Creation of an experimental rearing environment for microbiome animal research using an individually ventilated cage system and bioBUBBLEenclosure

摘要

To avoid microbial contamination risk, vinyl film isolators are generally used in animal microbiome experiments involving germ-free (GF) mice and/orgnotobiotic (GB) mice. However, it can take several months to gain expertise in operating the isolator competently. Furthermore, sterilization and sterilitytesting, which are essential for isolator preparation, can take more than 20 days. Hence, we built an experimental rearing environment that combines anindividual ventilation cage system and a bioBUBBLE clean room enclosure to easily set up an experimental animal microbiome environment for animal facilities. Inthis work, a three-step evaluation was conducted. First, we examined whether GF mice can be maintained in this rearing environment without bacterialcontamination. Next, we examined whether GF and GB mice can be maintained without cross-contamination in one individual ventilation cage rack. Finally, wetested whether GF mice can be maintained in a biological safety cabinet controlled by negative pressure. In our series of experiments, no microbialcontamination occurred over more than 3 months. These results indicated that our rearing system that combines the individual ventilation cage and bioBUBBLEsystems can be used not only for experiments with GF mice but also for Biosafety Level 2 experiments that handle bacteria. Our system can mitigate variousdisadvantages of using vinyl film isolators. In conclusion, we established an experimental method with improved working time and efficiency compared with thoseof the previous vinyl isolator method.