Virologic detection and molecular characterization of canine parvovirus-2 in dogs

This study aimed to search the extent of spread of various canine parvovirus variants in Egypt from year 2019 to year 2020 and the ability of the present used vaccines in the protection .In this study, twenty fecal samples were collected from diarrheic puppies. These samples were tested by rapid CPV Ag test kits for the detection of CPV-2 Ag. Ten samples were found positive for CPV2 by rapid Ag test kit (VDRG CPV Ag rapid kit).Positive samples were propagated on Vero cell culture for 8 passages, CPE appears in the form of cell rounding and detachment within 5 days.  A conventional polymerase chain reaction test was performed on tissue culture isolates. Partial sequencing of five randomly selected positive samples revealed the presence of 2 CPV2C and 3 CPV2B.CPV2B represents the highest level of the variant serotype of CPV circulating in Egypt through records of egyptian isolated cases at the gene bank . One of the isolate has 100% identity with a CPV2B of cat origin. Our isolates CPVS1 and CPVS4 have 100% nucleotide identity with each other and with CPV cairo1-19 and CPV cairo3-19 belonging to CPV2C , this variant is also widespread all over the country. Continuous accurate molecular and epidemiological studies are needed to follow-up the new mutation of the virus genome which may result in vaccination failure(The majority of the used vaccines in Egypt are of CPV2 origin not of variant origin). The use of CPV2b based vaccine gave better protection than cpv2 based vaccine(Wide range protection against CPV2 variants). The obvious spread and emergence of newly introduced CPV variants at different Egyptian governorates as cited at previous study necessitates updated molecular based epidemiological studies of field isolates continuously to follow up the efficacy of the concurrent used vaccines.