Safety aspects of working with Candida albicans-infected mice.
When the opportunity arose in the course of four experiments with mice and one with guinea pigs, all systemically infected with Candida albicans, the animals' bedding, work surfaces, surrounding walls, the balance pan and tools used in homogenization of tissues were sampled with contact plates or by water washing for the presence of viable C. albicans cells. Although substantial viable counts of C. albicans were measured in homogenized samples of kidneys and other tissues, no colonies of the fungus were recovered at any time from the work surfaces, walls or homogenizer stand. Contact samples of the homogenizer dispersal tool made on four occasions during the course of 24 successive homogenizations showed that few viable C. albicans could be cultured from the tool after two water washes, and none at all after two washes with 70% ethanol. Water samples of the contents of three cages that had housed infected mice were all negative for viable C. albicans, however, direct contact plate samples of the bedding material and excreta in seven cages yielded positive cultures with colony counts from 1 to 8 per sample in five instances and 18 in one instance. It is concluded that the potential infection risk to personnel of working with this hazard group 2 fungus is minimal and the highly stringent safety regulations for all organisms in hazard group 2 may err on the side of over-caution.
Department of Molecular and Cell Biology, Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, UK.
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D000818:Animals; D002176:Candida albicans / Q000302:isolation & purification*; D002177:Candidiasis / Q000517:prevention & control* / Q000635:transmission; D015169:Colony Count, Microbial; D004195:Disease Models, Animal; D004203:Disinfection / Q000379:methods; D004866:Equipment Contamination; D006168:Guinea Pigs; D006799:Housing, Animal; D006801:Humans; D007757:Laboratory Infection / Q000517:prevention & control*; D017056:Medical Laboratory Personnel; D051379:Mice; D008807:Mice, Inbred BALB C; D012449:Safety