute, Drs. Kumar and Thummel created a warm atmosphere to foster my growth as a researcher. This experience was invaluable and an encouragement for me to seek further collaborations in my career in academic ophthalmology,” Dr. Mei said. “Lastly, I would like to thank the Medical Summer Research Project through Wayne State and the Kresge Summer Internship for supporting me through this project.”

Their colleague, Dr. Zhou is a resident in her transitional year at NorthShore University Health System in Illinois. She completed a one-year fellowship at Bascom Palmer Eye Institute in Miami after graduation.

Moving forward, they plan to test zebrafish susceptibility to other bacterial and fungal pathogens.

The work was supported by grants from the National Institutes of Health (R01EY027381 and R01EY026964 to Dr. Kumar, and R01EY026551 to Dr. Thummel. Histology and imaging core resources were supported by a vision core grant (P30EY04068) and an unrestricted grant from Research to Prevent Blindness to the Department of Ophthalmology, Visual and Anatomical Sciences.