A retrospective study of the microbiological and parasitological status of laboratory rodents in France

Between 1988 and 1997, 72 mouse colonies and 38 rat colonies were examined for the presence of bacteria parasite infections. Among mouse and rat bacteria, high positive rates were observed with Proteus species (sp.), Pasteurella pneumotropica, Mycoplasma sp. and Pseudomonas aeruginosa. Concerning murine colonies, parasites frequently detected were Tritrichomonas sp., Syphacia sp., Aspiculuris tetraptera, Entamoeba muris, Spironucleus muris, Myobia musculi, Chilomastix sp. and Myocoptes musculinus. In rats, high rates were obtained with Syphacia sp., Tritrichomonas sp., Spironucleus muris, Entamoeba muris and Chilomastix sp. During the first part of the last decade, some agents such as Clostridium piliforme, Citrobacter sp., Mycoplasma sp., Pseudomonas aeruginosa, Myobia musculi, Radfordia ensifera, Spironucleus muris and Giardia muris were often found among rodents, and most of them were still present in 1997. At the time of our study, results point out that some agents are still persistent, even increasing during the same period. It is particularly the case for parasites such as Entamoeba muris and the oxyurids, but also for bacteria like Proteus sp. and Klebsiella pneumoniae. We can thus conclude that only very limited success has been achieved in preventing microbial and parasitic infections in mice and rats colonies.