• 미생물학회지
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• 제49권2호
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• pp.126-130
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• 2013

원유시료에서 분리한 장알균속 세균 245균주의 항생제 내성에 관여하는 다중약물 유출 펌프 유전자 분포도와 항생제 내성 패턴을 연구하였다. 그 결과 245 장알균속 균주의 ampicillin에 대한 내성률은 44.1%, erythromycin에 대한 내성률은 79.2%, tetracycline에 대한 내성률은 76.3%, chloramphenicol에 대한 내성률은 36.3%였으며 vancomycin과 ciprofloxacin에 대해서는 모두 감수성임을 알 수 있었다. 내성 관련 유전자 중 MFS타입의 eme(A)는 82.1%의 장알균에 분포하였으며, ABC 타입의 유전자인 efr(A)는 72.7%, efr(B)는 77.1%, lsa는 71.8%의 장알균에 분포하였다. 특히 이러한 유전자의 기원 세균인 Enterococcus faecalis의 경우 eme(A)는 92.5%, efr(A)는 87.4%, efr(B)는 88.4%, lsa는 88.4%의 분포도를 나타내었다. 한편 동일한 장알균속이지만 종이 다른 장알균에서 eme(A)는 E. faecium 4균주, E. avium 7균주, E. durans 4균주 및 E. raffinosus 2균주에 분포하고 있었다. efr(A)는 E. faecium 2균주와 E. durans 2균주에 분포하였으며, efr(B)는 E. faecium 4균주, E. avium 5균주 및 E. durans 4균주에 분포하였다. 본 연구는 우리나라 원유시료에서 분리한 장알균속의 여러 종의 세균에서 동일한 다중약물 유출 펌프(multidrug efflux pump)의 분포에 대한 첫 번째 보고라 사료되며 E. faecalis 이외의 장알균속에서 이러한 유전자의 분포는 서로 다른 종간의 유전자의 수평적인 이동의 가능성을 시사한다.

• Journal of Microbiology and Biotechnology
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• 제15권6호
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• pp.1214-1220
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• 2005

Decreased porin-mediated outer membrane penetration of hydrophilic antibiotics is a common mechanism of antibiotic resistance in Gram-negative bacteria. This study was undertaken to determine whether a null mutation in Pseudomonas putida would suppress porin synthesis, and therefore reduce the susceptibility of the organism to streptomycin, norfloxacin, and tetracycline. Inverse PCR amplification and double-stranded DNA sequencing were used to identify chromosomal genes carrying TnphoA'-1 inserts. Genome database available was used to identify putative homologue genes, one of which encodes protein with homology to domains of the MutS of P. putida, suggesting a crucial role in the multidrug resistance. Increased resistance to streptomycin, norfloxacin, and tetracycline might be due to accumulation of compensatory mutations. Either no growth or slow growth was observed in P. putida KH1027 when grown in minimal medium containing gluconate, glucose, or citrate; however, it is not clear whether the growth patterns contributed to the multidrug resistance.

• 통합자연과학논문집
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• 제4권1호
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• pp.23-30
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• 2011

Multidrug resistance (MDR) is one of the main obstacles in the chemotherapy of cancer. MDR is associated with the over expression of P-glycoprotein (P-gp), resulting in increased efflux of chemotherapy from cancer cells. Inhibiting P-gp as a method to reverse MDR in cancer patients has been studied extensively, but the results have generally been disappointing. First-generation agents were limited by unacceptable toxicity, whereas second-generation agents had better tolerability but were confounded by unpredictable pharmacokinetic interactions and interactions with other transporter proteins. Third-generation inhibitors have high potency and specificity for P-gp. Furthermore, pharmacokinetic studies to date have shown no appreciable impact on drug metabolism and no clinically significant drug interactions with common chemotherapy agents. Third-generation P-gp inhibitors have shown promise in clinical trials. The continued development of these agents may establish the true therapeutic potential of P-gp-mediated MDR reversal.

• Journal of Microbiology and Biotechnology
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• 제6권3호
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• pp.219-220
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• 1996

The pKH2 isolated from the multidrug-resistant Staphylococcus aureus SA2 is a 40.98-kb plasmid and mediates resistance to ampicillin, clindamycin, erythromycin, kanamycin, and streptomycin. The 3.4-kb HindIII fragment conferring kanamycin resistance was cloned from the pKH2 into pBluescriptII $KS^+$ and partial sequence determination of that fragment was carried out. Sequence analysis revealed that the kanamycin resistance gene which encoded aminoglycoside 3'-phosphotransferase was linked to the streptothricin resistance gene. But a nonsense mutation was found in the streptothricin resistance gene and this mutation resulted in a truncated protein of streptothricin acetyltransferase. Homology comparison with nucleotide sequence databases revealed that the 3.4-kb HindIII fragment of pKH2 had been derived not from S. aureus but from Gram-negative Campylobacter coli.

• 대한의생명과학회지
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• 제11권2호
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• pp.115-119
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• 2005

A total of 28 Salmonella enterica serovar Typhimurium isolated from diseased pigs and swine carcasses between 2001 and 2003 were characterized by the antimicrobial resistance profiles, PCR for detection of S. Typhimurium DT104 and pulsed-field gel electrophoresis (PFGE) with the restriction enzyme XbaI. All but one isolate presented multidrug resistance (MDR) to more than two antibiotics tested. A total of 11 resistance profiles were observed, and two phenotypes, ST and ASSuTG, were the most common among them. Two isolates were found to be S. Typhimurium DT104 isolates by PCR, and their resistance profile did not show the DT104 typical resistance type ACSSuT, but ACSSuTGK instead. PFGE identified 11 banding patterns in dendrogram, and three main clusters (designated A to C) were represented. Interestingly, sixteen of 19S. Typhimurium isolates belonging to cluster B showed an identical band pattern.

• 한국미생물·생명공학회지
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• 제24권2호
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• pp.242-246
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• 1996

Hatomarubigins inhibited the growth of various cancer cell lines including multidrug-resistance cells. Hatomarubigins were found to potentiate the colchicine- and vinblastine-induced cytotoxicity against KB-C2 cell, but not the adriamycin-induced cytotoxicity against KB-C2 cells. Hatomarubigins didn't affect the sensitive KB cells. These results suggest that hatomarubigins are specific potentiators of colchicine. Among four hatomarubigins, hatomarubigin A sho- wed the highest synergestic effect on colchine-induced cytotoxicity. Similar effect of hatomarubigin A was found against V79/ADM cells.

• Bulletin of the Korean Chemical Society
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• 제30권4호
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• pp.779-780
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• 2009

• Natural Product Sciences
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• 제23권4호
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• pp.286-290
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• 2017

Multidrug-resistant Acinetobacter baumannii and Pseudomonas aeruginosa are highly dangerous nosocomial pathogens, cause the symptoms of skin infections, pressure sores, sepsis, blood stream and wound infections. Unfortunately, these pathogens are immune to the most common antibiotics, such as, carbapenem, aminoglycoside and fluoroquinolone. Therefore, it is imperative that new and effective antibiotics be developed. In the present study, the antimicrobial effects of Aloe vera MAP (modified Aloe polysaccharide) on Staphylococcus aureus and Bacillus subtilis, Escherichia coli and Enterobacter aerogenes, and clinical Pseudomonas aeruginosa and clinical Acinetobacter baumannii were comprehensibly investigated. Prior to the growth inhibition effect measurement and antibiotic disc diffusion assay on gram-positive and gram-negative bacteria and selected multidrug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii, antimicrobial resistance screening was performed for the multidrug-resistant bacteria obtained from clinical isolates. The results for showed the Aloe vera MAP had a concentration-dependent effect on all of examined bacteria, particularly on Pseudomonas aeruginosa. Anti-inflammatory and anti-oxidant experiments were also performed dose dependently effects to confirm the beneficial physiological effects of Aloe vera MAP.

• 한국산학기술학회논문지
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• 제12권11호
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• pp.5012-5018
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• 2011

1965년부터 1995까지 결핵의 전국적인 조사에 의하면, 한국에서 결핵의 발생과 약제 내성율은 감소하였지만 다재약제내성율의 유행은 여전히 심각한 문제이다. 본 연구의 목적은 2001 년부터 2008까지 대전에 약제 내성율과 성향을 조사하였다. 총 581건의 약제감수성 검사가 수행 되었으며 이중 하나이상의 항결핵제의 약물에 내성이 있는 경우가 104건(17.9%)이였고 적어도 INH에 내성이 있는 경우가 68건 (11.7 %), RFP내성이 41건(7.1 %)이였다. 단일 약제 내성율은 37건 (6.4 %) 분리되었으며 이들 중 INH에서 18건 (3.1 %) RFP에서 5건(0.9 %)이 분리 되었다. 적어도 isoniazid와 refampin에 내성인 다제내성결핵은 35건(6.0 %)에서 발견되었다. 그리고 MDR - TB와 관련된 나이요인에 40-60 세 포함되었다. 폐결핵의 약제내성율, 특히 MDR - TB의 약제내성율은 공공의료분야보다 민간 병원의 초치료 환자에서 높게 나왔다. 초기 약제내성은 일반적이며 약제감수성 검사는 이전 결핵 치료를 받지 않은 폐결핵 환자에 대해 유용성이 있다. 내성의 확산과 증가를 줄이기 위해 MDR - TB의 조기 진단과 함께 향상된 제어프로그램이 필요하다. 다제내성율은 여전히 한국에서 문제이다. 독립적으로 혹은 공공의료분야와 공동으로 다제내성율을 감소하기 위한 노력이 필요하다.

• 한국미생물·생명공학회지
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• 제46권2호
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• pp.135-144
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• 2018

The rapid increase in number and diversity of Extended Spectrum ${\beta}$-Lactamases (ESBLs) producing Enterobacteriaceae in natural aquatic environment is a major health concern worldwide. This study investigates abundance and distribution of ESBL producing multidrug resistant Enterobacteriaceae and molecular characterization of ESBL genes among isolates from highly polluted stretch of river Yamuna, India. Water samples were collected from ten different sites distributed across Delhi stretch of river Yamuna, during 2014-15. A total of 506 non duplicate Enterobacteriaceae isolates were obtained. Phenotypic detection of ESBL production and antibiotic sensitivity for 15 different antibiotics were performed according to CLSI guidelines (Clinical and Laboratory Standard Institute, 2015). A subset of ESBL positive Enterobacteriaceae isolates were identified by 16S rRNA gene and screened for ESBL genes, such as $bla_{CTX-M}$, $bla_{TEM}$ and $bla_{OXA}$. Out of 506 non-duplicate bacterial isolates obtained, 175 (34.58%) were positive for ESBL production. Susceptibility pattern for fifteen antibiotics used in this study revealed higher resistance to cefazolin, rifampicin and ampicillin. A high proportion (76.57%) of ESBL positive isolates showed multidrug resistance phenotype, with MAR index of 0.39 at Buddha Vihar and Old Delhi Railway bridge sampling site. Identification and PCR based characterization of ESBL genes revealed the prevalence of $bla_{CTX-M}$ and $bla_{TEM}$ genes to be 88.33% and 61.66%, respectively. Co-occurrence of $bla_{CTX-M}$ and $bla_{TEM}$ genes was detected in 58.33% of the resistant bacteria. The $bla_{OXA}$ gene was not detected in any isolates. This study highlights deteriorating condition of urban aquatic environment due to rising level of ESBL producing Enterobacteriaceae with multidrug resistance phenotype.