Assessing Efficacy of NanoCeram Filters For Virus Concentration From Water: Risk Assessment for Listeria and Salmonella in Food

Abstract

Water quality, and therefore human health, may be significantly affected by the presence of pathogenic enteric microorganisms derived for improper disposal of wastewater to aquatic environments. Detection of waterborne viruses is complex due to the difficulties in concentrating the sample and then in detecting the virus by cell culture or molecular techniques. Methods used to concentrate enteric viruses from water have remained largely unchanged for nearly 30 years. The U.S. Environmental Protection Agency requires the use of 1MDS electropositive filters for concentrating enteric viruses from water; however, these filters are expensive for routine viral monitoring. The NanoCeram® filter, an electropositive cartridge filter, has been proposed as a new alternative for large volumes of water. The objective of the study was: to evaluate the effectiveness of NanoCeram® filters for the concentration of poliovirus-1 from wastewater samples and compare to 1MDS cartridge filters. This study suggested that NanoCeram® filters are a viable alternative to the use of 1MDS filters for viral monitoring in surface waters and wastewaters. L. monocytogenes outbreaks with Latin-style soft cheese have been well-documented; however, more information to characterize the human health risk associated with the consumption of queso fresco (QF) using unpasteurized milk is needed. The objectives of the study were: i) to evaluate the prevalence of Listeria, Escherichia coli, Salmonella and fecal coliforms in QF obtained from markets in the northwestern state of Sinaloa, Mexico, and ii) to address the human health impact associated with the consumption of QF contaminated with L. monocytogenes using quantitative microbial risk assessment (QMRA). The study suggested that QF produced in Culiacan, Sinaloa, Mexico have microbial loads above the maximum values recommended by the Official Mexican Regulations; and QMRA can be used to interpret microbial contamination data for impacts on public health.