• 약학회지
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• 제39권4호
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• pp.417-426
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• 1995

6-[(N-4-Chlorophenyl)amino]-7-chloro-5,8-quinolinedione (RCK20) was tested for antifungal activities, in vivo, against Candida albicans. RCK20 was compared vath ketoconazole and fluconazole in the treatment of systemic infection with Candida albicans in normal rats. The therapeutic potential of RCK20 had been assessed by evaluating their activities (survival rate) against systemic infections with in normal mice with Candida albicans. RCK20 improved survival rates as well as ketokonazole. RCK20 had ED$_{50}$. 0.25$\pm$0.18 mg/kg but ketoeonazole and fluconazole had ED$_{50}$, 8.00$\pm$0.73, 10$\pm$0.43 mg/kg respectively. Activities of RCK20 showed superior to that of ketoconazole and fluconazole. Intraperitoneauy administered RCK20 at the ED$_{50}$, 0.25 mg/kg for 7days and 14days reduced Candida albicans colony count in the kidneys and livers as well as ketoconazole and fluconazole at these ED$_{50}$, 8.00 and 10 mg/kg. Acute oral toxicity studies of RCK20 were carried out in ICR mice of both sexes. These acute oral toxicities of RCK20 were low and LD$_{50}$ values were over 2.850 mg/kg in ICR mice. The Genotoxicities of RCK20 had been evaluated. RCK20 was negative in Ames test with Salmonella typhimurium (TA98 and TA100). The clastogenicity was tested on the RCK20 with in vivo mouse micronucleus assay. RCK20 did not show any clastogenic effect in mouse peripheral blood and was negative in mouse micronucleus assay. These results indicate that RCK20 has no genotoxic potential under these experimental condition.

• Asian-Australasian Journal of Animal Sciences
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• 제16권12호
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• pp.1830-1836
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• 2003

Studies using natural resistance-associated macrophage protein (NRAMP) identification indicated that cattle could be selected for immunity. Several studies performed on intracellular organisms such as Mycobacterium, Salmonella, Brucella and Leishmania in human and mouse revealed that resistance against these bacteria was dependent on high activity of NRAMP1 in macrophages. However, hardly any researches have been done on Staphylococcus aureus in bovine mastitis, which is an intracellular organism and the main cause of bovine mastitis. The objectives of this study were to establish reverse transcriptase polymerase chain reaction (RT-PCR) methods, through which NRAMP1 mRNA expression could be compared and analyzed between mastitis-resistant and -susceptible cows. NRAMP1 gene and its expression were investigated using 20 cows (Holstein Friesian) in Korea. Cows were evenly split into two groups, with and without histories of clinical mastitis. Equivalent numbers of cows were randomly selected from each group. Monocytes were isolated from the bovine peripheral blood of each selected cows and activated with lipopolysaccharide (LPS). mRNA was separated from the monocytes and cDNA of NRAMP1 was synthesized and amplified using RT-PCR with amplification of $\beta$-actin as a control. The difference in NRAMP1 expressions of mastitis-resistant (n=10) and -susceptible (n=10) Holstein cows was analyzed. Results demonstrate that resistant cows produced more NRAMP1 mRNA than the susceptible ones, and ratios of NRAMP1:$\beta$-actin expression were higher in resistant cows with or without LPS activation. Therefore, this study could be applied to select bovine mastitis resistant cows before infection based on the expression of NRAMP1.

• 대한수의학회지
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• 제44권1호
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• pp.73-82
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• 2004

Chitosan is similar in structure to cellulose and are the second most abundant polysaccharides in nature, comprising the horny substance in the exoskeletons of crabs, shrimp and insects as well as fungi. This study was conducted to access the effect of immunomodulation responses of chitosan(N-acetyl-${\beta}$-D-glucosamine) chicken infected with in Fowl typhoid(Salmonella gallinarum). One-day-old broiler chicks were divided into eight groups: The 1st group was inoculated intra-peritoneally with chitosan and challenged intra-peritoneally with S. gallinarum. The 2nd group was inoculated intra-peritoneally with chitosan. The 3rd group was feeding with chitosan and intra-peritoneally inoculated with cyclophosphamide and challenged intra-peritoneally S. gallinarum. The 4th group was feeding with chitosan and intra-peritoneally with cyclophosphamide. The 5th group was feeding with chitosan and challenged intra-peritoneally with S. gallinarum. The 6th group was feeding with chitosan. The 7th group was challenged intra-peritoneally with S. gallinarum. The 8th group was nontreated-uninfected control group. The results shows that $CD4^+$, $CD8^+$ and B lymphocyte in lymphoid organs of chickens treated with chitosan increased in especially $CD4^+$, $CD8^+$ lymphocytes (p<0.05). The group of feeding chitosan showed the significantly increased $CD4^+$, $CD8^+$ and B lymphocyte than inoculated intra-peritoneally with chitosan. As the result suggests that the feeding of chitosan induced immunostimulatant effect than the inoculation intra-peritoeally of chitosan.

• Journal of Preventive Medicine and Public Health
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• 제38권4호
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• pp.457-464
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• 2005

Objectives : An outbreak of salmonellosis occurred among the student s and staff of D primary school in Yeongcheon-si, 2004. This investigation was carried out to prevent any recurrence of this outbreak and to study the infection source and transmission of the salmonellosis. Methods : The authors conducted a questionnaire survey among 1,205 students and staff members from D primary school about the ingestion of the school lunch and drinking water, and the manifestation of their symptoms. The author examined rectal swabs, the tap water and microorganism cultures, and we also investigated the dining facility and water supply facility. Results : The diarrheal cases were defined as the confirmed cases or the persons who had diarrhea more than one time with symptoms such as fever, vomiting and tenesmus. The diarrheal attack rate was 28.0%. Ingestion of fried bean curd with egg had a significantly high association with the diarrheal attack rate (p<0.05), and the relative risk of the fried bean curd with egg was 10.68 (95% CI=3.88-29.41), as was determined by logistic regression analysis. The bacterial counts in the tap water of the food preparation room and toilet (first floor) exceeded the maximum permissible counts. S. Enteritidis bacteria were only cultured from the fried bean curd with egg of all the supplied foods on September 3, 2004. Conclusions : The major cause of salmonellosis was presumed to be the contaminated bean curd via contaminated tap water due to a water leak of a school water pipe. This contaminated bean curd was under prepared, which allowed the S. Enteritidis to survive and multiply prior to its ingestion.

• Journal of Microbiology and Biotechnology
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• 제28권6호
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• pp.883-892
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• 2018

Probiotics, including Enterococcus faecium, confer a health benefit on the host. An Enterococcus strain was isolated from healthy chicken cecum, identified as E. faecium by 16S rDNA gene sequence analysis, and designated as E. faecium L11. To evaluate the potential of E. faecium L11 as a probiotic, the gastrointestinal tolerance, immunomodulatory activity, and lifespan extension properties of the strain were assayed. E. faecium L11 showed >66% and >62% survival in artificial gastric juice (0.3% pepsin, pH 2.5) and simulated small intestinal juice (0.5% bile salt and 0.1% pancreatin), respectively. Heat-killed E. faecium L11 significantly (p < 0.05) increased immune cell proliferation compared with controls, and stimulated the production of cytokines (IL-6 and $TNF-{\alpha}$) by activated macrophages obtained from ICR mice. In addition, E. faecium L11 showed a protective effect against Salmonella Typhimurium infection in Caenorhabditis elegans. In addition, feeding E. faecium L11 significantly (p < 0.05) extended the lifespan of C. elegans compared with the control. Furthermore, genes related to aging and host defense were upregulated in E. faecium L11-fed worms. In conclusion, E. faecium L11, which prolongs the lifespan of C. elegans, may be a potent probiotic supplement for livestock.

• 한국환경보건학회지
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• 제33권3호
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• pp.184-189
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• 2007

Pathogenic microbial foodborne disease outbreaks (PMFBDOs) have increased in many countries, the boom in food service establishment is not matched by effective food safety and control. In this study, we investigated the current state and the epidemic aspects of FBDOs in Korea and Japan. In Korea, the average prevalence rate of foodborne disease (FBD) was 15.0 per 100,000 population and cases per outbreak of FBD was 57.0. During the same period in Japan, the prevalence rate showed an average of 24.9, and the cases per outbreak were 16. When both prevalence rate and cases per outbreak were compared, the prevalence rate in Japan was much higher than that in Korea (p<0.01). However, average cases per outbreak of FBD in Japan were much lower than those in Korea (p<0.01). In Korea, outbreaks of FBDs were more common in spring (p<0.01), while in Japan, more frequent in summer and winter (p<0.01). Outbreaks of FBD occurred largely through restaurant and school foods (32.0% and 27.5%) in Korea. In Japan, the proportion of the outbreak cases in the restaurant and home were 23.7% and 12.1%, and cases of unknown causes of FBDs were 48.2%, respectively. Bacteria were the major causes of infection in both countries. The prevalence of PMFBDOs by Salmonella spp. Vibrio parahemolyticus and Staphylococcus aureus were much higher in Korea, while those by Camphylobacter spp. and SRSV were more common in Japan. The causes by virus were more frequent in Japan (13.7%) than in Korea (7.7%). The prevalence of FBDs in Korea and Japan showed characteristic differences, especially in the PMFBDOs due to such factors as geography, climate, culture, diet and food management.

• Journal of Microbiology and Biotechnology
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• 제32권6호
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• pp.816-823
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• 2022

The rapid spread of superbugs leads to the escalation of infectious diseases, which threatens public health. Endolysins derived from bacteriophages are spotlighted as promising alternative antibiotics against multi-drug resistant bacteria. In this study, we isolated and characterized the novel Salmonella typhimurium phage PBST08. Bioinformatics analysis of the PBST08 genome revealed putative endolysin ST01 with a lysozyme-like domain. Since the lytic activity of the purified ST01 was minor, probably owing to the outer membrane, which blocks accessibility to peptidoglycan, antimicrobial peptide cecropin A (CecA) was fused to the N-terminus of ST01 to disrupt the outer membrane. The resulting CecA::ST01 has been shown to have increased bactericidal activity against gram-negative pathogens including Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumannii, Escherichia coli, and Enterobacter cloacae and the most affected target was A. baumannii. In the presence of 0.25 µM CecA::ST01, A. baumannii ATCC 17978 strain was completely killed and CCARM 12026 strain was wiped out by 0.5 µM CecA::ST01, which is a clinical isolate of A. baumannii and resistant to multiple drugs including carbapenem. Moreover, the larvae of Galleria mellonella could be rescued up to 58% or 49% by the administration of CecA::ST01 upon infection by A. baumannii 17978 or CCARM 12026 strain. Finally, the antibacterial activity of CecA::ST01 was verified using 31 strains of five gram-negative pathogens by evaluation of minimal inhibitory concentration. Thus, the results indicate that a fusion of antimicrobial peptide to endolysin can enhance antibacterial activity and the spectrum of endolysin where multi-drug resistant gram-negative pathogens can be efficiently controlled.

• 대한의생명과학회지
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• 제9권3호
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• pp.139-144
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• 2003

Since water borne infection causes acute diseases and results in spread of diseases by secondary infection, the prevention is very important. Therefore, it is necessary to have a method that is rapid and effective to monitor pathogenic bacteria in drinking water. In this study, we employed a systematic method, Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) analysis, to develop an effective monitoring system for possible bacterial contaminants in drinking water. For this purpose, PCR primers were derived from 992 bp region of the 16s rRNA gene that is highly conserved through the different species of prokaryotes. To test whether the PCR primers designed are indeed useful for detecting all the possible microbial contaminants in the water, the primers were used to amplify 16s rRNA regions of different microbial water-borne pathogens such as E. coli, Salmonella, Yersinia, Listeria, and Staphylococcus. As expected, all of tested microorganisms amplified expected size of PCR products indicating designed PCR primers for 16s rRNA indeed can be useful to amplify all different microbial water-borne pathogens in the water. Furthermore, to test whether these 16s rRNA based PCR primers can detect bacterial populations present in the water, water samples taken from diverse sources, such as river, tap, and sewage, were used for amplification. PCR products were for then subjected for cloning into a T-vector to generate a library containing 16s rRNA sequences from various bacteria. With cloned PCR products, RFLP analysis was done using PCR products digested with restriction enzyme such as Hae III to obtain species-specific RFLP profiles. After PCR-RFLP, the bacterial clones which showed the same RFLP profiles were regarded as the same ones, and the clones which showed distinctive RFLP profiles were subsequently subjected for sequence analysis for species identification. By this PCR-RFLP analysis, we were able to reveal diverse populations of bacteria living in water. In brief, in unsterilized natural river water, over 60 different species of bacteria were found. On the other hand, no PCR products were detected in drinking tap-water. The results from this study clearly indicate that the PCR-RFLP-sequence analysis can be a useful method for monitoring diverse, perhaps pathogenic bacteria contaminated in water in a rapid fashion.

• 원예과학기술지
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• 제32권3호
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• pp.400-407
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• 2014

도시농업은 정서적 안정뿐만 아니라 수확의 즐거움을 제공하는 곳으로, 생산되는 농산물의 안전성 확보가 요구되나 이에 대한 자료가 없다. 본 과제에서는 2012년 9월부터 10월 사이에 서울시내 도시텃밭 4곳과 옥상농원 6곳에서 채취한 배추 및 상추 260 표본을 대상으로 세균 및 기생충 오염수준을 정량적으로 혹은 정성적으로 평가하였다. 조사한 농산물에 부착되어 있는 총호기성균과 대장균군의 수는 각각 $6.1{\pm}0.8log\;CFU{\cdot}g^{-1}$(범위, $5.4{\pm}0.6-7.1{\pm}0.8log\;CFU{\cdot}g^{-1}$) 및 $4.0{\pm}0.7lo\;CFU{\cdot}g^{-1}$(범위, $2.3{\pm}0.6-6.1{\pm}0.9log\;CFU{\cdot}g^{-1}$)이었다. 대장균군은 전체 표본의 59.6%에서 발견되었다. 농산물별로 분석 시 배추와 상추의 총호기성균 및 대장균군 오염 수준은 유의한 차이를 보이지 않았으나, 농산물 재배 장소별로 분석 시 옥상농원에 비하여 도시텃밭에서 더 많이 검출되었다(p > 0.05). 대장균은 전체 야채의 3.1%에서 발견되었으며, 오염수준은 $1.5{\pm}0.2log\;CFU{\cdot}g^{-1}$이었다. 식중독 유발 세균 중 황색포도상구균은 조사한 농산물의 1.5%에서 검출되었으나, 그 외의 Salmonella spp., Listeria monocytogenes, E. coli 0157:H7은 모든 표본에서 검출되지 않았다. 또한 2개의 배추 표본(전체 농산물의 0.8%)에서 미확인된 기생충란이 발견되었다. 이상의 결과로 보아, 서울시내 도시농업으로 생산되는 농산물에서 세균학적 오염이 있는 것이 확인되어, 재배 과정 중 생물학적 오염을 줄이기 위한 노력이 요구된다.

• 대한미생물학회지
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• 제3권1호
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• pp.35-41
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• 1968

한국(韓國)에는 매년(每年) 상당(相當)한 수(數)의 장(腸)지브스유행(流行)이 발생(發生) 되고있으나 대부분(大部分)의 경우(境遇) 기기록(其記錄)이 없거나 혹(惑)은 지극(至極)히 미비(未備)한 사실(事實)을 부인(否認)할수가 없다. 1959년(年)에 김상태(金相泰) 고상균(高相均)은 1957년(年)에 발생(發生)된 경북(慶北)의 16례(例), 서울 맹아학교(盲啞學校)의 70례(例), 부산(釜山)의 60례(例), 묵호(墨湖)의 245례등(例等)과 1958년(年)에 발생(發生)된 전북연도(全北煙島)의 60례(例)를 요약(要約)한바 있으나 거창(居昌)(1954년(年)) 함양(咸陽)(1965년(年))및 단양(丹陽)(1966년(年)) 등(等)의 대유행(大流行)에 관(關)하여서는 별(別)로 기록(記錄)되어 있는바가 없다. 이러한 점(點)에 비추어 저자등(著者等)은 1967년(年)에 경남삼천포시(慶南三千浦市)에 발생(發生)된 장(腸)지브스 유행(流行)에 관(關)하여 조사(調査)한바 있으므로 이에 기록(記錄)하는 바이다. 1. 인구(人口) 54,064의 삼천로시(三千浦市)에 638명(名)의 환자(患者)가 발생(發生)하여 1,180/100,000이라는 고율(高率)의 이환율(罹患率)을 나타냈고 사망(死亡)은 1명(名)이었다. 2. 이 유행(流行)은 1967년(年) 9월초(月初)에 시작(始作)되어 동년(同年) 11월말(月末)에 종식(終熄)되었으나 최고환자발생시기(最高患者發生時期)는 9월중(月中) 제3주(第3週)였으며 계연유행곡선(繼燃流行曲線)은 10월중순(月中旬)까지 계속(繼續)되었다. 3. 감염경로(感染經路)는 수인성(水因性)이었으며 감염원(感梁源)은 진구(陳舊)된 정호(井戶)(갈때샘))이었다. 4. 원인균(原因菌)은 Salmonella typhi로 동정(同定)되었다. 5. 모든 환자(患者)와 보균자(保菌者)는 삼천포시(三千補市) 의사회(醫師會)의 감독하(監督下)에 재가치료(在家治療)되었다. 6. 조사기중(調査期中)에 1년전(年前)에 장(腸)지브스에 이환(罹患)되었든 3명중(名中)에서 1명(名)이 보균자(保菌者)로 나타났으며 Shigella flexneri에 의(依)한 이질환자(痢疾患者)도 1명(名) 검출(檢出)되었다. 7. 1967년(年) 11월(月) 삼천포시유행(三千補市流行)이 거의 끝날무렵 인접고성군(隣接固城郡)에도 장(腸)지브스발생(發生)이 보고(報告)되었으며 역시(亦是) Salmonella typei가 검출(檢出)되었다. 8, 1968년(年) 춘계(春季)에 실시(實施)된 전년도환자(前年度患者)에 대(對)한 보균자검색(保菌者檢索)에서 1건(件)의 보균자(保菌者)도 검출(檢出)되지 않았으며 1968년(年) 10월(月)까지의 보고(報告)에서는 1건(件)의 신환(新患)도 발생(發生)되지 않았다.