• Research in Plant Disease
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• v.23 no.3
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• pp.234-240
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• 2017

Incidence of virus diseases in red pepper of open field in Yeongyang-Gun, Gyeongbuk Province was investigated by reverse transcription-polymerase chain reaction in 2012-2016. The infection rate of Cucumber mosaic virus (CMV), Broad bean wilt virus 2 (BBWV2), Pepper mottle virus, Potato virus Y, Pepper mild mottle virus and Tomato spotted wilt virus was 46.1%, 41.5%, 2.0%, 2.0%, 4.4% and 0.1% respectively. Incidence rate of single and mixed infection was 31.2% and 62.6%. Most of single infections were CMV and BBWV2. Among mixed infections, the incidence rate of CMV+BBWV2 mixed infection was the highest as 49.3% and most of mixed infections of triplex and tetraplex included CMV+BBWV2 mixed infection. CMV single infection caused mosaic, chlorosis, yellowing and vein necrosis and BBWV2 single infection induced cholosis and mosaic. CMV+BBWV2 mixed infection caused severe mosaic with chlorosis or malformation.

• The Journal of Korean Society of Virology
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• v.29 no.1
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• pp.11-22
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• 1999

Sero-epidemiologic survey has been carried out to establish serologically the presence of hantavirus in areas of South Africa. The survey was oriented to search natural infection in both of humans and wild rodents and involvement of human disease. The normal human sera were collected from the residents in urban and rural areas of Western Cape, and rural area of Eastern Cape province. The rodent sera came from various species of rodents trapped in Northern Cape and Western Free provinces. The patient sera were selected from the patients of renal failure, pulmonary syndrome and pyrexia of unknown origin (PUQ) according to diagnostic chart among the patients hospitalized in major hospitals of Cape Town area. The sera were screened and titrated by IFA test using antigens of Hantaan (HTN), Seoul (SEO), Puumala (PUU), and Prospect Hill (PH) viruses primarily. Positive cases were subjected to differential IFA test using HTN, PUU and PH antigens and plaque reduction neutralization test for further confirmation. Anti-hantavirus antibodies were detected from 2 of 352 rural, 1 of 172 urban residents of E. Cape, and 5 of 118 rural, 5 of 368 urban residents of W. Cape. The antibody was also demonstrated from 5 of 221 wild rodents, and it was appeared that 2 different species, Aethomys namaquensis and Tatem leucogaster, are involved. Among 318 patients tested, 3 who were diagnosed as chronic renal failure, acute respiratory distress syndrome (ARDS) and glomerulonephritis were proved to be positive. The reaction patterns obtained from all of these positive sera were distinct from hantaviral sero-patterns ever established. This result suggests that new viruses may exist in this area and play an possible etiologic role in human disease. The feature of serologic survey on anti-hantavirus antibody demonstrable newly from African wild rodents which are different from reservoir species in other continents elicits a conjecture that the virus may be different from known hantaviruses ever found. This fact also suggests that an expanded role in etiologic involvement with other unknown human diseases by newly emerging hantaviruses may be possible in this areas.

• Tuberculosis and Respiratory Diseases
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• v.68 no.4
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• pp.205-211
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• 2010

Background: Procalcitonin is a well known marker in infection that plays a role in distinguishing between bacterial and viral infections in screening. The aim of the present study was to evaluate the role of procalcitonin in differentiating between 2009 H1N1 influenza pneumonia and community acquired pneumonia of bacterial origin, or mixed bacterial origin and 2009 H1N1 influenza infection. Methods: A retrospective observational study was performed over the 6-month winter period during the 2009 H1N1 influenza pandemic. Ninety-six patient-subjects were enrolled, all of whom had been diagnosed with community acquired pneumonia in emergency department during the study period. On admission, laboratory studies were performed, which included 2009 H1N1 influenza real-time polymerase chain reaction of nasal secretions and procalcitonin on serum; the laboratory values were compared between the study groups. Receiver operating characteristic curve analyses were performed on the resulting data. Results: Compared to those with bacterial or mixed infections (n=62) and bacterial pneumonia with confirmed organisms (n=30), patients with 2009 H1N1 pneumonia (n=34) were significantly more likely to have low procalcitonin levels (p=0.008, 0.001). Using cutoff of value >0.3 ng/mL, the sensitivity and specificity of procalcitonin for detection of patients with confirmed bacterial pneumonia were 76.2% and 60.6%, respectively. A significant difference in procalcitonin was found between 2009 H1N1 pneumonia and pneumonia caused by mixed influenza viral and bacterial infections (0.15 [0.05~0.84] vs. 10.3 [0.05~22.87] ng/mL, p=0.045). Conclusion: Serum procalcitonin measurement may assist in the discrimination between pneumonia of bacterial and of 2009 H1N1 influenza origin. High values of procalcitonin suggest that bacterial infection or mixed infection of bacteria and 2009 H1N1 influenza is more likely.

• Pediatric Infection and Vaccine
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• v.29 no.2
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• pp.70-76
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• 2022

Coronavirus disease 2019 (COVID-19) in patients with underlying diseases, is associated with high infection and mortality rates, which may result in acute respiratory distress syndrome and death. Mucopolysaccharidosis (MPS) type II is a progressive metabolic disorder that stems from cellular accumulation of the glycosaminoglycans, heparan, and dermatan sulfate. Upper and lower airway obstruction and restrictive pulmonary diseases are common complaints of patients with MPS, and respiratory infections of bacterial or viral origin could result in fatal outcomes. We report a case of COVID-19 in a 16-year-old adolescent with MPS type II, who had been treated with idursulfase since 5 years of age. Prior to infection, the patient's clinical history included developmental delays, abdominal distension, snoring, and facial dysmorphism. His primary complaints at the time of admission included rhinorrhea, cough, and sputum without fever or increased oxygen demand. His heart rate, respiratory rate, and oxygen saturation were within the normal biological reference intervals, and chest radiography revealed no signs of pneumonia. Consequently, supportive therapy and quarantine were recommended. The patient experienced an uneventful course of COVID-19 despite underlying MPS type II, which may be the result of an unfavorable host cell environment and changes in expression patterns of proteins involved in interactions with viral proteins. Moreover, elevated serum heparan sulfate in patients with MPS may compete with cell surface heparan sulfate, which is essential for successful interaction between the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein and the host cell surface, thereby protecting against intracellular penetration by SARS-CoV-2.

• Pediatric Infection and Vaccine
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• v.19 no.1
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• pp.28-36
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• 2012

Purpose : This study was conducted to evaluate epidemiological data of the viral pathogens obtained from stool exams and provide information on the regional prevalence of infectious diarrheal disease west in Gyeonggi Province, Korea. Methods : We enrolled a cohort of children <10 years of age admitted for treatment of acute diarrhea at Bucheon St. Mary's Hospital, College of Medicine, The Catholic University of Korea. In total, 310 fecal specimens, documented to be free of common bacterial pathogens, were collected from pediatric patients during a 12-month period from January to December 2009 and were tested for the presence of rotavirus, parechovirus, adenovirus, astrovirus, enterovirus, and norovirus using polymerase chain reaction (PCR) and reverse transcription polymerase chain reaction (RT-PCR) assay. Results : The most common virus was parechovirus (16%), followed by adenovirus (15%), astrovirus (14%), rotavirus (13%), and enterovirus (5%). Interestingly, only one of the specimens was positive for norovirus. Single infection cases were detected in 173 (55.8%) of the 310 children, whereas mixed viral infections were detected in 10 (3.2%) of the same children. Viral gastroenteritis generally showed a double peak of incidence. Parechovirus, rotavirus, and adenovirus shared a similar pattern of peak incidence with overall viruses; however, astrovirus infections occurred more frequently in the spring. Eighty-five percent of the confirmed viral gastroenteritis cases developed in under 24 months. Conclusion : The results support the importance of parechovirus, adenovirus, astrovirus, and enterovirus as causative agents of diarrhea in children, which may be underestimated by current routine diagnostic testing.

• The Journal of Korean Society of Virology
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• v.26 no.1
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• pp.77-90
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• 1996

Nucleocapsid protein (NP)which exists in the particle of hantavirus and surrounds the viral RNA genome is one of the major structural proteins and plays role of antigen to elicit the antibody detected predorminantly right after infection of the virus in the patients of hemorragic fever with renal syndrome (HFRS)or experimental animals. NP is important target antigen in serological diagnostic system of HFRS utilizing whole antigens from the native virus particle, such as IFA, ELISA and Western blotting. Therefore, the preparation of this protein in the level of higher quantity and purity is desirasble for developed dianosis of the disease. The purpose of this study is the cloning of NP gene which exists in the S genome segment of Maaji (MAA) virus and expression of the gene to obtain qualified, genetically engineered NP to be utilized as an immunodiagnostic antigen. First of all, for the purpose of amplifing the MAA-NP gene by PCR, the specific primers were built from the known nucleotide sequence of Hantaan viral NP gene. The viral cDNA of the NP gene was synthesized by using the primers and RNase $H^-$ AMV reverse transcriptase. Thereafter, using this cDNA as a template, the NP gene was amplified specifically by Taq DNA polymrerase. The pT7blue (R)T-overhang vector systems were used for cloning of the amplified NP gene. The expression system was consisted of BL21 (DE3)pLysS and pET16b as a host and a plasmid repectively. Into Ndel site of pET16b, NP gene was ligated with cohesive end for the expression. Insertion of NP gene in the plasmid was confirmed by PCR and mini prep methods. For expression, IPTG was used and the expressed protein was characterized by Western blotting. The MAA-NP was expressed as the form of inclusion body (insoluble fraction)and the protein purified by affinity and metal chealating columns reacted specifically with the sera from patients of HFRS as to be tested by ELISA and Western blotting.

• Pediatric Infection and Vaccine
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• v.24 no.1
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• pp.44-53
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• 2017

Purpose: The aim of this study was to investigate the risk factors for posttransplant lymphoproliferative disorder (PTLD) and to evaluate the association between Epstein-Barr viral load and the development of PTLD in pediatric heart transplant recipients. Methods: We reviewed children aged <18 years who underwent heart transplantation and quantitative analysis of blood Epstein-Barr virus (EBV) viremia at our institute from January 2006 to March 2015. Clinical characteristics and EBV viral loads were compared according to the presence of PTLD. Results: Over 9 consecutive years, a total of 40 heart transplant recipients, were included. Among 28 children with available EBV viral load measurements, seven patients (25%) had EBV viremia only defined as at least one time of ${\geq}457copies/mL$. PTLD occurred in three recipients (7.5%) 4.3, 6.3, and 17.0 months after transplant and all PTLD cases had preceding EBV viremia. The median age at transplant was 5.3 years (range, 0.5 to 6.0 years) in the PTLD group, compared with 11.9 years (range, 0.3 to 17.8 years) in the non-PTLD group (P=0.021). The median values of the peak EBV levels in the PTLD group were 3,452,170 copies/mL (range, 46,750 to 7,622,910 copies/mL); the peak EBV levels in the non-PTLD group were 3,112 copies/mL (range, 2,250 to 103,000 copies/mL). Conclusions: Younger age at transplant and presence of EBV viremia were associated with the development of PTLD in pediatric heart transplant recipients. A prospective study will be required to determine the blood EBV load for predicting the development of PTLD in these patients.

• Research in Plant Disease
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• v.25 no.2
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• pp.49-61
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• 2019

Plant viruses are among the important pathogens that cause severe crop losses. The most efficient method to control viral diseases is currently to use virus resistant crops. In order to develop the virus resistant crops, a detailed understanding of the molecular interactions between viral and host proteins is necessary. Recessive resistance to a pathogen can be conferred when plant genes essential in the life cycle of a pathogens are deficient, while dominant resistance is mediated by host resistance (R) genes specifically interacting with effector proteins of pathogens. Thus, recessive resistance usually works more stably and broadly than dominant resistance. While most of the recessive resistance genes have so far been identified by forward genetic approaches, recent advances in genome editing technologies including CRISPR/Cas9 have increased interest in using these technologies as reverse genetic tools to engineer plant genes to confer recessive resistance. This review summarizes currently identified recessive resistance genes and introduces reverse genetic approaches to identify host interacting partner proteins of viral proteins and to evaluate the identified genes as genetic resources of recessive resistance. We further discuss recent advances in various precise genome editing technologies and how to apply these technologies to engineer plant immunity.

• Korean Journal of Environmental Biology
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• v.39 no.3
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• pp.259-265
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• 2021

A diagnostic test for viral hemorrhagic septicemia virus (VHSV), which infects more than 80 species of freshwater and marine fish at home and abroad, causing mass mortality, was conducted to provide quantitative data on the amount of virus expression in various tissues of flounder in chronological order. The tissues were collected in chronological order after the intraperitoneal injection of 3.0E+07 tissue culture infective dose₅₀ (TCID₅₀) per 0.1mL per fish of VHSV to randomly selected flounder. As a result of relative quantification through real-time PCR, the highest levels of virus expression were found in the spleen, kidney, gill, and liver on day 5. This study proved that the spleen was an appropriate site for the final diagnosis of VHSV in the early stages of infection and will provide important information for the diagnosis of legal infectious diseases in Korea.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 1997.06a
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• pp.5-21
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• 1997

Unique virus-like particles were associated with five eriophyid mite-borne plant diseases of unknown etiology; fig mosaic, redbud yellow ringspot, rose orsette, thistle mosaic, and high plains disease of corn and wheat. Quasi-spherical, double membrane-bound particles (DMPs), 120 - 200 nm in diameter, were observed in the cytoplasm of all cell types in symptomatic leaves of infected plants. No DMPs were observed in symptomless plants. The DMPs in symptomatic thistles were associated with two types of inclusions, electron-dense amorphous material and tubular aggregates. Similar amorphous inclusions were also found in corn and wheat with high plains disease, while tubular inclusions were observed in figs with mosaic symptoms. The particles and inclusions were similar in some aspects to immature particles associated with viroplasms of animal and insect poxviruses and also to the double-enveloped particles of tomato spotted wilt virus associated with viroplasms during early stages of infection, but were unique and unlike any known plant viruses. The DMPs and associated viroplasm-like inclusions in the high plains disease were specifically immunogold labeled in situ with the disease-specific antiserum. Thread-like structures, similar to tenuivirus particles, present in the partially purified virus preparations were also immunogold labeled with the antiserum. It is suggested that the thread-like structures are derived from the DMP. In many cells of symptomatic corn and wheat samples, DMPs occurred together with flexuous rod-shaped particles and cylindrical inclusions of wheat streak mosaic potyvirus (WSMV), suggesting that the disease is caused by a mixed infection of WSMV and the agent represented by the DMPs. Based on cytopathology, symptomatology and mite and/or graft-transmissibility, the five diseases described in this paper are potentially caused by virus(es) and the DMPs associated with these diseases may represent virus particles. If the DMPs are indeed viral in nature, they would comprise a new group of plant viruses.