title: Possible Internalization of an Enterovirus in Hydroponically Grown Lettuce.
abstract: Several studies have shown that enteric viruses can be transferred onto the surface of vegetables and fruits through spray irrigation, but, recently, reports have suggested viral contamination of vegetables sub-irrigated with reused wastewater. Hydroponic cultures, used to grow ready to eat fresh lettuce, have also been used to study the possibility of viral absorption through roots. This study was conducted to assess a possible risk of viral contamination in lettuce from contaminated water. The leaves of lettuce plants grown in hydroponic cultures where the roots were exposed to water containing Coxsakievirus B2, were analysed for evidence of the virus. The plants and water were sampled at different times and virus was measured using quantitative RT-PCR and infectivity assay. In leaf samples, the lowest observed infective data were lower than the qRT-PCR detection limits, suggesting that free viral RNA or damaged viruses are eliminated rapidly while infectious particles remain stable for a longer time. The obtained data revealed that the leaves were contaminated at a water concentration of 4.11 ± 1 Log Most Probable Number/L (8.03 ± 1 Log GC/L) a concentration observed in contaminated untreated water of wastewater treatment plants. However, the absorption dynamics and whether the virus is inactive in the leaves still remains to be clarified. Nevertheless, this work has practical implications for risk management in using reclaimed water for agricultural use; when irrigated vegetables are destined for raw consumption, virological contamination in water sources should be evaluated.
authors.affiliation: Laboratory of Hygiene and Environmental Virology, Department of Biology, University of Pisa, Via S. Zeno 35/39, 56127 Pisa, Italy. annalaura.carducci@unipi.it.
authors.forename: Annalaura
authors.initials: A
authors.lastname: Carducci
authors.affiliation: Laboratory of Hygiene and Environmental Virology, Department of Biology, University of Pisa, Via S. Zeno 35/39, 56127 Pisa, Italy. elicaponi@yahoo.it.
authors.forename: Elisa
authors.initials: E
authors.lastname: Caponi
authors.affiliation: Department of Agricultural, Food and Agro-Environmental Sciences, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy. ciurli@agr.unipi.it.
authors.forename: Adriana
authors.initials: A
authors.lastname: Ciurli
authors.affiliation: Laboratory of Hygiene and Environmental Virology, Department of Biology, University of Pisa, Via S. Zeno 35/39, 56127 Pisa, Italy. marco.verani@unipi.it.
authors.forename: Marco
authors.initials: M
authors.lastname: Verani
mesh_terms: D029822:Enterovirus B, Human / Q000302:isolation & purification*; D005506:Food Contamination; D005516:Food Microbiology; D018527:Hydroponics; D018545:Lactuca / Q000821:virology*; D018515:Plant Leaves / Q000821:virology; D018517:Plant Roots / Q000821:virology; D053586:Virus Internalization; D062065:Wastewater / Q000821:virology
chemical_list: D062065:Wastewater
keywords: Coxsakievirus; hydroponic culture; viral food contamination