By Kara Nuzback and Gail Stephens
Cooperative Science Center Fellow Alissa Riley, left, and Dr. Salina Parveen inspect oysters from the
bottom of the Honga River in Fishing Creek, Maryland.
A school of thought could prevent future global illness outbreaks caused by the transfer of disease or infection from animals to humans, or zoonosis, if widely adopted.
The term “One Health” was coined in the Wildlife Conservation Society’s 2004 Manhattan Principles. At the time, our increasingly global society was experiencing several outbreaks caused by zoonoses, including West Nile virus, Ebola hemorrhagic fever, SARS, mpox, mad cow disease and bird flu.
The Manhattan Principles posed:
Only by breaking down the barriers among agencies, individuals, specialties and sectors can we unleash the innovation and expertise needed to meet the many serious challenges to the health of people, domestic animals, and wildlife and to the integrity of ecosystems. … We are in an era of “One World, One Health” and we must devise adaptive, forwardlooking and multidisciplinary solutions to the challenges that undoubtedly lie ahead.
Several faculty members at University of Maryland Eastern Shore are answering the call to investigate how the health of the environment, animals and marine life is central to the health of humans.
Examining Seafood and Swimming Safety
Dr. Salina Parveen, professor of food microbiology and safety, environmental microbiology, and molecular biology at UMES, studies a bacterium called Vibrio that exists naturally in seawater.
Rising water temperatures affect the concentration of Vibrio in water, and high concentrations can lead to higher levels of this bacterium in oysters, which can accumulate Vibrio during their filtration process.
Since 2004, Parveen has investigated where and when Vibrio contamination occurs in oysters and coastal waters, in part because Vibrio can also affect humans who eat undercooked or raw oysters, or who go fishing or swimming in waters where the Vibrio concentration is high.
Parveen said immunocompromised people are especially at risk of infection, and symptoms can range in severity from diarrhea from ingesting a contaminated oyster to a flesh-eating disease from a wound infection that can result in amputation or death.
Parveen and her students are also studying an emerging pathogen called Shewanella that
survives in fish and shellfish and can continue to survive on food processing equipment. Some strains of Shewanella can have detrimental effects on humans who are exposed, including skin infections, sepsis and gastroenteritis.
These bacteria occur in the environment, but human interaction with the environment shifts their concentrations so the bacteria multiply. Then, the bacteria infect fish and humans. Through humans, the bacteria could spread to an entirely new environment, Parveen said.
“The same concept applies to Salmonella in poultry and other food,” she said. “Everything is interconnected. One thing is dependent on another.”
How Fido’s Food Affect Pet Owners
pet food in a University of Maryland Eastern Shore lab.
Dr. Janak Dhakal, an assistant professor in UMES’s Department of Agriculture, Food and Resource Sciences, is studying the occurrence of Salmonella in pet food, which can infect animals, but also humans.
“We hear about the Salmonella outbreaks linked to chicken, produce and vegetables, and pet foods contain a similar type of Salmonella, especially the raw ones,” Dhakal said. “When we handle and feed these feeds to our pets, we may get exposure through contaminated feed handling. Additionally, the pets then become a carrier for Salmonella and increase our risk for exposure.”
Processed human food is treated with antimicrobials and heat, but there is no established post-processing intervention for commercial pet foods leading to potentially higher load of the bacteria. Dhakal said that since 2015, there have been at least 58 recalls due to Salmonella in pet foods in the United States, and six of those were associated with human illness and hospitalization.
Tackling Transmission
To solve the problem of Vibrio or Shewanella infection, Parveen and her team first aim to know the bacteria, inside and out. “We have to know the sources. Where is it? What can we learn about it? How do we kill or control it? Our lab is conducting research on all these approaches,” she said.
Extensive research on ecology, antibiotic resistance, genomics, metagenomics and control of Vibrio has already helped Parveen’s lab develop methods to control its presence in oysters. She said that information can now inform aquaculturists, industry, consumers and policymakers.
UMES received a U.S. Department of Agriculture grant to aid its research into how commercial pet food transmits foodborne pathogens to humans. The $600,000 in funding, awarded through the USDA’s National Institute of Food and Agriculture, enables research to run through March 2027.
Dhakal said the grant aids UMES in becoming one of the forerunners in examining the safety of pet food. UMES looks to ultimately provide training to pet food manufacturers on applying proper safety measures.
On the Frontlines of Zoonoses
In academia, veterinary schools are central to the One Health concept, as students learn how to practice at the intersection of animal, human and environmental wellness. In the end, veterinarians are at the frontline of zoonotic disease detection. UMES’ new School of Veterinary Medicine will be the first in Maryland.
(Photos by Todd Dudek, UMES Ag Communications)
This work is supported by: Shewanella, no. 2018-38821-27759, U.S. Department of Agriculture’s National Institute of Food and Agriculture. Vibrio, no. NI251445XXXXG003 and no. 2021-38821-34583, respectively, USDA’s Evans-Allen and Capacity Building Grant. Salmonella in Commercial Pet Foods, no. MDX-AS202404, USDA
