Exhaust air particle pcr as a new method for the hygienic monitoring of ivc reared rodent colonies: A contribution to the reduction of experimental animals.

The hygienic status of laboratory animals is pivotal for animal health as well as for the reliability and reproducibility of experimental results in biomedical research. Common health monitoring strategies of individually ventilated cage (IVC) reared rodent colonies involve sentinel animals exposed to soiled bedding of the colony to monitor. After an adequate exposure time these sentinel mice representing all animals housed in the respective racks are euthanized and examined for unwanted organisms which results in higher numbers of animals used for the sole purpose of health monitoring. Sentinel monitoring is subject to limitations: IVCs prevent transmission of airborne pathogens; transmission of unwanted organisms to sentinels by used bedding is uncertain due to dilution and susceptibility of sentinels to some pathogens is low. Screening of exhaust air dust of IVC racks for nucleic acids of unwanted pathogens is a relatively new and promising approach to improve health monitoring in IVC systems whilst avoiding the additional use of animals for this purpose. This review article summarizes current studies on the new health monitoring technology. Exhaust Air Particle (EAP) PCR outperformed sentinel monitoring by far. Infections have been detected newly or at lower prevalence. Hence, laboratory animals can be replaced in biomedical research and knowledge on the hygienic status of rodent colonies can be improved. Since the technology has a broad applicability the possible impact as replacement according to the 3Rs is remarkable