|Xiao, Zhenlei - University Of Maryland|
|Luo, Yaguang - Sunny|
|Wang, Qin - University Of Maryland|
Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2015
Publication Date: 7/1/2015
Citation: Xiao, Z., Bauchan, G.R., Nichols-Russell, L.K., Luo, Y., Wang, Q., Nou, X. 2015. Proliferation of Escherichia coli O157:H7 in soil and hydroponic microgreen production systems. Journal of Food Protection. doi: 10.4315/0362-028X.JFP-15-063. Interpretive Summary: Microgreens are a new class of fresh vegetables that are produced in controlled indoor facilities. Scientific data on the potential for pathogen contamination in these production systems is lacking. This information is needed in order to formulate science-based regulations. This study examined the potential for growth by E. coli O157:H7 in different microgreen production systems, including the spatial distribution of E. coli cells on the microgreen plants and in the growth substrata. The data indicate that E. coli O157:H7 grew significantly in all production systems, resulting in contamination of both edible and inedible part of the plants. This information will be useful to other scientists, the microgreen industry and regulatory agencies.
Technical Abstract: Radish (Raphanus sativus var. longipinnatus) microgreens were produced from seeds inoculated with Escherichia coli O157: H7 using soil substitute and hydroponic production systems. E. coli populations on the edible and inedible parts of harvested microgreen plants and in growth medium were examined. E. coli O157: H7 was shown to survive and proliferate significantly during microgreen growth in both production systems, with higher level in hydroponic production system. Examination of the spatial distribution of bacterial cells on different parts of microgreen plants showed that contaminated seeds led to systematic contamination of whole plants, and seed coats were the focal point of E. coli O157: H7 survival and growth.