Sentinel Mice and Their Role in Microbiological Monitoring

May 07, 2023

Mice are small and unassuming creatures that often go unnoticed by humans. Nevertheless, these small creatures can perform a crucial role in the identification of biosafety issues and concerns that could endanger humans and other living organisms. Specifically bred mice, known as "sentinel mice," are utilized by environmental and biosafety professionals to surveil work and living environments and identify potential hazards.


What are Sentinel Animals?

Sentinel animals are living probes to detect environmental risks and biosafety concerns, such as infectious diseases and the spread of chemical contaminants in a specific area. Which animal to choose is based on their susceptibility to specific toxins or diseases, and their health is routinely monitored for signs of illness or infection. Sentinel animals have been used to monitor environmental conditions for decades. Herring gulls, for example, have been providing data on contaminants in the United States and Canada’s Great Lakes region since the 1970’s.


The Role of Sentinel Mice

Sentinel mice are a relatively new addition to the family of sentinel animals. They are bred to become highly sensitive to environmental chemicals and pathogens and are used to assess environmental conditions in a variety of locals, such as research laboratories, industrial sites, and agricultural areas. Sentinel mice are very helpful in laboratories where scientists work with genetically engineered animals or potentially harmful substances or conditions. These mice are kept in cages near the laboratory and are monitored on a regular basis. Any signs of illness in a sentinel mouse could indicate that conditions in the lab are unsafe and need to be improved.


How to Choose Desired Sentinel Mice?

Sentinel mice must be selected from immunocompetent strains that are susceptible to viral infections and develop robust antibody responses when exposed to potential pathogens. Female mice are preferred over males due to the risk of fighting and injury among group-housed males. It is desired to set up mice as sentinels when they are three to five weeks and no older than ten weeks of age. They should be placed in the location or in the same environment as the animals to be monitored and tested for the presence of pathogens according to established protocols.

Sentinel mice should be germ-free or specific pathogen free. In the rare and unusual event when such mice are not available and sentinels are urgently needed, the microbiological status of the mice should be known to be used as sentinels. Mice without clearly identified microbiological status should not be used as sentinels. When possible, the same strain of mice can be used as sentinels. However, different strains can be used to suffice the purpose of the monitoring. When introducing new sentinels into an existing practice, mice must undergo isolation, clinical observation and health monitoring according to standard operating procedures, to eliminate the risk of accidental pathogen transmission by sentinel mice.


The Benefits of Sentinel Mice

Sentinel mice provide many advantages over other sentinel animals. First and foremost, they are economical from a husbandry perspective, making them more accessible to academic and research institutes. Secondly, commonly used sentinel mice are extremely sensitive to environmental toxins and infections, enabling them to detect even minute levels of such substances effectively. Overall, sentinel mice are an essential tool for monitoring environmental and biosafety status and detecting microbiological contaminations.