Confirmation of Pathogen 'Burnout' in Mouse Colonies with Previous Evidence of Infection with Parvovirus and
Erin Nz Yu1, Amanda K Darbyshire2, Lauren E Himmel1
1Division of Animal Care, Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee.
Abstract:
Pathogen monitoring and colony health management are critical components of any rodent research program. From an operational perspective, rodent facilities are protected from unwanted infectious agents by facility-specific bioexclusion criteria, sanitation of the physical environment, and personal protective equipment. Another important preventative measure is the use of room health levels to provide traffic patterns for animal care and research staff as they move between rooms of differing health status. For mice, our institution uses a tiered room level system with 6 defined categories, ranging from level 1 (strictest entry criteria) to 6 (least stringent entry criteria). Level 6 is defined as rooms with mice that have tested positive for mouse parvovirus (MPV) or mouse rotavirus (MRV) or both on sentinel serology at any point in time in the past and no decontamination. Because many of our mouse rooms had historically been positive for MPV and/or MRV and because of the high financial and logistic challenges of using repeated test-and-cull for elimination, we had tolerated the potential presence of MPV and MRV and had developed management practices that would promote 'burnout' (that is, elimination of infectious agents due to absence of susceptible hosts) of these pathogens. Analysis of sentinel data showed that we had 28 rooms in 4 facilities for which excluded pathogens had not been identified in 3 y or more. We therefore developed a hybrid testing strategy involving both PCR analysis and serology and implemented it in sentinels and in select colony mice to determine whether the rooms had undergone successful burnout and were free of MPV and MRV. All test results obtained during the assessment were negative for both viruses, and the rooms were subsequently upgraded to level 5 (free from excluded pathogens and allowing two-way movement in and out of housing room). All upgraded rooms have remained negative on subsequent quarterly routine sentinel serology for over 3 y. Our testing strategy for confirming pathogen burnout may be a useful and cost-efficient model for other academic rodent research programs that face a similar situation.
Insights
Rodent facilities can confirm pathogen burnout using a hybrid PCR and serology testing strategy. This cost-efficient model successfully cleared mouse parvovirus and mouse rotavirus from research rooms, allowing them to be upgraded to a higher health status.
Area of Science:
- Laboratory animal science
- Veterinary pathology
- Infectious disease control
Background:
- Effective pathogen monitoring and colony health management are crucial for rodent research programs.
- Rodent facilities employ bioexclusion, sanitation, and room health levels to prevent infectious agents.
- Historically, mouse parvovirus (MPV) and mouse rotavirus (MRV) presence led to management challenges, with some rooms designated Level 6.
Purpose of the Study:
- To develop and validate a cost-efficient strategy for confirming the burnout of MPV and MRV in research mouse rooms.
- To assess the feasibility of upgrading rooms previously positive for MPV and/or MRV to a higher health status.
Main Methods:
- Utilized sentinel data to identify rooms with no excluded pathogens detected for over 3 years.
- Implemented a hybrid testing strategy combining PCR analysis and serology on sentinels and colony mice.
- Monitored upgraded rooms via quarterly sentinel serology for over 3 years post-upgrade.
Main Results:
- A hybrid testing strategy was developed and implemented to assess pathogen burnout.
- All tested rooms were confirmed negative for MPV and MRV, indicating successful pathogen burnout.
- 28 rooms across 4 facilities were successfully upgraded from Level 6 to Level 5 health status.
Conclusions:
- The hybrid PCR and serology testing strategy is an effective and cost-efficient method for confirming pathogen burnout in rodent research facilities.
- Successful confirmation of burnout allowed for the upgrade of previously contaminated rooms, optimizing facility management.
- This model offers a practical solution for other academic rodent research programs facing similar challenges with endemic pathogens.
