AUTHOR=Shen Xiaoye , Sheng Lina , Benedict Chris , Kruger Chad E. , Su Yuan , Schacht Elizabeth , Zhang Yifan , Zhu Mei-Jun 

TITLE=Evaluation of Pre-harvest Microbiological Safety of Blueberry Production With or Without Manure-Derived Fertilizer

JOURNAL=Frontiers in Microbiology

VOLUME=10

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2019.03130

DOI=10.3389/fmicb.2019.03130

ISSN=1664-302X

ABSTRACT=<p>Blueberry is an important commodity in Washington State, which was one of the leading blueberry producers in the United States. As a ready-to-eat fruit, blueberry has no or limited post-harvest processing, highlighting an imperative need to evaluate its microbial safety during pre-harvest practice. This study accessed the microbiological safety of blueberry produced in a commercial blueberry field applied with or without manure-derived ammonium sulfate (AS) fertilizer in a 2-year study. Indicator microorganisms of total coliforms and generic <italic>E. coli</italic>, Shiga toxin-producing <italic>Escherichia coli</italic> (STEC), <italic>Salmonella</italic>, and <italic>Listeria monocytogenes</italic> were monitored in fertilizer, soil, foliar, and blueberry fruit samples by culture methods for each production season. The population of total coliforms in soils was 3.17–3.82 Log<sub>10</sub> CFU/g, which was stable throughout the production season and similar between two cropping seasons. Generic <italic>E. coli</italic> in soils remained at very low levels throughout the 2018 production season. Total coliforms or generic <italic>E. coli</italic> was not detected in fertilizer, foliar, and blueberry fruit samples collected in both 2017 and 2018 production seasons. STEC and <italic>L. monocytogenes</italic> were below the detection limit in fertilizer, soil, foliar, and blueberry fruit samples collected in both production seasons. <italic>Salmonella</italic> was not detected except for soil samples collected pre- and post-fertilizer application in the 2018 cropping season. Collectively, data indicated, under good agricultural practices, blueberry fruits produced in the field with or without manure-derived AS fertilizers had no microbiological safety concern.</p>