ABSTRACT
Background@#Canine distemper virus (CDV) infection results in high morbidity and mortality in dogs. There has been no report about Isolation of Korean CDV since 1980 in Korea. @*Objectives@#To investigate the biological properties and the genetic characterization of Korean CDV. @*Methods@#Vero cells expressing dog signaling lymphocyte activation molecule (dSLAM) gene named as Vero/dSLAM were used to isolate CDV using 17 samples. Diagnostic methods such as cytopathic effects, immunofluorescence assay, peroxidase linked assay, electron microscopy, rapid immunodiagnostic assay, and reverse transcription polymerase chain reaction were used to confirm the Korean CDV isolate as a CDV. The genetic analysis was performed through cloning and sequencing of hemagglutinin gene of CDV isolate. @*Results@#A virus propagated in Vero/dSLAM cell was confirmed as CDV (CD1901 strain) based on the above methods. The CD1901 strain showed the highest viral titer (10 5.5 50% tissue culture infectious dose [TCID 50 ]/mL) in the Vero/dSLAM cells at 4 days post inoculation, but did not form a fork on chorioallantoic membrane of 7-day-old egg. Ribavirin, a nucleotide analogue anti-viral agent, inhibits moderately the Korean CDV propagation in the Vero/dSLAM cells. The nucleotide and amino acid sequences of the H gene of CD1901 strain were compared with those of other CDV strains. The CD1901 strain belonged to Asia 1 group and had the highest similarity (99.9%) with the BA134 strain, which was isolated in China in 2008. @*Conclusions@#We constructed successfully Vero/dSLAM and isolated one Korean CDV isolate (CD1901 strain) from a naturally infected dog. The CD1901 strain belonged to Asia 1 genotype.
ABSTRACT
Rabid raccoon dogs (Nyctereutes procyonoides koreensis) have been responsible for animal rabies in South Korea since the 1990s. A recombinant rabies vaccine strain, designated as ERAGS, was constructed for use as a bait vaccine. Therefore, new means of differentiating ERAGS from other rabies virus (RABV) strains will be required in biological manufacturing and diagnostic service centers. In this study, we designed two specific primer sets for differentiation between ERAGS and other RABVs based on mutation in the RABV glycoprotein gene. Polymerase chain reaction analysis of the glycoprotein gene revealed two DNA bands of 383 bp and 583 bp in the ERAGS strain but a single DNA band of 383 bp in the field strains. The detection limits of multiplex reverse transcription polymerase chain reaction (RT-PCR) were 80 and 8 FAID 50 /reaction for the ERAGS and Evelyn-Rokitnicki-Abelseth strains, respectively. No crossreactions were detected in the non-RABV reference viruses, including canine distemper virus, parvovirus, canine adenovirus type 1 and 2, and parainfluenza virus. The results of multiplex RT-PCR were 100% consistent with those of the fluorescent antibody test. Therefore, one-step multiplex RT-PCR is likely useful for differentiation between RABVs with and those without mutation at position 333 of the RABV glycoprotein gene.
ABSTRACT
Background@#Canine adenovirus type 2 (CAV-2) induces infectious laryngotracheitis in members of the family Canidae, including dogs. To date, no ELISA kits specific for CAV-2 antibody have been commercialized for dogs in Korea. @*Objectives@#We aimed to develop new indirect enzyme-linked immunosorbent assay (I-ELISA) to perform rapid, accurate serological surveys of CAV-2 in dog serum samples. @*Methods@#In total, 165 serum samples were collected from dogs residing in Chungbuk and Gyeongbuk provinces between 2016 and 2018. The Korean CAV-2, named the APQA1701-40P strain, was propagated in Madin–Darby canine kidney cells and purified in an anion-exchange chromatography column for use as an antigen for I-ELISA. The virus-neutralizing antibody titers of CAV-2 in the dog sera were measured by virus neutralization (VN) test. @*Results@#We compared the results obtained between the VN and new I-ELISA tests. The sensitivity, specificity, and accuracy of new I-ELISA were 98.6%, 86.4% and 97.0% compared with VN test, respectively. New I-ELISA was significantly correlated with VN (r = 0.91). @*Conclusions@#These results indicate that new I-ELISA is useful for sero-surveillance of CAV-2 in dog serum.
ABSTRACT
Canine adenovirus type 1 (CAV-1) causes infectious hepatitis in members of the family Canidae, including dogs. An indirect enzyme-linked immunosorbent assay (I-ELISA) that detects CAV-1 antibodies is required for large-throughput tests of dog sera. We collected 165 serum samples from dogs of Chungbuk and Gyeongbuk provinces between February 2016 and October 2018. The Korean CAV-1 vaccine strain CAV1V was propagated in Madin-Darby canine kidney (MDCK) cells and purified via Nuvia cPrime anion-exchange chromatography; the virus served as an I-ELISA antigen. Virus-neutralizing anti-CAV-1 titers in dog sera were measured using the virus neutralization (VN) method. The I-ELISA was optimized using purified CAV-1 antigen and serum samples. This kit was used to evaluate dog sera. The VN and I-ELISA data were compared. The sensitivity, specificity, and accuracy of the I-ELISA were 97.0%, 74.2%, and 92.7% compared to the VN assay, respectively. The I-ELISA data significantly correlated with those of VN (r = 0.88). These results suggest that the I-ELISA is useful for serosurveillance of CAV-1 in dog sera.