Rodent Pathogen Detection via Testing of Soiled Nesting Material

Murine pathogens affect laboratory animal health and research outcomes, and the prevention of pathogen incursion or the elimination of pathogen outbreaks is paramount. To this end, sensitive methods for pathogen detection are continually being developed and improved. Environmental health monitoring has become a popular and sensitive method for pathogen detection. Published methods for environmental sampling include the collection and testing of exhaust air filters, exhaust air duct swabs, and swabs or filter media placement in empty cages with soiled bedding. Our study tested soiled, cotton nesting material (Nestlet™) in occupied cages for the detection of nucleic acid from certain, high-prevalence, murine pathogens. Nesting material from cages housing mice positive for mouse norovirus, Helicobacter spp., and Rodentibacter heylii consistently tested positive for these agents. In addition, nesting material from cages housing naïve mice to which soiled bedding from the infected cages was transferred tested positive for these agents more often than testing the mice directly. This study concluded that testing of particulate material (for example, dust) from soiled nesting material is a sensitive detection method for certain, high-prevalence murine pathogens.