• Journal of Korean Society of Environmental Engineers
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• v.29 no.8
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• pp.904-908
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• 2007

The protozoan pathogen Giardia lamblia has been major cause of waterborne enteric disease. In this study, we tried to identify G. lamlbia of human infectious species and to detect viable C. lamblia in river water samples including three sites of Han River mainstream and an its creek using PCR and RT-PCR technique. The PCR/RT-PCR methods were performed by using giardin primer based on the giardin gene targeting ventral disk of Giardia. Sensitivity testing in the DNA/RNA extraction and PCR/RT-PCR amplification steps showed that it was possible to detect a single cyst of G. lamblia and viable G. lamblia. The PCR/RT-PCR methods were compared with immunofluorescence(IF) assay by analyzing 48 samples collected from the mainstream water and the creek water. The mean concentration of the total cysts were 6.3 cysts/10 L(arithmetic mean, n = 48) and the positive detection rate were 62.5%(30/48). And the mean concentration of the cysts excluding empty cysts were 4.5 cysts/10 L and the positive detection rate were 52.1%(25/48). It resulted that 24 of 48 samples included Giardia lamblia by PCR assay and 10 of 48 samples included viable G. lamblia by RT-PCR assay. It resulted that the PCR/RT-PCR technique would be available to river water samples with low concentration of Giardia cysts. And it could support the Korean protozoan standard method, which provides useful information for species and viability.

• Food Science of Animal Resources
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• v.24 no.1
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• pp.86-91
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• 2004

The ability of probiotics containing Lactobacillus acidophilus to adhere to the intestinal epithelium may play an important role in colonization of the gastrointestinal tract and preventing enteric pathogen such as enterohemorrhagic E. coli(EHEC O157:H7. In the study, we investigated the adhesion to human intestinal epithelial cells(HT-29) of strains of L. acidophilus(3 from human, 2 from pig, and 1 from calf). All of the tested strains of L. acidophilus were highly observed adhesion ability(from 10$\^$6/ to 10$\^$7/ cfu/mL), compared to L. rhamnosus GG as control. Also, adhered strains of L. acidophilus were significantly preserved in serial wash-out steps. However, no correlation could be observed between cell surface hydrophobicity and adhesion abilities of the tested strains of L. acidophilus. Inhibition of adhesion of EHEC O157:H7 was also examined, a 2 log cycle reduction was observed by all of the tested strains of L. acidophilus. These results suggest that the strains of L. acidophilus with high adhesion ability are resistant to wash-out and adhesion ability inhibition by selected strains of L. acidophilus helps to prevent adhesion of EHEC O157:H7 to intestinal epithelial cells.

• The Journal of the Korean Society for Microbiology
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• v.19 no.1
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• pp.11-24
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• 1984

Shigella remains to be an important enteric pathogen in this country for the present. Moreover, most of the isolates have become multiple resistant to various antibiotics which used to be drugs of choice for shigellosis. This study was made as an attempt to assess the present stage of antibiotic resistance and the incidence and transferability of R factors of Shigella. A total of one hundred and seventeen strains of Shigella isolated from patients in Seoul and provincial area between 1982 and 1983 were tested for their resistant to antimicrobial agents and transmission of R-plasmid. Antibiotic susceptibilities were determined by an agar dilution method. Muller hinton agar were used for the assay of drug resistance and tryptic soy broth were used for propagating medium for conjugation. Shigella isolated found to be one or more antibiotics were considered potential donor of R-plasmid. The following results were obtained. 1. Among 117 strains of Shigella isolated, 111 strains(94.9%) were found to be resistant to one or more drugs tested and 97.3% of these resistant strains were multiply resistant, indicating the multiply resistant strains were more than the single resistant strains. Only six strains were susceptible to all drugs tested. 2. Among 117 strains of Shigella isolated, 107 strains(91.5%) were resistant to Tetracyclin(Tc), 106 strains(90.6%) to Chloramphenicol(Cp) and Streptomycin(Sm), 97 strains(82.9%) to Ampicillin(Ap), 68 strains(58.1%) to Cephaloridine(Cr), 10 strains(8.5%) to Nalidixic acid(Na), 5 strains(4.3%) to Kanamycin(Km) and 2 strains(1.7%) to Rifampicin. No strain was resisfant to Amikacin(Ak) and Gentamicin(Gm). 3. All drug-resistant Shigella strains, except three, were multiply resistant to two or more drugs. Fifty eight strains were resistant to five drugs, followed by 26 strains resistant to dour drugs, 12 strains resistant to three drugs and 11 strains resistant to six drugs. 4. The 73% of multiply drug-resistant Shigella transferred their resistance to E. coli by conjugation and the resistance was considered to be mediated by R-plasmid. Resistance to Nalidixic acid and Rifampicin were not transferred by conjugation to recipient. As for the transferability of resistance to each seperate drug, Ap resistance was transferred with 73.2% frequence and Cm and Tc resistance were transferred with approximately 50-60% frequence whereas Sm and Cr resistance were transferred in 19.1-21.4% The other four drugs resistant failed to transfer their resistance to recipient. 5. As for the incidence and transferability of resistance to each seperate drug, the strains resistant to Tc and Cm were encountered most frequently with the rate of 91-92%, whereas transfer of Tc and Cm were low, 51-52%. The incidence of Sm resistance was very high(90.6%) but transferability of drugs resistance was much lower(25.4%). Though the incidence of Km reristance was much lower(4.3%) transferability of Km resistance was considerably higher(60%). 6. The greater the multiplicity of resistance, the greater was the likelihood that part of all of the resistance markers would be transferable.

• Journal of the Korean Child Neurology Society
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• v.26 no.4
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• pp.246-250
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• 2018

Purpose: Meningitis is an acute childhood infection caused by viral or bacterial infection. The purpose of the present study is to analyze the differences between enteroviral meningitis and non-enteroviral aseptic meningitis. Methods: From January 2013 to December 2016, we retrospectively reviewed the medical records of a total of 303 aseptic meningitis patients who visited Wonju Severance Christian Hospital. We examined demographics of all patients and analyzed serologic and cerebrospinal fluid tests, clinical symptoms, and outcomes. Results: Of a total of 303 patients, 197(65.0%) were male, and the most cases occurred from June to November (91.8%). The most common pathogen of meningitis was found to be enterovirus (65.0%). According to the etiology, the enteroviral meningitis group had significantly more headache and enteric symptoms (P=0.0003 and P=0.0013, respectively). Furthermore, the non-enteroviral meningitis group showed pleocytosis in the cerebrospinal fluid and a significantly higher rate of seizure at 1 to 4 years (P=0.0360 and P=0.0002, respectively). Conclusion: In this study, enteroviral meningitis was the most common and the prognosis was good. When compared between two groups, neurological symptoms were frequent in patients with non-enteroviral meningitis in groups 1 to 4 years.

• Journal of Animal Science and Technology
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• v.64 no.6
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• pp.1105-1116
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• 2022

Recently, we reported the robust in vitro three-dimensional (3D) expansion of intestinal organoids derived from adult bovine (> 24 months) samples. The present study aimed to establish an in vitro 3D system for the cultivation of intestinal organoids derived from growing cattle (12 months old) for practical use as a potential alternative to in vivo systems for various purposes. However, very few studies on the functional characterization and 3D expansion of adult stem cells from livestock species compared to those from other species are available. In this study, intestinal crypts, including intestinal stem cells, from the small intestines (ileum and jejunum) of growing cattle were isolated and long-term 3D cultures were successfully established using a scaffold-based method. Furthermore, we generated an apical-out intestinal organoid derived from growing cattle. Interestingly, intestinal organoids derived from the ileum, but not the jejunum, could be expanded without losing the ability to recapitulate crypts, and these organoids specifically expressed several specific markers of intestinal stem cells and the intestinal epithelium. Furthermore, these organoids exhibited key functionality with regard to high permeability for compounds up to 4 kDa in size (e.g., fluorescein isothiocyanate [FITC]-dextran), indicating that apical-out intestinal organoids are better than other models. Collectively, these results indicate the establishment of growing cattle-derived intestinal organoids and subsequent generation of apical-out intestinal organoids. These organoids may be valuable tools and potential alternatives to in vivo systems for examining host-pathogen interactions involving epithelial cells, such as enteric virus infection and nutrient absorption, and may be used for various purposes.

• Pediatric Infection and Vaccine
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• v.21 no.1
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• pp.43-52
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• 2014

Purpose: This study aimed to evaluate the disease severity of children suffering from gastroenteritis using different scales. The results are compared and subsequently classified on the basis of the type of virus causing the disease in order to investigate the differences in clinical characteristics and disease severity according to pathogen. Method: This study was conducted prospectively with patients under 5 years of age diagnosed with acute gastroenteritis and hospitalized at 9 medical institutions in 8 regions across the Republic of Korea. Disease severity was evaluated using the Vesikari Scale, the Clark Scale, and the modified Flores Scale. Fecal samples collected from patients were used to detect rotavirus and enteric adenovirus by enzyme immunoassay, and for RT-PCR of norovirus, astrovirus, and sapovirus. Results: There were a total of 214 patients with a male : female ratio of 1.58 : 1, of which 35 were under the age of 6 months (16.4%), 105 were aged 6-23 months (49.1%), and 74 were aged 24-59 months (34.5%). The rate of concordance between the Vesikari and Clark Scales was 0.521 (P<0.001) and, in severe cases, the Vesikari Scale was 60.7% and Clark Scale was 2.3%, indicating that the Clark Scale was stricter in the evaluation of severe cases. Conclusions: In children with gastroenteritis, there were differences in disease severity based on the scale used. Therefore, to achieve consistent results among researchers, either only a single scale or a measure of all scales should be used to determine disease severity.

• Clinical and Experimental Pediatrics
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• v.48 no.12
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• pp.1354-1361
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• 2005

Purpose : Rotavirus is an enteric pathogen that affects millions of children globally each year. But no specific therapy is available for the management of rotavirus diarrhea. Due to the clear need to define improved modality for treatment of rotavirus diarrhea, we evaluated the efficacy of antirotavirus IgY in the treatment of infants and children with gastroenteritis. Methods : First, the amount of viral particle in the stools of thirteen patients(seven were given IgY, 6 placebo) infected by rotavirus were evaluated for 3 days with the quantitative RT-PCR method. Second, 36 children with known rotavirus infection identified by ELISA or semi-quantitative RT-PCR were evaluated. We gave 5 g anti-rotavirus egg yolk daily in two equally divided doses for 3 days to two groups(an 18 IgY group and an 18 placebo group), respectively after parenteral consent. Daily vomiting frequency, stool frequency, oral intake and urine output were monitored for 3 days, and electrolyte and blood chemistry were checked at the first and third days. Results : First, in the placebo group, the amount of virus particles increased daily, but in the IgY group it decreased daily. Second, when IgY and placebos were given to children infected with rotavirus, diarrhea on the third day decreased significantly in the IgY group, compared with the placebo group. Conclusion : Treatment with antirotavirus immunoglobulin from immunized chicken's egg resulted in a decrease in the amount of viral particles in stools and diarrhea frequency in children. These results suggest that anti-rotavirus IgY is effective in the treatment of rotavirus gastroenteritis.

• Journal of Veterinary Clinics
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• v.29 no.5
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• pp.377-383
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• 2012

Bovine diarrhea is a major economical burden to the bovine industry in Korea. Since multiple infectious agents can be involved in bovine diarrhea, differential diagnosis is essential for effective treatment. Therefore, a panel of two multiplex real-time PCR assays which can simultaneously detect six major bovine enteric pathogens [i.e., bovine viral diarrhea virus (BVDV), bovine coronavirus (BCoV), group A bovine rotavirus (BRV), Salmonella spp., Escherichia coli (E. coli) $K99^+$, and Cryptosporidium parvum] was developed and applied to test 97 fecal samples collected from cattle farms in Korea. In addition, microscopic examination was also preformed on the samples to detect Coccidium oocyst. The estimated sensitivity of the multiplex PCR was 0.1 $TCID_{50}$ for BVDV, BCoV and group A BRV, 5 and 0.5 CFU for E. coli $K99^+$ and Salmonella, respectively, and 50 oocysts for Cryptosporidium. The amplification efficiency of the multiplex PCR ranged between 0.97 and 0.99 for each pathogen. Among 97 samples, 36 samples were positive for at least one of the 6 major pathogens and 6 samples were simultaneously positive for 2 pathogens by the multiplex PCR assay. Coccidium oocysts were also detected in 48 samples, which were all collected from over 1 month old calves. In conclusion, the multiplex real-time PCR panel can be a useful tool for fast and accurate diagnosis of calf diarrhea associated with BVDV, BCoV, group A BRV, E. coli $K99^+$, Salmonella, and/or Cryptosporidium and Coccidium may be an important target which needs to be included in the multiplex PCR panel in the future.

• Tuberculosis and Respiratory Diseases
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• v.64 no.3
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• pp.194-199
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• 2008

Background: Early identification of pathogens can improve the prognosis of patients with ventilator associated pneumonia (VAP). In the present study, we evaluated the feasibility of performing multiplex PCR for endotracheal aspirates to detect three important pathogens (P. aeruginosa, K. pneumoniae and MRSA) in patients with VAP. Methods: The endotracheal aspirates of 24 patients were collected within 24 hours of the diagnosis of VAP for performing multiplex PCR. Forward and reverse primers were designed to target the specific site of each pathogen (the oprL gene for P. aeruginosa, 16S rRNA for K. pneumoniae and the mec gene for MRSA). We analyzed the clinical data of the VAP patients, including the culture reports for the endotracheal aspirates. Results: Twenty-four patients (M:F=18:6, mean age=$70{\pm}11$) with VAP were enrolled. Pathogens were isolated from 11 patients (P. aeruginosa in 2, K. pneumoniae in 1, MRSA in 2, other enteric Gram negative bacilli in 3, S. pneumoniae in 2 and mixed infection in 1). Multiplex PCR detected three cases of P.aeruginosa (2 cases coincided with the culture reports) and four cases of K. pneumoniae (1 matched with the culture report). PCR detected two MRSA cases, which did not coincide with the culture reports. Conclusion: Multiplex PCR of the endotracheal aspirate showed some ability to detect Gram negative bacilli, although caution is required when interpreting the results.

• Korean Journal of Food Science and Technology
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• v.30 no.4
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• pp.916-923
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• 1998

To provide more information on the enteric pathogen Campylobacter jejuni in the view of food sanitation, survival characteristics of two strains of C. jejuni in the different conditions were investigated. When $10^7{\;}or{\;}10^3{\;}per{\;}ml$ of C. jejuni cells were inoculated in the supplemented Brucella broth and kept at $42^{\circ}C,{\;}25^{\circ}C{\;}and{\;}5^{\circ}C$ under the static aerobic condition for 7 days, organisms exponentially proliferated to $a{\;}>10^8$, even in the $10^3{\;}per{\;}ml$ inoculated-sample at $42^{\circ}C{\;}for{\;}1{\sim}2{\;}days$ and the considerable level of viability maintained during 7 days. At $5^{\circ}C$, most of the initial level of organisms survived at the early period and only $a{\;}<{\;}0.5-log_{10}$ cells decrease were observed during the 7 days. At $25^{\circ}C$, a remarkable number of C. jejuni declined within $1{\sim}2{\;}days$ and showed undetectable level of cells after 4 days. When sterile milk and minced chicken meat were artifically inoculated with $10^7{\;}per{\;}ml$ of C. jejuni, mostly, a $1-to{\;}2-log_{10}$ count decrease occurred at $42^{\circ}C{\;}and{\;}5^{\circ}C$ while $a{\;}>3{\;}log_{10}$ decrease at $25^{\circ}C$ during 7 days. Unexpectedly, no colonies appeared on the plate inoculated from the minced chicken meat sample kept at $42^{\circ}C$ after 4 days. The results suggest that C. jejuni contaminated to food can survive at the refrigeration temperature whereas they are sensitive to at the room temperature. Also, it is shown that the growth of C. jejuni at the optimal temperature may vary to the food sources.