MICROBIOLOGICAL EFFECTS AND QUALITY-CONTROL IN LABORATORY RODENTS

Numerous viruses, mycoplasmas, bacteria and parasites have been associ ated with infectious diseases in laboratory animals. It is clear that pathogenic agents causing overt disease represent a serious hazard to research results in both short- as well as long-term studies. However, these organisms may contaminate colonies without causing any clinical or pathological symptom. This makes research less reliable because of the more subtle effects of the silent infections, especially in long- term studies as in aging research. The establishment of animal colonie s that were free from these (micro-) organisms has increased substanti ally the value of animals used in biomedical research. Characterizatio n of the health status and microbiological monitoring of the animals i n experiments are particularly important. This paper reviews many of t he major considerations in the efforts to maintain animals free of unw anted organisms, including quality and sources of animals, transportat ion and quarantine, maintenance during experimentation, microbiologica l characterization and monitoring of animals and environment.