Bacteriological examination of specified-pathogen-free animals: a procedure for small rodents

Organs of 10 mice or 5 rats were pooled and homogenized. A portion of the homogenate was cultured on several selective and enrichment media. The method was tested by adding various pathogenic organisms to organ homogenates. 10(3)-10(4) microorganisms in homogenates of 10 organs were readily detected. This procedure allows even a small microbiological laboratory to detect a low frequency of infected animals in a colony.