Antibiotic Uptake by Vegetable Crops from Manure-Applied Soils

Antibiotic Uptake by Vegetable Crops from Manure-Applied Soils

Summary

We analyzed peptone water extracts from manure, soil, and plant samples from our field studies for antibiotics. We also recruited 7 vegetable producers for our antibiotic survey. Most of these producers were organic producers. One producer used conventional turkey manure as a nutrient source. We also bought vegetable samples from two stores that sell organic produce. We analyzed the vegetables both from producers and stores for presence of antibiotics. Tylosin was not present in any of the samples. Except for sulfamethazine, most other antibiotics were below the limits of quantification (LOQ). Sulfamethazine was above LOQ for many vegetables.

Objectives/Performance Targets

(1) To test the extent of antibiotic (chlortetracycline, tylosin, or sulfamethazine) uptake by eleven vegetable crops (spinach, lettuce, cabbage, carrots, radish, onion, garlic, tomatoes, green pepper, sweet corn and potatoes) from two different textured soils that have been fertilized with antibiotic-containing turkey manure and hog manure,
(2) to document the differences in antibiotic uptake by vegetables that have been fertilized with fresh vs. composted turkey and hog manures, and
(3) to document the presence or absence of antibiotics in certified organic vs. conventional commercial vegetables that have been grown in manure applied soils.

Accomplishments/Milestones

We have completed the work on antibiotic analysis from vegetable, soil, and manure samples from our field experiments as well as from producers and stores. Next year, we will be synthesizing the data and write the final report.

Impacts and Contributions/Outcomes

The senior PI gave an interview to Greg Cima of the American Veterinary Medical Association (AVMA). He wrote a brief article about our research “Researchers study antimicrobial uptake in crops” in AVMA Vol 236, No. 5, 1 March 2010.
The senior PI also gave invited talks on:
“Does Antibiotic Use in Livestock Affect Human Health?” at the Minnesota Fruit & Vegetable Growers Association, St. Cloud, MN. 21 January 2010.
“Antibiotic Feeding in Livestock and Its Consequences on the Environment” to the University of Minnesota Women’s Club, St. Paul, MN. 24 March 2010.
The senior PI also served as the Panel Manager for Agriculture and Food Research Institute (AFRI) program of USDA on “Agricultural Water Science”. One objective of the program dealt with potential of vegetables to uptake antibiotics and other pharmaceuticals from wastewater used for irrigation. This objective of AFRI program was mainly based on our SARE funded research- antibiotic uptake by vegetable crops from manure applied soils. About one half of $4.5 million was awarded to various investigators to work on pharmaceuticals uptake by vegetable plants.

Collaborators: