• 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.

• 한국식품영양학회지
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• 제26권1호
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• pp.132-136
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• 2013

Antimicrobial resistance and multi-drug resistance patterns have been carried out on total of 210 isolated of Salmonella spp. and pathogenic E. coli isolated from food poisoning patients on January through December 2012 in Incheon, Korea. The highest percentage of antibiotics resistance was found to the following antimicrobial agents: tetracycline 43.8%, ampicillin 34.8%, nalidixic acid 23.8%, sulfamethoxazole/trimethoprim and chloramphenicol 12.4%, and ampicillin/sulbactam 11.4%. The highest percentage of resistance was 37.5% to ampicillin for Salmonella spp. and 59.0% to tetracycline for pathogenic E. coli. Overall the multidrug resistance rates of 1 drug was 26.2%, 2 drugs 9.0%, 3 drugs 9.5%, 4 drugs 7.1%, and 5 or more drugs 12.46%. The multi-drug (MDR) strains to four or more antimicrobial agents among the resistant organisms were quite high: 15.9% and 22.1% for Salmonella spp. and pathogenic E. coli, respectively. The study implies that limitation of unnecessary medication use is pertinent in order to maintaining the efficacy of drugs.

• Clinical and Experimental Pediatrics
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• 제52권5호
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• pp.529-537
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• 2009

Drug-resistant tuberculosis in children has important implications for both the patients and tuberculosis control programs. In Korea, among all new patients, the isoniazid resistance rate was 9.9% and multidrug-resistant tuberculosis rate was 2.7% in 2004 (in patients aged 10-19 yr, the multidrug-resistant tuberculosis rate reached 2.1%). Tuberculosis in pediatric patients is difficult to diagnose because many children have nonspecific clinical signs and the detection rates of acid-fast bacilli smears and cultures are low. Therefore, every effort should be made to identify adult sources and obtain information on drug susceptibility because symptomatic adult patients have a higher chance of culture positivity and drug-susceptibility patterns are the same in most adult-child pair patients. Korean children are at significant risk of drug-resistant tuberculosis. As the isoniazid resistance rate is greater than 4% among the new cases in Korea, a four-drug regimen should be considered for initial treatment of children with active tuberculosis, unless drug-susceptibility test results are available. Treatment of drug-resistant tuberculosis in children is challenging and there are only few available data. Tuberculosis control programs should be continuous with specific focus on pediatric populations because they can serve as reservoirs for future active cases. Further studies are needed regarding treatment of drug-resistant tuberculosis in children.

• Journal of Microbiology
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• 제45권1호
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• pp.64-68
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• 2007

In this study we examined the multi-drug resistance profiles of the tetracycline (TC) resistant genus Vibrio to determine its susceptibility to two ${\beta}-lactams$, ampicillin (ABPC), and mecillinam (MPC), as well as to macrolide, erythromycin (EM). The results showed various patterns of resistance among strains that were isolated from very close geographical areas during the same year, suggesting diverse patterns of drug resistance in environmental bacteria from this area. In addition, the cross-resistance patterns suggested that the resistance determinants among Vibrio spp. are acquired differently within the sediment and seawater environments.

• Molecules and Cells
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• 제25권1호
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• pp.119-123
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• 2008

Pyrimidine antagonists including 5-Fluorouracil (5-FU) have been used in chemotherapy for cancer patients for over 40 years. 5-FU, especially, is a mainstay treatment for colorectal cancer. It is a pro-drug that is converted to the active drug via the nucleic acid biosynthetic pathway. The metabolites of 5-FU inhibit normal RNA and DNA function, and induce apoptosis of cancer cells. One of the major obstacles to successful chemotherapy is the resistance of cancer cells to anti-cancer drugs. Therefore, it is important to elucidate resistance mechanisms to improve the efficacy of chemotherapy. We have used C. elegans as a model system to investigate the mechanism of resistance to 5-FU, which induces germ cell death and inhibits larval development in C. elegans. We screened 5-FU resistant mutants no longer arrested as larvae by 5-FU. We obtained 18 mutants out of 72,000 F1 individuals screened, and mapped them into three complementation groups. We propose that C. elegans could be a useful model system for studying mechanisms of resistance to anti-cancer drugs.

• Food Science and Biotechnology
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• 제15권3호
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• pp.339-340
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• 2006

The pattern of drug resistance and incidence of R-factors were studied in Shigella sonnei as food-borne pathogen strains isolated from chicken meat in Iran. In this study we examined for transferring R-factors of S. sonnei to sensitive Escherichia coli $k_{12}{\bar{F}}(\lambda)$. The results showed that 19 out of 57 strains (33.3%) were resistant to one or more drugs and multiple drug resistance was more common than single drug resistance. The most predominant pattern of resistance observed was Tetracycline (Tc), Chloramphenicol (Cm), Streptomycin (Sm), and Sulfonamide (Su). 100% of the strains from the Caspian littoral transferred at least a part of their resistance pattern to sensitive E.coli $k_{12}{\bar{F}}(\lambda)$.

• Biomolecules & Therapeutics
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• 제31권2호
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• pp.141-147
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• 2023

Antibiotic resistance has emerged as a global threat to modern healthcare systems and has nullified many commonly used antibiotics. β-Lactam antibiotics are among the most successful and occupy approximately two-thirds of the prescription antibiotic market. They inhibit the synthesis of the peptidoglycan layer in the bacterial cell wall by mimicking the D-Ala-D-Ala in the pentapeptide crosslinking neighboring glycan chains. To date, various β-lactam antibiotics have been developed to increase the spectrum of activity and evade drug resistance. This review emphasizes the three-dimensional structural characteristics of β-lactam antibiotics regarding the overall scaffold, working mechanism, chemical diversity, and hydrolysis mechanism by β-lactamases. The structural insight into various β-lactams will provide an in-depth understanding of the antibacterial efficacy and susceptibility to drug resistance in multidrug-resistant bacteria and help to develop better β-lactam antibiotics and inhibitors.

• 한국수산과학회지
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• 제54권4호
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• pp.388-396
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• 2021

Antimicrobial resistance patterns of Escherichia coli were investigated. Strains were isolated from 310 shellfish, 36 crustaceans, and 12 fish collected off the West Coast of Korea from April 2019 to October 2020. Two hundred and ninety-five E. coli strains were isolated from shellfish, 100 from crustaceans, and 54 from fish. Strains isolated from shellfish showed the highest resistance to ampicillin (27.5%), whereas those from crustaceans were resistant to sulfisoxazole (30.0%) and those from fish were resistant to ampicillin (59.3%) and sulfisoxazole (59.3%). Ceftazidime resistance was observed in strains isolated from short neck and hard clams, whereas gentamicin resistance was observed in strains from fish. Multi-drug resistance was observed in 56 strains (48.7%) isolated from shellfish, 11 (28.2%) from crustaceans and 27 (73.0%) from fish. Depending on the source of isolation, the strains showed specific antimicrobial resistance tendency. Strains isolated from shellfish showed 12 different multi-drug resistance patterns, whereas those from crustaceans showed high resistance (59%) to a single antimicrobial agent and those from fish showed a broad trend of multi-drug resistance to more than eight antimicrobials.

• 대한의생명과학회지
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• 제22권4호
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• pp.215-219
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• 2016

The problems of tuberculosis and its drug resistance are very severe. Therefore, rapid and accurate drug susceptibility assay is required. Recently, there has been an increased understanding of the genetic mechanism of Mycobacterium tuberculosis (MTB) drug resistance as well as advancement of molecular technologies. While many gene mutations correlate well with drug resistance, many genes do not show a strong correlation with drug resistance. For this reason, the current study assessed the utility of rpoB mRNA as a target to detect live mycobacteria. In this study, RT-PCR targeting of rpoB mRNA in BCG treated with rifampin was performed. Conventional RT-PCR and real-time PCR targeting rpoB mRNA as well as 85B mRNA was performed to determine whether these two methods could distinguish between viable and non-viable MTB. The levels of rpoB and 85B mRNA detected by RT- PCR were compared in parallel with colony forming unit counts of BCG that were treated with rifampin for different periods of time. The data suggests that that even though both mRNA levels of rpoB and 85B decreased gradually when rifampin-treatment increased, the rpoB mRNA seemed to represent live bacteria better than 85B mRNA. This study clearly indicates that RT-PCR is a good method to monitor viable cell counts in the liquid culture treated with the anti-tuberculosis drug.

• 대한수의학회지
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• 제21권1호
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• pp.25-31
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• 1981

A total of 250 enteric bacteria (148 Escherichia coli, 41 Klebsiella pneumoniae, 46 Enterobacter spp. and 15 Proteus spp.) isolated from bovine udder infections in 1979 through 1980 were examined for drug resistance and prevalence of R. plasmids. The drug tested were streptomycin (SM), kanamycin (KM), ampicillin (AP), chloramphenicol (CP), tetracycline (TC), gentamicin (GM), oxolinic acid (OA) and nalidixic acid (NA). The detection of R. plasmids was performed with Escherichia coli ML 1410 NAr as the recipient. Of the 148 Escherichia coli isolated, 68(45.9%) were found to be resistant to one or more drugs tested, and about 50% of the resistant strains were multiply resistant. of the 68 drugresistant strains, 13(19.1%) were found to carry R. plasmids which were capable of performing a conjugal transfer. CP resistance was transfered together with the other resistance. Of 41 strains of Klebsiella pneumoniae isolated, 90.2% were resistant to the drugs, alone or in combination thereof. Strains resistant to AP and TC were 63.4%, and 48.8%, respectively. R. plasmids were detected in 78.4% of the drug-resistant strains, and these strains transfered all or a part of their drug resistance pattern. AP and CP resistance were transfered in 100% of AP and CP-resistant strains. Eleven (37.9%) of 29 R. plasmids showed a thermosensitive transfer. Of the 46 strains of Enterobacter spp. isolated, 37(80.4%) were resistant to the drugs tested. A high percentage of resistance was noted for AP(65.2%). All strains resistant to four or more drugs transferred their resistances to Escherichia coli ML 1410, but strains resistant to three or fewer drugs did not transfer the resistances. All of the 15 Proteus strains isolated were resistant to more than two drugs. of them, 6 were quadruple resistance to SM, KM, CP and TC, and 9 were double one to AP and TC. Three (20.0%) of the drug-resistant isolates had R.plasmids conferring AP and TC resistance. GM, OA and NA of the drugs tested were very active to all of 250 Gram-negative enteric bacteria isolated from bovine udder infections.