• Asian Pacific Journal of Cancer Prevention
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• 제14권12호
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• pp.7375-7379
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• 2013

The main aim of this study was to investigate the roles of GST-${\pi}$ and $pol{\beta}$ genes in the chemoresistance of esophageal carcinoma cells. Eukaryotic expression vectors containing each gene were constructed and transfected into EC9706 cells, and the biological effects of the two genes assessed based on a resistance index. We additionally investigated the in vitro and in vivo anti-resistance effects of GST-${\pi}$ and $pol{\beta}$ genes using recombinant lentiviruses carrying siRNAs against the two genes. Our results showed that upregulation of GST-${\pi}$ and $pol{\beta}$ genes suppresses chemosensitivity of esophageal carcinoma cells to cisplatin, while downregulation of these two genes with RNAi technology reverses this chemoresistance. Multi-site injection of recombinant lentivirus targeting the GST-${\pi}$ gene into transplanted cDDP tumors effectively reversed their chemoresistant phenotype. However, the same treatment against the $pol{\beta}$ gene did not lead to significant efficacy against chemoresistance.

• 한국동물위생학회지
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• 제29권3호
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• pp.297-308
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• 2006

Fowl typhoid (FT) is a septicemic disease caused by Salmonella gallinarum. The purpose of this study was to investigate the antimicrobial resistance and pulsed -field gel electrophoresis (PFGE) patterns of S gallinarum isolated from broiler. During 1999 to 2004, there was isolated a total of 26 strains in liver and spleen. The biochemical characteristics of S gallinarum isolates was nonmotile, no production of $H_2S$, glucose gas, non-fermented rhamnose, indole-negative, fermentation of dulcitol, mannitol, maltose, and ornithine decarboxylase. At antimicrobial susceptibility, all of isolates were susceptible to amoxicillin/clavulanic acid, amikacin, neomycin, kanamycin, and cephalothin. Twenty-six isolates were divided into 19 resistant patterns and 6 strains was 8-multi-drug resistance. PFGE of Xba I restriction fragments of S gallinarum isolates was 22 patterns.

• 한국동물위생학회지
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• 제32권2호
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• pp.155-163
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• 2009

Fowl typhoid (FT) is a septicemic disease caused by Salmonella Gallinarum. The purpose of this study was to investigate the antimicrobial resistance and pulsed-field gel electrophoresis (PFGE) patterns of S. Gallinarum isolated from chicken. During 1999 to 2004, there was isolated a total of 100 strains in liver and spleen. The biochemical characteristics of S. Gallinarum isolates was nonmotile, no production of H$_2$S, glucose gas, non-fermented rhamnose, indole-negative, fermentation of dulcitol, mannitol, maltose, and ornithine decarboxylase. At antimicrobial susceptibility, all of isolates were susceptible to amoxicillin/clavulanic acid, amikacin, neomycin, kanamycin, norfloxacin and enrofloxacin. One hundred isolates were divided into 54 resistant patterns and 37 strains was 6-multi drug resistance. PFGE of Xba I restriction fragments of S. Gallinarum isolates was 20 patterns.

• 한국동물위생학회지
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• 제36권2호
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• pp.111-119
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• 2013

The aim of this study was to investigate the isolation frequency and antimicrobial resistance of Escherichia coli (E. coli) and Enterococcus spp. from domestic beef and pork on sale in Seoul, Korea. A total of 106 (10.4%) E. coli and 114 (11.2%) Enterococcus spp. from 635 domestic beef and 381 pork samples were isolated and examined for susceptibility to 15 and 11 antimicrobial agents, respectively. The most frequent antimicrobial resistance observed in E. coli isolates was to ampicillin (38.6%), followed by streptocmycin (34.9%) and tetracycline (32.0%). The most frequent antimicrobial resistance in E. faecium isolates was to erythromycin (53.8%) and rifampin (46.1%), and in E. faecalis isolates was to tetracycline (55.7%) and rifampin (55.0%). Among the isolates, multi-drug resistant (MDR) E. coli and Enterococcus spp. strains showing resistances to more than two antimicrobial agents tested were 10.4% and 11.2%, respectively. As a result, appropriate protocols for antimicrobial agents and strategies to reduce antimicrobial resistance will be needed in future.

• Toxicological Research
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• 제24권1호
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• pp.29-36
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• 2008

The present study investigated the anti-proliferative and chemosensitizing effects of Crinum asiaticum var. japonicum against multi-drug resistant (MDR) cancer cells. The 80% methanol extract, chloroform ($CHCl_3$) fraction and butanol (BuOH) fraction of C. asiaticum inhibited the growth of mitoxantrone (MX) resistant HL-60 (HL-60/MX2) cells. When HL-60/MX2 cells were treated with the $CHCl_3$ and BuOH fractions, DNA ladder and sub-G1 hypodiploid cells were observed. Furthermore, the fractions reduced BcI-2 mRNA levels, whereas Bax mRNA levels were increased. These results suggest that the inhibitory effect of C. asiaticum on the growth of the HL-60/MX2 cells might arise from the induction of apoptosis. Treatment of HL-60/MX2 cells with the fractions markedly decreased the mRNA levels of the multi-drug resistance protein-1 and breast cancer resistance protein. The $CHCl_3$ fraction and hexane fraction increased MX accumulation in HL-60/MX2 cells. These results imply that the $CHCl_3$ fraction of C. asiaticum plays a pivotal role as a chemosensitizer. We suggest that components of C. asiaticum might have a therapeutic potential for the treatment of MDR leukemia.

• 한국임상수의학회지
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• 제34권5호
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• pp.335-340
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• 2017

Methicillin-resistant staphylococci (MRS), which are often multi-drug resistant (MDR), are important pathogens in both human and veterinary healthcare. The purpose of this study was to characterize the antimicrobial resistance of MRS isolated from dog ears in Korea. From 827 dog ears, staphylococci were cultured from both ears with otitis externa (n = 161, 41.0%) and healthy ears (n = 135, 31.1%). The prevalence of coagulase-positive staphylococci (CoPS) in ears with otitis externa (58.4%) was significantly higher (p < 0.05) than in healthy ears (28.2%), while the prevalence of coagulase-negative staphylococci (CoNS) in healthy ears (74.8%) was higher (P < 0.05) than in ears with otitis externa (41.6%). Forty-six (35.1%) and 74 (44.8%) CoPS and CoNS isolates, respectively, were determined to be MRS. Antimicrobial resistance in MRS was most frequently observed for penicillin (76.7%), ampicillin (61.7%), kanamycin (61.7%), erythromycin (47.5%), tetracycline (47.5%), and trimethoprim/sulfamethoxazole (46.7%). Overall, the MDR isolates were resistant to significantly more (P < 0.05) antimicrobial agents tested than methicillin-sensitive staphylococci in this study. These results provide therapeutic guidelines for the treatment of otitis externa in dogs from Korean veterinary hospitals, and the significant associated health concern to companion animals and their human contacts.

• 미생물학회지
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• 제51권4호
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• pp.440-443
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• 2015

임상과 자연환경에서 발견되는 항생제내성균의 문제는 보건학적 관심의 대상이 되고 있으며 환경 중의 미생물은 항생제 내성유전자 확산의 한 요인으로 판단되고 있다. 본 연구에서는 국내 하천 7지점으로부터 분리한 배양성 ampicillin 내성균의 다양성을 조사하였다. 분리된 498종의 세균들 중에서 Aeromonas와 Acidovorax 속의 내성균 분포가 가장 높았으며, 66%의 분리균들이 조사된 14종의 항생제 중 6종 이상의 항생제에 내성을 나타내었다. 그리고 7종의 항생제에 내성을 보이는 비율이 19.7%로 가장 높았다. 또한 항생제감수성 조사 결과를 바탕으로, 분포율이 높았던 Aeromonas, Acidovorax, Pseudomonas, Elizabethkingia 속의 내성균에 대한 자연내성 특징을 파악하였다.

• 미생물학회지
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• 제36권3호
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• pp.216-220
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• 2000

부산시 동아대학병원으로 내원한 83명의 환자 가건물로부터 methcillin 내성 Stphylococcus aureus(MRSA) 88 균주를 분리하고 응고 효소의 유형별 분석과 다약제 내성의 상호 관계를 연구하였다. 농(64.7%), 객담(26.2%), 기타 혈액, 장액 및 뇨로부터 균주가 분리되었고 mec A 유전자에 특이적인 primer 5'-AAAATCGATGGTAAAGGTT-GGC-3'와 5'-AGTTCTGCAGTACCGGATTTGC3'를 사용하여 PCR을 한결과 86균주에서 mec 유전자가 확인되었다. 응고효소형은 제 III형이 50%m IV형이 12.5%, III형이 6.8%, I, VII, VIII형이 4.5%로 제 II형이 가장 많았으며 제 V형은 전혀 분리되지 않았다. 응고효소형의 병동별 분포는 일반외과에서 제 II형이, 이비인후과 외래에서는 제 IV형이 우점종으로 분리되었다. 항균제 감수성 시험결과, vancomycin과 teicoplanin에서 전균주가 감수성을 나타내었었고 penionillin, cephalothin, erythromycin, gentamycin, imipenem, clindamycin, ciprofloxacin과 oxacillin등 8가지의 항균제에 대하여 동시내성을 나타낸 균주가 71주 (81%)였다. 항균제 내성과 응고효소형과의 상관관계는 없었다.

• 한국동물위생학회지
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• 제44권4호
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• pp.271-281
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• 2021

Pathogenic Escherichia coli (E. coli) is one among the most important agents of diarrhea in calves. From January to December 2021, 108 isolates from feces of calves with diarrhea were investigated for enterotoxigenic E. coli (ETEC), enteropathogenic E. coli (EPEC), shiga toxin-producing E. coli (STEC), enteroaggregative E. coli (EAEC), and enteroinvasive E. coli (EIEC) using real-time PCR. In addition, the genes for F5, F17 and F41 fimbriae were detected by PCR. The most frequently isolated pathotypes were EPEC/STEC (29 isolates), and ETEC/EPEC/STEC (29 isolates). ETEC/EPEC, and ETEC/STEC were also found in 10 isolates. EPEC, STEC, and ETEC were detected in 13, 11, and 6 respectively. EAEC, and EIEC was not detected. Antimicrobial resistance test was carried out by agar disc diffusion method with 14 antimicrobials. Among 108 pathogenic E. coli isolates, 107 isolates were resistant to at least one of 14 antibiotics used in this study, 99 (91.7%) were resistant to two or more antimicrobials, and a single remarkable isolate was resistant to 14 antimicrobials. The isolates were primarily resistant to penicillins, streptomycin, tetracycline, ceftiofur, Trimethoprim/sulfamethoxazole, Kanamycin, and Ciprofloxacin. The high rate of resistance in pathogenic E. coli, sometimes to multiple drugs, may complicate future options for treating human infections. These results may bu used for diagnosis and therpeitic purposes in calves with diarrhea.

• Asian Pacific Journal of Cancer Prevention
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• 제16권7호
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• pp.2839-2843
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• 2015

Background: MDR1, one of the most important drug-transporter genes, encodes P- glycoprotein (P-gp)-a transporter involved in protecting against xenobiotics and multi-drug resistance. The significance of the genetic background in childhood acute lymphoblastic leukemia (ALL) is not well understood. Materials and Methods: To evaluate whether C3435T and C1236T MDR1 polymorphisms are associated with the occurrence and outcome of ALL, 208 children with ALL (median age 5.0 yr) and 101 healthy Thai children were studied by polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) assay. Results: C3435T and C1236T MDR1 polymorphism are significantly associated with the high-risk group (OR= 2.6, 95%CI =1.164-5.808; P=0.028 and OR= 2.231, 95%CI =1.068-4.659; p=0.047, respectively), indicating that both may be candidates for molecular markers in the high-risk group of ALL.