High-Pressure Homogenization for the Inactivation of Human Enteric Virus Surrogates

Abstract

Novel inactivation methods are needed to control the spread of foodborne viruses responsible for nonbacterial gastroenteritis worldwide. The advent of high-pressure homogenization combining high pressure, shear stress, and cavitation provides the opportunity to evaluate this technology for viral inactivation in fluid foods under continuous processing conditions. Our objective was to evaluate murine norovirus (MNV-1) and MS2 coliphage (single-stranded RNA) as human enteric virus surrogates for their susceptibility to a novel high-pressure homogenization process for application in commercial settings. Experiments were conducted in duplicate with MNV-1 and MS2 coliphage in phosphate-buffered saline, using homogenization pressures of 0, 100, 200, 250, and 300 MPa (the maximum achievable by the homogenizer), resulting in exposure temperatures of 24, 46, 63, 70, and 75 degrees C, respectively, for <2 s. Only homogenization pressures of 300 MPa at 75 degrees C showed inactivation of approximately 3 log PFU for MS2 from an initial approximately 6 log PFU. Also, MNV-1 showed inactivation of approximately 0.8 log PFU at 300 MPa. Further studies are warranted to validate this inactivation process, which can retain the sensory and nutritional value of fluid food and shows promise for application in industrial environments.

Determination of which virus to use as a process control when testing for the presence of hepatitis A virus and norovirus in food and water

“…Moreover, MNV-1 is currently regarded as a better surrogate for human noroviruses than FCV in stability studies (Bae and Schwab, 2008;Cannon et al, 2006). In recent years, studies have underlined the large differences between different viral surrogates and pathogenic viruses with regard to their environmental stability and susceptibility to commercial food processing (heating, freezing) (Bozkurt et al, 2013;Cannon et al, 2006;D'Souza et al, 2009;Fraisse et al, 2011). Thus, given that not all viruses are equal and that a satisfactory process control should be extracted in a similar way to and at a comparable efficiency as the viral target (Lees and CEN WG6 TAG4, 2010), a study to determine the best process control virus was clearly necessary.…”

Comparative Persistence of Subgroups of F-Specific RNA Phages in River Water

“…In order to assess the usefulness of viral indicators and to collect quantitative information necessary for risk assessment of water quality and water disinfection processes, investigations on the survival characteristics of some phages have been conducted (9,10). However, most of these studies have investigated the impact of only one stressor on the survival characteristics of phage indicators (1), or employed one phage strain as a surrogate to determine the effect of environmental or processing stresses on viral survival or activity (11). Little information is currently available about the differential persistence among the four subgroups of Fϩ RNA bacteriophages in surface water, a main source of water for irrigation.…”

Inactivation of Human Enteric Virus Surrogates by High-Intensity Ultrasound

“…Viral stocks of FCV-F9 and MNV-1 were prepared by inoculation of FCV-F9 and MNV-1 stock to confluent monolayers of CRFK and RAW 264.7 cells, respectively, and cultured until >90% cell lysis. The virus suspensions were harvested by two to three cycles of freeze-thawing and centrifuged for 10 min at 5000 g. The resulting supernatants were filtered through 0.2-mm membrane filters, aliquoted, and stored at À808C until use as reported earlier (D'Souza and Su, 2009). MS2 coliphage was propagated in E. coli B-15597 host in 3% Trypticase Soy Broth containing 0.1% glucose, 2 mM CaCl 2 , and 10 mg=mL thiamine at 378C overnight and harvested by centrifugation and filtration using the same procedure as described above for FCV-F9 and MNV-1.…”

“…For MNV-1, the protocol described by Wobus et al (2004) andD'Souza et al (2009) was followed with minor changes. Briefly, 10-fold serial dilutions of MNV-1 viral samples were prepared in DMEM containing 10% FBS.…”