A
total of 27 strains (positive rate=82%) were successfully isolated from
fecal samples and showed positive in the PCR test.
The
specific CPE of CPV-2 in F81 cells
was
elongated and thinned cells with gaps between them(Figure 1). F81 cells
incubated with CPV-2 emitted green fluorescence under the fluorescence
microscope, indicating the reproduction and reproduction of CPV-2 in F81
cells.
Figure 1. CPV-2 isolation and
direct immunofluorescent (DIF) assay results. (a) CPE of
F81
cells incubated with CPV-2. (b) Normal F81 cell. (c) The DIF assay
result of F81 cell incubated with CPV-2. (d) Negative control.
Amplification of VP2 Gene and GenotypeAnalysis
Full-length
VP2 nucleotide sequences were amplified from 27 samples, which is 2293bp
in length. After aligned with reference strains, extra sequences were
cut off and simplified into 1755bp, namely the full VP2 gene. Table 1
provided the background information of CPV-2 strains isolated in this
study.