• Journal of Veterinary Science
• /
• v.24 no.2
• /
• pp.29.1-29.12
• /
• 2023

Background: Feline panleukopenia virus (FPV) is a widespread and highly infectious pathogen in cats with a high mortality rate. Although Yanji has a developed cat breeding industry, the variation of FPV locally is still unclear. Objectives: This study aimed to isolate and investigate the epidemiology of FPV in Yanji between 2021 and 2022. Methods: A strain of FPV was isolated from F81 cells. Cats suspected of FPV infection (n = 80) between 2021 and 2022 from Yanji were enrolled in this study. The capsid protein 2 (VP2) of FPV was amplified. It was cloned into the pMD-19T vector and transformed into a competent Escherichia coli strain. The positive colonies were analyzed via VP2 Sanger sequencing. A phylogenetic analysis based on a VP2 coding sequence was performed to identify the genetic relationships between the strains. Results: An FPV strain named YBYJ-1 was successfully isolated. The virus diameter was approximately 20-24 nm, 50% tissue culture infectious dose = 1 × 10^-4.94/mL, which caused cytopathic effect in F81 cells. The epidemiological survey from 2021 to 2022 showed that 27 of the 80 samples were FPV-positive. Additionally, three strains positive for CPV-2c were unexpectedly found. Phylogenetic analysis showed that most of the 27 FPV strains belonged to the same group, and no mutations were found in the critical amino acids. Conclusions: A local FPV strain named YBYJ-1 was successfully isolated. There was no critical mutation in FPV in Yanji, but some cases with CPV-2c infected cats were identified.

• Korean Journal of Veterinary Research
• /
• v.45 no.3
• /
• pp.311-323
• /
• 2005

This study tested the effect of a trivalent (feline panleukopenia; FPV, feline viral rhinotracheitis; FHV, feline calicivirus infection; FCV) inactivated vaccine in cats. The vaccine was tested for the safety in guinea pigs, mice and cats. Also, it was tested for the efficacy in cats. The vaccine was inoculated to cats at 7~9 and 10~12 weeks of age (conventional schedule) and the serological response to vaccination was assessed and was compared to the unvaccinated group. All cats were bled by jugular venipuncture for FPV, FHV and FCV specific serological test (virus neutralizing antibody, VN) at 7~9, 10~12 and 13~15 weeks. After last bleeding, all cats were inoculated with each virus (FPV : orally $2ml\;10^{7.5}\;TCID_{50}/ml$, FHV : nasally $1ml\;10^{7.0}\;TCID_{50}/ml$ and FCV : nasally $1ml\;10^{7.0}\;TCID_{50}/ml$). The Vaccine verified excellent protective effect in guinea pigs, mice and cats. The VN antibody titers of the unvaccinated group cats against FPV, FHV and FCV were <2~16, on the other hand the vaccinated group cats were $512{\sim}{\geq}4096$, 64~1024 and 64~1024, respectively. When all cats were challenged with virulent viruses, the survival rates of the vaccinated group cats were over 80%, while the survival rates of the unvaccinated group cats were less 20%. The typical clinical signs were not observed in the vaccinated group cats, but the typical clinical signs and histopathological lesions were observed in the unvaccinated group cats. As the result of tests, the VN values obtained in this study appeared to be high enough to protect cats from viral challenges. The trivalent (FPV, FHV, and FCV) inactivated vaccine seemed to be very effective, for prevention of feline viral diseases (FPV, FHV, and FCV).

• Korean Journal of Veterinary Research
• /
• v.61 no.2
• /
• pp.19.1-19.7
• /
• 2021

Feline panleukopenia virus (FPV) causes leukopenia and severe hemorrhagic diarrhea, killing 50% of naturally infected cats. Although intact FPV can serve as an antigen in the hemagglutination inhibition (HI) test, an accidental laboratory-mediated infection is concern. A non-infectious diagnostic reagent is required for the HI test. Here, we expressed the viral protein 2 (VP2) gene of the FPV strain currently prevalent in South Korea in a baculovirus expression system; VP2 protein was identified by an indirect immunofluorescence assay, electron microscopy (EM), Western blotting (WB), and a hemagglutination assay (HA). EM showed that the recombinant VP2 protein self-assembled to form virus-like particles. WB revealed that the recombinant VP2 was 65 kDa in size. The HA activity of the recombinant VP2 protein was very high at 1:2¹⁵. A total of 143 cat serum samples were tested using FPV (HI-FPV test) and the recombinant VP2 protein (HI-VP2 test) as HI antigens. The sensitivity, specificity, and accuracy of the HI-VP2 test were 99.3%, 88.9%, and 99.3%, respectively, compared to the HI-FPV test. The HI-VP2 and HI-FPV results correlated significantly (r = 0.978). Thus, recombinant VP2 can substitute for intact FPV as the serological diagnostic reagent of the HI test for FPV.

• The Journal of the Convergence on Culture Technology
• /
• v.9 no.3
• /
• pp.263-270
• /
• 2023

The Ukraine-Russia war is a testing ground for High-Tech weapons and the first full-scale drone warfare. The Ukrainian military has been aggressively deploying a variety of reconnaissance and attack drones on the battlefield, and more recently, FPV drones, also known as racing drones, have been fitted with bombs as a game-changer in small-unit combat. To better understand these FPV drones, this article reviews their definition, aircraft components, and key characteristics, and draws implications from the Ukrainian military's FPV combat experience. In the future, the combination of artificial intelligence and swarming technology will make FPV drones even more lethal. Accordingly, the need to develop FPV drones suitable for the future operational environment on the Korean Peninsula is increasing, and follow-up research is needed to specify fighting methods and optimize related technologies.

• Korean Journal of Veterinary Research
• /
• v.62 no.1
• /
• pp.10.1-10.9
• /
• 2022

Feline panleukopenia virus (FPV) causes fatal leukopenia and severe hemorrhagic diarrhea in cats. Although FPV isolates have been reported worldwide from several animals, the biological and genetic features of South Korean FPVs remain unclear. We characterized molecularly South Korean FPV isolates. Crandell-Rees feline kidney (CRFK) cells were used to isolate FPV from 60 organ homogenates. The isolates were confirmed to be FPVs via analyses of cytopathic effects, immunofluorescence studies, electron microscopy, and polymerase chain reaction. Viral genetic analyses used the full VP2 sequences. Eight isolates propagated in CRFK cells were confirmed to be FPVs. All isolates yielded viral titers ranging from 10^4.5 to 10^6.0 TCID₅₀/mL 5 days after inoculation into CRFK cells and exhibited hemagglutination titers ranging from 2⁷ to 2¹² (using pig erythrocytes). The Korean FPV isolates grew well in cat cells such as CRFK and Fcwf-4 cells. The FPV isolates were most similar to the KS42 strain isolated from a Korean cat in 2008. The FPV isolates will serve as useful antigens in future sero-epidemiological studies and will aid in the development of diagnostic tools.

• Journal of Veterinary Science
• /
• v.21 no.3
• /
• pp.43.1-43.13
• /
• 2020

Background: Canine parvovirus (CPV) and feline panleukopenia (FPV) cause severe intestinal disease and leukopenia. Objectives: In Korea, there have been a few studies on Korean FPV and CPV-2 strains. We attempted to investigate several genetic properties of FPV and CPV-2. Methods: Several FPV and CPV sequences from around world were analyzed by Bayesian phylo-geographical analysis. Results: The parvoviruses strains were newly classified into FPV, CPV 2-I, CPV 2-II, and CPV 2-III genotypes. In the strains isolated in this study, Gigucheon, Rara and Jun belong to the FPV, while Rachi strain belong to CPV 2-III. With respect to CPV type 2, the new genotypes are inconsistent with the previous genotype classifications (CPV-2a, -2b, and -2c). The root of CPV-I strains were inferred to be originated from a USA strain, while the CPV-II and III were derived from Italy strains that originated in the USA. Based on VP2 protein analysis, CPV 2-I included CPV-2a-like isolates only, as differentiated by the change in residue S297A/N. Almost CPV-2a isolates were classified into CPV 2-III, and a large portion of CPV-2c isolates was classified into CPV 2-II. Two residue substitutions F267Y and Y324I of the VP2 protein were characterized in the isolates of CPV 2-III only. Conclusions: We provided an updated insight on FPV and CPV-2 genotypes by molecular-based and our findings demonstrate the genetic characterization according to the new genotypes.

• Korean Journal of Ecology and Environment
• /
• v.52 no.4
• /
• pp.293-305
• /
• 2019

In this study we investigated the effect of a floating photovoltaic (FPV) system in Cheongpung Lake on water quality. The FPV with a tilt angle of 33° covered ca. 0.04% of surface area (97 ㎢) of Chungju Lake. The water qualities of the whole lake before and after installation of FPV were first compared. DO, BOD, TOC, and Chl-a of the whole lake were increased, while conductivity decreased after installation period at the significance level of 0.05. This change was probably due to the increased influx of nutrients by 40% resulting from increased precipitation during the same period. We also measured water quality parameters on May and Nov. 2017 at the FPV center (FPVC) and nearby control sites, and compared water quality. The result showed that the FPVC and nearby sites were not significantly different (p>0.05), demonstrating that the FPV does not cause a decline of water quality. The water temperature, light intensity, and phytoplankton community were also measured. The water temperature was not different between the sites, while the light intensity decreased to 27~50%. Despite reduced light intensity at FPVC, the phytoplankton standing crops and the number of species were not significantly different (p>0.05). However, in the early November samples, standing crops was significantly higher in FPVC than control with periphytic diatoms belonging to Aulacoseira genus being dominant. This may be due to the temporal water body behavior or local retention of current by FPV system. This study may provide a measure of future installation of a FPV system.

• Smart Structures and Systems
• /
• v.21 no.2
• /
• pp.139-149
• /
• 2018

Understanding the current status of a construction project is necessary to achieve successful on-site management. Real-time information delivery is a major concern for construction industry practitioners in order to expedite decisions and discussions. We propose the use of a first personal view (FPV) system of a quadcopter drone as a tool for monitoring on-site status and communicating between construction participants. The most important function of the drone FPV system is its ability to visually monitor construction site situations in real time. An on-site management system process is developed, verified, and applied to several construction work tasks after determining factors that affect efficient construction management. The proposed system is expected to assist the construction manager in achieving high efficiency.

• Korean Journal of Veterinary Research
• /
• v.62 no.3
• /
• pp.24.1-24.7
• /
• 2022

Incidences of major feline viral diseases provide basic information for preventing viral disease in cats. Despite the growing interest in feline viral diseases, sero-surveillances have been lacking. In this study, we analyzed the diagnoses of feline viral diseases and conducted a sero surveillance of feline panleukopenia virus (FPV), feline calicivirus (FCV), feline herpesvirus-1 (FHV-1), and feline infectious peritonitis virus (FIPV) in Korean cats. Of the 204 confirmed cases since 2015, the numbers of diagnoses for FPV, FIPV, FCV, feline influenza virus, and FHV-1 were 156, 32, 12, 3, and 1 case, respectively. In total, 200 sera, collected between 2019 and 2021, were screened for the presence of antibodies against FPV, 2 FCVs, FHV-1, and FIPV using a hemagglutination inhibition test and a virus-neutralizing assay (VNA). The overall seropositive rates in cats tested for FPV, the 2 FCVs, FHV-1, and FIPV were 92.5%. 42.0%, 37.0%, 52.0%, and 14.0%, respectively. A low correlation (r = 0.466) was detected between the VNA titers of 2 FCV strains. The highest incidence and seropositive rate of FPV reveal that FPV is circulating in Korean cats. The low r-value between 2 FCVs suggests that a new feline vaccine containing the 2 kinds of FCVs is required.

• Korean Journal of Veterinary Research
• /
• v.63 no.1
• /
• pp.5.1-5.9
• /
• 2023

Feline panleukopenia virus (FPV), feline calicivirus (FCV), and feline herpesvirus type-1 (FHV-1) are major infectious pathogens in cats. We evaluated the immunogenicity of a new vaccine containing inactivated FPV, two FCVs, and FHV-1 in animals. An FPV, two FCVs, and an FHV-1 isolate were continuously passaged 70, 50, 80, and 100 times in CRFK cells. FP70, FC50, FC80, and FH100 were propagated and used as vaccine antigens. Two inactivated feline virus vaccines, feline rehydragel-adjuvanted vaccine (FRAV) and feline cabopol-adjuvanted vaccine (FCAV) were prepared and inoculated into mice and guinea pigs. Humoral immune responses were measured using hemagglutination inhibition (HI) for FPV and virus-neutralizing antibody (VNA) for two FCVs and FHV-1 tests. Serial passages in CRFK cells resulted in increase in titers of FPV and two FCVs but not FHV-1 The FCAV induced higher mean HI and VNA titers than the FRAV in guinea pigs; therefore, the FCAV was selected. Cats inoculated with FCAV developed a mean HI titer of 259.9 against FPV, and VNA titers of 64, 256, and 3.2 against FCV17D03, FCV17D283, and FHV191071, respectively. Therefore, cats inoculated with the FCAV showed a considerable immune response after receiving a booster vaccination.