$2 million UF/IFAS study to focus on antibiotic resistance; $500,000 study on taste retention

April 20, 2015 -- GAINESVILLE, Fla. — A University of Florida scientist will try to figure out how antibiotic-resistant microorganisms get into cattle. Another will study how to get tomatoes and strawberries to retain their flavors and last longer.

The two vastly different questions will be the focus of separate studies led by UF Institute of Food and Agricultural Sciences faculty members. The National Institute of Food and Agriculture, part of the U.S. Department of Agriculture, has awarded KC Jeong $2.19 million to study the cattle antibiotic question. NIFA also has awarded Kevin Folta and Thomas Colquhoun $500,000 to investigate the strawberry/tomato issue.

About 23,000 people are killed annually by pathogens because some don’t respond to antibiotics, said Jeong, a UF animal sciences assistant professor and a faculty member with UF’s Emerging Pathogens Institute.

Researchers believe the overuse of antibiotics has led to resistant strains of bacteria. But there may be reasons beyond the overuse of antibiotics, Jeong said. He cites the grass cattle eat, the water they drink and other factors as possible sources of resistant bacteria. Jeong said scientists simply don’t know the pathogens’ origins.

Jeong is particularly interested in tracing how microbes – specifically the extended-spectrum b-lactamase-producing bacteria (ESBLs) ─ move throughout grass-fed, pre-feedlot cattle. He will investigate the source of the microbes in soil and plants by determining contributions from genetics, physiological factors, animal husbandry and other possibilities.

“By understanding the source, occurrence and migration of ESBLs into cattle, we can bring up new ideas to reduce these life-threatening pathogens in cattle that will result in enhanced food safety and fewer victims of antibiotic-resistant microorganisms,” Jeong said. “Our long-term goal is to help mitigate antibiotic-resistance in farm animals.”

Much of the research so far has focused on feedlots, but Jeong said his team will study cow-calf operations and more. Jeong and his team will study cattle all over North Florida during the next three years.

Florida cow-calf operations provide perfect study settings to look at all possible factors that may affect the occurrence of ESBLs, Jeong said. Researchers will examine the insides of the gastrointestinal tracts of cows and calves grown in 20 mid-size farms to identify factors that significantly affect the occurrence ESBLs.

Another NIFA-funded project will examine how light can affect the quality of fruits and vegetables after harvest, said Folta, a UF/IFAS horticultural sciences professor. About 50 percent of harvested produce goes to waste, so increasing shelf life, nutrient and flavor retention may help increase consumption of healthy food.

“Harvested fruits and vegetables are metabolically active, living tissues,” Folta said. “We’ve found that we can manipulate their quality by stimulating their light-sensing networks. This non-chemical treatment has been shown to have clear effects on the production of flavor compounds and genes associated with central metabolic pathways.”

Folta and Environmental Horticulture Assistant Professor Thomas Colquhoun will examine the effects of specific light wavelengths, or colors, on reprogramming fruit metabolism and breakdown. These treatments are delivered by specialized, LED-light devices immediately after harvest or at retail. Plants possess light-sensing pathways that change which genes are turned on and off and can affect quality in harvested plant products.

“These simple, low-cost applications could have big dividends for retailers and consumers, as produce would retain nutrient content and quality longer,” Folta said. “Their use in the developing could help ensure that more nutrient-dense foods get to people that need them, and it is exciting that a cheap, durable and solar-powered solution could bring such benefits.”

Writer

Brad Buck, bradbuck@ufl.edu