Affiliation:
1. Research Models and Services, Charles River, Wilmington, MA, USA
2. Riverside, CA, USA
Abstract
A prevalent and distinctive infectious interstitial pneumonia (IIP) of immunocompetent laboratory rats was suspected to be caused by a putative virus, termed rat respiratory virus, but this was never substantiated. To study this disease, 2 isolators were independently populated with rats from colonies with endemic disease, which was perpetuated by the regular addition of naive rats. After Pneumocystis was demonstrated by histopathology and polymerase chain reaction (PCR) in the lungs of rats from both isolators and an earlier bedding transmission study, the relationship between Pneumocystis and IIP was explored further by analyzing specimens from 3 contact transmission experiments, diagnostic submissions, and barrier room breeding colonies, including 1 with and 49 without IIP. Quantitative (q) PCR and immunofluorescence assay only detected Pneumocystis infection and serum antibodies in rats from experiments or colonies in which IIP was diagnosed by histopathology. In immunocompetent hosts, the Pneumocystis concentration in lungs corresponded to the severity and prevalence of IIP; seroconversion occurred when IIP developed and was followed by the concurrent clearance of Pneumocystis from lungs and resolution of disease. Experimentally infected immunodeficient RNU rats, by contrast, did not seroconvert to Pneumocystis or recover from infection. qPCR found Pneumocystis at significantly higher concentrations and much more often in lungs than in bronchial and nasal washes and failed to detect Pneumocystis in oral swabs. The sequences of a mitochondrial ribosomal large-subunit gene region for Pneumocystis from 11 distinct IIP sources were all identical to that of P. carinii. These data provide substantial evidence that P. carinii causes IIP in immunocompetent rats.
Cited by
23 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献