Natural infection of murine norovirus in conventional and specific pathogen-free laboratory mice

Abstract

Noroviruses cause most cases of acute viral gastroenteritis worldwide. The lack of a cell culture infection model for human norovirus necessitates the use of molecular methods and/or viral surrogate models amenable to cell culture to predict norovirus inactivation. Murine norovirus (MNV) may be used to construct a small animal model for studying the biology and pathogenesis of noroviruses because MNV is the only norovirus that replicates in cell culture and a small animal model. However, recent studies have shown that natural MNV infection is widespread in laboratory mouse colonies. We investigated MNV infection in both conventional and specific pathogen-free (SPF) genetically modified mice from Japan and the US, and commercial mice from several animal breeders in Japan, using serological and molecular techniques. MNV antibodies were detected in 67.3% of conventional mice and 39.1% of SPF mice from Japan and 62.5% of conventional mice from the US. MNV antibodies were also found in 20% of commercial SPF C57BL/6 mice from one of three breeders. Partial gene amplification of fecal isolates from infected animals showed that the isolates were homologous to reported MNV sequences. These results suggest that both conventional and SPF laboratory mice, including commercial mice, are widely infected with MNV, which might require considerable attention as an animal model of human disease.

Norovirus

“…MNVs are widespread in laboratory mice, and in contrast to human noroviruses, they can be propagated in tissue culture (276). Although MNV produces little or no outward signs of infection in wild-type laboratory mice (277), knockout studies indicate that both innate and adaptive immunity play critical roles in the control of MNV infection.…”

Incorporation of β-Amino Acids Enhances the Antifungal Activity and Selectivity of the Helical Antimicrobial Peptide Aurein 1.2

“…3, 4 Antimicrobial peptides (AMPs) are attractive as antifungal agents because the mechanisms of membrane disruption through which they act are less likely to lead to the development of resistance than targeted therapeutics. 5 However, AMPs exhibit low structural stability at physiological pH and ionic strength and are susceptible to proteolytic degradation in vivo . Peptidomimetic compounds offer the potential to improve native α-amino acid peptide properties, including structural and metabolic stability.…”

Detection of murine norovirus by reverse transcription loop-mediated isothermal amplification

“…In North America, 22.1% of 12,639 mouse sera were positive for anti-MNV-1 antibodies (Hsu et al, 2005). The high prevalence of MNV in laboratory mice was also confirmed by serological survey in Europe and Japan (Pritchett-Corning et al, 2009;Kitagawa et al, 2010). Currently, MNV is recognized as the most common contaminant in laboratory mice, and thought to be prevalent in mouse colonies worldwide.…”