Online Issues

Journal Vol 49 (3)

Rodent and Germplasm Trafficking: Risks of Microbial Contamination in a High-Tech Biomedical World

Esther Mahabir, Beth Bauer, and Jörg Schmidt

Esther Mahabir, PhD, is head of research and development in Reproductive Biology and Microbiology, head of the Mouse Core Unit, and head of CryoGene Services – Embryo Cryopreservation and Rederivation in the Department of Comparative Medicine at the Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH) in Neuherberg, Germany. Beth A. Bauer, DVM, is a clinical assistant professor at the Research Animal Diagnostic Laboratory (RADIL), Rat Resource and Research Center (RRRC), and Mutant Mouse Regional Resource Centers (MMRRC) at the University of Missouri, Columbia. Jörg Schmidt, DVM, is a professor in and head of the Department of Comparative Medicine at the German Research Center for Environmental Health (GmbH) in Neuherberg.

Address correspondence and reprint requests to Dr. Esther Mahabir, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstädter Landstrasse 1, D-85764 Neuherberg, Germany or email mahabir@helmholtz-muenchen.de.

Abstract

High-tech biomedical advances have led to increases both in the number of mice used for research and in exchanges of mice and/or their tissues between institutions. The latter are associated with the risk of dissemination of infectious agents. Because of the lack of international standardization of health surveillance programs, health certificates for imported rodents may be informative but may not address the needs of the importing facility. Preservation of mouse germplasm is achieved by cryopreservation of spermatozoa, embryos, or ovaries, and embryonic stem cells are used for the production of genetically engineered mice. After embryo transfer, recipients and rederived pups that test negative in microbiological screening for relevant microorganisms are released into full barrier holding areas. However, current research shows that embryos may also transmit microorganisms, especially viruses, to the recipient mice. In this article, we discuss regulations and practical issues in the shipping of live mice and mouse tissues, including spermatozoa, embryos, ovaries, and embryonic stem cells, and review work on microbial contamination of these biological materials. In addition, we present ways to reduce the risk of transmission of pathogens to mice under routine conditions.

Key Words: assisted reproductive technologies; embryos; germplasm; mice; microbial contamination; pathogens