Housing Gnotobiotic Mice in Conventional Animal Facilities

Abstract

Gnotobiotic mice are an established, robust model utilized in current research to study host‐microbiota interactions. For years isolators have been used to rear germ‐free and gnotobiotic mice. However, isolators can be costly and the segregation of treatments within the same isolator is problematic. Recently, methodologies for housing germ‐free mice in specially designed individually ventilated cages (IVCs) operated under barrier mode have been developed; however, this equipment is costly and its operation in barrier mode for research involving germ‐free mice and pathogens is not permissible under modern biosafety and biosecurity regulations. This article describes a method to house germ‐free mice in a commonly available conventional IVC system operated under containment mode. This technique allows researchers to maintain the germ‐free or gnotobiotic status of mice tested up to 4 weeks with weekly handling while working with pathogens using each IVC as a separate experimental unit. © 2019 Her Majesty the Queen in Right of Canada.

Gut Fecal Microbiota Transplant in a Mouse Model of Orthotopic Rectal Cancer

“…For example, Campylobacter jejuni was proved to induce colitis and subsequent CRC tumorigenesis in a germ-free animal model (26)(27)(28). However, maintenance of germ-free or gnotobiotic conditions can be expensive (29,30). By contrast, a conventional mouse model with cocktail antibiotic pretreatment is also feasible means of investigating specific bacterial species (13,15,17).…”

Investigating causality with fecal microbiota transplantation in rodents: applications, recommendations and pitfalls

“… 2 The term “gnotobiotic animals” includes GF animals but also GF animals recolonized with a defined microbiota to study specific germs (mono-associated or defined microbiota animals). 12 Gnotobiotic rodents are fundamental tools to understand the role of the gut microbiota and have been employed in a number of studies to successfully demonstrate the adoptive transfer of various behavioral phenotypes. GF rodents are raised in isolators and are devoid of all microorganisms including: bacteria, viruses, fungi, archaea, protozoa and other parasites – within the range of detection limits used (sequencing- or cultured-based techniques).…”

“…To counteract the expenses of isolators, a cost-effective solution would be the use of individually ventilated cages to house GF mice according to Lange et al protocol. 12 They present a protocol for the use of a conventional IVC system operating under containment mode and provide details for cage changing and sampling without compromising the sterile status. Importantly, the use of IVC system might have an impact for behavioral studies.…”

Contaminants and Where to Find Them: Microbiological Quality Control in Axenic Animal Facilities

“…Therefore, isolators have considerable disadvantages. For example, all the animals contained in the isolators share the same air, meaning all axenic animals in a given isolator are at risk of losing their axenic status in the event of a contamination (Hecht et al, 2014;Paik et al, 2015;Basic and Bleich, 2019;Lange et al, 2019;. At the opposite, all Isocages are their own isolator at cage level and can allow multiple simultaneous protocols at a time in the same rack.…”

“…For culture methods, feces, bedding, and food are the most frequently used samples. Samples are incubated in two or more culture media, in aerobic and anaerobic conditions, at a single or multiples temperatures (Arvidsson et al, 2012;Hecht et al, 2014;Fontaine et al, 2015;Karaman, 2015;Nicklas et al, 2015;Paik et al, 2015;Basic and Bleich, 2019;Lange et al, 2019;. The liquid and solid culture media used vary a lot.…”