• Journal of Microbiology and Biotechnology
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• v.28 no.10
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• pp.1716-1722
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• 2018

Immunosuppressive drugs are used to make the body less likely to reject transplanted organs or to treat autoimmune diseases. In this study, five immunosuppressive drugs including two glucocorticoids (dexamethasone and prednisolone), one calcineurin inhibitor (cyclosporin A), one non-steroid anti-inflammatory drug (aspirin), and one antimetabolite (methotrexate) were tested for their effects on viral proliferation using feline foamy virus (FFV). The five drugs had different cytotoxic effects on the Crandell-Ress feline kidney (CRFK) cells, the natural host cell of FFV. Dexamethasone-pretreated CRFK cells were susceptible to FFV infection, but pretreatment with prednisolone, cyclosporin A, aspirin, and methotrexate showed obvious inhibitory effects on FFV proliferation, by reducing viral production to 29.8-83.8% of that of an untreated control. These results were supported by western blot, which detected viral Gag structural protein in the infected cell lysate. As our results showed a correlation between immunosuppressive drugs and susceptibility to viral infections, it is proposed that immune-compromised individuals who are using immune-suppressive drugs may be especially vulnerable to viral infection originated from pets.

• Biomolecules & Therapeutics
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• v.32 no.6
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• pp.659-684
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• 2024

Viral infections are increasingly recognized as triggers for depressive disorders, particularly following the SARS-CoV-2 pandemic and the rise of long COVID. Viruses such as Herpes Simplex Virus (HSV), Epstein-Barr Virus (EBV), Cytomegalovirus (CMV), and Human Immunodeficiency Virus (HIV) are linked to depression through complex neurobiological mechanisms. These include immune system dysregulation, chronic inflammation, and neurotransmitter imbalances that affect brain function and mood regulation. Viral activation of the immune system leads to the release of pro-inflammatory cytokines, resulting in neuroinflammation and associated depressive symptoms. Furthermore, specific viruses can disrupt neurotransmitter systems, including serotonin, dopamine, and glutamate, all of which are essential for mood stabilization. The unique interactions of different viruses with these systems underscore the need for virus-specific therapeutic approaches. Current broad-spectrum treatments often overlook the precise neurobiological pathways involved in post-viral depression, reducing their efficacy. This review emphasizes the need to understand these virus-specific interactions to create tailored interventions that directly address the neurobiological effects induced by each type of virus. These interventions may include immunomodulatory treatments that target persistent inflammation, antiviral therapies to reduce the viral load, or neuroprotective strategies that restore neurotransmitter balance. Precision medicine offers promising avenues for the effective management of virus-induced depression, providing patient-specific approaches that address the specific biological mechanisms involved. By focusing on the development of these targeted treatments, this review aims to pave the way for a new era in psychiatric care that fully addresses the root causes of depression induced by viral infections.

• Microbiology and Biotechnology Letters
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• v.49 no.2
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• pp.249-254
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• 2021

The study of the impact of weather on viral respiratory infections enables the assignment of causality to disease outbreaks caused by climatic factors. A better understanding of the seasonal distribution of viruses may facilitate the development of potential treatment approaches and effective preventive strategies for respiratory viral infections. We analyzed the incidence of human mastadenovirus infection using real-time reverse transcription polymerase chain reaction in 9,010 test samples obtained from Cheonan, South Korea, and simultaneously collected the weather data from January 1, 2012, to December 31, 2018. We used the data collected on the infection frequency to detect seasonal patterns of human mastadenovirus prevalence, which were directly compared with local weather data obtained over the same period. Descriptive statistical analysis, frequency analysis, t-test, and binomial logistic regression analysis were performed to examine the relationship between weather, particulate matter, and human mastadenovirus infections. Patients under 10 years of age showed the highest mastadenovirus infection rates (89.78%) at an average monthly temperature of 18.2℃. Moreover, we observed a negative correlation between human mastadenovirus infection and temperature, wind chill, and air pressure. The obtained results indicate that climatic factors affect the rate of human mastadenovirus infection. Therefore, it may be possible to predict the instance when preventive strategies would yield the most effective results.

• Journal of Veterinary Clinics
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• v.23 no.3
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• pp.300-307
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• 2006

In the present study, methods of the reverse transcription-polymerase chain reaction(RT-PCR) were evaluated for the rapid detection and differentiation of transmissible gastroenteritis virus(TGEV), porcine epidemic diarrhea virus(PEDV) and rotavirus in piglets suffering from diarrhea. For the purposes, the PCR conditions were first confirmed for the amplification of VP7 gene of rotavirus and N gene of TGEV and PEDV using each specific primers and their annealing temperature. Multiplex RT-PCR methods were further determined to distinguish these viral infections and the results are as follows. For the specific amplification of these viral genes, the reliable PCR condition was determined as 30 cycles of reaction consisting each 1 min of denature at $94^{\circ}C$, annealing at $42^{\circ}C$ and polymerization at $72^{\circ}C$ with 1.0 mM $MgCl_2$. It was able to differentiate these viral infections in the intestines and feces of piglets suffering from diarrhea by duplex PCR for TGEV and PEDV and single PCR for rotavirus with a primer-annealing temperature of $42^{\circ}C$. When the multiplex RT-PCR were undertaken for the field samples, 17 cases of PEDV and 5 cases of rotavirus infections were differential diagnosed in a total of 92 samples of intestines and feces of the piglets with diarrhea.

• Childhood Kidney Diseases
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• v.21 no.2
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• pp.101-106
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• 2017

Purpose: The aim of this study was to analyze the incidence and microbiological characteristics of urinary tract infection in infants aged younger three months and to compare with other infection with positive urine culture. Methods: We retrospectively reviewed the medical records of 425 infants with a tympanic temperature >$37.6^{\circ}C$, aged younger than three months, who were admitted to Cheil General Hospital in Seoul, Korea, from January 2013 to December 2016. Demographic and clinical features, laboratory findings, respiratory virus PCR and the pathogens of a urine culture were analyzed. Results: A total of 88 infants (63 males, 25 females) had urinary pathogens detected in the urine culture test. The incidence of UTI in febrile infants aged younger 3 months was 11%. The most common pathogen which causes UTI was E. coli as same as in previous studies. They were divided into a UTI group (n=48) and a non-UTI group (n=40). In comparison of both group, leukocytosis, C-reactive protein level, Absolute neutrophil count level, peak temperature is statistically significant. In both group, there were co-infections with viral pathogens in some cases, and the odd ratio of non-UTI group with viral infection was 3.28. Conclusion: The study determined the incidence and pathogen of UTI in febrile infants, aged younger three months. E. coli was responsible for the majority UTI. There were some viral co-infections in febrile infants with bacteriuria and incidence was higher in non-UTI group. WBC count, ANC count and CRP level were the differentiating factors of UTI from non-UTI group.

• Tuberculosis and Respiratory Diseases
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• v.80 no.4
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• pp.358-367
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• 2017

Background: Bacterial pneumonia occurring after respiratory viral infection is common. However, the predominant bacterial species causing pneumonia secondary to respiratory viral infections other than influenza remain unknown. The purpose of this study was to know whether the pathogens causing post-viral bacterial pneumonia vary according to the type of respiratory virus. Methods: Study subjects were 5,298 patients, who underwent multiplex real-time polymerase chain reaction for simultaneous detection of respiratory viruses, among who visited the emergency department or outpatient clinic with respiratory symptoms at Ulsan University Hospital between April 2013 and March 2016. The patients' medical records were retrospectively reviewed. Results: A total of 251 clinically significant bacteria were identified in 233 patients with post-viral bacterial pneumonia. Mycoplasma pneumoniae was the most frequent bacterium in patients aged <16 years, regardless of the preceding virus type (p=0.630). In patients aged ${\geq}16years$, the isolated bacteria varied according to the preceding virus type. The major results were as follows (p<0.001): pneumonia in patients with influenza virus (type A/B), rhinovirus, and human metapneumovirus infections was caused by similar bacteria, and the findings indicated that Staphylococcus aureus pneumonia was very common in these patients. In contrast, coronavirus, parainfluenza virus, and respiratory syncytial virus infections were associated with pneumonia caused by gram-negative bacteria. Conclusion: The pathogens causing post-viral bacterial pneumonia vary according to the type of preceding respiratory virus. This information could help in selecting empirical antibiotics in patients with post-viral pneumonia.

• IMMUNE NETWORK
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• v.16 no.5
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• pp.261-270
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• 2016

The human immune system has evolved to fight against foreign pathogens. It plays a central role in the body's defense mechanism. However, the immune memory geared to fight off a previously recognized pathogen, tends to remember an original form of the pathogen when a variant form subsequently invades. This has been termed 'original antigenic sin'. This adverse immunological effect can alter vaccine effectiveness and sometimes cause enhanced pathogenicity or additional inflammatory responses, according to the type of pathogen and the circumstances of infection. Here we aim to give a simplified conceptual understanding of virus infection and original antigenic sin by comparing and contrasting the two examples of recurring infections such as influenza and dengue viruses in humans.

• The Journal of the Korean Society for Microbiology
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• v.16 no.1
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• pp.57-64
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• 1981

The clinical need for agents to modify immune response in the treatment of viral infection has lead to an increased interest in cellular and biochemical mechanisms regulating the immune response and to the development of a variety of biological and chemical substance with immunomodulatory activity. Inosiplex has shown antiviral activity in tissue culture, animal models and huamn studies through augmentation of immune response. However, the effect of inosiplex on immune response in animal has not been extensively analyzed, and the effect of inosiplex on immune response has been paradoxical depending on the time of administration of inosiplex in relation to that of antigen. Therefore, this study was undertaken to assess the effect of inosiplex on the immune response to sheep red blood cells(SRBC) in normal and viral infected mice. Inosiplex increased cellular immune response and plaque forming lymphocyte response to SRBC, decreased the recovery of S. typhimurium from infected mice spleen, and restored the depressed cellular immune response by measle and newcastle disease virus infections. All of the above results were observed only when inosiplex was given after immunization but did not when given before immunization. These results indicate that inosiplex stimulate the efferent are of immune response and may even block the afferent are, and suggest that inosiplex is a very promising drug in therapy of many viral infections.

• Korean Journal of Clinical Laboratory Science
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• v.54 no.3
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• pp.173-178
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• 2022

The majority of the children experience milder coronavirus disease 2019 (COVID-19) symptoms. Children represent a significant source of community transmission. Children under 18 years of age account for an estimated 4.8% of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections globally. However, no conclusive statements pertaining to the multi-fold aspects of the virus in children could be drawn due to the lower prevalence of pediatric cases. The present study was conducted to identify the indirect impact of SARS-CoV-2 infections on developing herd immunity among children in the age group 3 to 18 years by investigating their antibody levels. In the study, 240 children aged 3~18 years were recruited by the Department of Pediatrics, Government Medical College and Hospital, Amritsar, India, and quantification of the antibodies was performed at the Viral Research and Diagnostic Laboratory (VRDL), Government Medical College (GMC), Amritsar, India. Out of the 240 serum samples, 197 (82.08%) showed seropositivity, while 43 (17.92%) were seronegative. When stratified, it was observed that in the age group 3~6 years, 22.33% of children were found to have anti-SARS-CoV-2 antibodies while in the age groups 7~10 years, 11~14 years, and 15~18 years, respectively, 37.06%, 30.46%, and 10.15% were seropositive. Although there was seroconversion among children which was useful for predicting the next wave, no differences in seropositivity were observed between adults and children.

• The Plant Pathology Journal
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• v.30 no.4
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• pp.407-415
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• 2014

Viral diseases have been a major limiting factor threating sustainable potato (Solanum tuberosum L.) production in Pakistan. Surveys were conducted to serologically quantify the incidence of RNA viruses infecting potato; Potato virus X (PVX), Potato virus Y (PVY), Potato virus S (PVS), Potato virus A (PVA), Potato virus M (PVM) and Potato leaf roll virus (PLRV) in two major potato cultivars (Desiree and Cardinal). The results suggest the prevalence of multiple viruses in all surveyed areas with PVY, PVS and PVX dominantly widespread with infection levels of up to 50% in some regions. Co-infections were detected with the highest incidence (15.5%) for PVX and PVS. Additionally the data showed a positive correlation between co-infecting viruses with significant increase in absorbance value (virus titre) for at least one of the virus in an infected plant and suggested a synergistic interaction. To test this hypothesis, glasshouse grown potato plants were challenged with multiple viruses and analyzed for systemic infections and symptomology studies. The results obtained conclude that multiple viral infections dramatically increase disease epidemics as compared to single infection and an effective resistance strategy in targeting multiple RNA viruses is required to save potato crop.