Zebrafish (Danio rerio) are considered a unique model for biomedical research given their genomic and molecular similarities to vertebrates. As use of zebrafish as a model of disease increases, spanning studies on diet-induced diseases, intestinal diseases, metabolic disorders, drug screening, and liver diseases, among others, researchers must ensure the validity and reproducibility of their experimental data.
To improve operational efficiencies and promote better husbandry practices, many institutions using aquatic species have centralized their facilities by housing colonies of multiple investigators in multi-rack recirculating aquaculture systems. While this practice can foster collaboration and facilitate fish transfers, these systems may house numerous zebrafish lines that may differ in immune status or even more than one species of fish that may harbor other infectious agents.
The value of a standardized health monitoring program for zebrafish
The introduction of infectious agents could potentially devastate numerous research programs, stressing the importance and necessity of standardized, routine health monitoring programs. However, many research institutions may have limited knowledge regarding transmission, diagnosis, and treatment of infectious agents of zebrafish.
A routine colony health monitoring program along with the adoption of standardized reporting for health monitoring can support:
+ Efficient transfers of fish between institutions or facilities
+ Faster and easier risk evaluations when importing fish
+ Rapid procedures to mitigate the risk of infectious agents spreading
By minimizing — or potentially eliminating — the impact of infectious diseases in zebrafish colonies, a health monitoring program can help remove uncontrolled variables in research, leading to more reliable results.
A health monitoring program can also support results generated from animal research to include models’ health status, such as the presence or absence of clinical or subclinical infection. These infections in zebrafish can result in confounded experimental results, misinterpretation of experimental data, and poor reproducibility.
Research institutions can consider several factors when designing a health monitoring program including:
+ The size and diversity of the research program
+ Frequency of importation
+ Type of housing (facility design)
+ Husbandry methods
+ Use of live versus commercial feed
+ Agents to be monitored
+ Testing methodologies to be used
+ Frequency of monitoring
+ Financial costs
Well-designed health monitoring programs will track the health of a zebrafish colony over time and assist in the identification of biosecurity and husbandry issues as they arise. And, by detecting new pathogens as soon as possible, researchers can rapidly assess risks to animal health and research programs, take action for biocontainment, treat infected animals if possible, and/or prevent further spread of infectious agents within or between facilities.
Reflecting changing needs in zebrafish research
A zebrafish colony health monitoring program must also reflect the current needs of the research and offer flexibility to accommodate any changes. For example, research utilizing immunocompromised animal models or performing toxicology studies should exclude as many pathogens as possible, whereas opportunistic pathogens may be considered acceptable for other research objectives.
Along with a plan to review their health monitoring program as new information becomes available, each facility or program must also determine the frequency of testing and their specific agents of concern. Most commonly, sampling every six months is recommended with regards to frozen fish, water, and biofilm swabs. But agents that may have a significant impact on the research program should be tested for more frequently, while agents that present less risk to the program because of low prevalence or low pathogenicity can be tested for less frequently.
To support comprehensive zebrafish health monitoring, Envigo–an Inotiv company offers new multiple diagnostic health monitoring panels for zebrafish colonies, water, and environmental samples. As a qPCR-based testing service available for individual agents or as a full panel, these tests use the same processes, integrity, and quality assurance methods to deliver a harmonized method for monitoring and reporting the health status of zebrafish and many other research species.
Contact us to learn how we can support your research with full spectrum health monitoring for zebrafish through custom tailored health monitoring, support during sampling, and result interpretation.