Background:

Tumors, cell lines and other biological materials, including serum and embryonic stem cells, may be contaminated with adventitious rodent pathogens. Usually this occurs by deriving cell lines or other biologicals from rodents, or by passaging them through rodents that are themselves contaminated. Many rodent pathogens survive quite well in cell cultures and may be passed back into other rodents. Unfortunately, while the major suppliers of cell lines and tumors usually test for bacteria, fungi and Mycoplasma, they do not generally test for rodent viruses. In one survey, 70% of samples propagated in mice were positive for murine viruses (1). An earlier study found a similar % of contamination (2). The most common contamination of mouse tumors was lactate dehydrogenase-elevating virus, followed by Reo 3, lymphocytic choriomeningitis virus (LCMV), minute virus of mice, and mouse hepatitis virus. Most of the contaminants are known to affect tumorigenesis, the immune system or other physiological parameters. One contaminant, LCMV, is a known zoonotic. There are several reports of human disease associated with outbreaks in hamster colonies or infected tumors (3,4,5).

Inadvertent introduction of untested biologicals carrying pathogens can endanger the health of rodents in the campus vivaria.  Therefore, all biological materials of unknown status should be tested prior to incorporation into rodents. 

Policy:

The following materials must be tested for pathogens, and the results provided to the Campus Veterinarian for approval, prior to their use in live animals:

Cell lines, transplantable tumors, tissues, embryonic stem cells, serum components of cell culture media, ascites fluid, myelomas, hybridomas, spermatozoa, and any other biological material that will be inoculated into rodents, unless certified to be pathogen-free (note: the ATCC does not certify lines as pathogen-free).  

The murine pathogen PCR testing profile should include the following agents:  

The rat pathogen PCR testing profile should contain agents specific to rat.   Contact the Campus Veterinarian for more information about testing for rat pathogens.  

Laboratories offering this testing service (these are listed for investigator convenience, the UCR Office of the Campus Veterinarian does not require the tests to be performed by these specific labs, nor do we specifically endorse their services).

·          Charles River Laboratories and The Diagnostic Laboratory at the University of Missouri offer PCR test panels that detect the presence of rodent pathogens in biological materials.  Additional information can be found in the sites below. 

·          http://www.criver.com/flex_content_area/documents/rm_ld_c_molecular_diagnostic_services.pdf

·          http://www.radil.missouri.edu/info/DiagTesting/services/molecularbiology.asp

References

1. Nicklas, W., V. Kraft, and B. Meyer. 1993. Contamination of transplantable tumors, cell lines, and monoclonal antibodies with rodent viruses. Lab Anim. Sci. 43:296-300.

2. Collins, M.J. and J.C, Parker. 1972. Murine virus contaminants of leukemia viruses and transplantable tumors. J. Natl. Cancer Inst. 49:1139-1143.

3. Bowen, G.S., C.H. Calisher, W.G. Winkler, et al. 1975. Laboratory studies of a lymphocytic choriomeningitis virus outbreak in man and laboratory animals. Am. J. Epidemiol. 102:233-240.

4. Kawamata, J., T. Yamanouchi, K. Dohmae, et al. 1987. Control of laboratory acquired hemorrhagic fever with renal syndrome (HFRS) in Japan. Lab. Anim. Sci. 37: