• Journal of Microbiology and Biotechnology
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• v.31 no.7
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• pp.956-966
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• 2021

To prevent the outbreak of infectious diseases that inflict huge economic and social losses, domestic livestock farms and related facilities have introduced automatic and semiautomatic disinfectant solution-spraying systems for vehicles. However, the facility standards and specifications vary by manufacturer, and no scientific performance evaluation has been conducted. The puropose of this study is to develop physical and biological evaluation methods. Physical and biological appraisals were conducted using two types of disinfection facilities (tunnel- and U-type) and two types of vehicles (passenger car, truck). Water-sensitive paper was used to evaluate the physical performance values for the disinfection facilities. In addition, to assess their biological performance, carriers containing low-pathogenic avian influenza virus were attached to vehicles, and the viral reduction was measured after the vehicles moved through the facility. The tunnel-type had rates of coverage in the range of 70-90% for the passenger car and 60-90% for the truck. At least 4-log virus reduction after spraying for 1-5 min was shown for both vehicles. For the U-type facility evaluation, the coverage rates were in the range of 60-90% for the passenger car and at least 90% for the truck. More than 4-log viral reduction was estimated within a spraying time of 5 min. To reduce viruses on the surface of vehicles by at least 4 log within a short period, the disinfectant solution should cover at least 71% of the pathogens. In conclusion, we were able to assess the physical and biological performance criteria for disinfection facilities aboard transportation vehicles.

• Particle and aerosol research
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• v.16 no.4
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• pp.73-94
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• 2020

Particulate infectious sources, including infectious viruses, can float in the air, causing airborne infections. To prevent indoor airborne infection, dilution control by ventilation and indoor air cleaners are frequently used. In this study, the risk of airborne infection by the operation of these two techniques was evaluated. In case of dilution control by ventilation, a high efficiency air filter was embedded at the inlet of supply air. In this study, infectious source reduction devices such as indoor air cleaner include all kinds of mechanical-filters, UV-photo catalysts and air ionizers through which air flow is forced by fans. Two mathematical models for influenza virus were applied in an infant care room where infants and young children are active, and the risk reduction efficiency was compared. As a result, in the case of individually operating the ventilator or the infectious source reduction device, the airborne infection risk reduction efficiencies were 55.2~61.2% and 53.8~59.9%, respectively. When both facilities were operated, it was found that the risk of airborne infection was reduced about 72.2~76.8%. Therefore, simultaneous operation of ventilation equipment and infectious source reduction device is the most effective method for safe environment that minimizes the risk of airborne infection of respiratory infectious diseases. In the case of a space where sufficient ventilation operation is difficult, it was found that the operation of an infectious source reduction device is important to prevent the spread of infectious diseases. This study is meaningful in that it provides an academic basis for strategies for preventing airborne infection of respiratory infectious diseases.

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

• Applied Chemistry for Engineering
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• v.34 no.5
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• pp.479-487
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• 2023

Copper is cost-effective and abundantly available as a biocidal coating agent for a wide range of material surfaces. Natural oxidation does not compromise the efficacy of copper, allowing it to maintain antimicrobial activity under prolonged exposure conditions. Furthermore, copper compounds exhibit a broad spectrum of antimicrobial activity against pathogenic yeast, both enveloped and non-enveloped types of viruses, as well as gram-negative and gram-positive bacteria. Contact killing of copper-coated surfaces causes the denaturation of proteins and damage to the cell membrane, leading to the release of essential components such as nucleotides and cytoplasm. Additionally, redox-active copper generates reactive oxygen species (ROS), which cause permanent cell damage through enzyme deactivation and DNA destruction. Owing to its robust stability, copper has been utilized in diverse forms, such as nanoparticles, ions, composites, and alloys, resulting in the creation of various coating methods. This mini-review describes representative coating processes involving copper ions and copper oxides on various material surfaces, highlighting the antibacterial and antiviral properties associated with different oxidation states of copper.

• Korean Journal of Poultry Science
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• v.38 no.3
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• pp.181-189
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• 2011

A 5-month (May to November in 2009) monitoring program for five viral pathogens in litter, such as avian influenza virus A (AIV), infectious bronchitis virus (IBV), infectious bursal disease virus (IBDV), fowl adenovirus (FAdV), and chicken infectious anemia virus (CIAV) was conducted in 62 flocks at 31 broiler farms (two flocks in each farm) in Korea in 2009. Viral pathogens were examined twice (before and at the end of the rearing period) at 31 broiler farms, and included fresh litter (n = 16) and recycled litter (n = 15) farms. Thirty-seven viruses (14 IBVs, 2 IBDVs, 9 FAdVs, and 12 CIAVs) were isolated from 75% (12/16) and 73% (11/15) of fresh litter and reused litter farms during the period, respectively, indicating no difference in viral contamination rate between farms using new and reused litter. Of these isolates, three (two CIAVs and one IBDV) were isolated from recycled litter samples collected before the rearing period at three broiler farms, whereas the others (n=34) were isolated from fresh and recycled litter samples collected at the end of the rearing period. When the performances, involving viability, body weight, and feed conversion ratio, were compared, no significant differences were found between farms using fresh and recycled litter during the period.

• Journal of Microbiology and Biotechnology
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• v.28 no.11
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• pp.1928-1936
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• 2018

Recently, human infections caused by severe fever with thrombocytopenia syndrome virus (SFTSV), which can lead to fatality, have dramatically increased in East Asia. With the unavailability of vaccines or antiviral drugs to prevent and/or treat SFTSV infection, early rapid diagnosis is critical for prevention and control of the disease. Here, we report the development of a simple, rapid and sensitive portable detection method for SFTSV infection applying reverse transcription-loop mediated isothermal amplification (RT-LAMP) combined with one-pot colorimetric visualization and electro-free reaction platform. This method utilizes a pocket warmer to facilitate diagnosis in a resource-limited setting. Specific primers were designed to target the highly-conserved region of L gene of SFTSV. The detection limit of the RT-LAMP assay was approximately $10^0$ viral genome copies from three different SFTSV strains. This assay exhibited comparable sensitivity to qRT-PCR and 10-fold more sensitivity than conventional RT-PCR, with a rapid detection time of 30 to 60 minutes. The RT-LAMP assay using SFTSV clinical specimens has demonstrated a similar detection rate to qRT-PCR and a higher detection rate compared to conventional RT-PCR. Moreover, there was no observed cross-reactive amplification of other human infectious viruses including Japanese Encephalitis Virus (JEV), Dengue, Enterovirus, Zika, Influenza and Middle East Respiratory Syndrome Coronavirus (MERS-CoV). This highly sensitive, electro- and equipment-free rapid colorimetric visualization method is feasible for resource-limited SFTSV field diagnosis.

• Korean Journal of Veterinary Service
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• v.28 no.2
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• pp.121-146
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• 2005

Newcastle disease (ND), infectious bronchitis (IB), low pathogenic avian Influenza (LPAI) and fowl typhoid (FT) have been known as egg drop laying diseases because of the serious layer damage from mass zone layer. In this study, such egg drop laying diseases were investigated. To access this study, we peformed to evaluate antibody titers in serum and isolated bacteria and virus from organs and feces on May, July and September in 2003. The distribution of ND from January to May, IB and LPAI from October to February of the next year, and FT from March to September were inspected by the question survey in 21 farms. ND revealed to be positive rates of 490 to 474 $(96.7\%)$ in May, 510 to 506 $(99.2\%)$ in July and 510 to 510 $(100\%)$ in September with hemagglutination inhibition (HI) test. The mean antibody titers were 10.2, 9.9 and 10.2, respectively. With regard to IB, 484 out of 490 samples $(98.7\%)$ in May, 508 of 510 $(99.6\%)$ in July and 509 of 510 $(99.8\%)$ in September showed positive results and the mean antibody titers were gradually increased with 8.2, 9.0 and 9.4, respectively. According to HI test of LPAI, the positive results were shown in 442 of 480 $(92.1\%)$, 394 of 494 $(79.8\%)$ and 402 of 483 $(83.2\%)$ in May, July and September, respectively The mean antibody titers were decreased with 4.6, 4.3 and 4.0. The distribution of LPAI also elicited the positive rates of 480 to 475 $(99.0\%)$ in May, 494 to 485$(98.2\%)$ in July, 483 to 472 $(97.7\%)$ in September as determined by ELISA and the mean S/P ratio were 2.319, 2.557 and 2.380, respectively. Compared ELISA results with HI test of LPAI the positive results were 480 to 422 $(92.1\%),\;475(99.0\%),\;494\;to\;394 (79.8\%),\;485 (98.2\%)\;and\;483\;to\;402(83.2\%),\;472(97.7\%)$. Therefore, the positive rate determined by ELISA was higher than that of HI test with 6.9, 18.4 and $14.5\%$, respectively. When performed RT-PCR for ND using organ and feces samples, the pathotypes were detected $5(15.6\%)\;in\;May,\; 2(5.3\%) in\;July,\;2(7.1\%)$ in September but there is no samples showing positive band for LPAI. In attempt to isolate Salmonella gallinarum, bacteria were obtained from 4 cases (12.5%) in May, 9 (23.6%) in July, 5 (17.8%) in September. Thus the highest rate for isolation revealed to be shown in July When evaluated the antimicrobial susceptibility to 18 isolated strains of 5. gallinarum, bacteria were sensitive to trimethoprim/sulfamethox$(61.1\%),\;kanamycin\;(55.5\%),\;ampicillin\;(55.5\%)$ and amoxacillin/clavulanic acid $(55.5\%)$, cephalothin $(50.0\%)$, but resistant to penicillin $(88.9\%)$, streptomycin $(88.9\%)$, erythromycin $(83_4\%)$ and tetracycline $(61.1\%)$. According to HI test of ND and LPAI using captured 164 wild Korean tree sparrows (Passer nontanus), the positive rates were $47.6\%\;and\;57.3\%$, and the mean HI titers were 5.32 and 4.02, respectively. 71 $(43.2\%)\;and\;58(35.3\%)$ in captured sparrows also showed more than 4 titers for HI test to ND and LPAI, respectively However, the attempt for isolation of viruses failed in all samples.

• Pediatric Infection and Vaccine
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• v.15 no.2
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• pp.129-137
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• 2008

Purpose : Human metapneumovirus (hMPV) was recently discovered in children with respiratory tract infection. The aim of this study was to determine the frequency and the clinical manifestation of hMPV infection in Korean children. Methods : From January to December, 2005, we collected throat swabs from 1,098 children who were hospitalized for acute respiratory illness at the Department of Pediatrics, Kwang-Ju Christian Hospital. hMPV was detected by performing reverse transcriptase-polymerase chain reaction (RT-PCR). The medical records of the patients with positive results were retrospectively reviewed. Results : We detected hMPV in 25 (2.2%) of the 1,098 hospitalized children. The mean age of the hMPV infected children was 2.3 years, and 84% of the illnesses occurred between April and June. The most common diagnoses were pneumonia (60%) and bronchiolitis (20 %). The clinical manifestations included cough, fever, coryza, rale, wheezing and injected throats. Peribronchial infiltration and consolidation were the common chest X-ray findings. Four (16%) of 25 patients with hMPV infection had exacerbation of asthma. Coinfection with other respiratory viruses was found in six children (24%). Conclusion : hMPV is the cause of an important proportion of acute respiratory tract infection in Korean children. Additional studies are required to define the epidemiology and the extent of disease caused by hMPV and to determine future development of this illness in Korean children.

• Pediatric Infection and Vaccine
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• v.5 no.2
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• pp.258-266
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• 1998

Purpose : Cases of adenoviral penumonia with rapidly progressive clinical course were experienced. We reviewed these patients in viewpoint of clinical manifestation and adenoviral serotypes. Methods : Culture and indirect immunofluorescence for respiratory viruses including respiratory syncytial virus, influenza virus, parainfluenza virus, adenovirus was done with nasopharyngeal aspirates from patients who admitted due to respiratory infections in Fatima Hospital, Masan from Nov. 1996 to Jul. 1997. Cultured adenovirus was serotyped by both neutralization and hemagglutination inhibition test. Medical records were reviewed for 5 patients with respiratory failure from adenovirus was isolated and serotyped. Results : The total number of examined patients was 460 patients. We isolated respiratory viruses in 143(30.9%) patients. Adenovirus was isolated from 66 out of 143(46.2%) patients. During Jan 1997 to May 1997, five patients with ages of 18 days to 11 months who were infected by adenovirus and had high fever with dyspnea and required assisted mechanical ventilation. One patients discharged against doctor's advice then died. Two of four patients had complications of disseminated intravascular coagulation; two had bronchiolitis obliterans. Two isolates were serotype 7, and one was serotype 5, and two were untyped. Conclusion : Severe pneumonia caused by serotype 7 continued to occur in 1997 following the epidemic in 1996, and severe pneumonia may also be caused by serotype 5 and other serotypes.