Related Experiment Video
Updated: Nov 9, 2025
Operating and Biocontainment Procedures of a Facility for Laboratory Mice with a Natural Microbiome: Immunophenotyping Procedure
Published on: December 13, 2024
Managing the bacterial contamination risk in an axenic mice animal facility
Maria Lebeuf1, Nathalie Turgeon2, Cynthia Faubert3
1Département de biochimie, microbiologie et bioinformatique, Université Laval, Quebec city, Quebec, Canada.
Abstract:
A gap exists between good laboratory practices with axenic animals and the procedures applied. This work examined the efficacy of sodium dichloroisocyanurate (MB-10) and potassium peroxymonosulfate (Virkon™) disinfectants, as well as the appropriate soaking time for materials used with the ISOcage Biosafety Station™. We also compared the microbial load in cage systems hosting mice over 2 weeks in axenic rooms (ARs) and in typical specific-pathogen-free (SPF) non-axenic rooms (NARs) to identify resistant microorganisms, targeted for longer soaking disinfection, and evaluated the necessary procedures for reducing the microbial load in AR. Staphylococcus was the most frequently isolated genus (in both ARs and NARs). An average of three spore-forming microorganisms per cage were counted from AR. The disinfection time to reach 1 log reduction for Bacillus atrophaeus spores varied from 138 s (100 ppm MB-10) to 290 (Virkon™) to <20 s for S. epidermidis (100 ppm MB-10). AR management protocols lead to a microbial load that is 1000 times lower than that found in NARs. Data comparing the microbial load in SPF and axenic facilities can be used to improve the effectiveness of their microbial control procedures.
Insights
Disinfectants MB-10 and Virkon™ effectively reduced microbial load in laboratory animal facilities. Axenic room management significantly lowered microbial counts compared to specific-pathogen-free rooms.
Area of Science:
- Laboratory animal science
- Microbiology
- Disinfection and sterilization
Background:
- A discrepancy exists between established good laboratory practices for axenic animals and their practical application.
- Effective microbial control is crucial for maintaining axenic conditions and ensuring reliable research outcomes.
Purpose of the Study:
- To evaluate the efficacy of sodium dichloroisocyanurate (MB-10) and potassium peroxymonosulfate (Virkon™) disinfectants.
- To determine optimal soaking times for materials used with the ISOcage Biosafety Station™.
- To compare microbial loads in axenic rooms (ARs) versus specific-pathogen-free non-axenic rooms (NARs) and identify disinfection strategies.
Main Methods:
- Tested disinfectant efficacy (MB-10, Virkon™) against common laboratory microorganisms, including spore-forming bacteria.
- Assessed microbial load in mouse cage systems over two weeks in both ARs and NARs.
- Calculated disinfection times for a 1-log reduction of specific microbial spores.
Main Results:
- Staphylococcus was the predominant genus in both ARs and NARs.
- ARs exhibited significantly lower microbial loads (1000 times less) than NARs.
- Disinfection times for Bacillus atrophaeus spores ranged from <20s to 290s depending on the disinfectant and concentration.
Conclusions:
- MB-10 and Virkon™ are effective disinfectants for laboratory animal facilities.
- AR management protocols substantially reduce microbial load compared to NARs.
- Data supports refining microbial control procedures in both axenic and SPF facilities.
