• 한국가금학회지
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• 제31권1호
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• pp.37-44
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• 2004

It has been recognized that the hen, like its mammalian counterparts, provides young chicks with antibodies as protection against hostile invaders. This system facilitates the transfer of specific antibodies from serum to egg yolk, and provides a supply of antibodies called immunoglobulin Y(IgY) to the developing embryo and the hatched chick. The protection against pathogens that the relatively immune-incompetent newly hatched chick has, is through transmission of antibodies from the mother via the egg. Egg yolk, therefore, can be loaded with a large amount of IgY against pathogens which can immobilize the existing or invading pathogens during the embryo development or in day-old chicks. Thus, the immunization of laying hens to various pathogens results in production of different antigen-specific IgY in eggs. Egg yolk contains 8∼20 mg of jmmunoglobulins (IgY) per ml or 136∼340 mg per yolk suggesting that more than 30 g of IgY can be obtained from one immunized hen in a year. By immunizing laying hens with antigens and collecting IgY from egg yolk, low cost antibodies at less than $10 per g compared to more than $20,000 per g of mammalian IgG can be obtained. This IgY technology opens new potential market applications in medicine, public health, veterinary medicine and food safety. A broader use of IgY technology could be applied as biological or diagnostic tool, nutraceutical or functional food development, oral-supplementation for prophylaxis, and as pathogen-specific antimicrobial agents for infectious disease control. This paper has emphasized that when IgY-loaded chicken eggs are produced and consumed, the specific antibody binds, immobilizes and consequently reduces or inhibits the growth or colony forming abilities of microbial pathogens. This concept could serve as an alternative agent to replace the use of antibiotics, since today, more and more antibiotics are less effective in the treatment of infections, due to the emergence of drug-resistant bacteria.

• 대한약침학회지
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• 제22권1호
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• pp.49-54
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• 2019

Objective: Antibiotic resistance is a global health problem and threatens health of societies. These problems have led to a search for alternative approaches such as combination therapy. The aim of the present study was to investigate the effect of caffeine and omeprazole in combination with gentamicin or ciprofloxacin against standard and clinically resistant isolates of Staphylococcus aureus and Escherichia coli. Methods: The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of different agents against bacterial strains were determined. The interaction of non- antibiotic drugs with gentamicin and ciprofloxacin was studied in vitro using a checkerboard method and calculating fraction inhibitory concentration index (FICI). Verapamil as efflux pump inhibitor was used to evaluate the possible mechanism of bacterial resistance to antibiotics. Results: The MIC and MBC values of gentamicin against bacterial strains were in the range of $20-80{\mu}g/ml$ and $40-200{\mu}g/ml$, respectively. Caffeine and omeprazole had no intrinsic inhibitory activity against tested microorganisms. However, upon combination of caffeine with antibiotics, the synergistic effects were observed. Verapamil was able to reduce the MIC values of gentamicin (4 folds) only in some bacterial strains. Conclusion: These findings indicated that caffeine was effective in removing bacterial infection caused by S. aureus and E. coli. The relevant mechanisms of antibiotic resistance were not related to the drug efflux.

• Journal of Microbiology and Biotechnology
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• 제29권6호
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• pp.863-876
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• 2019

Farm animals such as piglets are often affected by environmental stress, which can disturb the gut ecosystem. Antibiotics were commonly used to prevent diarrhea in weaned piglets, but this was banned by the European Union due to the development of antibiotic resistance. However, the use of probiotics instead of antibiotics may reduce the risk posed by pathogenic microorganisms and reduce the incidence of gastrointestinal diseases. Therefore, this study was conducted to investigate the effects of Lactobacillus casei Zhang on the mechanical barrier and immune function of early-weaned piglets infected using Escherichia coli K88 based on histomorphology and immunology. Fourteen-day-old weaned piglets were divided into a control group and experimental groups that were fed L. casei Zhang and infected with E. coli K88 with or without prefeeding and/or postfeeding of L. casei Zhang. The L. casei Zhang dose used was $10^7CFU/g$ diet. Jejunum segments were obtained before histological, immunohistochemical, and western blot analyses were performed. In addition, the relative mRNA expression of toll receptors and cytokines was measured. Piglets fed L. casei Zhang showed significantly increased jejunum villus height, villus height-crypt depth ratio, muscle thickness, and expression of proliferating cell nuclear antigen and tight junction proteins ZO-1 and occludin. The use of L. casei Zhang effectively reduced intestinal inflammation after infection. We found that L. casei Zhang feeding prevented the jejunum damage induced by E. coli K88, suggesting that it may be a potential alternative to antibiotics for preventing diarrhea in early-weaned piglets.

• 융합정보논문지
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• 제11권6호
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• pp.198-205
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• 2021

본 배경 : 질염은 항생제를 복용하는 방식으로 치료를 하고 있으며, 이러한 항생제의 지속적인 치료는 내성을 유발할 수 있다. 연구 방법 : Lactic acid bacteria 2종에 에센셜 오일을 이용한 항균 활성을 보고자 한다. SE(Grapefruit Seed Extract), eucalyptus, tea tree, clove bud oil, cinnamon oil, lemongrass oil, thyme oil, ginger oil을 일정 비율로 넣어 배양 후, 병원성 미생물- E. coli, C. albicans와 Lactic acid bacteria은 균주에 맞는 배지를 사용하여 균 수를 측정하였다. 결과 : Essential oil 7종과 GSE가 병원성 미생물에 억제 효과가 있으며, 병원성균(E. coli, C. albicans)에 대한 Grapefruit seed extract(GSE)의 억제농도를 확인하였다, 병원성균은 억제하고 Lactic acid bacteria는 억제하지 않는 배합비도 확인하였다(GSE 농도가 200ppm에서 Eucalyptus globulus(EG) oil 50㎕와 Melaleuca alternifolia oil(Tea tree oil, TTO) 50㎕(pH 5.0, 5.5, 6.0)). 결론 : 본 실험에서 Essential oil은 다양한 항균 활성 가지고 있어 항생제 대안으로도 생각할 수 있으며, 장기 항생제 치료환자에 대한 보조 항균제로서도 유용할 것으로 생각된다.

• Journal of Animal Science and Technology
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• 제64권6호
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• pp.1092-1104
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• 2022

Using antibiotics as growth promoter has been banned in poultry feed industry, thus various researchers try to seek an alternative to replace the growth-promoting antibiotics. In this study, we aimed to evaluate the growth performance via intestinal nutrient utilization and cecal microbial composition of broiler after dietary supplementation with most commonly using antibiotics, zinc bacitracin, and sophorolipid. A total of 180 1-day-old chicks were randomly assigned, and dietary treatment was as follow: CON, basal diet; ZB, 100 ppm of zinc bacitracin supplemented diet; and SPL, 250 ppm of sophorolipid supplemented diet. Their growth performance was evaluated and the samples of blood, small intestine, and ileal and cecal digesta were collected for biochemical, histological, and genomic analyses. The body weight and average daily gain of 7-day-old chicks were higher in ZB and those in overall experimental period were improved by ZB and SPL supplementation (p < 0.05). Their intestinal characteristics were not affected by dietary treatments in duodenum and ileum. Nonetheless, villus height was increased by SPL supplementation in jejunum (p < 0.05). Moreover, dietary SPL supplementation could down-regulate the expression level of pro-inflammatory cytokine, IL-1β (p < 0.05). mRNA levels of lipid and protein transporters did not differ among the treatments, however, relative expression levels of carbohydrate transporters, GLUT2 and SGLT1 were increased in broiler chicken's jejumum fed zinc bacitracin and sophorolipid supplemented diets (p < 0.05). Dietary zinc bacitracin supplementation could increase the population of Firmicutes in phylum level, and the portion of Turiciacter in genus level. On the other hands, the portion of Faecalibacterium was increased by dietary SPL supplementation compared to the other treatments. Our findings suggest that SPL supplementation improves growth performance through enhanced carbohydrate utilization capacity via improvement of gut morphological status and modulation of the cecal microbial population of broilers.

• Restorative Dentistry and Endodontics
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• 제45권4호
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• pp.50.1-50.11
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• 2020

Objectives: In this study, we investigated the potential of amoxicillin-loaded polymeric microspheres to be delivered to tooth root infection sites via a bioactive reparative cement. Materials and Methods: Amoxicillin-loaded microspheres were synthesized by a spray-dray method and incorporated at 2.5% and 5% into a mineral trioxide aggregate cement clinically used to induce a mineralized barrier at the root tip of young permanent teeth with incomplete root development and necrotic pulp. The formulations were modified in liquid:powder ratios and in composition by the microspheres. The optimized formulations were evaluated in vitro for physical and mechanical eligibility. The morphology of microspheres was observed under scanning electron microscopy. Results: The optimized cement formulation containing microspheres at 5% exhibited a delayed-release response and maintained its fundamental functional properties. When mixed with amoxicillin-loaded microspheres, the setting times of both test materials significantly increased. The diametral tensile strength of cement containing microspheres at 5% was similar to control. However, phytic acid had no effect on this outcome (p > 0.05). When mixed with modified liquid:powder ratio, the setting time was significantly longer than that original liquid:powder ratio (p < 0.05). Conclusions: Lack of optimal concentrations of antibiotics at anatomical sites of the dental tissues is a hallmark of recurrent endodontic infections. Therefore, targeting the controlled release of broad-spectrum antibiotics may improve the therapeutic outcomes of current treatments. Overall, these results indicate that the carry of amoxicillin by microspheres could provide an alternative strategy for the local delivery of antibiotics for the management of tooth infections.

• 한국어병학회지
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• 제37권1호
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• pp.133-138
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• 2024

This study is a report on combinational effects between four sesquiterpene lactones (SLs) from bay laurel (Laurus nobilis) leaves, and oxytetracycline (OTC) or amoxicillin (AMX) against four fish pathogenic bacteria such as Vibrio anguillarum, V. harveyi, Edwardsiella tarda, and Streptococcus iniae. Individually, four SLs exerted little antibacterial activity against fish pathogenic bacteria. However, when combined with OTC or AMX, they showed synergistic interaction against pathogenic bacteria. Especailly, zaluzanin C (1) reduced the MIC of OTC (or AMX) eight-fold. Our results showed that combinations of SLs with antibiotics (ABTs) are more effective than ABTs alone to control pathogenic bacteria. The highest synergistic effect was observed when zaluzanin C (1) was combined with OTC or AMX against V. harvey or S. iniae, displaying significant reductions of MICs up to 8-fold (0.125 to 0.015 ㎍/mL and 0.0078 to 0.0009 ㎍/mL). In addition, zaluzanin C (1) improved the antibiotic potency of OTC against OTC resistant V. harveyi (250 ㎍/mL to 62.5 ㎍/mL). Synergism between ABTs and phytochemical such as SLs could be a therapeutically helpful concept to improve the efficacy of ABTs and prevent antibiotic resistance. These results suggest that SLs can be used as an alternative to reduce antibiotic resistance in aquaculture.

• Asian-Australasian Journal of Animal Sciences
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• 제19권12호
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• pp.1784-1789
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• 2006

Two experiments were conducted to determine the effect of phytobiotics and organic acids on growth performance of nursery pigs as an alternative to antibiotics. Phytobiotics refer bioactive compounds from plant materials including essential oils and herbal extracts. In Exp. 1,144 pigs, weaned at 23.4${\pm}$0.3 d age, were allotted to three dietary treatments. Treatment diets were: 1) NC (no antibiotics and no phytobiotics); 2) PC (NC+carbadox, 50 mg/kg); and 3) PB (NC+phytobiotics; 0.1% PEP1000-$1^{(R)}$. Each treatment had six replicates with eight pigs per pen. Pigs were fed the experimental diets for 5 wks in 3 phases (phase 1 for 2 wk; phase 2 for 2 wk; phase 3 for 1 wk). In Exp. 2, 192 pigs, weaned at 19.2${\pm}$0.3 d age, were allotted to three dietary treatments: 1) NC; 2) PC; and 3) PBO (NC+phytobiotics; 0.2% or 0.1% PEP1000-$1^{(R)}$ and organic acids; 0.4% or 0.2% $Biotronic^{(R)}$for the phase 1 and 2, respectively) with eight replicates per treatment and eight pigs per pen. Pigs were fed the assigned diets for 5 wks in 2 phases (phase 1 for 2 wk; phase 2 for 3 wk). Body weights were measured at the beginning of the experiment and at the end of each week in both Exp. 1 and 2. Feed intake was measured at the end of each week in both Exp. 1 and 2. Diarrhea score was measured daily during the entire period for Exp. 1 and during the phase 1 for Exp. 2. In Exp. 1, the PC had a higher (p<0.05) overall ADG than the NC, but the overall ADG of the PB did not differ (p>0.05) from the NC or the PC. In Exp. 2, the overall ADG did not differ (p>0.05) among all the treatments during the entire experimental period. The overall ADFI and the overall gain:feed ratio did not differ (p>0.05) among all the treatments during the entire experimental period in both Exp. 1 and 2. The PC had a higher (p<0.05) overall diarrhea score (harder stools) than the NC and the PB in Exp. 1, and a higher (p<0.05) overall diarrhea score than the NC in Exp. 2. The overall diarrhea score of the PB and the PBO did not differ (p>0.05) from the NC or the PC in Exp. 1 and 2. Results from this study show that the growth of pigs fed the diets with phytobiotics or the combination of phytobiotics and organic acids did not differ from those both with antibiotics and without antibiotics when tested in an environmentally controlled research facility. Further experiments are required to study the growth performance in disease challenged conditions.

• International journal of advanced smart convergence
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• 제11권4호
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• pp.227-239
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• 2022

Purpose: In our study, in order to find lactic acid bacteria (LAB) with multi-drug resistance to antibiotics, we isolated 140 strains from 15 types of kimchi commercially available in Korea and 20 types of Kimchi made at home from January to December in 2016, and investigated their H₂O₂ generating ability and multi-drug resistance to antibiotics. Methods: In order to observe the H₂O₂ generation ability of LAB, we performed the experiment with methods such as Rabe, Hillier, and Kang. To test the antibacterial susceptibility of LAB, we used the disc agar diffusion method using MRS agar (Difco, USA) according to the CLSI and WHO test methods. There are 18 types of antibiotic discs used. Results: Out of the total numbers of 140 strains, 6 strains of Ent. Faecium, 25 strains of L. plantarum, 1 strain of L. rhamnosus, 3 strains of L. sakei, 1 strain of L. acidophilus, 1 strains St. thermophilus, and 7 of unidentified strains generated H₂O₂. The antibiotic susceptibility of Ent. Faecium indicated SXT, OX, NA, and E; and the antibiotic susceptibility of L. plantarum indicated NA; and the antibiotic susceptibility of St. thermophilus indicated NA, CC, RA, CTT, CM, and P ; and the antibiotic susceptibility of L. rhamnosus indicated SXT, VA, NA and CTT; and the antibiotic susceptibility of 6 strains of L. sakei indicated SXT, OX, NOR, NA, CTT and CIP, all indicating antibiotic resistance. In the case of multi-drug resistance to antibiotics for 53 strains of L. antarum, 8-drug resistance was the most common with 25 strains, followed by 7-drug-resistant strains with 18 strains, 9-drug-resistant strains with 4 strains, 6-drug-resistant strains with 3 strains, 5-drug-resistant strains with 2 strains, and 17-drug-resistant strains with 1 strain. In the case of multi-drug resistance to antibiotics for Ent. Faecium 27 strains, 9-drug resistance was most commonly identified as 9 strains, 8-drug resistance was identified as 6 strains, 7- and 11 drug resistances were identified as 4 strains each, and 4- and 6-drug resistances were identified as 1 strain each. Conclusion: Ent. Faecium, L. plantarum, L. rhamnosus, L. sakei, and St. thermophilus, shown to have anantibacterial activity in previous studies on LAB and shown to have and H₂O₂ generating ability, antibiotic resistance and multi-drug resistance in this study, are expected to be able to play an excellent role for long-term inpatients to use as an alternative to antibiotics and to cope with emerging antibiotic resistance.

• Journal of Animal Science and Technology
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• 제49권5호
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• pp.611-620
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• 2007

1950년대 이후 어린 가축의 성장 촉진과 사료효율을 개선하고 축산물의 생산효율을 향상시킬 목적으로 penicillin, bacitracin 등과 같은 항생제가 사료첨가제로서 널리 사용되어 왔다. 항생제의 작용기전은 먼저 가축체내에 존재하는 살모넬라, 대장균, 클로스트리디움 등과 같은 장내 병원성균의 세포막을 분해하여 사멸시키고(Leitner 등, 2001) 소장 흡수세포벽을 얇게 하여 영양소의 흡수율을 증대시켜 성장을 촉진시킨다고 알려져 있다(Ravindran 등, 1984; Collington 등, 1990). 그러나 가축 생산성 증대와 같은 긍정적인 효과에도 불구하고 항생물질이 고기, 우유, 계란 등의 축산물에 잔류될 수 있다는 점과 축산물을 통하여 섭취된 항생물질이 인체의 내성을 증가시켜 항생물질에 대하여 저항성을 나타낼 수 있다는 일부 부정적인 효과가 밝혀지면서 최근 항생제의 사용에 문제점이 제기되고 있다(Lee 등, 2001). 스웨덴, 덴마크 등과 같은 유럽 국가들을 중심으로 가축 사료첨가제로서 항생제 사용이 금지 또는 극도로 제한되고 있다. 최근 이와 같은 시대적 흐름에 따라 사료에 첨가되는 항생제를 53종에서 25종으로 대폭 축소하고, 2012년 농장에 대한 HACCP 제도를 도입하는 등 사료 위생관리를 엄격히 관리하는 단계로 접어들면서, 항생제를 대치 할 수 있는 대체제제에 대한 연구가 절실히 요구된다. 따라서 축산식품 소비자는 물론 생산자를 위해서도 사료에 첨가되는 항생제를 대체할 수 있는 안전성이 확보된 후보 물질의 연구 개발 및 효능 연구는 미래 지속가능한 동물산업을 위해 필연적으로 해결해야만 하는 향후의 숙제이다. 이러한 사실과 더불어 국민소득이 증가함에 따라 웰빙에 대한 관심 고조로 동물성 식품에 대한 선호도가 양 보다는 질 위주로 급격하게 변화되고 있어 천연자원을 이용한 다양한 항생제 대체 사료첨가제의 개발이 주목을 받고 있는바, 본 연구에서 사용된 매실(Prunus mume)은 섬유소, 탄닌과 무기물이 풍부하고 시트릭산(구연산) 등을 포함한 각종 유기산이 다량 함유된 것으로(임, 1999), 한방과 민간에서 잎, 청매(미성숙 매실)는 살균, 구충, 해독, 해열 등과 같은 다양한 효과를 나타내는 한약제로 널이 이용되고 있다. 매실의 효능은 다양한 연구에서 항균작용(이 등, 2003), 항산화작용(한 등, 2001), 간 기능 증진(서 등, 1990) 등의 효과들이 과학적으로 검정되었다. 특히 매실의 항균작용 연구에서 매실추출물로서 paper disc법으로 항균작용을 조사한 결과 그람(+) 세균인 Micrococcus leteus, Bacillus subtilis, Staphy- lococcus aureus 등과 그람(－) 세균인 E. coli. Salmonella typhimurium, Proteus vulgaris 등에 효과적인 저해 활성을 나타내었다(임, 1999; 이 등, 2003). 또한 유기산의 일종은 유산(lactic acid)은 이미 위장관의 환경을 긍정적으로 조절하여 가축 사료첨가제로서 상당히 많이 이용되고 있다(van de Broek, 2000). 그러나 장관내 환경조절물질로서 고품질의 축산물을 생산할 수 있는 천연 소재인 매실 또는 그 부산물을 이용하여 가축 사료첨가제로서의 가능성을 과학적으로 연구한 사례는 극히 일부분에 지나지 않고 있다. 따라서 본 연구는 매실추출 혼합물의 in vitro 항균효과를 검정하고 이를 근거로 육계사료에 위장관 환경조절제로서 매실추출물 및 유산(lactic aicd) 그리고 항산화제로서 포도씨앗추출물을 혼합한 제제를 급여하여 성장 및 사료효율, 혈액성상, 소장의 소화 효소 활성도 및 세균총에 미치는 작용에 대하여 조사하여 항생제 대체제로서의 가능성에 대한 연구를 실시하였다.