AUTHOR=Gu Ganyu , Strawn Laura K. , Ottesen Andrea R. , Ramachandran Padmini , Reed Elizabeth A. , Zheng Jie , Boyer Renee R. , Rideout Steven L. 

TITLE=Correlation of Salmonella enterica and Listeria monocytogenes in Irrigation Water to Environmental Factors, Fecal Indicators, and Bacterial Communities

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.557289

DOI=10.3389/fmicb.2020.557289

ISSN=1664-302X

ABSTRACT=<p>Outbreaks of foodborne illnesses linked to fresh fruits and vegetables have been key drivers behind a wide breadth of research aiming to fill data gaps in our understanding of the total ecology of agricultural water sources such as ponds and wells and the relationship of this ecology to foodborne pathogens such as <italic>Salmonella enterica</italic> and <italic>Listeria monocytogenes</italic>. Both <italic>S. enterica</italic> and <italic>L. monocytogenes</italic> can persist in irrigation water and have been linked to produce contamination events. Data describing the abundance of these organisms in specific agricultural water sources are valuable to guide water treatment measures. Here, we profiled the culture independent water microbiota of four farm ponds and wells correlated with microbiological recovery of <italic>S. enterica</italic> (prevalence: pond, 19.4%; well, 3.3%), <italic>L. monocytogenes</italic> (pond, 27.1%; well, 4.2%) and fecal indicator testing. Correlation between abiotic factors, including water parameters (temperature, pH, conductivity, dissolved oxygen percentage, oxidation reduction potential, and turbidity) and weather (temperature and rainfall), and foodborne pathogens were also evaluated. Although abiotic factors did not correlate with recovery of <italic>S. enterica</italic> or <italic>L. monocytogenes</italic> (<italic>p</italic> &gt; 0.05), fecal indicators were positively correlated with incidence of <italic>S. enterica</italic> in well water. Bacterial taxa such as <italic>Sphingomonadaceae</italic> and <italic>Hymenobacter</italic> were positively correlated with the prevalence and population of <italic>S. enterica</italic>, and recovery of <italic>L. monocytogenes</italic> was positively correlated with the abundance of <italic>Rhizobacter</italic> and <italic>Comamonadaceae</italic> (<italic>p</italic> &lt; 0.03). These data will support evolving mitigation strategies to reduce the risk of produce contamination by foodborne pathogens through irrigation.</p>