Pneumocystis Murina Infection in Immunodeficient Mice in a Closed Barrier Unit: a Case Report

Pneumocystis pneumonia is considered one of the most serious fungal respiratory infections in immunocompromised patients and animals. Molecular comparisons of various gene sequences clearly demonstrated that the single name P. carinii corresponds in fact to a complex group of eukaryotic organisms, which should be assigned to the kingdom Fungi (Edman et al., 1988; Stringer, 1996; AliouatDenis et al., 2008; Li et al., 2008 ). Thus, several Pneumocystis species can be distinguished, each of them residing in a specific mammalian host (Wakefield, 2002; Aliouat-Denis et al, 2008). P. murina is the species found in laboratory mice (Keely et al., 2004). The concept of host specificity has been further supported by the failure of most cross-infection experiments (Aliouat et al., 1994; Gigliotti et al., 2003). However, Sethi (Sethi, 1992) described the possibility for human-derived P. carinii to develop in SCID mice, and one study suggested transient colonization of owl monkeys (Aotus nancymai) by human-derived P. carinii (Beard et al., 1999). Because a continuous in vitro propagation system for Pneumocystis is still lacking, the basic biology of this fungus as well as the epidemiology of Pneumocystis pneumonia remain poorly understood (Cailliez et al., 1996; Stringer, 1996). Airborne Scand. J. Lab. Anim. Sci. 2011 Vol. 38 No. 2