Fig. 1. Pathological lesions and immunohistochemical analyses
of CPV-2 infected pangolins (sub-adult females) suffering from severe
diarrhea. Representative images of gross changes and histopathological
lesions are shown. Panel A presents a gross observation of the internal
organs, showing apparent congestion and hemorrhage. Panels B and C show
histopathological lesions in the jejunum.
Pronounced injury in the mucosa layer of small intestine is a prominent
feature, notably the necrosis and shedding of the intestinal mucosal
intraepithelial cells and glands. Panels D and E show the
immunohistochemistry results for the jejunum and
ileum, respectively. The black arrows indicate the significant
pathological lesion or CPV antigen-positive area. Scale bars are shown
in the lower right-hand corners.
Virus
screening, isolation, and transmission electron microscopy observations
The findings of our PCR analyses revealed that samples obtained from the
two pangolins were CPV-positive, whereas there was no evidence to
indicate infection with CCoV, CDV, or DogCV. Moreover, typical
parvovirus-associated CPV were detected after four passages in F81
cells, and typical parvovirus-like particles, approximately 20 nm in
diameter, were observed in the cell supernatants (Fig. 2). Based on
these observations, we believe CPV-2s to be the etiological agents
causing pangolin diarrhea.