• Journal of Dairy Science and Biotechnology
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• 제17권1호
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• pp.58-71
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• 1999

This study was designed to investigate the health promotion effect of fermented milk and historical story of Korean dairy products from the ancient period to present. Although the origin of fermented milk is Europe, the recede of fermented milk was founded in far-east and middle east areas at BC 4C. After the spread of fermented milk to Korea and Japan. The consumption of fermented milk in Korea was dramatically increased to 14.2 kg per person in 1997. Health promotion effect of fermented milk can be devided to 5 major effected improvements of intestinal microflora, anticancer, cholesterol assimilation anti-pathogenic activity. Fermented milk reduced the level of ${\beta}$-glucornidase and nitroreductase to 50% and it provides anticancer activity by cell wall an polysaccharides. Fermented milk has cholesterol assimilation activity ca. 54${\sim}$40% (B. longum, Str. thermophillus). Anti-pathogenic activity of fermented milk was significant. It appeared that Sal. ser. typhimurium was more susceptible than 5. coli 0157 at low pH fermented milk. Viable cells of E. coli 0157 were not dramatically decreased in most of fermented milks tested, but in general, Sal. ser. typhimurium was drastically decreased in most of the fermented milks.

• Journal of Dairy Science and Biotechnology
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• 제38권4호
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• pp.197-206
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• 2020

This study was conducted to evaluate the antibacterial activity against Cronobacter sakazakii and Salmonella enteritidis as well as the sensory attributes of milk products supplemented with various concentrations (control, 0.5%, 1.0%, 1.5%, and 2.0%) of clove oil. In this study, clove oil was shown to have strong antibacterial activities. In addition, all the samples were assessed by ten researchers trained in five sensory attributes, namely, taste, flavor, color, texture, and overall acceptability. Compared to the control, 5% clove oil supplemented was the best in market milk, while in yogurt and kefir, 1.0% supplementation was the best. In terms of sensory attributes, the low score of color and flavor of market milk, yogurt, and kefir is attributed to the characteristics of the supplemented clove oil. Consequently, this study presents the possibility of producing bio-functional milk products supplemented with clove oil, and for controlling the growth of foodborne pathogenic bacteria in milk products using clove oil.

• Parasites, Hosts and Diseases
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• 제61권2호
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• pp.127-137
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• 2023

Bovine trypanosomiasis is a significant health concern for livestock intensification in Côte d'Ivoire. This study aimed to determine the prevalence and distribution of pathogenic trypanosomes and identify the most infected cattle breed in northern Côte d'Ivoire. We examined 700 cattle and found that polymerase chain reaction (PCR) was more sensitive (12.3%) than microscopic observation (5.6%). Among the trypanosome species detected in naturally infected cattle, Trypanosoma vivax was 7.3%, Trypanosoma simiae tsavo was 6.7%, and Trypanosoma congolense was 0.4%. The overall prevalence of trypanosome infection in all cattle breeds was 12.3%, while the prevalence in individual breeds was 14.8%, 7.3%, 10.6%, and 12.3% for N'Dama, Baoule, Zebu, and Mere breed, respectively. The infected animals had low packed cell volume, influencing the prevalence. Our findings indicate that bovine trypanosomes are prevalent in Côte d'Ivoire, and their prevalence varies by region and breed. These pathogens include T. vivax, T. simiae tsavo, and T. congolense.

• 대한의생명과학회지
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• 제29권4호
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• pp.256-262
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• 2023

The purpose of this study is to investigate microbial contamination in water purifiers from two universities (A and B) in Chungcheong region and to evaluate about the harmfulness of the isolated bacteria to the human. The degree of microbiological contamination of six water purifiers at university A was investigated three times from July 2018 to September 2019, and nine water purifiers at university B were investigated in 2023. The isolated bacteria were biochemically identified using an API kit and Vitek-2 system, and then the bacteria were identified to the species level using MALDI-TOF MS. In addition, the possibility of human infection of the isolated bacteria was evaluated through a literature search. In July 2018 and September 2019, the number of bacteria isolated inside the faucet was below the acceptable standard for hot water, but exceed for cold water in all water purifiers. In January and September 2019, bacteria exceeding the acceptable standards were isolated nine times from the cold water of six water purifies (a total of 12 water purifiers). Bacteria identified by MALDI-TOF MS included anaerobic bacteria (Clostridium novyi, Clostridium themopalmarium etc.), Gram-positive bacilli (Microbacterium testaceum, Arthrobacter woluwensis etc.), and Gramnegative bacilli (Acinetobacter nosocomialis, Comamonas kerstersii etc.), which are difficult identify by biochemical methods. In conclusion, bacteria exceeding the acceptable standard were isolated from the cold water of most of the water purifiers. Most of the isolated bacteria were low-pathogenic bacteria from natural environment, but opportunistic bacteria that can cause infection in humans were also isolated from some water purifiers.

• Journal of Plant Biotechnology
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• 제50권
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• pp.215-224
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• 2023

Disinfecting water containing pathogenic microbes is crucial to the food safety of fresh green agricultural products. The UV-activated peracetic acid (UV/PAA) treatment process is an efficient advanced oxidation process (AOP) and a versatile approach to disinfecting waterborne pathogens. However, its effects on plant growth remain largely unknown. This study found that low-dose UV/PAA treatment induced moderate oxidative stress but enhanced the innate immunity of Arabidopsis against Pseudomonas syringae pv. (Pst) DC3000. When applied as water sources, 5- and 10-ppm UV/PAA treatments slightly reduced biomass and root elongation in Arabidopsis seedlings grown under hydroponic conditions. Meanwhile, treatments of the same doses enhanced defense against Pst DC3000 infection in leaves. Accumulation of hydrogen peroxide and callose increased in UV/PAA-treated Arabidopsis samples, and during the post-infection period, UV/PAA-treated seedlings maintained vegetative growth, whereas untreated seedlings showed severe growth retardation. Regarding molecular aspects, priming-related defense marker genes were rapidly and markedly upregulated in UV/PAA-treated Arabidopsis samples. Conclusively, UV/PAA treatment is an efficient AOP for disinfecting water and protecting plants against secondary pathogenic attacks.

• 한국가금학회:학술대회논문집
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• 한국가금학회 2006년도 제23차 정기총회 및 학술발표회
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• pp.90-91
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• 2006

To reduce the economic impact and control Low pathogenic avian influenza (LPAI), vaccination with inactivated vaccine has been considered in this country. We tried to develop inactivated vaccine with reassorted H9N3 AI virus which has different type of neuraminidase compare to those of field AI virus. Before reassorted vaccine was produced, we confirm the virus as master seed by limiting dilution, RT-PCR and sequencing method. Also, we evaluate the biological characteristics of the virus to find out the possibility of prevention against field infection of AI virus. Finally, we evaluate the safety and efficacy of the vaccine made of reassorted AI virus in the specific pathogen free (SPF) chickens. After limiting dilution, we choose RV7CE4 as a vaccine candidate and compare the gene sequence of this vaccine strain to those of AI05GA which is parents strain. Compared to amino acid sequences of specific gene of AI05GA and RV7CE4, exhibited a high degree of amino acid sequence homology. In the safety and efficacy test, there were no specific clinical signs or mortality. Reassorted H9N3 viruses were reisolated in cloaca swab on 5 days post inoculation. In the vaccine study, once or twice vaccination was performed and challenged with H9N2 field virus (01310). Vaccine has no adverse effect on birds and formed good immune capability which reduce viral shedding in the birds infected with 01310. Based on the above result, we developed reassorted H9N3 vaccine which will efficiently prevent the low pathogenic AIV (H9N2) infection in the poultry farms.

• Journal of Microbiology and Biotechnology
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• 제23권9호
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• pp.1293-1303
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• 2013

Antibiotic resistance of soilborne Acinetobacter species has been poorly explored. In this study, norfloxacin resistance of a soil bacterium, Acinetobacter oleivorans DR1, was investigated. The frequencies of mutant appearance of all tested non-pathogenic Acinetobacter strains were lower than those of pathogenic strains under minimum inhibitory concentration (MIC). When the quinolone-resistance-determining region of the gyrA gene was examined, only one mutant (His78Asn) out of 10 resistant variants had a mutation. Whole transcriptome analysis using a RNA-Seq demonstrated that genes involved in SOS response and DNA repair were significantly up-regulated by norfloxacin. Determining the MICs of survival cells after norfloxacin treatment confirmed some of those cells were indeed persister cells. Ten colonies, randomly selected from among those that survived in the presence of norfloxacin, did not exhibit increased MIC. Thus, both the low mutation frequency of the target gene and SOS response under norfloxacin suggested that persister formation might contribute to the resistance of DR1 against norfloxacin. The persister frequency increased without a change in MIC when stationary phase cells, low growth rates conditions, and growth-deficient dnaJ mutant were used. Taken together, our comprehensive approach, which included mutational analysis of the target gene, persister formation assays, and RNA sequencing, indicated that DR1 survival when exposed to norfloxacin is related not only to target gene mutation but also to persister formation, possibly through up-regulation of the SOS response and DNA repair genes.

• 한국가금학회지
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• 제33권4호
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• pp.295-301
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• 2006

본 실험은 육계에서의 Marek's disease(MD) 백신에 대한 안전성과 효용성을 국내에 기 도입된 18일령 계란에서의 백신 접종 방법(In-Ovo vaccination)을 이용하여 평가하고자 실시하였다. 육계에서의 MD 오염율은 nested PCR을 이용하였으며 백신 접종군과 비접종군간의 생산성 차이를 출하 일령, 평균출하체중, 출하율, 사료 효율을 기본으로 하는 생산 지수를 측정하여 비교하였다. 백신에 의한 면역 억제 현상을 파악하기 위하여 접종 농장에서 채취한 혈청에서의 항체 역가수준과 F낭의 무게 변화를 검사하였다. 국내 육계에서의 MD 발생율을 파악하기 위하여 nested PCR을 실시한 결과 조사 대상 농장 중 26.09%가 오염되었으며, 백신 접종 농장과 비접종 농장간의 생산 지수의 차이는 통계학적으로 유의한 차이가 없었다. 그러나 MDV 오염군에서의 MD 백신 접종 농장의 생산 지수가 비접종 농장보다 높아 간접적으로 효과가 있음이 인정되었다. 면역 억제여부를 파악하기 위한 검사에서는 두 그룹 간 B/B ratio 차이는 없었으나 두 계군 모두 출하 시 심한 위축을 보여주어 혈청 검사 성적과 연계하여 볼 때 국내 육계 농장에서의 IBD 감염이 만연되어 있다는 것을 알 수 있었다. 본 연구를 통해서 국내 육계에서의 MDV 오염율이 파악되었으며, In-Ovo 백신 접종에 의한 MD 백신 접종은 안전성에 있어서는 별다른 문제가 없었으나 효능면에 있어서는 MD 야외감염율이 낮고 IBD와 같은 면역 억제 질병의 감염이 만연되어 있어 정확한 평가가 되지 않아 앞으로 후속 연구가 진행되어야 할 것으로 판단되었다.

• 생명과학회지
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• 제28권8호
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• pp.962-968
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• 2018

A형 인플루엔자바이러스는 야생조류에 존재하며, 사람, 돼지, 가금 및 다른 포유류등 다양한 숙주를 감염한다. 본 연구에서는, 2016년 한국 서쪽의 철새도래지에서 채취한 철새 분변에서 재조합된 새로운 H7N7 조류인플루엔자를 분리하였으며 이 바이러스의 8개 유전자를 분석하였다. 분리된 A/waterfowl/Korea/S017/2016(H7N7) 바이러스의 유전자 분석 결과 이 바이러스는 야생조류 및 가금 오리에서 유래한 조류인플루엔자로 구성된 재조합된 유전자를 가지고 있었다. 계통 분석결과 이 바이러스는 유럽과 아시아계에 속하였다. 조류인플루엔자 바이러스가 계속 진화를 하고 H7 형 조류인플루엔자는 고 병원성 조류인플루엔자로 변하여 사람과 동물에게 커다란 위협이 될 수 있기에 계속 된 역학조사가 필요하다.

• Journal of Animal Science and Technology
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• 제53권1호
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• pp.67-74
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• 2011

본 연구는 한우, 젖소, 돼지, 산란계 HACCP 적용 농장의 분변, 원유 및 사육환경에서 병원성세균 등 분석을 통하여 HACCP 적용 농장의 생물학적 위해 관리 실태를 파악하고자 하고 이를 농장 HACCP 시스템 적용에 관한 기초 연구 자료로 사용하는 것을 목적으로 하였다. 미생물 시료는 HACCP을 적용 중인 한우, 젖소, 돼지, 산란계농장의 축사바닥분뇨, 퇴비사, 원유탱크, 집란기, 분변 벨트 등에서 채취 하였으며 축산식품의 생물학적 위해인 Pathogenic E. coli, Salmonella spp. S. aureus 등을 분석하였다. 각 축종별 대장균은 분변에서 100% 검출되었으나 Salmonella spp.는 검출되지 않았다. 또한 젖소농장의 원유 냉각기에서도 S. aurues가 검출되지 않았다. 그러나 돼지농장의 돈사바닥 및 퇴비장에서는 검사건수 30건당 각각 2건, 1건의 Salmonella spp.가 검출되었다. 마찬가지로 산란계농장의 계사바닥 및 분변벨트에서도 전체분석 건수 대비 10~20%의 Salmonella spp.가 검출되었다. 이러한 결과는 문헌상 보고되고 있는 일반축산농가의 병원성세균 관리실태와 간접 비교하였을 경우 HACCP 시스템을 적용중인 축산농가에서의 일반축산농가보다 병원성 세균관리가 더욱 철저히 이루어지고 있는 것으로 판단된다.