Description of SPF Barrier Facilities 

 The RIKEN BDR Animal Facility was opened in September of 2003. The facility, housing mice and rats, was sentinel tested by room or area. Since occupancy, the facility has undergone periodical health monitoring and no disease outbreaks have been detected in the rooms and areas where the mice to supply are bred and/or reared.
A high percentage of colony mice are obtained from approved vendors (Charles River Japan, CLEA Japan Inc.) and occasionally from other sources (i.e., universities and/or private industries). For animals from other sources, IVF and embryo transfer techniques are always conducted to prevent from contamination.  
Entry into the facility is maintained through keys. Thus access to animal rooms is restricted. Personal protective equipment (PPE) is required to enter the facility including: sterile gown, disposable hair bonnets, gloves, facemasks, and shoe covers. All materials going into the facilities are sterilized or decontaminated (wiped clean with an appropriate disinfectant). Animals are maintained in autoclaved cages placed in ventilating isoracks and are provided with irradiated food, and automatically filtrated watering. Animal changing/transfer stations, which are working space, are used for cage changing and animal procedures.

BDR Animal Facilities Policy Concerning Mouse Microbiological Standards

 The risk of contamination when transferring animals should be avoided by monitoring microbes in the distribution side and by quarantine (or isolation) on the reception side. However, even on both sides, there is a limit to avoiding contamination risks. With regard to the distribution side, the difference in quality standards becomes a problem. Lists of regularly checked microbes or lists of microbes which are considered dangerous are not standardized between research facilities. Examination procedures and quarantine methods are also not unified. In addition, no international standards have been reached to control the specificity or sensitivity of these checks. As a result, quarantine must be carried out to determine whether or not the quality of the received animals is in accordance with oneユs own quality standards. Aside from quarantine, it may be necessary to eliminate infected animals by in vitro fertilization techniques. To reduce complex procedures and possible confusion, we have adopted the following policies regarding mouse transfer and monitoring procedures.

BDR Animal Facilities Policy

  • In order to increase the scientific reliability of experiments conducted at the BDR, and to enforce ethical animal experiments, we will establish a microbiological profile (quality standard) for breeding mice

  • Monitoring of microbes must be carried out (1) to guarantee the maintenance of quality according to standards, (2) to prevent the onset and spread of infectious diseases in the research facilities, and (3) to avoid unnecessary trouble when transferring mice.

  • To insure that the results of the animal monitoring are objective, we will request the services of a third party operation.

  • As a principle, transfer of mice as frozen embryos is preferred.

  • If requested by the reception side, we will give assistance regarding the thawing technology for frozen embryos.

  • When distributing live mice, we will openly disclose the results of all microbiological examinations. By taking this information into account, we will make every effort to promote the safe and smooth transfer of transgenic mice.

  • In regards to the responsibility of preventing the contamination by infectious agents when transferring animals between scientific colleagues, we consider both sides of the animal transfer to share this responsibility equally.



 In the following attachment from the ICLAS Monitoring Center (a function/part of the Central Institute for Experimental Animals), microbes and parasites which are known to infect mice are classified into categories A-E, based on their virulence.

  A: Zoonotic pathogens from mice which can cause illness in humans

  B: Fatal pathogens which can cause death in mice

  C: Non-fatal pathogens that have the potential to alter physical/immunological functions in mice (with apparent or non-apparent symptoms).

  D: Opportunistic pathogens which can cause illness in mice with special conditions (irradiated mice, imunosuppressed mice, etc).

  E: Non-pathogenic parasites which serve as an indicator of facility contamination.

 Since the above list of organisms can be quite extensive, ICLAS has prepared a set menu from the above categories. This set monitoring list has been narrowed down by prevalence in Europe, America, and nationally, then divided into groups by detection method: serology, cultivation, microscopy. We will schedule periodic monitoring of organisms on this set list.


The BDR Mouse Microbiological Profile

 Due to their virulence towards people or mice, microbes belonging to the above mentioned category A or B pose a threat to both research development and animal welfare, and must be eliminated at all cost. Some of the microbes from categories C, D, and E may give us useful information to identify the microbiological status of animals at the time of transfer, and should also be included in the monitoring. Additionally, we must check for other microbes and parasites (from categories C, D, or E) if requested by the facilities receiving our mice. Furthermore, we cannot ignore organisms which might adversely affect immunocompromised host mice, especially if the contamination prevalence of such organisms is high. By taking the above into consideration, we have decided to monitor selected microbes and parasites belonging to categories C, D, or E, in addition to those in A and B. Using the above mentioned notes as a foundation, guidelines concerning the BDR mouse microbe profile are outlined below.

  • Core Battery:

  • We have chosen a total of seven microbes from categories A and B of the ICLAS list of microbes.

 From category

  A: lymphocytic choriomeningitis virus, Salmonella spp. From category

  B: ectromelia virus, mouse hepatitis virus, Sendai virus, Mycoplasma pulmonis, and Citrobacter rodentium. 

 These microbes are included in the Core Battery of RIKEN BDR Mouse Pathogens because they pose a great threat to both the facility personnel and the mouse colony. To maintain our colony and to avoid risk of contaminating other facilities, we will work to ensure that these organisms do not contaminate our facilities. Thus, all examinations for the Core Battery of organisms must always be shown negative (no contaminating organisms present). This level of quality is standard for the BDR mouse facilities.

  • Supplemental Battery: Aside from microorganisms included in category A or B, we will also monitor microbes and parasites which have been adopted by the above mentioned ICLAS monitoring set, according to contamination prevalence. We have chosen Clostridium piliforme, Corynebacterium kutscheri, Pasteurella pneumotropica, intestinal protozoa from category C, as well as helminth and external parasites in category E. Although these are not included in the Core Battery of RIKEN BDR Mouse Pathogens, they are listed in the Supplemental Battery as organisms to be monitored as useful information. The results of monitoring for this supplemental battery of microorganisms will be disclosed to those facilities receiving our organisms.

  • Spot Check: In addition to regular monitoring of the above mentioned microbes, spot checks will be performed according to necessity or demand. We will conduct spot checks for seven murine viruses (from EDIM virus to reovirus type 3 in the attached Microbe Checklist), and four bacteria (from CAR bacillus to Staphylococcus aureus), as well as dermatophytes Pneumocystis carinii and Aspiculuris tetraptera. The full list of microbes we will conduct spot checks for are listed under "Spot Check" in the Microbe Checklist.

Examination enforcement and correspondence of the examination results.
Please refer to the Microbe Checklist for further details on the following categories of microorganisms:

  • Core battery: We will request periodical the Charles River Laboratories Japan, Inc. examinations at least 4 times a year. The results of this monitoring must be negative. If it becomes clear that the colony has been contaminated with these organisms, we must eliminate the colony and reestablish it from frozen embryos or by in vitro fertilization.

  • Supplemental Battery: We will request a periodical exam from the Charles River Laboratories Japan, Inc. at least 2 times a year. The results of this test will not be as severely regarded as those for the monitoring of the core battery. If contamination by these organisms has been identified, we will breed the infected animals separately and start a new, uncontaminated colony by in vitro fertilization, or isolate the contaminated colony and work hard to replace it. We will permit mice from these colonies to be transferred; however, receiving facilities will be informed with a clear warning that these organisms may be present.

  • Spot Check: No regular monitoring. We will do spot checks for this class of organisms according to demand, or according to the particular immunological conditions of the mice. The results of the spot checks will be used as information, as they do not warrant extreme measures. However, if contamination has been identified, we will consider cleaning the infected colony via in vitro fertilization. We will offer the results of each examination to the facilities we distribute to.


  In the past, when contamination by a particular organism was discovered through monitoring, the policy was to destroy the colony immediately. Due to such policies, scientists often hesitated to check mild pathogens. We have recognized that there are some organisms which must be checked even though their detection will not necessitate extreme measures. Thus, we will check a more comprehensive list of organisms, at three levels of security:

Core Battery - organisms dangerous enough to warrant the immediate elimination of the colony.
Supplemental Battery - controllable organisms which require isolation, but not immediate elimination of infected colonies.
Spot Check - possibly harmful organisms not checked by the ICLAS set menu, which will be checked for, when necessary.

 Finally, in order to prevent the spread of infection, animals will be transferred as frozen embryos, in principle. If the receiving facility, wishes, we will consider the transfer of live animals. In all cases, we will disclose the results of the microbial monitoring and spot checks.

Microbe Check List

Core Battery of RIKEN BDR mouse pathogens
Lymphocytic choriomengitis virus(リンパ球性脈絡髄膜炎ウイルス)
Salmonella spp.(サルモネラ)
Ectromelia virus (エクロトメリアウイルス)
Mouse hepatitis virus (マウス肝炎ウイルス)
Sendai virus (センダイウイルス)
Mycoplasma pulmonis (肺マイコプラズマ)
Citrobacter rodentium (腸粘膜肥厚症菌)
Dangerous organisms which must be eliminated
To monitor periodically

Supplemental Battery
Clostridium piriforme (ティザー菌)
Corynebacterium kutscheri (ネズミコリネ菌)
Pasteurella pneumotropica (肺パスツレラ)
Intestinal protozoa (消化管内原虫)
Helminth (蠕虫類)
External parasites (外部寄生虫)
Organisms to be monitored as useful infomation
To monitor periodically

Spot Check
EDIM (Rota) virus, Minute virus of mice/Mouse parvovirus, Mouse adenovirus, Mouse cytomegalovirus, Mouse encephalomyelitis virus GDVII, Pneumonia virus of mice, Reovirus Type 3, Cilia-associated respiratory (CAR) bacillus, Helicobacter hepaticus/bilis, Pseudomonas aeruginosa (緑膿菌), Staphylococcus aureus, Dermatophytes(皮膚糸状菌), Pneumocystis carinii(カリニ原虫), Aspiculuris tetraptera(ネズミ大腸蟯虫)
To check as needed/requested