• Asian-Australasian Journal of Animal Sciences
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• 제31권4호
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• pp.585-594
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• 2018

Objective: This study was to determine the bacterial diversity and monitor the community dynamic changes during storage of vacuum-packaged sliced raw beef as affected by Lactobacillus sakei and Lactobacillus curvatus. Methods: L. sakei and L. curvatus were separately incubated in vacuumed-packaged raw beef as bio-protective cultures to inhibit the naturally contaminating microbial load. Dynamic changes of the microbial diversity of inoculated or non-inoculated (control) samples were monitored at $4^{\circ}C$ for 0 to 38 days, using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). Results: The DGGE profiles of DNA directly extracted from non-inoculated control samples highlighted the order of appearance of spoilage bacteria during storage, showing that Enterbacteriaceae and Pseudomonas fragi emerged early, then Brochothrix thermosphacta shared the dominant position, and finally, Pseudomonas putida showed up became predominant. Compared with control, the inoculation of either L. sakei or L. curvatus significantly lowered the complexity of microbial diversity and inhibited the growth of spoilage bacteria (p<0.05). Interestingly, we also found that the dominant position of L. curvatus was replaced by indigenous L. sakei after 13 d for L. curvatus-inoculated samples. Plate counts on selective agars further showed that inoculation with L. sakei or L. curvatus obviously reduced the viable counts of Enterbacteraceae, Pseudomonas spp. and B. thermosphacta during later storage (p<0.05), with L. sakei exerting greater inhibitory effect. Inoculation with both bio-protective cultures also significantly decreased the total volatile basic nitrogen values of stored samples (p<0.05). Conclusion: Taken together, the results proved the benefits of inoculation with lactic acid bacteria especially L. sakei as a potential way to inhibit growth of spoilage-related bacteria and improve the shelf life of vacuum-packaged raw beef.

• 대한미생물학회지
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• 제35권4호
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• pp.289-297
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• 2000

Background: Staphylococcus aureus (s. aureus) and Escherichia coli (E. coli) are major pathogens in community and hospital. And they sometimes cause the outbreak in hospital in the immunocompromised patients. Pulsed-field gel electrophoresis (PFGE) has been regarded as a standard method for genotyping in epidemiologic studies, but it is laborious and time-consuming. Infrequent restriction site-polymerase chain reaction (IRS-PCR), a new genotyping methods, was performed to compare the applicability with PFGE. Methods: We performed PFGE and IRS-PCR on S. aurues (n=120) and E. coli (n=117) which were collected clinically in 4 different hospitals. We assessed each method in terms of discriminatory power, quality, and efficiency. Results: In E. coli, the discriminatory power of IRS-PCR was $46.7{\sim}86.7%$, and that of PFGE was $88.9{\sim}96.7%$ according to hospital. But in S. aurues, the discriminatory power of IRS-PCR was $20{\sim}56.7%$, and that of PFGE was $40{\sim}90%$ according to hospital. The typablity and reproducibility of IRS-PCR were 100% of each. PFGE needed four days to complete the procedure, but IRS-PCR could be performed within one day, IRS-PCR showed better resolution than PFGE. Conclusion: In case of gram negative bacteria (like E. coli), IRS-PCR could be a reliable alternative for epidemiologic typing due to better efficiency and comparable discriminatory power. But in the case of gram positive bacteria (like S. aureus), IRS-PCR does not seem to be suitable for the strain-to-strain differentiation. More trials and changes of restriction enzymes or primers could reveal the efficacy of IRS-PCR in the field of molecular typing.

• 농촌의학ㆍ지역보건
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• 제32권2호
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• pp.87-96
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• 2007

Background: Apolipoprotein E has been one of the most thoroughly studied genetic polymorphisms, particularly for its effects on lipid profiles and coronary heart disease risk. This study investigated the relationship between the apolipoprotein E polymorphism and essential hypertension in a Korean population. Methods: The subjects (n=1,243) were participants in a population-based study in Incheon metropolitan City, Korea. The apolipoprotein E polymorphism was determined using a polymerase chain reaction method. Results: The frequencies of the genotypes did not differ significantly between the hypertensive groups (60.0% ε2 / ε2, 30.8% ε2 / ε3, 44.4% ε2 / ε4, 33.3% ε3 / ε3, 32.3% ε3 / ε4, and 15.4% ε4 / ε4; p=0.498). After adjusting for other risk factors, genotypes were not associated with hypertension(OR 5.74, 95% CI 0.81-40.76, ε2 / ε2 vs. ε3 / ε3; OR 0.94, 95% CI 0.60-1.47, ε2 / ε3 vs. ε3 / ε3; OR 1.21, 95% CI 0.30-4.89, ε2 / ε4 vs. ε3 / ε3; OR 0.79, 95% CI 0.56-1.13, ε3 / ε4 vs. ε3 / ε3; OR 0.29, 95% CI 0.06-1.45, ε4 / ε4 vs. ε3 / ε3). Conclusions: These findings suggest that the apolipoprotein E polymorphism is not associated with hypertension.

• The Plant Pathology Journal
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• 제31권3호
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• pp.212-218
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• 2015

In this study, we developed a species-specific PCR assay for rapid and accurate detection of three Xanthomonas species, X. axonopodis pv. poinsettiicola (XAP), X. hyacinthi (XH) and X. campestris pv. zantedeschiae (XCZ), based on their draft genome sequences. XAP, XH and XCZ genomes consist of single chromosomes that contain 5,221, 4,395 and 7,986 protein coding genes, respectively. Species-specific primers were designed from variable regions of the draft genome sequence data and assessed by a PCR-based detection method. These primers were also tested for specificity against 17 allied Xanthomonas species as well as against the host DNA and the microbial community of the host surface. Three primer sets were found to be very specific and no amplification product was obtained with the host DNA and the microbial community of the host surface. In addition, a detection limit of $1pg/{\mu}l$ per PCR reaction was detected when these primer sets were used to amplify corresponding bacterial DNAs. Therefore, these primer sets and the developed species-specific PCR assay represent a valuable, sensitive, and rapid diagnostic tool that can be used to detect three specific pathogens at early stages of infection and may help control diseases.

• 대한지역사회영양학회지
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• 제10권3호
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• pp.264-270
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• 2005

Breastfeeding has been known as the best feeding practice to prevent allergies including atopic dermatitis (AD) However, the benefit on the prevention of allergic disease is still controversial. The objectives of this study were to examine the rate of sensitization to the protein of eggs, cow's milk and soy in exclusively breastfed infants and to evaluate antigen-antibody reaction between breast milk and serum of AD infant. Data on feeding and food hypersensitivity were obtained for 62 AD infants (32 male, 30 female) aged < 6 month who had visited Samsung Medical Center from September 2001 to May 2003. Food hypersensitivity was determined by measuring specific IgE to egg, cow's milk and soy. Specific IgE levels > 0.7 kU/L by CAP assay (Pharmacia, Uppsala, Sweden) were considered positive. The rates of sensitization in breastfed infants were $41.9\%$ (26/62) to egg, $30.6\%$ (19/62) to milk and $18.0\%$ (11/62) to soy. Immunoblotting analyses were performed using breast milk with the matched serum of seven AD infants (4 male/3 female). Binding patterns of AD infant's IgE to breast milk extract showed visible specific band for immunoglobulin, especially in case of a lactating mother who did not completely restricted ingestion of egg, milk and soy. These results indicate that sensitization to food allergen develops via breast milk feeding. Breast milk feeding should be recommended in infants at risk of developing allergic disease, but maternal intake of highly allergenic food might be restricted for prevention and treatment of food allergy among the babies with AD.

• 한국환경보건학회지
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• 제46권5호
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• pp.599-609
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• 2020

Objectives: Coronavirus disease 2019 (COVID-19) first emerged in December 2019 in Wuhan, China, and has rapidly become a global pandemic with over 26.4 million confirmed cases and approximately 871,000 fatalities worldwide as of this writing. In the Republic of Korea, disease clusters frequently occurred in long-term care hospitals where the majority of residents are elderly with underlying medical conditions. Despite the fact that public health authorities and local community health centers have put tremendous efforts into preventing the spread of disease, positive cases have continued to occur. Thus, the Korea Centers for Disease Control & Prevention rapid response team decided to conduct an environmental investigation of a long-term care hospital to identify whether environmental contamination has remained and contributed to the spread of COVID-19. Methods: An environmental investigation was conducted at Hospital A. The characteristics of the facility and its HVAC system were assessed by checking the layout and interviewing the people in charge. A total of 64 surface samples were collected from areas of concern, including patient rooms, toilets, elevators, and nurses' station. These samples were tested by a regional health and environmental research institute using real-time reverse transcription polymerase chain reaction. Results: All samples from Hospital A were confirmed to be negative. Through interviews with high-level personnel at the regional community health center, we found that extensive disinfection is frequently performed on potentially contaminated areas in Hospital A in accordance with government guidelines. Conclusion: The environmental control measures implemented in Hospital A had been sufficient for mitigating the risk of further infection, suggesting that such measures may also be effective for other long-term health care facilities.

• 한국습지학회지
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• 제14권3호
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• pp.419-428
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• 2012

식물플랑크톤의 동정은 숙련된 전문가에게도 어려운 과제이다. 별 특징없는 외형과 다양한 크기와 종은 형태학적으로 구분하기에 어려움이 있다. 본 연구에서는 미생물 군집의 다양성을 분석하는데 효과적인 fingerprinting 기법인 PCR-DGGE 방법을 사용하여 이런 형태학적 동정의 제한점을 보완하고자 하는데 목적이 있다. 5곳의 호수 샘플로부터 2008년 8월 총 46개의 band를 찾을 수 있었고, 2008년 11월 총 26개 band를 찾을 수 있었다. 이 fingerprint 결과는 각각 다른 샘플링 장소를 비교하는데 용이하였다. 본 연구에서 PCR-DGGE 방법은 북한강 호수들의 플랑크톤 군집의 다양성을 파악하는데 사용되었고, 이 DGGE 기법이 플랑크톤의 동정기법으로써의 가능성을 검토해보았다.

• 농촌의학ㆍ지역보건
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• 제3권1호
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• pp.35-41
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• 1978

Clonorchiasis sinensis is the most important endemic disease in In Korea, and this disease has been known to be one of public health concern in mary areas of southern part of Korea. This survey was undertaken to evaluate the status of clonorchiasis in Eui-Seong Gun, Kyungpook Province from March 1974 to August 1974. A total number of 3,771(male 2,037. female 1,734) consisting of 2,948 primary school children, 774 middle school students, 49 high school students were examined by the intradermal test with clonorchis antigen. In order to detect clonorchis egg, the stool examinations were undertaken on the residents in Bong Yang Myun. And, the intensity of the clonorchis infection was estimated by the Stoll's egg count. The following results were obtained in this survey; 1. As a whole, 6.0 per cent of the examiners showed positive reaction by the intradermal test (male 8.0%, female 3.6%). 2. Among 249 residents in Bong Yang Myun, the prevalence rate of clonorchis eggs was shown as 45.8 per cent. 3. The mean E. P. G. in Bong Yang Myun 114 inhabitants was 2,197. 4. The degree of the intensity of clonorchis infection by E. P. G. counts was distributed to the light (50.9%) medium (43.9%) and heavy infection groups(5.3%).

• Asian-Australasian Journal of Animal Sciences
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• 제28권6호
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• pp.888-895
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• 2015

Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and subsequent sub-cloning and sequencing were used in this study to analyze the molecular phylogenetic diversity and spatial distribution of bacterial communities in different spatial locations during the cooling stage of composted swine manure. Total microbial DNA was extracted, and bacterial near full-length 16S rRNA genes were subsequently amplified, cloned, RFLP-screened, and sequenced. A total of 420 positive clones were classified by RFLP and near-full-length 16S rDNA sequences. Approximately 48 operational taxonomic units (OTUs) were found among 139 positive clones from the superstratum sample; 26 among 149 were from the middle-level sample and 35 among 132 were from the substrate sample. Thermobifida fusca was common in the superstratum layer of the pile. Some Bacillus spp. were remarkable in the middle-level layer, and Clostridium sp. was dominant in the substrate layer. Among 109 OTUs, 99 displayed homology with those in the GenBank database. Ten OTUs were not closely related to any known species. The superstratum sample had the highest microbial diversity, and different and distinct bacterial communities were detected in the three different layers. This study demonstrated the spatial characteristics of the microbial community distribution in the cooling stage of swine manure compost.

• 대한지역사회영양학회지
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• 제15권5호
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• pp.679-686
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• 2010

The purpose of this study is to monitor genetically modified bean sprouts at traditional markets in Seoul and to investigate perception of traditional market merchants and high school students on genetically modified organisms (GMOs). We analyzed 30 bean sprouts that were selected at 11 traditional markets in Seoul using the method of polymerase chain reaction (PCR). Also, we compared perception of GMOs between merchants (n = 30) and students (n = 126). Knowledge test about GMOs was performed by students. The result of PCR, 16.7% of bean sprouts were confirmed as GM bean sprouts (n = 5). Students had significantly more exposure to information about GMOs than merchants (p < 0.05). Major information sources about GMOs were from mass media (television, newspaper and radio). About half of subjects were not aware that they eat GMOs and GMOs are sold to consumers. Only 17.3% of subjects had constant eating intent for GMOs after perceiving foods that he/she usually eats are GMOs. 51.3% of subjects had willingness to purchase GMOs if GMOs have same quality and lower cost than natural foods. 37.2% of subjects thought that GMOs would be harmful to humans. Students had more positive perception of GMOs' side effects than merchants (p < 0.01). There was no merchant who knew labeling of GMOs. 19.1% of students knew labeling of GMOs. Students' mean percentage of correct answers of six questions about GMOs was 45.2%. Therefore, providing adequate information about GMOs is needed for consumer's choice whether to purchase GMOs or not.