UNIVERSITY PARK, Pa. — Erika Ganda, assistant professor of food animal microbiomes and executive committee member of Penn State’s One Health Microbiome Center, was recently awarded two grants totaling $1.3 million from the U.S. Department of Agriculture to lead teams of scientists in the College of Agricultural Sciences and Penn State Extension in studies of pathogenic threats to livestock and people.
The grants from USDA’s National Institute for Food and Agriculture will fund Ganda’s teams as they investigate the links between harmful microbes and animal and human health.
Antimicrobial resistance. In the first project, the Ganda Lab plans to devise and test a comprehensive and cost-effective method to understand the impact of feed additives on antimicrobial resistance. A $1 million grant is funding this research. Antimicrobial resistance is often transmitted from animals to humans, Ganda said.
“While the link between antimicrobial use and the rise of antimicrobial resistance transmission has been established, specific agricultural practices that may mitigate the transmission of antimicrobial resistance are yet to be identified,” she said.
The existing methods are time-consuming and cost-prohibitive to broadly apply for surveillance, Ganda said.
Along with her project co-investigators, Ganda said she intends to apply the refined method to answer a biologically relevant question: What is the impact of different alternatives to antibiotic feed additives on antimicrobial resistance in broiler chicken production?
“We know that by feeding higher levels of copper and zinc, which are not antibiotics, we still see rises in antimicrobial resistance because the bacteria have similar mechanisms to resist metals and antibiotics,” Ganda said. “There is very limited data on what the impact of feeding essential oils, prebiotics and probiotics have on antimicrobial resistance. We aim to help fill that gap.”
Salmonella. In the second project, funded by a $300,000 grant, Ganda and her colleagues will work with farmers to develop mitigation methods to deal with Salmonella Dublin, an emerging pathogen in dairy farms in the U.S. Northeast.
The pathogen is adapted to cattle and can also infect humans, she said. It can persist on farms for months to years, can be extremely difficult to treat due to its multi-drug resistance, and can be transmitted from animals to humans.
“This strain is slowly increasing in prevalence across the United States and can result in severe economic loss,” Ganda said. “However, no data are available regarding the herd prevalence of Salmonella Dublin in Pennsylvania dairy herds, despite this pathogen being isolated from several human cases in Pennsylvania since 2014 and many animal cases in the past two years.”
This project aims to address the potentially underdiagnosed problems caused by Salmonella Dublin in the Pennsylvania dairy industry. Researchers plan to screen bulk tank milk samples for Salmonella Dublin antibodies to determine how widespread the pathogen is.
For positive herds, the researchers plan to offer to work with farmers and use advanced-detection methods to isolate the bacteria from animals and the environment in a “seek and destroy” approach, Ganda said.
The team said they will develop a suite of extension resources to increase the level of knowledge about Salmonella Dublin, and to change attitudes and behaviors toward the prevention, detection and control of Salmonella in dairy herds.
Researchers plan to leverage the extensive reach of Penn State Extension to provide educational resources for Pennsylvania dairy farm owners and employees, as well as the veterinarians who work with these dairy farms. They are actively recruiting farms interested in having their bulk tank milk tested for free.
(Information provided by Jeff Mulhollem, Penn State Extension.)
