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

• Published in: Experimental Animals Vol. 70; no. 2; pp. 177 - 184
• Main Authors: Ka, Yuyo, Ogura, Tomoyuki, Tomiyama, Kayo, Ueno, Masami, Nozu, Ryoko, Tsuruzono, Nobuyuki, Nozawa, Yuya, Hamano, Mariko, Takakura, Akira, Takahashi, Riichi
• Format: Journal Article
• Language: English
• Published: Japan Japanese Association for Laboratory Animal Science 01.01.2021; Japan Science and Technology Agency
• Subjects: Animal models; bioBUBBLE enclosure; Biosafety; Cages; Cleanrooms; Contamination; Enclosures; Environments; Experimental methods; Experiments; germ-free; Germfree; Gnotobiotic; individually ventilated cages; Isolators; microbial animal research; Microbial contamination; Microbiomes; Microorganisms; Original; Safety cabinets; Sterility; Sterility testing; Sterilization; Ventilation; germ-free; gnotobiotic; microbial animal research; individually ventilated cages; bioBUBBLE enclosure
• ISSN: 1341-1357; 1881-7122
• DOI: 10.1538/expanim.20-0129

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