• IMMUNE NETWORK
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• v.21 no.2
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• pp.12.1-12.17
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• 2021

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since the emergence of SARS-CoV-2 in the human population in late 2019, it has spread on an unprecedented scale worldwide leading to the first coronavirus pandemic. SARS-CoV-2 infection results in a wide range of clinical manifestations from asymptomatic to fatal cases. Although intensive research has been undertaken to increase understanding of the complex biology of SARS-CoV-2 infection, the detailed mechanisms underpinning the severe pathogenesis and interactions between the virus and the host immune response are not well understood. Thus, the development of appropriate animal models that recapitulate human clinical manifestations and immune responses against SARS-CoV-2 is crucial. Although many animal models are currently available for the study of SARS-CoV-2 infection, each has distinct advantages and disadvantages, and some models show variable results between and within species. Thus, we aim to discuss the different animal models, including mice, hamsters, ferrets, and non-human primates, employed for SARS-CoV-2 infection studies and outline their individual strengths and limitations for use in studies aimed at increasing understanding of coronavirus pathogenesis. Moreover, a significant advantage of these animal models is that they can be tailored, providing unique options specific to the scientific goals of each researcher.

• Molecules and Cells
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• v.44 no.6
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• pp.377-383
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• 2021

Severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) is a novel virus that causes coronavirus disease 2019 (COVID-19). To understand the identity, functional characteristics and therapeutic targets of the virus and the diseases, appropriate infection models that recapitulate the in vivo pathophysiology of the viral infection are necessary. This article reviews the various infection models, including Vero cells, human cell lines, organoids, and animal models, and discusses their advantages and disadvantages. This knowledge will be helpful for establishing an efficient system for defense against emerging infectious diseases.

• BMB Reports
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• v.54 no.8
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• pp.425-430
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• 2021

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces coronavirus disease 2019 (COVID-19) and may increase the risk of adverse outcomes in lung cancer patients. In this study, we investigated the expression and function of mucin 1 (MUC1) after SARS-CoV-2 infection in the lung epithelial cancer cell line Calu-3. MUC1 is a major constituent of the mucus layer in the respiratory tract and contributes to pathogen defense. SARS-CoV-2 infection induced MUC1 C-terminal subunit (MUC1-C) expression in a STAT3 activation-dependent manner. Inhibition of MUC1-C signaling increased apoptosis-related protein levels and reduced proliferation-related protein levels; however, SARS-CoV-2 replication was not affected. Together, these results suggest that increased MUC1-C expression in response to SARS-CoV-2 infection may trigger the growth of lung cancer cells, and COVID-19 may be a risk factor for lung cancer patients.

• Journal of Microbiology and Biotechnology
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• v.30 no.3
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• pp.313-324
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• 2020

Coronavirus disease 2019 (COVID-19), which causes serious respiratory illness such as pneumonia and lung failure, was first reported in Wuhan, the capital of Hubei, China. The etiological agent of COVID-19 has been confirmed as a novel coronavirus, now known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is most likely originated from zoonotic coronaviruses, like SARS-CoV, which emerged in 2002. Within a few months of the first report, SARS-CoV-2 had spread across China and worldwide, reaching a pandemic level. As COVID-19 has triggered enormous human casualties and serious economic loss posing global threat, an understanding of the ongoing situation and the development of strategies to contain the virus's spread are urgently needed. Currently, various diagnostic kits to test for COVID-19 are available and several repurposing therapeutics for COVID-19 have shown to be clinically effective. In addition, global institutions and companies have begun to develop vaccines for the prevention of COVID-19. Here, we review the current status of epidemiology, diagnosis, treatment, and vaccine development for COVID-19.

• IMMUNE NETWORK
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• v.22 no.6
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• pp.48.1-48.13
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• 2022

With the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants, which are randomly mutated, the dominant strains in regions are changing globally. The development of preclinical animal models is imperative to validate vaccines and therapeutics against SARS-CoV-2 variants. The objective of this study was to develop a non-human primate (NHP) model for SARS-CoV-2 Delta variant infection. Cynomolgus macaques infected with Delta variants showed infectious viruses and viral RNA in the upper (nasal and throat) and lower respiratory (lung) tracts during the acute phase of infection. After 3 days of infection, lesions consistent with diffuse alveolar damage were observed in the lungs. For cellular immune responses, all macaques displayed transient lymphopenia and neutrophilia in the early stages of infection. SARS-CoV-2 Delta variant spike protein-specific IgM, IgG, and IgA levels were significantly increased in the plasma of these animals 14 days after infection. This new NHP Delta variant infection model can be used for comparative analysis of the difference in severity between SARS-CoV-2 variants of concern and may be useful in the efficacy evaluation of vaccines and universal therapeutic drugs for mutations.

• The Plant Pathology Journal
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• v.32 no.3
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• pp.260-265
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• 2016

We observed the changes in aggressiveness and fecundity of the anthracnose pathogen Colletotrichum acutatum on hot pepper, under the ambient and the twice-ambient treatments. Artificial infection was repeated over 100 cycles for ambient ($25^{\circ}C/400ppm$ $CO_2$) and twice-ambient ($30^{\circ}C/700ppm$ $CO_2$) growth chamber conditions, over 3 years. During repeated infection cycles (ICs) on green-pepper fruits, the aggressiveness (incidence [% of diseased fruits among 20 inoculated fruits] and severity [lesion length in mm] of infection) and fecundity (the average number of spores per five lesions) of the pathogen were measured in each cycle and compared between the ambient and twice-ambient treatments, and also between the early (ICs 31-50) and late (ICs 81-100) generations. In summary, the pathogen's aggressiveness and fecundity were significantly lower in the late generation. It is likely that aggressiveness and fecundity of C. acutatum may be reduced as global $CO_2$ and temperatures increase.

• Korean Journal of Veterinary Service
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• v.46 no.4
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• pp.283-291
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• 2023

Brucellosis and tuberculosis are major infectious and contagious bacterial diseases in cattle. These diseases are malicious diseases that must be inspected at the slaughterhouse of cattle in accordance with the practice of quarantine in Korea. Furthermore, both diseases lead to abortion, reproductive disorder, and calf disease, causing major difficulty in the breeding of Korean Native cattle (Hanwoo), a representative industrial animal currently being raised in Korea. Co-infections of these diseases intensify clinical symptoms such as abortion and have a particularly significant effect on increasing mortality. Thus, serological tests were performed in Hanwoo, to establish the association of co-infection between brucellosis and tuberculosis in cattle. ELISA and PCR tests were conducted on blood samples collected from a total of 102 cattle in Jeonnam province, Korea, to detect brucellosis and tuberculosis infections. The PCR results revealed that 41 samples tested positive for Brucella abortus (B. abortus) infection (40.20%), and 5 samples tested positive for Mycobacterium bovis (M. bovis) (4.90%) infection confirmed by PCR. Notably, 9.76% (4/41) of the cattle infected with brucellosis also tested positive for tuberculosis. In conclusion, this study highlights the co-infection of brucellosis and tuberculosis among Hanwoo cattle in Jeonnam province, which is expected to contribute to our understanding of disease transmission, pathogenicity, the establishment of future prevention strategies.

• Tuberculosis and Respiratory Diseases
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• v.80 no.2
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• pp.201-209
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• 2017

Background: Methicillin-resistant Staphylococcus aureus (MRSA) infection is a severe and life-threatening disease in patients with community-onset (CO) pneumonia. However, the current guidelines lack specificity for a screening test for MRSA infection. Methods: This study was retrospectively conducted in elderly patients aged ${\geq}65years$, who had contracted CO-pneumonia during hospitalization at the Jeju National University Hospital, between January 2012 and December 2014. We analyzed the risk factors of MRSA in these patients and developed a scoring system to predict MRSA infection. Results: A total of 762 patients were enrolled in this study, including 19 (2.4%) with MRSA infection. Healthcare-associated pneumonia (HCAP) showed more frequent MRSA infection compared to community-acquired pneumonia (4.4% vs. 1.5%, respectively; p=0.016). In a multivariate logistic regression analysis, admissions during the influenza season (odds ratio [OR], 2.896; 95% confidence interval [CI], 1.022-8.202; p=0.045), chronic kidney disease (OR, 3.555; 95% CI, 1.157-10.926; p=0.027), and intensive care unit admission (OR, 3.385; 95% CI, 1.035-11.075; p=0.044) were identified as predictive factors for MRSA infection. However, the presence of HCAP was not significantly associated with MRSA infection (OR, 1.991; 95% CI, 0.720-5.505; p=0.185). The scoring system consisted of three variables based on the multivariate analysis, and showed moderately accurate diagnostic prediction (area under curve, 0.790; 95% CI, 0.680-0.899; p<0.001). Conclusion: MRSA infection would be considered in elderly CO-pneumonia patients, with three risk factors identified herein. When managing elderly patients with pneumonia, clinicians might keep in mind that these risk factors are associated with MRSA infection, which may help in selecting appropriate antibiotics.

• Pediatric Infection and Vaccine
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• v.22 no.3
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• pp.143-146
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• 2015

Since 2012, outbreaks of the Middle East respiratory coronavirus (MERS-CoV) have been reported, including the Republic of Korea. To date, most of the people infected with the virus are adults. Herein we describe the clinical characteristics of cases of MERS-CoV infection among children. As of October 29, 2015, MERS-CoV has caused 34 pediatric infections, which accounts for 2.1% of all cases. The median age was 13 years (range 9 months to 17 years) and where gender has been reported (n=33), 57.6% cases were male. About half of the patients were asymptomatic and the majority of the symptomatic patients had respiratory symptoms. In general, the clinical outcome in children was favorable. Among the four patients who died of progressive pneumonia, three had documented comorbidities. MERS-CoV infection in children has a lower incidence and mortality compared to adults.

• Journal of Korean Medical Science
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• v.33 no.53
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• pp.348.1-348.6
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• 2018

We report a case of Middle East respiratory syndrome coronavirus (MERS-CoV) infection in a 61-year-old businessman returning from Kuwait. The patient arrived there on August 16, 2018, developed watery diarrhea on August 28 (day 0), and came back to Korea on September 7 (day 10) as his condition worsened. Upon arrival, he complained of diarrhea and weakness, but denied any respiratory symptoms, and he directly went to visit an emergency room. Chest radiography revealed interstitial infiltrates in the lungs, and he was immediately transferred to an isolation unit. Quantitative real-time PCR analysis of sputum samples taken on day 11 returned positive for MERS-CoV. No secondary MERS-CoV infection was identified among people who had close contact with him. This case underscores the importance of a high index of suspicion of MERS-CoV infection in any febrile patients who present after a trip to the Middle East.