• Journal of Yeungnam Medical Science
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• 제28권1호
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• pp.13-19
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• 2011

The emergence of antibiotic-resistant pathogens is a Serious clinical problem in the treatment of infectious diseases that increase mortality, morbidity, hospitalization length, and the cost of healthcare. In particular, $Streptococcus$ $pneumoniae$ is a major etiologic pathogen of pneumonia, sinusitis, otitis media, and meningitis. As the definition of penicillin resistance to $S.$ $pneumoniae$ was recently changed, macrolide-resistant $S.$ $pneumoniae$ is a major resistant pathogen in the community. Infections caused by antibiotic-resistant strains are associated with incorrect use of antibiotics and critical clinical outcomes. For the appropriate use of antibiotics to treat infections, physicians always should have up-to-date information on the current epidemiologic status of antibiotic resistance for common pathogens and their susceptibility to antimicrobials. Appropriate selection of antimicrobials, strict control of infection, vaccination, and development of a feasible national policy of infection control are important strategies for the control of antimicrobial resistance. This review article focuses on the current status of antibiotic-resistant $S.$ $pneumoniae$ in community-acquired pneumonia in Korea.

• Journal of Microbiology and Biotechnology
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• 제34권7호
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• pp.1365-1375
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• 2024

The rise of Candida auris, a multidrug-resistant fungal pathogen, across more than 40 countries, has signaled an alarming threat to global health due to its significant resistance to existing antifungal therapies. Characterized by its rapid spread and robust drug resistance, C. auris presents a critical challenge in managing infections, particularly in healthcare settings. With research on its biological traits and genetic basis of virulence and resistance still in the early stages, there is a pressing need for a concerted effort to understand and counteract this pathogen. This review synthesizes current knowledge on the epidemiology, biology, genetic manipulation, pathogenicity, diagnostics, and resistance mechanisms of C. auris, and discusses future directions in research and therapeutic development. By exploring the complexities surrounding C. auris, we aim to underscore the importance of advancing research to devise effective control and treatment strategies.

• Natural Product Sciences
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• 제24권4호
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• pp.225-228
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• 2018

By activity-guided fractionation, gliotoxin was isolated as an antibacterial metabolite of the fungus Penicillium decumbens which was derived from the jellyfish Nemopilema nomurai. Gliotoxin was further evaluated for antibacterial activity against several piscine and human MDR (multidrug resistance) pathogens. Gliotoxin showed significant antibacterial activity against Gram-positive piscine pathogens such as Streptococcus iniae FP5228, Streptococcus iniae FP3187, Streptococcus parauberis FP3287, Streptococcus parauberis SPOF3K, S. parauberis KSP28, and Lactococcus garvieae FP5245. Gliotoxin showed strong activity especially against S. parauberis SPOF3K and S. iniae FP5228, which are resistant to oxytetracycline. It is noteworthy that gliotoxin effectively suppressed streptococci which are the major pathogens for piscine infection and mortality in aquaculture industry. Gliotoxin also showed strong antibacterial activity against multidrug- resistant human pathogens (MDR) including Enterococcus faecium 5270 and MRSA (methicillin-resistant Staphylococcus aureus) 3089.

• 생약학회지
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• 제42권4호
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• pp.336-340
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• 2011

The aim of this study was to investigate the possible utilization of Zanthoxylum schinifolium as a source of antimicrobial agents. The antimicrobial effects of Zanthoxylum schinifolium extracts were investigated against Acinetobacter baumannii, which is a multi-drug resistant pathogen, and 5 other pathogenic microorganisms. The hexane extract of Zanthoxylum schinifolium was more effective than the ethyl acetate, n-butanol and methanol extracts which were active against Acinetobacter baumannii 25, with minimum inhibitory concentrations(MIC) ranging from 0.8 mg/ml to 1.6 mg/ml. Tetracycline had no effect on Acinetobacter baumanniii. The hexane extract was highly active against Candida albicans IFO 6258, with an MIC of 1.5 mg/ml. In contrast, the ethyl acetate, n-butanol and methanol extracts showed no activity against the 5 pathogenic microorganisms. Furthermore, a combination of hexane extract and ethyl acetate extract was significantly more active against the 5 Acinetobacter baumannii strains than n-butanol and methanol. These results suggest that Zanthoxylum schinifolium extracts have great potential as antimicrobial compounds against multi-drug resistant pathogens, and further studies are warranted.

• 대한미생물학회지
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• 제19권1호
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• pp.11-24
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• 1984

Shigella remains to be an important enteric pathogen in this country for the present. Moreover, most of the isolates have become multiple resistant to various antibiotics which used to be drugs of choice for shigellosis. This study was made as an attempt to assess the present stage of antibiotic resistance and the incidence and transferability of R factors of Shigella. A total of one hundred and seventeen strains of Shigella isolated from patients in Seoul and provincial area between 1982 and 1983 were tested for their resistant to antimicrobial agents and transmission of R-plasmid. Antibiotic susceptibilities were determined by an agar dilution method. Muller hinton agar were used for the assay of drug resistance and tryptic soy broth were used for propagating medium for conjugation. Shigella isolated found to be one or more antibiotics were considered potential donor of R-plasmid. The following results were obtained. 1. Among 117 strains of Shigella isolated, 111 strains(94.9%) were found to be resistant to one or more drugs tested and 97.3% of these resistant strains were multiply resistant, indicating the multiply resistant strains were more than the single resistant strains. Only six strains were susceptible to all drugs tested. 2. Among 117 strains of Shigella isolated, 107 strains(91.5%) were resistant to Tetracyclin(Tc), 106 strains(90.6%) to Chloramphenicol(Cp) and Streptomycin(Sm), 97 strains(82.9%) to Ampicillin(Ap), 68 strains(58.1%) to Cephaloridine(Cr), 10 strains(8.5%) to Nalidixic acid(Na), 5 strains(4.3%) to Kanamycin(Km) and 2 strains(1.7%) to Rifampicin. No strain was resisfant to Amikacin(Ak) and Gentamicin(Gm). 3. All drug-resistant Shigella strains, except three, were multiply resistant to two or more drugs. Fifty eight strains were resistant to five drugs, followed by 26 strains resistant to dour drugs, 12 strains resistant to three drugs and 11 strains resistant to six drugs. 4. The 73% of multiply drug-resistant Shigella transferred their resistance to E. coli by conjugation and the resistance was considered to be mediated by R-plasmid. Resistance to Nalidixic acid and Rifampicin were not transferred by conjugation to recipient. As for the transferability of resistance to each seperate drug, Ap resistance was transferred with 73.2% frequence and Cm and Tc resistance were transferred with approximately 50-60% frequence whereas Sm and Cr resistance were transferred in 19.1-21.4% The other four drugs resistant failed to transfer their resistance to recipient. 5. As for the incidence and transferability of resistance to each seperate drug, the strains resistant to Tc and Cm were encountered most frequently with the rate of 91-92%, whereas transfer of Tc and Cm were low, 51-52%. The incidence of Sm resistance was very high(90.6%) but transferability of drugs resistance was much lower(25.4%). Though the incidence of Km reristance was much lower(4.3%) transferability of Km resistance was considerably higher(60%). 6. The greater the multiplicity of resistance, the greater was the likelihood that part of all of the resistance markers would be transferable.

• 미생물학회지
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• 제52권3호
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• pp.327-335
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• 2016

본 연구에서는 신규 Amycolatopsis 균주 KCTC 29142를 분리하여 형태학적 관찰, 계통분석 및 화학분류학적 분석 등 다상 분류분석을 통해 분석하였다. KCTC 29142 균주의 에틸아세테이트추출물은 강한 항균활성을 나타났고, 활성물질은 철 이온 킬레이트 물질인 siderochelin A로 동정되었다. 본 연구에서 분리된 siderochelin A는 다제내성균인 Acinetobacter baumanii, methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Staphylococcus aureus (VRSA), 및 Escherichia coli (E. coli)에 대해 강한 활성을 보였고, 임상에서 분리된 다제내성균에 대한 MIC를 결정하였다.

• Tuberculosis and Respiratory Diseases
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• 제76권5호
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• pp.245-248
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• 2014

Miliary tuberculosis (TB) is a rare extrapulmonary form of TB, and there have been only two reports of miliary TB associated with infection with multidrug-resistant (MDR)-TB pathogen in an immunocompetent host. A 32-year-old woman was referred to our hospital because of abnormal findings on chest X-ray. The patient was diagnosed with MDR-TB by a line probe assay and was administered proper antituberculous drugs. After eight weeks, a solid-media drug sensitivity test revealed that the pathogen was resistant to ethambutol and streptomycin in addition to isoniazid and rifampicin. The patient was then treated with effective antituberculous drugs without delay after diagnosis of MDR-TB. To the best of our knowledge, this is the first case of miliary TB caused by MDR-TB pathogen in Korea.

• 대한임상검사과학회지
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• 제48권3호
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• pp.217-224
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• 2016

Acinetobacter baumannii는 병원환경에 광범위하게 분포하고 있으며, 원내감염의 중요한 원인균으로 병원에서 집단감염 일으키고, 중증의 기저질환을 가진 환자에게 감염되면 감염환자의 사망률이 다른 환자에 비해 월등히 높은 것으로 알려져 있다. 본 연구는 충청남도 천안시에 소재한 대학병원 두 곳의 진단검사의학과에 의뢰된 가검물에서 분리한 다제 내성 A. baumannii 85주의 항생제 내성률과 내성유전자 양상에 대해 조사하였다. Carbapenemase와 Class B ${\beta}$-lactamase의 생성균주를 선별하기 위하여 modified Hodge test (MHT)와 IMP-EDTA double-disk synergy test를 실시하였다. 항생제 내성을 유발하는 carbapenemases, 16S rRNA methylases, aminoglycoside-modifying enzymes (AMEs)을 확인하기 위하여 PCR을 시행 하였으며, A. baumannii가 분리된 두 대학병원간 분리균주의 유전학적인 근연도를 확인하기 위해 REP-PCR을 시행하였다. 실험결과 3균주를 제외한 82균주(96.5%)에서 $bla_{OXA-23-like}$과 $bla_{OXA-51-like}$이 검출되었다. $bla_{OXA-23-like}$ 유전자가 검출된 균주에서는 $bla_{OXA-23-like}$ 유전자 상부에 ISAba1 유전자가 확인되어 carbapenemase에 대한 내성을 유도하는 것으로 확인 되었다. Aminoglycoside에 대한 내성을 유발하는 16S rRNA methylase 유전자인 armA는 A병원에서 분리한 38균주 중 34균주(89.5%)에서, B병원에서 분리한 47균주 중 40균주(85.1%)에서 확인되었고, aminoglycoside modifying emzyme 유전자는 A병원 유래 38 균주 중 33 균주(70.2%)에서, B병원 유래 47균주 중 44 균주(93.6%)에서 aac(3)-IIa/ant(2")-Ia/aac(6')-Ib가 확인됨에 따라 천안지역에서 분리되는 대부분의 다제 내성 A. baumannii 균주는 acethyltransferase와 adenyltransferase를 동시에 발현하는 것을 알 수 있었다. 본 실험 결과는 충청남도 천안시에서 분리된 MDR A. baumannii를 대상으로 한 보고서로서, 항생제 내성유형과 내성 유전자의 분포를 확인하여 MDR A. baumannii 균주에 의한 감염증의 치료 지침과 내성세균 확산 방지를 위해 필요한 기초 자료로 활용할 수 있을 것으로 생각된다.

• 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 $k_{12}{\bar{F}}(\lambda)$.

• 대한임상검사과학회지
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• 제43권2호
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• pp.68-74
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• 2011

Pseudomonas aeruginosa is an aerobic, Gram-negative, glucose-nonfermenting bacterium, which has emerged as a serious opportunistic pathogen. Recently, outbreaks of carbapenem resistant P. aeruginosa give rise to significant therapeutic challenges for treating nosocomial infections. The genes of metallo-${\beta}$-lactamase (MBL), a powerful carbapenemase, are carried as a part of the mobile gene cassettes inserted into integrons playing an important role in rapid dissemination of antibiotic resistance genes among bacterial isolates. In this study, we investigated the prevalence of integron in imipenem resistant P. aeruginosa isolates. A total of 61 consecutive, non-duplicate, and imipenem resistant P. aeruginosa strains were isolated from a university hospital in the Chungcheong province of Korea. We employed repetitive extragenic palindromic sequence-based PCR (rep-PCR) method for the selection of clonally different P. aerusinosa strains. PCR and DNA sequencing were conducted for the detection of integrons. Twenty-one clonally different P. aeruginosa strains were isolated. Only one (P28) of the strains harbored $bla_{VIM-2}$ that was found as gene cassettes in class 1 integrons. Four of 21 carbapenem resistant P. aeruginosa strains harbored class 1 integron containing aminoglycoside resistance determinant. All of the integrons detected in the study contained more than one resistance gene cassette, which can mediate resistance to multiple antibiotics. To prevent further spreading of the multi-drug resistant P. aeruginosa, conseguent monitoring and clinical polices are required.