• Pediatric Infection and Vaccine
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• v.23 no.1
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• pp.40-45
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• 2016

Purpose: The purpose of this study was to investigate the etiology of acute pharygotonsillitis in pediatric patients. Methods: Pharyngeal swabs from patients with acute pharyngotonsillitis were evaluated for viruses and bacterial organisms from March 2010 through March 2011. Results: Of 615 patients, potentially pathogenic bacteria were isolated in 40 (6.5%), viruses were isolated in 310 (50.4%), and no pathogens were isolated in 267 patients (43.4%). Both viral and bacterial pathogens were found in 2 (0.3%). Of 40 patients with bacterial pathogens, group A streptococci were found in 31 (77.5%). Among 310 patients with virus infection, adenovirus was the most frequently recovered (203 patients; 65.5%), followed by rhinovirus (65 patients; 21.0%), enterovirus (43 patients; 13.9%) and coronavirus (18 patients; 5.8%). There were 25 patients who had been coinfected with 2 viruses. In viral pharyngotonsillitis, cough, rhinorrhea, conjunctivitis and diarrhea were prominent. On the other hand, pharyngeal injection and pharyngeal petechiae were prominent in bacterial pharyngotonsillitis. Conclusions: Virus infection was a big part of acute pharyngotonsillitis and there were differences in clinical manifestations among viral and bacterial infections. Therefore, we need to distinguish between virus infection and bacterial infection using clinical signs for preventing the abuse of antibiotics.

• Journal of Microbiology and Biotechnology
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• v.28 no.9
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• pp.1413-1425
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• 2018

Shiga toxins (Stxs) are the main virulence factors expressed by the pathogenic Stx-producing bacteria, namely, Shigella dysenteriae serotype 1 and certain Escherichia coli strains. These bacteria cause widespread outbreaks of bloody diarrhea (hemorrhagic colitis) that in severe cases can progress to life-threatening systemic complications, including hemolytic uremic syndrome (HUS) characterized by the acute onset of microangiopathic hemolytic anemia and kidney dysfunction. Shiga toxicosis has a distinct pathogenesis and animal models of Stx-associated HUS have allowed us to investigate this. Since these models will also be useful for developing effective countermeasures to Stx-associated HUS, it is important to have clinically relevant animal models of this disease. Multiple studies over the last few decades have shown that mice injected with purified Stxs develop some of the pathophysiological features seen in HUS patients infected with the Stx-producing bacteria. These features are also efficiently recapitulated in a non-human primate model (baboons). In addition, rats, calves, chicks, piglets, and rabbits have been used as models to study symptoms of HUS that are characteristic of each animal. These models have been very useful for testing hypotheses about how Stx induces HUS and its neurological sequelae. In this review, we describe in detail the current knowledge about the most well-studied in vivo models of Stx-induced HUS; namely, those in mice, piglets, non-human primates, and rabbits. The aim of this review is to show how each human clinical outcome-mimicking animal model can serve as an experimental tool to promote our understanding of Stx-induced pathogenesis.

• 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.

• Pediatric Infection and Vaccine
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• v.26 no.1
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• pp.22-31
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• 2019

Purpose: Campylobacter species are common causes of bacterial enteritis. There is limited knowledge on its prevalence and clinical features because of its fastidious culture conditions. The purpose of this study was to identify the clinical features of Campylobacter enteritis in children. Methods: We obtained stool specimens from patients diagnosed with acute gastroenteritis in the Department of Pediatrics, Nowon Eulji Medical Center (NEMC) and identified the pathogens by performing cultures or polymerase chain reactions (PCR). We retrospectively reviewed the medical records of patients with Campylobacter enteritis at NEMC between January 2012 and December 2017. Results: Overall, 123 patients were diagnosed with Campylobacter enteritis (60 by culture and PCR in EnterNet and 110 by multiplex PCR). The median (interquartile range [IQR]) age of patients was 12 years (IQR, 8 to 16 years). The disease occurred all year round, but 69.9% from June to September. Symptoms included diarrhea (97.6%), fever (96.7%), abdominal pain (94.3%), vomiting (37.4%), and headache (34.1%). Compared with other treatments, treatment with azithromycin was associated with a shorter hospitalization period (P<0.05). Conclusions: Campylobacter enteritis is common during summer and mostly infects adolescent patients. It causes severe abdominal pain and fever preceding the onset of diarrhea. Prompt diagnosis and appropriate use of antibiotics reduces the duration of the disease.

• Pediatric Infection and Vaccine
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• v.15 no.2
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• pp.138-145
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• 2008

Purpose : Acute gastroenteritis is a frequent childhood disease. The purpose of this study is to determine if certain pathogens are related to more severe clinical disease in children with acute gastroenteritis. Methods : Two hundred seventy one stool samples were obtained from pediatric patients with acute gastroenteritis that was associated with virus, bacteria and protozoa infection between January 2006 and December 2006. The clinical severity was assessed by using the 24 point scale Clark score. We evaluate the Clark score according to the pathogens. Results : One hundred thirty seven children were noted to have virus, bacteria or protozoal infection. Rotavirus was the most common pathogen found in the children with gastroenteritis (20.6%). Other frequent pathogens were norovirus (10.7%) and E. coli (12.9%). Vomiting (P=0.049) and diarrhea (P=0.003) symptoms were more frequent in the rotavirus group than that in the rotavirus negative group. There were no statistical differences in the Clark score between the virus positive group and the virus negative group. Conclusion : We concluded that rotavirus was the most common pathogen in children with gastroenteritis, yet the clinical severity was not dependent on the presence of viral or bacterial pathogens.

• Journal of Environmental Health Sciences
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• v.46 no.5
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• pp.525-531
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• 2020

Objectives: This study was performed to identify the epidemiological features of a food poisoning outbreak in a company cafeteria located in Chungcheongnam-do Province, Korea in June of 2020 and to suggest preventive measures for a similar incidence. Methods: A total of 84 patients with acute gastroenteritis were examined. Environmental samples were obtained from 16 food handlers, six food utensils, 135 preserved foods served over three days and nine menus, and six drinking water samples. These are analyzed to detect viruses and bacteria. Results: Ninety-four out of the 402 people who were served meals (23.4%) predominantly showed symptoms of diarrhea, and the number was over 3 times. Among the 84 patients under investigation, 17 cases (20.2%) were positive for Enteropathogenic E. coli (EPEC) and 18 cases were positive for Clostridium (C.) perfringens (21.4%). Based on the investigation, it was concluded that the main pathogens were EPEC and C. perfringens. For EPEC, it was detected in three of the food service employees and in the preserved food and curry rice. The results of pulsed field gel electrophoresis indicate that all EPEC cases are closely related except for one food service employee. Assuming that isolated EPEC originated from the preserved food, the incubation period is about 25 hours. The origin of the C. perfringens was not determined as it was not detected in the food service employees or environmental samples. Conclusions: This case suggests that food provided in group food service centers must be thoroughly managed. In addition, identifying the pathogens in preserved food is very important for tracing the causes of food poisoning, so food must be preserved in an appropriate condition. To prevent similar food poisoning cases, analyzing cases based on epidemiological investigation and sharing the results is needed.

• 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.21 no.2
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• pp.96-103
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• 2014

Purpose: The aim of this study is that the prevalence of rotavirus infection was evaluated by each group and clinical features of group A, B and C rotaviruses infections were described respectively to compare one with another. Methods: Between January 2010 and December 2010, we enrolled a group of children below 10 years of age admitted for management of acute diarrhea at the Catholic University of Korea Bucheon St. Mary's Hospital. A total of 310 stool samples documented to be free of common bacterial pathogens were collected from children with diarrhea. The presence of group A, B or C rotavirus is indicated by amplification of DNA segments of the expected lengths after the first and second PCRs Results: In a total of 310 stool specimens, 40 (12.9%) specimens were positive for rotaviruses. These included 23 (7.4%) positive for group A, 5 (1.6%) for group B and 12 (3.9%) for group C rotaviruses. Group B rotavirus infected patients had significantly less diarrheas per day (group A: P =0.01, group C: P =0.01) and shorter duration of vomiting days (group A: P =0.03, group C: P =0.03) than those with group A and C rotaviruses infection respectively. All the group B rotaviruses had been isolated in March and October. Group C rotavirus infections were prevalent during late summer and early winter and peaked in October. Conclusion: These findings indicate that group B and C rotaviruses are notable causes or the contributing causes of diarrhea among infants and children in Korea.

• Korean Journal of Veterinary Research
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• v.38 no.4
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• pp.793-802
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• 1998

Salmonellosis caused by a number of serotypes of Salmonella is an infectious, acute or chronic, zoonotic disease and characterized by enteritis and diarrhea, septicemia in animal. In these studies we investigated the prevalent serotypes of Salmonella causing animal salmonellosis in Korea and the 71 strains of Salmonella spp. were isolated from materials such as mesenteric lymph nodes, fecal samples from slaughtered animal. With the identification test results, the most prevalent serotypes were, in order, S stanley 31 strains (43.7%), S typhimurium 19 strains (26.8%) and S montevideo 11 strains (15.5%), respectively. And we could establish the method for detection of antibodies to broad variety of Salmonella serotypes. Lipopolysaccharide(LPS) antigen extracted from Salmonella was more sensitive and specific than outer membrane protein antigen from that for detection of Salmonella antibody by using an indirect ELISA. The optimal concentration of antigen was 100ng/ml of LPS, the dilutions of conjugate and serum were 1 : 1,000~2,000 and 1 : 200~400, respectively. The mix LPS-ELISA which was used by mixing LPS from S typhimurium (group B), S choleraesuis (group C) and S enteritidis (group D) were more rapid and effective than that used LPS from individual strain for detection of Salmonella serogroup O4, O7 and O9 antibody at the same time. We could obtain the high values of optical density ($0.73{\pm}0.32$) by mix LPS-ELISA on the farm which had occurred salmonellosis, but very low values of $0.17{\pm}0.06$ on the negative farm of salmonellosis. So, the mix LPS-ELISA may be used to monitor the serological surveillance for the presence of infection with a number of serotypes of Salmonella and would be useful for prevention and control of salmonellosis in animal.

• Pediatric Infection and Vaccine
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• v.3 no.2
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• pp.154-162
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• 1996

Purpose : Adenoviruses(Ad) have been shown to play an important role in the etiology of severely acute respiratory diseases, particulary in infants and young children, and the occurrence of fatal outcome and chronic pulmonary sequelae in association with adenoviral infection has been a cause of great interest and concern. This report presents the resul of a retrospective analysis on 30 cases of lower respiratory infection from which adenovirus was isolated. Patients & Methods : The 30 patients in this study represent all detected cases of adenovial infection out of 240 children who were admitted to Sang Sung Medical Center between February to June 1996 showing signs and symptoms of lower respiratory tract infection. The diagnosis of adenovirus infection was based on microscopic visualization of typical cytopathic effect in HEp-2 tissue culture and used monoclonal Ab with nasopharyngeal aspiration. Results : The male/female ratio was 2:1 and the majority of age range was below 36months. Clinical diagnoses in all 30 patients were pneumonia(n=21), bronchitis and Bronchiolitis(n=5) and ARDS(n=4). We recieved the most of patients in the month of May. The chief complaints were fever(93.3%) and cough(80%) and extrapulmonary symptoms were diarrhea(n=5), seizure(n=4), abdominal pain(n=1). The mean duration of fever was $11.95{\pm}6.54$days. Physical examination on admission were crackles(73.3%), coarse breathing sounds(60%), hepatosplenomegaly(33.3%), decreased brething sounds(30%). In WBC counts, 8cases were below $4000/mm^3$ and 14 cases were above $10,000/mm^3$. In platelets counts, 4cases were below $150,000/mm^3$ and 10 cases were above $450,000/mm^3$. 21 cases were above 1 in CRP. GOT and GPT were abnormal in some cases. Chest X-ray revealed diffuse pulmonary infiltration(n=15), pleural effusion(n=6), consolidation(n=4) and hyperaeration(n=3). Seven patients were treated at the peditric intensive care unit with respiratory support and high dose of gammaglobulin. However, one patients died even through he was treated with NO ventilation and high frequency ventilation. Conclusion : Those with adenoviral pneumonia and respiratory infection having long fever duration and symptoms like bacterial pneumonia must be carefully differentiated in order to provide proper treatement and preventive measures due to possible fatal outcome.