Real-time PCR assay for screening Pneumocystis in free-living wild squirrels and river rats in Italy

Abstract

We used a real-time PCR (rtPCR) targeting a 150-bp amplicon of the mitochondrial small subunit of ribosomal RNA (mtSSU rRNA) to screen for Pneumocystis DNA in lungs of wild squirrels ( Callosciurus finlaysonii, n = 85) and river rats ( Myocastor coypus, n = 43) in Italy. The rtPCR revealed Pneumocystis DNA in 20 of 85 (24%) squirrels and in 35 of 43 (81%) river rats, and was more sensitive than a nested PCR that targets a portion of the mtSSU rRNA and the mitochondrial large subunit of rRNA (mtLSU rRNA). Phylogenetic analysis based on mtSSU rRNA and mtLSU rRNA sequences showed distinct Pneumocystis sequence types in these rodents. The rtPCR assay should be reliable for screening large populations for this potential pathogen, thereby allowing cost-effective monitoring of the disease in wild animals.

Revisiting the Pneumocystis host specificity paradigm and transmission ecology in wild Southeast Asian rodents

“…The epidemiology and transmission of Pneumocystis in natural host populations remain poorly understood to date and, to our knowledge, this study is the first to investigate the factors explaining the probability of infection of wild rodents by these airborne-transmitted organisms in their natural habitat. The global Pneumocystis prevalence level observed in this study (43.6%) is similar to the prevalence found in other wild rodent studies (Danesi et al, 2018;Petružela et al, 2019). Our models suggest that the probability of Pneumocystis infection in rodent hosts is positively correlated to environmental variables reflecting habitat fragmentation and landscape patchiness (i.e.…”