(Submitted by Divya Rose)
By Alaina Dismukes
Mississippi is the top aquaculture-producing state in the country, known for its farm-raised catfish. As a leader in aquaculture, it is of the utmost importance to address any signs of antimicrobial resistance (AMR) to maintain a stable supply of catfish and prevent instances of fish loss due to disease. Luckily, Mississippi State University is home to one of four global U.N. Food and Agriculture Organization (FAO) Reference Centers on Antimicrobial Resistance and Aquaculture Biosecurity through the Global Center for Aquatic Health and Food Security, or GCAHFS, which is affiliated with the university’s College of Veterinary Medicine (CVM).
The FAO Reference Center on AMR and Aquaculture Biosecurity provides independent, technical, and scientific advice as a hub for research on AMR conducted by MSU faculty and students in the field. One such student is Divya Rose, a PhD candidate in veterinary biomedical science with a concentration in infectious disease within the College of Veterinary Medicine and stationed at the Thad Cochran National Warmwater Aquaculture Center.
"It is important to study AMR because there are still a lot of unknowns," Rose said. "It is like knowing your enemy in a battle; the more we know about how resistance works and where it comes from, the better equipped we will be to address and manage it effectively."
In August 2024, Rose gave two talks at the 2024 American Fisheries Society (AFS), Fish Health Section (FHS) annual meeting in Boise, ID, thanks to receiving the virtual Summer Seminar Series "Best Student Presentation" award in 2023, which provided her travel support to attend the in-person meeting and present her work this year.
"The virtual Summer Seminar Series organized by the AFS, FHS has been a great opportunity for students and early career professionals to share their research and network within the fish health community over the last four years," she said. "Personally, it has helped me a lot in terms of learning, sharing, and knowing what’s happening in fish health."
The Summer Seminar Series has many generous sponsors, including CVM and GCAHFS. Support from sponsors goes directly toward allowing students the opportunity to participate in the annual AFS, FHS meeting.
"At the meeting, I got to present my research to a bigger group, and my first presentation was titled 'Microbiome Analysis of Channel Catfish Pond Water Samples,'" she said. "The other presentation I gave at the meeting was 'Searching for the Environmental Reservoirs of Antibiotic Resistance in Commercial Catfish Ponds in the Mississippi Delta.' The first presentation discussed the environmental microbiome of catfish ponds from two different catfish farms, specifically looking at different management strategies in response to bacterial disease outbreaks—whether they use antibiotics or not—and how that affects microbial communities."
The second presentation focused on more targeted approaches to identify the potential environmental reservoirs of antibiotic resistance in catfish production systems.
"One interesting finding from the research is that the antibiotic florfenicol was first approved for use in the catfish industry in 2007," Rose said. "However, the genetic machinery for the uptake and maintenance of the genes responsible for florfenicol resistance was present in E. ictaluri isolates 30 years ago in 1994, suggesting this machinery can be present in bacterial communities with or without the presence of external antibiotic selection pressure."
Matt Griffin, Rose's PhD advisor and a research professor at the College of Veterinary Medicine’s Aquatic Research and Diagnostic Lab, a part of the Thad Cochran National Warmwater Aquaculture Center in Stoneville, MS, said that Rose's work is crucial to the sustainability of the U.S. catfish industry.
"She is laying the foundation for a deeper understanding of the factors driving AMR in catfish aquaculture," Griffin said. "By utilizing state-of-the-art technology, she is unraveling the complexities of microbial community dynamics in catfish ponds—an essential step in mitigating potential reservoirs of AMR within the industry."
"AMR is a concern not just in aquaculture, but everywhere microbes are present," Rose said. "It is important to study AMR, which will give us insights into how we can tackle the problem of resistance. Being able to work directly with our stakeholders has helped me understand the industry and their concerns better, such as the financial viability of a practice. It is crucial to develop sustainable practices in aquaculture while also considering the industry’s long-term success, which depends on ensuring that sustainable practices and the producers’ bottom line are given equal importance."