Important factors for testing barrier materials with surrogate viruses

Abstract

This study evaluated bacteriophages 1)X174, T7, PRD1, and 4)6 as possible surrogates for pathogenic human viruses to challenge barrier materials and demonstrated some important factors for their use. Chemical incompatibility with test material was demonstrated when lipid-enveloped 1)6 was inactivated by an aqueous eluate of vinyl gloves, but 0.5% calf serum protected (D6 from the eluate. Low concentrations (2%) of calf serum also prevented the exaggerated binding of the bacteriophages to filters. Recovery of viruses from surfaces decreased with increasing time before recovery. Penetration through punctures displayed different types of kinetics. The combined data indicate that (i) some bacteriophages may serve as surrogate viruses, (ii) experimental conditions determine whether a particular virus is appropriate as a challenge, and (iii) 1)X174 is an excellent choice as a surrogate virus to test barrier materials. The data further indicate that before barrier materials are challenged with viruses, adequate tests should be performed to ensure that the virus is compatible with the test material and test conditions, so that meaningful data will result.

The Use of Indicators and Surrogate Microorganisms for the Evaluation of Pathogens in Fresh and Fresh‐Cut Produce

“…-Indicator organisms = markers whose presence in given numbers points to failure to comply with applying GMPDs -Index organisms = markers whose presence in numbers exceeding given numerical values points to the possible occurrence of ecologically similar pathogens • Indicators are consequently never to be considered as surrogate markers for the occurrence of pathogenic organisms in foods • Index organisms may not be considered valid as surrogate markers for food pathogens, unless a correlation between their occurrence and that of well-defined pathogens-or at least a marker threshold level below which contamination with the pathogen under study is unlikely at a given P-level-has been firmly established (Mossel and others 1995, p 289) organisms (Drucker and others 1989) and surrogate organisms (Haas and others 1983;Lytle and others 1991;Payment and Franco 1993). Buchanan (2000) made a distinction between direct analyses of single specific pathogens and indirect assessments for microbiological safety:…”

Removal of influenza A virus, phage T1, and PP7 from fluids with a nylon 0.04‐μM membrane filter

“…Several mechanisms contribute to the reduction of infectious virus in the filtrate, including adsorption, entrapment, and inactivation. Many factors can influence the adsorptive characteristics of a filter, including the chemical composition of the filter matrix, surface treatment to the filter, ionic composition of the virus suspension, presence or absence of interfering substances such as serum protein in the virus suspension, and the surface and size characteristics of the viruses (Wallis and Melnick, 1967;Mix, 1974;Bitton, 1975;Farrah, 1982;Shields et al, 1983;Borrego et al, 1991;Lytle et al, 1991). Previous studies have shown that the greatest amount of adsorption was observed when the protein concentration in the challenge fluid was low, and adsorption could be prevented or minimized by adding serum to a virus suspension or by pretreating a normally adsorbent membrane with serum or gelatin (Cliver, 1965).…”

Methods for the recovery of a model virus from healthcare personal protective equipment

“…MS2 is a nonpathogenic, nonenveloped virus, and has been used extensively as a surrogate for nonenveloped pathogenic viruses of humans (Allwood et al 2003;Meschke and Sobsey 2003;Dawson et al 2005;Sickbert-Bennett et al 2005;Bae and Schwab 2008). MS2 has also been shown to have a higher binding potential for PPE materials than other viruses traditionally used as viral surrogates, such as FX174 (Lytle et al 1991;Lytle and Routson 1995), making it a conservative surrogate for studies of disruption of viral binding to PPE. These qualities suggest that MS2 may be a promising surrogate for evaluating methods for recovery of viruses from healthcare PPE.…”