• Korean Journal of Clinical Laboratory Science
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• v.49 no.2
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• pp.141-149
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• 2017

To examine the cause of acute diarrheal disease in children and adolescents, 521 fecal samples underwent multiple-PCR for a period of two years, between March 2015 and February 20178, in the Jeju region of Korea. Based on the analysis of 179 positive samples, 102 samples were male (56.98%) and 77 were female (43.02%), and highest positive rates were shown in the age group of 3~4 years (51.96%) and 5~6 years (12.29%). When 209 cases (40.12%), including double infection were analyzed, there were 88 cases (16.89%) of norovirus-GII infection, 26 cases (4.99%) of Campylobacter spp. infection, 18 cases (3.45%) of rotavirus infection, 18 cases (3.45%) of Clostridium difficile Toxin B infection, 17 cases (3.26%) of adenovirus infection, 16 cases (3.07%) of Clostridium perfringens infection, 11 cases (2.11%) of astrovirus infection, 5 cases (0.96%) of Salmonella spp. infection, 3 cases (0.58%) of norovirus-GI, Yersinia spp. and Aeromonas spp. infections, and 1 case (0.19%) of verocytotoxin-producing E. coli infection. Based on a seasonal separation of early childhood, norovirus-GI and norovirus-GII mainly prevailed during the winter, when the temperature is low. Typical enteritis with an increased prevalence of rotavirus during the spring. Astrovirus prevailed between the months of April and October, when norovirus-GI, norovirus-GII, and rotavirus did not prevail. With increasing age, acute diarrheal disease was not only induced by a virus, but also by bacteria. Although a test for virus is an effective method when trying to identify the cause during early childhood by multiplex-PCR, it would be desirable to undergo tests for both virus and bacteria concurrently as age increases.

• Pediatric Infection and Vaccine
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• v.13 no.2
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• pp.147-155
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• 2006

Purpose : The purpose of this study is to evaluate epidemiological data of pathogens obtained from stool exams and compare them with the clinical course in pediatric patients with symptoms of acute gastroenteritis. Methods : Subjects were selected from patients presenting with symptoms of acute gastroenteritis who visited the outpatient clinic or who were admitted to the Dankook University Hospital from December of 2004 to December of 2005. Stool exams for 17 pathogens was performed. RT-PCR was used to detect norovirus and enzyme-linked immunoabsorbant assay (ELISA) was used to detect rotavirus, adenovirus and astrovirus in the subjects stool samples. Ten different species of bacteria(Salmonella spp., Shigella spp., Clostridium perfrigens, Campylobacter spp., Escherichia coli, Vibrio spp., Staphylococcus aureus, Bacillus cereus, Yersinia spp., and L. monocytogenes) were each selectively cultivated and enzyme immunoassays(EIA) was used to test for antigens for C. parvum, E. histolytica and G. lamblia. Retrospective chart review was performed for comparisons of clinical manifestations. Results : A total of 215 subjects was selected and of these 89 cases(41.4%) showed positive results for at least one pathogen. Male to female ratio was 1.3:1. Age distribution showed 4 cases less than one month(4.5%), 4 cases from 1~2 months(4.5%), 24 cases from 3~12 months(26.7%), 47 cases form 13~48 months(52.8%), 10 cases greater than 48 months (21.2%). Viruses showed the greatest proportion of cases with 68 subjects(77.5%), of these rotavirus being the most commonly reported in 50 cases. Bacteria was identified in 26 cases (29.2%), of these nontyphoidal salmonella was noted in 10 cases. Protozoa followed with 21 cases(23.6%), of these C. parvum was noted in 11 cases and G. lamblia was noted in 10 cases. Mixed infections with more than two pathogens were seen in 22 cases(24.7%), of these viral infection with accompanying parasitic infection was seen in 12(54.5%) cases. Conclusion : In this study we examined various pathogens known to cause acute gastroenteritis in children. Further studies for various pathogens can provide useful information for management of the acute gastroenteritis.

• Pediatric Infection and Vaccine
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• v.16 no.2
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• pp.123-130
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• 2009

Purpose : This study was performed to determine the clinical and epidemiologic characteristics of nosocomial rotavirus gastroenteritis. Methods : We retrospectively analyzed 628 medical records of patients with rotavirus gastroenteritis between 2001 and 2005. The patients were divided into two groups (the community-acquired group [528 cases] and the nosocomial group [100 cases]. The epidemiologic and clinical indices between the groups were analysed. For clinical comparison, 100 agematched cases were selected from the community-acquired group. Results : The male-to-female ratio was similar (1.4:1 vs. 1.5:1), but the mean age was lower in the nosocomial group compared to the community-acquired group (21.9${\pm}$15.5 months vs. 16.6${\pm}$10.3 months, P <0.001). The patterns of age distribution, annual frequency, and seasonal distribution were similar in both groups. The proportions of nosocomial cases in each year ranged from 9.8% to 22.4% of annual rotaviral infections, and these were not proportional to annual cases. The duration of fever appeared more prominent in the nosocomial group, and the severity of diarrhea was not different between the groups. The cases with a BUN >20 mg/dL were more in the community-acquired group (16% vs. 4%, P=0.01). Conclusion : The clinical and epidemiologic charateristics of nosocomial rotavirus gastroenteritis were similar and correlated to those of the community-acquired gastroenteritis.

• Korean Journal of Animal Reproduction
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• v.27 no.1
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• pp.15-23
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• 2003

Lactadherin (formerly known as BA46), a major glycoprotein of the human milk fat globule membrane, is abundant in human breast milk and breast carcinomas and may prevent symptomatic rotavirus infections. In this study, under the control of tissue specific and hormonal inducible mouse whey acidic protein (WAP) promote., the expression pattern of lactadherin (Ltd) in lactogenic hormone-dependent mouse mammary epithelial cell line HC11 were tested. pLNWLtd construct containing 2.4 kilobases of the WAP promoter and 1.5 kilobases of human lactadherin gene was stably transfered into HC11 cells using retroviral vector system. Integration and expression level of the transgene was estimated using PCR and RT-PCR, respectively. Prominent induction of Ltd gene under the WAP promoter was accomplished in the presence of insulin, hydrocortisone and prolactin. Compared to the control (cells cultured with insulin alone), however we observed that the WAP promoter was leaky. These data indicate that luther studies are needed in finding an appropriate promoter other than WAP promoter because of its leakiness.

• Clinical and Experimental Pediatrics
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• v.46 no.12
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• pp.1217-1223
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• 2003

Purpose : This study was conducted to assess clinical practices related to the evaluation and treatment of patients with acute gastrointestinal infection(AGI) in infants and children. This survey also evaluated the current opinion regarding the use of rotavirus vaccine. Methods : This survey was conducted using a self-administered questionnaire provided to 82 pediatricians in private clinics of Jeonbuk province. From April to June, 2002, 63 of 82 pediatricians(76.8 %) responded to the survey. Results : The annual proportion of patients with AGI was 13%. The highest proportion of patients with diarrhea were reported for the months of October through December. For the treatment of diarrhea, pediatricians preferred to prescribe lactobacillus products, oral rehydration solution, enzyme products, anti-emetics, anti-diarrheal formula, nothing by mouth(NPO) and bowel movement inhibitors in descending order of frequency. Most pediatricians(79.4%) prescribed antibiotics in less than 20% of patients with AGI. Amoxicillin was the most commonly prescribed antibiotics followed by trimethoprim/sulfamethoxazole(TMP/SMX) and amoxicillin/clavulanate. Clinical manifestations that pediatricians considered as important factors in prescribing antibiotics were bloody diarrhea, mucoid diarrhea, high fever, persisting disease and abdominal pain. Diagnostic procedures that pediatricians preferred for AGI patients were stool examination(rotavirus antigen, RBC, WBC), abdominal X-ray, and serum electrolytes. Pediatricians had a strong interest in rotavirus vaccine(71.4%). Conclusion : Acute gastrointestinal illness remains a common problem, especially during the winter months in Korea. AGI manifesting as watery diarrhea is appropriately treated with commonly available agents but pediatricians appear ready to consider additional approaches to decrease the sizable disease burden of AGI among children in Korea.

• Korean Journal of Animal Reproduction
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• v.27 no.3
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• pp.259-268
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• 2003

Lactadherin (formerly known as BA46), a major glycoprotein of the human milk fat globule membrane, is abundant in human breast milk and breast carcinoma cells and is known to prevent symptomatic rotavirus infections. In this study, we tried to transfer the human lactadherin gene to the Chinese Hamster Ovary (CHO) cells using retrovirus vector system and tested inducible expression of the gene under the tetracycline-controllable promoter. At first, tetracycline-mediated inducibility was tested using E.coli LacZ marker gene. NIH3T3 cells co-infected with RevTet-On and RevTRE-LacZ retrovirus vectors showed that the cells responded to doxycycline (a derivative of tetracycline) in a dose-dependent manner, and prominent induction of the lacZ gene expression was observed from 1 $\mu\textrm{g}$/ml of doxycycline concentration. Based on the results of the pilot experiment, inductional expression of the human lactadherin gene was conducted using RevTet-On and RevTRE-Ltd retrovirus vectors. Analysis with the RT-PCR demonstrated successful inductional expression of the lactadherin gene in the Chinese Hamster Ovary (CHO) cells. Considering that constitutive overexpression of the exogenous genes in the target cells causes serious physiological imbalance, the results obtained in this study will be very useful especially in the studies of gene therapy and transgenic animal production.

• 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.