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Evaluation of In-cage Filter Paper as a Replacement for Sentinel Mice in the Detection of Murine Pathogens
Kathryn A O'Connell1, Gabor J Tigyi2, Robert S Livingston3
1Departments of Comparative Medicine, University of Tennessee Health Science Center, Memphis, Tennessee;,
Abstract:
Recent studies have evaluated alternatives to the use of live animals in colony health monitoring. Currently, an alternative method that is suitable for all rack types and that has been verified to detect the infectious agents most commonly excluded from mouse colonies is unavailable. We compared the use of filter paper placed on the inside floor of mouse cages to the traditional use of sentinel mice in the detection of several prevalent murine pathogens including mouse hepatitis virus (MHV), murine norovirus (MNV), minute virus of mice (MVM), mouse parvovirus (MPV), Theiler murine encephalomyelitis virus (TMEV), Helicobacter spp., Syphacia obvelata, and Aspiculuris tetraptera. Experimental groups comprised 7 cages containing either 2 pieces of filter paper on the cage floor or 2 ICR sentinel mice. Soiled bedding from pet-store mice was transferred to the experimental cages weekly for 8 wk. At 1 and 2 mo after bedding transfer, the filter papers were evaluated by PCR and sentinel mice were tested by serology and fecal PCR. Filter papers detected all pathogens as effectively (MHV, MNV, MPV, MVM, TMEV S. obvelata, and A. tetraptera) or more effectively (Helicobacter spp.) than sentinel mice at both time points. Filter papers more readily detected pathogens with a high copy number per RT-PCR analysis than a low copy number. Helicobacter spp. were not detected by sentinel mice at either time point. These results indicate that the use of filter paper placed on the interior floor of empty mouse cages and exposed to soiled bedding is efficient in detecting bacteria, endoparasites, and most of the common mouse viruses included in an animal health monitoring program.
Insights
Filter paper in mouse cages effectively detects common pathogens, offering a viable alternative to sentinel mice for animal health monitoring. This method efficiently identifies viruses, bacteria, and parasites, improving colony health surveillance.
Area of Science:
- Veterinary Pathology
- Microbiology
- Animal Health Monitoring
Background:
- Live sentinel mice are traditionally used for monitoring mouse colony health.
- Current alternative methods lack universal applicability across rack types and comprehensive pathogen detection.
- There is a need for validated, non-animal-based methods for detecting common murine pathogens.
Purpose of the Study:
- To compare the efficacy of filter paper as an alternative to sentinel mice for detecting prevalent murine pathogens.
- To evaluate the suitability of filter paper for detecting viruses, bacteria, and endoparasites in mouse colonies.
- To assess the performance of filter paper across different time points post-exposure.
Main Methods:
- Filter papers placed on cage floors were exposed to soiled bedding from infected mice for 8 weeks.
- Sentinel mice were housed in separate cages and exposed to the same soiled bedding.
- Filter papers were analyzed by PCR, and sentinel mice were tested by serology and fecal PCR at 1 and 2 months.
Main Results:
- Filter papers detected all tested pathogens, including mouse hepatitis virus (MHV), murine norovirus (MNV), and others, as effectively or more effectively than sentinel mice.
- Helicobacter spp. were detected by filter paper but not by sentinel mice.
- Filter paper showed higher sensitivity for detecting pathogens with higher copy numbers via RT-PCR.
Conclusions:
- Filter paper placed in mouse cages is an efficient and effective alternative for detecting common murine pathogens, including viruses, bacteria, and endoparasites.
- This method offers a promising non-animal-based approach for routine animal health monitoring programs.
- Filter paper provides a versatile and reliable tool for enhancing the health surveillance of mouse colonies.
