• Journal of Microbiology and Biotechnology
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• 제25권5호
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• pp.709-717
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• 2015

Airborne bacteria from hog farms may have detrimental impacts on human health, particularly in terms of antibiotic resistance and pathogen zoonosis. Despite human health risks, very little is known about the composition and diversity of airborne bacteria from hog farms and hog-related spray fields. We used pyrosequencing analysis of 16S rRNA genes to compare airborne bacterial communities in a North Carolina hog farm and lagoon spray field. In addition, we isolated and identified antibiotic-resistant bacteria from both air samples. Based on 16S rRNA gene pyrosequence analysis, Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria were the dominant phyla in airborne bacterial communities from both hog farm and spray field sites. Within the Firmicutes genera, Clostridium spp. were more abundant in the hog farm, whereas Staphylococcus spp. were higher in the spray field. The presence of opportunitic pathogens, including several Staphylococcus species and Propionibacterium acnes, was detected in both bioaerosol communities based on phylogenetic analysis. The isolation and identification of antibiotic-resistant bacteria from air samples also showed similar results with dominance of Actinobacteria and Proteobacteria in both hog farm and spray field air. Thus, the existence of opportunistic pathogens and antibiotic resistant bacteria in airborne communities evidences potential health risks to farmers and other residents from swine bioaerosol exposure.

• International Journal of Oral Biology
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• 제38권2호
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• pp.61-65
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• 2013

Erythromycin is a macrolide antibiotic and inhibits bacterial protein synthesis by stimulating the dissociation of the peptidyl-tRNA molecule from the ribosomes during elongation. The use of macrolides has increased dramatically over the last few years and has led to an increase in bacterial resistance to these antibiotics. Bacterial resistance to erythromycin is generally conferred by the ribosome methylation and/or transport (efflux) protein genes. Among the identified erythromycin-resistant genes, erm(B) (erythromycin methylation) and mef(A) (macrolide efflux) are generally detectable in erythromycin-resistant streptococcal species. The distribution of these genes in oral streptococcal isolates has been reported in studies from other countries but has not been previously examined in a Korean study. We here examined by PCR the presence of erm(B) and mef(A) in oral streptococci isolated from Korean dental plaques. Among the 57 erythromycin-resistant strains tested, 64.9% harbored erm(B) whereas 40.4% were positive for mef(A). Eleven isolates had both the erm(B) and mef(A) genes. Twenty six isolates had only erm(B) and 12 isolates had only mef(A). Eight of the 57 strains examined were negative for both genes.

• 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
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• 제44권4호
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• pp.453-456
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• 2006

16 chicken isolates and four clinical isolates of VanB-vanA incongruent vancomycinresistant Enterococcus faecium strains without vanS were isolated in 1999. Pulsed-field gel electrophoresis revealed only a peripheral relationship between the chicken isolates and clinical isolates, but suggested clonal spread in the chicken isolates.

• 한국연초학회지
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• 제9권2호
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• pp.11-24
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• 1987

Lines were developed from the two crosses, BY4 X NC 82 and BY 4 X BY 104, by bulk, backcross and anther-derived dihaploid methods of breeding , and their variations in major agronomic, chemical characters, heritability, and response to selection were compared. 1. The anther-derived dihaploid lines showed a greater genetic variability and heritability in characters investigated than the lines developed by the other two methods of breeding . However, those were Inferior In agronomic characters and yielded 15.4% less leaf tobacco than the lines developed by the bulk method. 2. The lines developed by bulk method were higher In the frequency of lines resistant to bacterial wilt and in the yield, but Its lines appeared later flowering. inferior leaf Quality, and higher total nitrogen contents than those developed by the backcross method of breeding. 3. In the population of the lines developed by the backcross method, bacterial wilt resistant lines were less frequent, but the lines with a good leaf quality were more frequent.

• 보건의료산업학회지
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• 제8권4호
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• pp.163-173
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• 2014

This study was performed to investigate the current status of isolation precautions of multidrug resistant organisms(MDROs) in general hospitals with more than 200bed. The questionnaires were mailed from 3rd, April 2013 to 30th, April 2013. Methicillin resistant Staphylococcus aureus:(MRSA), vancomycin resistant Staphylococcus aureus:(VRSA), vancomycin resistant Enterococcus(VRE), multidrug-resistant Acinetobacter baumannii, carbapenem-resistant Enterobacteriaceae multidrug-resistant Pseudomonas aeruginosa were enrolled. MRSA(100.0%) and VRE(98.7%) were isolated respectively. VRE(97.3%) and MRSA(64.0%) were regulated strictly respectively. VRE(91.5%) and VRSA(50.7%) were isolated in a single room respectively. Hospital being located in Seoul(p<0.001), and beds(${\geq}600$)(p=0.008) were different significantly. The isolation space limitation(71.1%) was the highest difficulty. The development of refunding the costs of the extra supplies and other hygienic materials for infection control was discovered as the most urgent strategy.

• 한국응용곤충학회지
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• 제23권2호
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• pp.96-101
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• 1984

[ $1982\~1983$ ]년 사이에 한국인삼연초연구소 음성시험장의 세균성마름병 상습발병포지에서 이 병의 방제체계 확립을 위해 시험한 결과 1. 세균성마름병은 세균증식에 적합한 온도와 토양습도가 주어진 7월하순${\cdot}$8월하순에 가장 큰 피해를 나타냈으며 토양훈증제처리구 및 저항성품종재배구에서는 병발생이 적고 느리게 나타낮다. 2. 세균성마름병의 방제효과는 감수성품종인 NC23 26에 비하여 저항성품종인 NC82의 무처리재배의 경우 $44.7\%\~55.8\%$의 방제효과를 보았으며 토양훈증제처리에 저항성품종인 NC82를 재배 할 경우 $95\~99\%$의 방제효과를 보았다. 경종적처리에서는 무처리재배에 비하여 $0.8\~20\%$로 낮게 나타났으며 저항성품종이나 토양훈증제를 함께 사용 할 경우 그 상승효과는 거의 인정되지 않았다. 3. 세균성마름병의 종합적인 방제체계확립은 경종적처리(춘추경, 잔간근제거, 조기이식, 피복물제거)에 토양훈증(Cylon)를 10a당 40l 토양관주한 후 저항성 품종(NC82)을 재배할 때 $95\%$ 이상의 방제효과를 거둘 수 있었다.

• 한국임상수의학회지
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• 제32권2호
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• pp.158-161
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• 2015

세균성 피부염은 항생제 치료가 필요한 흔한 질환이다. 최근 항생제 내성 세균이 전 세계적으로 증가하고 있는 추세이다. 본 연구에서는 개 피부염 병변에서 분리한 S. pseudintermedius의 항생제 내성 유전자 발현을 조사하고, 이를 디스크 감수성 시험결과와 비교하였다. 총 7개의 S. pseudintermedius 균주가 연구에 포함되었다. 세균 동정은 16S rDNA 염기 서열 분석으로 실시하였다. 조사 결과 분리한 S. pseudintermedius 모두가 1개 이상의 항생제 내성유전자(mecA, blaZ and aac[6']/aph[2"])를 보유하였다. 전체 분리균주가 blaZ 유전자에 양성을 보였으나, 두 개 균주만이 amoxicillin/clavulanate에 내성을 나타냈다. Gentamicin 내성을 나타낸 5개 균주 중, 1개는 aac(6')/aph(2") 유전자에 대한 PCR 검사에서 음성을 나타냈다. 이 결과는 내성 유전자 검출 PCR 기법과 디스크 감수성 시험 기법이 항생제 내성을 검사하는 데에 있어 상호보완적인 관계를 가짐을 제시한다.

• 식물병연구
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• 제20권4호
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• pp.253-258
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• 2014

Ralstonia solanacearum에 의해 발생하는 토마토 풋마름병에 대하여 저항성 품종이나 육성계통을 선발하기 위하여 국립농업유전자원센터로부터 국내 유전자원을 분양받아 국내 병원균에 대한 저항성 여부를 평가하였다. 한국에서 분리된 R. solanacearum SL341 균주로 52개의 품종과 계통의 저항성을 Hawaii 7996 품종과 Moneymaker 품종을 각각 저항성, 감수성 대조품종으로 사용하여 저항성 반응을 평가하였다. 그 결과 32개의 품종이 감수성이며, 10개의 품종과 계통은 저항성이 고정되지 않은 품종으로 나타났다. 5개의 시판품종과 5개의 육성 계통이 저항성 반응을 보였다. 본 연구결과를 통해 5개의 육성 계통은 저항성/방어반응의 후속연구와 저항성 품종 육종에 활용할 수 있음을 제시한다.

• 식물병연구
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• 제15권3호
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• pp.198-201
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• 2009

국내에서 Ralstonia solanacearum에 의한 풋마름병은 토마토 재배에 심각한 피해를 주고 있다. 이에 풋마름병 발생의 감소와 방제를 위해서는 저항성 품종이 최선의 해결책으로 대두되고 있다. 따라서, 저항성으로 개발된 품종이 풋마름병 방제에 사용되어 지고 있다. 국내에서 시판되고 있는 완숙토마토 39품종, 방울토마토 21품종, 대목토마토 13품종에 대하여 저항성 품종을 선별하기 위해 Ralstonia solanacearum을 이용하여 저항성 검정을 실시하였다. 그중 37품종이 61-100%의 발병율로 감수성임을 알 수 있었고, 접종 10일안에 대부분 시들다가 고사되었다. 또한 24품종은 중도 저항성, 12품종은 풋마름병에 대해 저항성품종으로 확인되었다. 시판되는 73품종중 릴리앙스, TP-7, 초이스, 다다끼, 아끼꼬, 레드스타, 매치, Bblocking, 마그넷, 써포트, 프렌즈, 스페셜 품종이 풋마름병에 대해 높은 저항성을 나타내었다.