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Determining the viability of faecal bacteria present in germ-free mice
- Taylor, D. M., Read, Lesley, Neal, D. L.
- Laboratory animals 1986 v.20 no.1 pp. 22-26
- Bacilli, Gram-positive bacteria, artificial diets, false positive results, feces, germ-free animals, intestinal microorganisms, laboratory animals, viability
- Gram-positive bacilli, originating from the diet, are present in the faeces of germ-free mice in this Unit. Although these organisms have never grown on culture and are assumed to be dead it was considered desirable to test this by non-cultural methods because some gut bacteria are difficult or impossible to grow in vitro by present techniques. Germ-free mice were fed a synthetic diet free from live or dead organisms for 10 days during which time the bacilli disappeared from the faeces, re-appearing when the usual diet was re-introduced. This was regarded as confirmation of the non-viability of the bacilli. The use of Wayson's stain for confirmation of non-viability was found to be inappropriate since it produced false-positive reactions with irradiation-killed bacteria.