• Journal of Microbiology and Biotechnology
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• v.9 no.2
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• pp.184-190
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• 1999

The use of the polymerase chain reaction (PCR) method was described using two sets of primers based on the ceuN gene (JEJ 1 and JEJ 2) which encodes a protein involved in siderophore transport and 16S rRNA gene (pA and pB) for the sensitive and specific detection of enteropathogen Campylobacter jejuni. Six oligonucleotides were utilized in an amplification experiment and PCR products of predicted sizes were generated from whole cells and boiled cell lysates at the same intensity. Two sets of the primer pairs, JEJ and pAB, were specific enough for all C. jejuni strains tested for the direct use of whole cells without DNA extraction or lysis steps. In the PCR using the pAB primer pair, the detection limit, as determined by the ethidium bromide staining of the amplification products on agarose gels, was at the level of $10^1$ bacteria cells or less in both the pure culture and artificially inoculated milk and chicken enrichment samples, whereas the detection limit with the JEJ primer pair was relatively low, i.e. $10^3$ cells or more in the same PCR samples. The PCR method using either a primer JEJ or pAB was both repeatable and specific for the detection of C. jejuni in food. This method is simply completed within 4 h.

• Microbiology and Biotechnology Letters
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• v.17 no.1
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• pp.56-62
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• 1989

To find bacteria which can inhibit growth of enteropathogenic Clostridium perfringens ATCC 13124, spore forming butyric acid bacteria were isolated from 26 fecal samples of infants. Fourteen strains were found to be antagonistic to the enteropathogen and five of them produced butyric acid. A strain which produced the highest butyric acid was selected and identified as Clostridium butyricum. This organism sporulated in SM medium in 36 hours with optimum rates at 37$^{\circ}C$ and at pH 5.5. The spores tolerated well at high heat and acidity, and possible application of Clostridium butyricum as intestinal controller was discussed.

• Journal of Animal Science and Technology
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• v.44 no.4
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• pp.491-498
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• 2002

The inhibitory effect of lactobacilli and bifidobacteria on the growth of typical intestinal pathogens, Escherichia coli and Salmonella typhimurium was studied. The degree of inhibition was measured by well disc assay and turbidimetry method. The strains which showed the higher antimicrobial activity were L. acidophilus La-5, L. acidophilus NCFM, L. casei Lc-01 on the average by using two different methods. The associative cultures were performed with selected 3 lactobacilli and 2 enteropathogens E. coli and S. typhimurium, respectively. Inhibition of pathogen began at 9hr after culturing so that viable counts was decreased rapidly. After 30hr incubation, there were no viable pathogens from the mixed culture. Under this experimental condition, the antimicrobial activity of lactic acid bacteria was not due to pH alone and supposed to different to the strains.

• Parasites, Hosts and Diseases
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• v.55 no.5
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• pp.513-521
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• 2017

Infectious diarrhea is endemic in most developing countries. We aimed to investigate the protozoan, viral, and bacterial causes of acute diarrhea in Taif, Saudi Arabia. A cross-sectional prospective 1-year study was conducted on 163 diarrheal patients of various ages. Stool samples were collected, 1 per patient, and tested for 3 protozoa, 3 viruses, and 9 bacteria with the Luminex Gastrointestinal Pathogen Panel. Overall, 53.4% (87/163) of samples were positives (20.8% protozoa, 19.6% viruses, 2.8% bacteria, and 9.8% mixed). Rotavirus (19.6%), Giardia duodenalis (16.5%), and Cryptosporidium spp. (8.5%) were the mostly detected pathogens. Adenovirus 40/41 (4.2%), Salmonella (3%), Shiga toxin-producing Escherichia coli (3%), and Entamoeba histolytica (2.4%) were also detected. Norovirus GI/II, Vibrio cholerae, Yersinia enterocolitica, and Clostridium difficile toxin A/B were not detected in any patients. All pathogens were involved in coinfections except E. histolytica. Giardia (5.5%) and rotavirus (3%) were the most commonly detected in co-infections. Enterotoxigenic E. coli (2.4%), Campylobacter spp. (2.4%), E. coli 0157 (1.8%), and Shigella spp. (1.2%) were detected in patients only as co-infections. Infections were more in children 0-4 years, less in adults <40 years, and least >40 years, with statistically significant differences in risk across age groups observed with rotavirus (P<0.001), Giardia (P=0.006), and Cryptosporidium (P=0.036) infections. Lastly, infections were not significantly more in the spring. This report demonstrates the high burden of various enteropathogens in the setting. Further studies are needed to define the impact of these findings on the clinical course of the disease.

• Korean Journal of Veterinary Research
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• v.44 no.4
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• pp.551-559
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• 2004

Shiga toxin-producing Escherichia coli (STEC) causes various clinical signs in human and animals, and has been indicated as a global enteropathogen with zoonotic importance. In this study, the feces of healthy pigs were collected from the slaughtered pigs of Daejon abattoir during the period from December 2001 to October 2002. Of 326 specimens, 13 STEC were confirmed by culture, PCR and colony hybridization. The isolates were further studied for toxin types, pathogenic factors, plasmid profiles, and antimicrobial resistance to characterize the genetic and toxigenic properties. In PCR, all of 13 isolates were evident to have shiga toxin gene (stx). Of 13 isolates stx1 gene was detected in 4 and stx2 gene in 9. The genes of eaeA, hlyA and rfbE were not present in any isolates. In colony hybridization using shiga toxin common primer (STXc), 2 to 9 per 100 colonies subcultured from 13 isolates showed the positive reaction. In the examination for plasmid profiles of the isolates, one to eleven plasmids with varying sizes of 1.0 Kb to 100 Kb were detected, and the 13 STEC could be classified into four groups by the plasmid patterns. The antimicrobial resistance patterns of the isolates were comparably corresponded with the plasmid profile patterns.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.9 no.1
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• pp.1-13
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• 2006

Purpose: Acute gastroenteritis in children is one of the frequently encountered diseases with relatively high admission rate. The aim of this study is to determine the isolation trends of common and emerging pathogens in acute gastroenteritis in children over a 12-month period in a community hospital. Methods: The study group included the children who were hospitalized to Seoul National University Boramae Hospital from April, 2003 to March, 2004 or visited outpatient clinic from April, 2003 to July, 2003 with presenting features of acute gastroenteritis. Stool specimens were obtained within 2 days after the visit and examined for the following pathogens: rotavirus, adenovirus, Salmonella, Shigella, Vibrio, pathogenic Escherichia coli (E.coli), Campylobacter and Yersinia species. Viral study was done with commercial kits for antigen detection. Identification of the bacterial pathogens was done by culture using selective media. For pathogenic E.coli, polymerase chain reaction (PCR) was done with the target genes related to the pathogenecity of enterotoxigenic E.coli (ETEC), enteropathogenic E.coli (EPEC) and enterohemorrhagic E.coli (EHEC). Results: The 130 hospitalized children and 28 outpatients were included in this study. The majority of children (>93%) were less than 6 years. Pathogens were isolated in 47% of inpatients and 43% of outpatients, respectively. Rotavirus was the most frequently identified pathogen, accounting for 42.3% of inpatients and 29.6% of outpatients. Nontyphoidal salmonella is the most commonly isolated bacterial pathogen (3.9%) in hospitalized children. Pathogenic E.coli (EPEC, ETEC) was detected in 2.1% (2/97) of inpatients and 25% (3/12) of outpatients. EHEC, adenovirus, Campylobacter, Yersinia and Shigella species were not detected in this study. Conclusion: Rotavirus is the most common enteropathogen in children with acute gastroenteritis. Nontyphoidal salmonella and pathogenic E.coli are important bacterial pathogens. Campylobacter species may not be commonly detected organism in hospitalized children with acute diarrhea.

• Journal of Plant Biotechnology
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• v.29 no.4
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• pp.287-293
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• 2002

We are trying to develop a transgenic carrot with aims of production and delivery of oral vaccine against microbial enteropathogen using a K88ac pilin gene. A K88ac antigen (pilin) gene was isolated by PCR from the K88ac genomic DNA. The pilin gene was constructed in pGA748 and introduced via Agrobacterium tumefaciens to the explants of carrot hypocotyl and then 494 transgenic lines were established. The amounts of the K88ac antigen produced in each of the cell lines were determined by western and two elite cell lines (M1-17, Y14-1) were selected based on higher levels of expression of the antigens as well as rate of cell growth and efficiency of embryogenesis. In order to test an immunization induced by oral administration of the transgenic carrot, serum of the mice fed with the carrot vaccine were tested in ELISA. It tumed out that the mice fed with 3 g of transgenic carrot showed a similar level of antibody compared to those applied with 10 $\mu\textrm{g}$ of the purified recombinant pilin protein. Besides, various clinical responses were measured after challenging with ETEC K88ac strain to the piglets experiencing an oral immunization with the transgenic carrot. The piglets fed with carrot vaccine showed a lower level of diarrhea in fecal score compared to those fed with non-transgenic carrot. A higher level of increase in weight of the piglets fed with the transgenic carrot vaccine was observed comparing to those fed with non-transgenic carrot as control.

• Korean Journal of Veterinary Service
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• v.42 no.2
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• pp.93-112
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• 2019

Calf diarrhea is a common disease in young claves and is still a major cause of productivity and economic loss in livestock farms. Fecal samples from Korean native cattle (n=100) with diarrhea from 64 farms in Gwangju area, Korea from september 2017 to December 2018 were examined for shedding of important protozoan parasitic, viral and bacterial pathogens using culture, rapid test kit and PCR methods. Of 57 (89.1%) of the 64 Korean native cattle farms examined had samples infected with at least one of the investigated pathogens. Among 100 fecal samples, 88 samples were positive for at least one the twelve pathogens and 51 samples were simultaneously positive for two or more pathogens by culture and PCR assay. Bovine group A rotavirus (BRV) was the most common pathogen, found in 43/100 (43.0%) samples on 32/64 (50.0%) farms. Subsequently, kobuvirus (30.0%), pathogenic E. coli (29.0%), bovine parvovirus (17.0%), Giardia spp. (13.0%), Eimeria spp. (10.0%), Clostridium perfringens type A (8.0%), bovine torovirus (8.0%), bovine viral diarrhea virus (6.0%), bovine coronavirus (5.0%), bovine norovirus (2.0%) and Cryptosporidium spp. (2.0%) were detected. Nebovirus, kırklareli virus, bovine adenovirus, Salmonella spp. and intestinal parasites were not detected. Of the 72 calves sampled in this age group, 64 (88.9%) samples were positive for at least one enteropathogen. BRV was identified in 34/72 (47.2%) samples from 27/48 (56.3%) farms. Subsequently, pathogenic E. coli (30.6%), kobuvirus (29.2%), BPaV (22.2%), Giardia spp. (15.3%), Eimeria spp. (9.7%), BVDV (6.9%), Cl. perfringens type A (6.9%), BCoV (4.6%) and Cryptosporidium spp. (2.8%) were detected in fecal samples. A total of ninety-six strains of E. coli were isolated from one hundred fecal samples collected from Korean native cattle with diarrhea. The presence of stx1, stx2, eaeA, LT, STa, STb, ehxA, saa, F4, F5(K99), F6, F17, F18 and F41 genes in the isolates was investigated by PCR. Out of ninety-six E. coli isolates screened for specific genes, 30 strains E. coli were identified to harbor shiga toxin-producing E. coli (STEC) 7 (7.3%), enterohemorrhagic E. coli (EHEC) 8 (8.3%), enteropathogenic E. coli (EPEC) 6 (6.3%), enterotoxigenic E. coli (ETEC) 2 (2.1%) and STEC/ETEC hybrid 7 (7.3%). This study provides epidemiological estimates of the prevalence of Korean native cattle's enteropathogens in Gwangju area, Korea, which would be used for cattle farmers and veterinarians to select appropriate therapeutic method.