• Korean Journal of Veterinary Research
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• v.60 no.4
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• pp.195-202
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• 2020

Feline calicivirus (FCV) infection results in a common upper respiratory disease associated with oral ulceration in cats. Although FCV infection has been reported in cats worldwide, the biologic and genetic features of South Korean FCV are unclear. We aimed to investigate the biological and genetic features of South Korean FCV isolates. Crandell-Rees feline kidney (CRFK) cells were used to isolate FCV from 58 organ homogenate samples. The FCV isolates were confirmed by cytopathic effects, immunofluorescence, electron microscopy, and reverse transcription polymerase chain reaction assays. Viral genetic analysis was carried out with VP2 gene and complete genomes of FCVs. Five viruses propagated in CRFK cells were confirmed to be FCVs. The FCV17D283 isolate showed the highest viral titer of 107.2 TCID50/mL at 36 h post-inoculation. Korean FCV isolates did not grow well in Vero, BHK-21, A72, or Madin-Darby canine kidney cells. The FCV17D03 and FCV17D283 isolates had the highest genetic similarity (80.1% and 86.9%) with the UTCVM-H1 and 14Q315 strains, which were isolated in the United States and South Korea in 1995 and 2014, respectively. We isolated five FCVs from cats and detected important genetic differences among them. FCV isolates did not show any virulent effects in mice.

• Korean Journal of Veterinary Research
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• v.45 no.3
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• pp.311-323
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• 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 Fisheries and Aquatic Sciences
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• v.43 no.5
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• pp.415-420
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• 2010

In Korea, oysters are used as an ingredient of Kimchi (Korean pickled cabbage) in early winter. Although viral contamination of oysters, including contamination by norovirus, can provoke gastroenteric illness, little is known of the epidemiological relationship to outbreaks. We postulated that Kimchi ripening can reduce the infectivity of norovirus, in order to test this hypothesis, we carried out a model experiment. Since norovirus is currently regarded as non-culturable, feline calicivirus (FCV) was used as a surrogate to examine the activation of norovirus with Kimchi ripening. In commercial well-prepared Kimchi, the infectivity ($TCID_{50}$) of FCV decreased by 2 log every 12 hours and reached the limit of detection after 48 hours during over-aging at $25^{\circ}C$. During storage at $4^{\circ}C$, the infectivity ($TCID_{50}$) of FCV decreased slowly and reached 5.00 $TCID_{50}$ after 48 hours. The low pH appears to affect the infectivity of FCV directly via organic acids produced by ripening during over-aging and storage. In neutralized lab-prepared Kimchi (pH 7.0), the infectivity ($TCID_{50}$) of FCV also decreased and reached the limit of detection after 72 hours at $4^{\circ}C$. This indicates that there are substances beside organic acids in Kimchi that originate from the raw materials and are produced during ripening. Among the raw materials, salt-fermented anchovies and garlic showed high direct antiviral activity. The main factor decreasing the infectivity of FCV in Kimchi was the high acidity caused by organic acids, regardless of the type, produced by ripening. Furthermore, unknown secondary products of microorganisms associated with Kimchi ripening and antiviral materials originating from raw material might contribute to the decreased infectivity of FCV, the surrogate of norovirus.

• Korean Journal of Veterinary Service
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• v.45 no.3
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• pp.145-153
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• 2022

Pathogens such as feline herpesvirus, feline calicivirus, Bordetella bronchiseptica, Chlamydia felis, Mycoplasma felis and Pasteurella multocida usually cause feline upper respiratory tract disease (URTD). Real-time PCR was used to analyze the detection and prevalence of the most common respiratory pathogens in cats with (n=69) and without respiratory signs (n=31). Pathogens were detected in 53 cats, divided into 37 (69.8%) with a single pathogen, 15 (28.3%) with two pathogens, and 1 (1.9%) with three pathogens. M. felis had the highest detection rate in 29 (42.0%) cats, P. multocida was detected in 18 (26.1%), FHV in 10 (14.5%), FCV in 7 (10.1%), B. bronchiseptica in 3 (4.3%), and C. felis in 2 (2.9%). M. felis was the most frequently detected pathogen in cats living outdoors without vaccination. Of the 37 cats infected with single pathogen, nasal discharge was observed in 13 (35.1%), ocular signs in 6 (16.2%), drooling in 5 (13.5%), dyspnea in 3 (8.1%), and asymptomatic in 10 (27.0%). In 51 outdoor and 49 indoor cats, pathogens were detected in 35 (68.6%) and 18 (36.7%) cats, respectively. Of the 29 cats infected with M. felis, 22 (75.9%) showed respiratory signs, and 7 (24.1%) were healthy. In the age of the 53 positive cats, 10 (18.9%) were under the age of 1 year, 26 (49.1%) were aged 1~3 years, and 17 (32.1%) were aged 3 years or older. Although the number of cats in the study was small, the results can provide valuable data on the prevalence of URTD in Korean cats.

• Journal of Veterinary Clinics
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• v.30 no.2
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• pp.115-118
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• 2013

An 8-year-old spayed female domestic shorthair cat was presented with a chief complaint of chronic nasal discharge and dyspnea. Physical examination revealed pyohemorrhagic nasal discharge, inspiratory dyspnea and stertor, and an enlarged right mandibular lymph node. Abnormalities of blood works and serum chemistry included mildly increased hematocrit, and globulin concentration. Serologic tests for FeLV and FIV, and a panel of polymerase chain reaction tests for Chlamydophila felis, Feline Calicivirus, Herpesvirus, Bordetella, Mycoplasma felis, and H1N1 influenza was all negative. Only radiographic finding showed increasing soft tissue density in the right nasal cavity and computed tomography disclosed soft tissue/fluid opacification in the right nasal cavity, paranasal sinus, and pharyinx along with slight deviation to the right of the osseous nasal septum. Focal lysis of ventral nasal septum was also suspected in CT scan. Cytological evaluation of fine needle aspirate smears of the enlarged mandibular lymph nodes revealed numerous fungal yeasts having variably thick capsule both extracellularly and intracellularly with low numbers of macrophages. Some yeasts showed narrow based budding, which was a consistent finding with Cryptococcus organisms. Serum protein electrophoresis was a polyclonal consistent with chronic infection and serum was submitted for a fungal serology panel test. In serologic tests Cryptococcus antigen titer was 1 : 32,768. In vitro culture was unsuccessful. Treatment was initiated with administration of fluconazole, clindamycin, and tocopherol. Clinical signs resolved within 3 days after the initial treatment. The cat was discharged and scheduled for periodic evaluation and continued therapy, but was lost to follow-up thereafter.

• Journal of Life Science
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• v.21 no.9
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• pp.1244-1250
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• 2011

The study was performed to evaluate the antibacterial and antiviral activities of ginseng fine root in order to search for antibacterial substances. Among 8 kinds of fermentation strains, Lactobacillus plantarum was selected based on viable cell count and antibacterial activities during incubation. Optimum conditions of ginseng fine root fermentation for L. plantarum were incubation at $35^{\circ}C$ for 48 hr in 5% ginseng fine root broth. That methanolic extract of fermented ginseng fine root broth was observed to be antibacterial and have antiviral activities. The results of paper disc method of non-fermented extract and fermented extract measured against E. coli was 11 mm and 20 mm, S. aureus was 15 mm and 22 mm, respectively. Shaking flask method was observed to inhibit the growth E. coli and S. aureus in fermented extract by 99.9%. However, antiviral activity of Feline calicivirus (FCV) was mostly activated. Fermented extract was used to investigate the compositional changes of ginsenosides on HPLC analysis. By fermentation, ginsenoside Rg1, Re and Rd were increased, with Rd showing a significant increase of 50 ${\mu}g/g$. These results suggest that ginseng fine root extract is a useful resource.

• Korean Journal of Food Science and Technology
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• v.53 no.1
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• pp.1-11
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• 2021

In this review, recent foodborne outbreaks caused by viruses in the Republic of Korea (2010-2019) were analyzed. The human norovirus was found to be the major foodborne virus causing an average of 94.9% of the viral outbreaks. Reverse-transcription polymerase chain reaction (PCR) with electrophoresis has been widely used to detect viruses, but several rapid detection methods, including real-time PCR, multiplex PCR, and quantum dot assay, have also been suggested. For norovirus inactivation studies, surrogates such as murine norovirus and feline calicivirus have been widely used to identify the reduction rate owing to the limitations in laboratory cultivation. Conversely, direct cell infection studies have been conducted for other foodborne viruses such as adenovirus, astrovirus, rotavirus, and hepatitis A or E virus. Moreover, virucidal mechanisms using various physical and chemical treatments have been revealed. These recent studies suggest that rapid in situ detection and effective control are valuable for ensuring food safety against viral infections.