Virus’ (MS2, ϕX174, and Aichi) Attachment on Sand Measured by Atomic Force Microscopy and Their Transport through Sand Columns

Abstract

Atomic force microscopy (AFM) was used to study the attachment of phiX174, MS2, and Aichi viruses on sands of different surface properties: oxide-removed (clean), goethite-coated, and aluminum oxide-coated. Interaction forces between viruses and sand surfaces were measured by contact mode AFM using tips coated with particles of each virus. Column experiments were conducted to quantify the macroscopic transport and retention of the viruses in sand. The average adhesion force measured with AFM was highest between aluminum oxide-coated sand and all three viruses, followed by goethite-coated sand, and was significantly lower on oxide-removed sand. Among the viruses, adhesion on goethite-coated and aluminum oxide-coated sands followed the order of MS2 > Aichi > phiX174, and on oxide-removed sand it was phiX174 > Aichi > MS2. Column breakthrough results revealed the same retention trend, which was completely consistent with AFM force measurements. Strong electrostatic attraction and, to a lesser extent, hydrophobic interactions are responsible for the much greater removal of all three viruses observed in the oxide-coated sands compared to the oxide-removed sand. Mass recovery data indicate that the removal of phiX174, MS2, and Aichi was largely reversible when eluted with 3% beef extract solution at pH 9.5. The Derjaguin-Landau-Verwey-Overbeek (DLVO) and extended DLVO theories provided correct qualitative predictions on the deposition trend observed in the experiments. This study, to the best of our knowledge, was the first to employ AFM to directly measure interaction forces between viruses and solid surfaces; and it was the first to evaluate the retention and transport behavior of Aichi virus, a human pathogen.

Effects of Abiotic and Biotic Stresses on the Internalization and Dissemination of Human Norovirus Surrogates in Growing Romaine Lettuce

“…The plant growth medium has been shown to play the most significant role in pathogen internalization via uptake by the root system (51). The factors that contribute the most significantly to viral transport in the soil include the soil type, water saturation, pH, conductivity, and organic matter (58,59). Based on the variability that soil growth medium adds to pathogen internalization, the detection of virus internalization and dissemination in fresh produce grown in soil has been less well established than in hydroponic systems (51,52).…”

“…Thus, the virus may adhere to positively charged materials found in the soil and be tightly bound in the soil matrix. In terms of soil, pH 6.1 to 6.5 is considered slightly acidic, and pH 6.6 to 7.3 is considered neutral (58,59). Under drought conditions, the soil pH was 6.4 with TV and 6.3 with MNV-1, which may account for the decrease in viral dissemination for TV, since the virus was bound to soil.…”

Transport of Human Adenoviruses in Water Saturated Laboratory Columns

“…Moreover, they are nonpathogenic to human, specific to host bacteria, simple to assay, and have good survival characteristics (Cao et al 2010). However, relatively less attention has been given to pathogenic viruses (Pancorbo et al 1988;Quanrud et al 2003;Attinti et al 2010), and specifically to adenoviruses as indicator viruses (Davies et al 2006;Horswell et al 2010;Wong et al 2012Wong et al , 2014. Fluorescent polystyrene nanospheres (FPNS) have also been used as virus surrogates in studies of virus transport in porous media, where 70-nm sized silica nanoparticles were covalently coupled with specific proteins and a DNA marker for sensitive detection (Pang et al 2014).…”

Relative transport of human adenovirus and MS2 in porous media

“…DLVO theory thus fails to explain why retention of HAdV was much higher than MS2 at 1 and 10 mM. The hydrophobic interaction is not accounted for here since previous studies have shown hydrophobic interaction between sand and HAdV/MS2 is not significant [14,16]; however, hydrophobic interaction should be considered if the future studies are conducted in clay colloids [36].…”

“…Due to its prevalence in environmental waters, HAdV is a promising fecal source tracker [7] and has been included in the U.S. Environmental Protection Agency's contaminant candidate lists one, two and three in 1998, 2005 and 2007, respectively [8]. Most viral transport studies, however, focus on bacteriophages [9][10][11][12][13], with MS2 being the most common [5,[9][10][11][13][14][15]. For the first time, a sorption isotherm approach to evaluate the influence of ion composition and organic carbon on the sorption behavior of HAdV to soil and sand particles [16,17] was utilized by our research group.…”