• Childhood Kidney Diseases
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• 제23권1호
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• pp.29-35
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• 2019

Purpose: We aimed to determine characteristics of host, causative organisms, and antibiotic susceptibility of bacteria in pediatric patients with UTI living in metropolitan area of Korea. Methods: Retrospective investigation was done for the causative organisms of UTI in 683 pediatric cases treated at Ajou University Hospital from 2012 to 2017. Patients were classified into Escherichia coli and non-E. coli group, where E. coli group was subdivided into ESBL(+) and ESBL(-) groups based on whether the bacteria could produce extended spectrum beta-lactamase (ESBL). Antibiotic susceptibility of the causative organism was also determined. Results: A total of 683 UTIs occurred in 550 patients, of which 463 (67.8%) were first-time infection and 87 (32.2%) were recurrent ones (2-7 recurrences, 2.52 average), and 64.9% were male and 35.1% were female. The most common causative organism was E. coli (77.2%) and ESBL(+) E. coli was found in 126 cases. The susceptibility of E. coli to 3rd or 4th generation cephalosporin was relatively higher than that to ampicillin or amoxicillin/clavulanic acid. ESBL(+) E. coli showed higher resistance rate to 3rd or 4th generation cephalosporin than ESBL(-) E. coli. Conclusion: New treatment guideline should be considered due to the incidence of ESBL(+) E. coli increased up to one quarter of UTI cases.

• Journal of Oral Medicine and Pain
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• 제47권1호
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• pp.52-61
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• 2022

Purpose: Most cases of oral and maxillofacial infections are usually easily treated by proper diagnosis, elimination of causative factors, and antibiotic therapy. However, the emergence and the increase of multidrug-resistant bacteria make treatment challenging. "ESKAPE" pathogens are the most common opportunistic organisms in nosocomial infections and have resistant to commonly used antibiotics. There are many medical reviews of ESKAPE pathogens, but few in dentistry. This study focuses on oral and maxillofacial infection especially with ESKAPE pathogens. The purpose of this study is to prepare feasible data about tracing and treatment of infection related to pathogens that may be beneficial to clinicians. Methods: A total of 154 patients with oral and maxillofacial infections were reviewed by analyzing retrospectively hospitalized data in the Department of Oral and Maxillofacial surgery, Chosun University Hospital, Korea, past 5 years from January 2014 to December 2018. Based on the medical records and microbiological tests, the results were divided into two groups: infections with ESKAPE pathogens and other bacteria. Results: A total of 22 species were isolated from 154 patients. The proportion of ESKAPE pathogens among all bacterial isolates collected from infected patients was 39.6%. Causative factors, especially in post-operative infection, showed a statistically significant correlation to ESKAPE infections (29 cases). And average of treatment period in ESKAPE group was longer than non-ESKAPE groups. Overall, Klebsiella pneumoniae (60.7%) was the most frequently isolated ESKAPE pathogen. And high antibiotic resistance rates had been detected in the ESKAPE during the five-year period. Conclusions: Infections with ESKAPE pathogens are now a problem that can no longer be overlooked in Dentistry. Based on results of this study, ESKAPE pathogens were highly associated with post-operative or opportunistic infections. Clinicians should be careful about these antibiotic resistant pathogens and use appropriate antibiotics to patients while having dental treatments.

• Journal of Plant Biotechnology
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• 제6권1호
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• pp.25-37
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• 2004

Successful genetic transformation of plants requires non-chimeric selection of transformed tissues and their subsequent regeneration. With rare exceptions, most transformation protocols still rely heavily on antibiotics for selecting transgenic cells that contain an antibiotic-degrading selectable marker gene. Here, the morphogenic capacity of in-vitro explants of chrysanthemnum and tobacco stems and leaves (control and transgenic) changed with the addition of aminoglycoside antibiotics (AAs), In a test of 6 AAs, phytotoxicity occurred at concentrations of 10 to 25 and 50 to 100$\mu\textrm{g}$ $mL^{-1}$ in chrysanthemum and tobacco explants, respectively. Light conditions as well as explant source and size also had significant effects. The use of transverse thin cell layers (tTCLs), in conjunction with high initial AA selection levels, supported the greatest regeneration of transgenic material (adventitious shoots or callus) and the lowest number of escapes. Flow-cytometric analyses revealed no endodu-plication in chrysanthemum, even at high AA levels. However, this phenomenon was observed in tobacco calli(8C or more), even at low AA concentrations (i.e., 5 to 10 $\mu\textrm{g}$ mL$^{-1}$ ).

• Advances in environmental research
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• 제9권1호
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• pp.1-17
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• 2020

Pharmaceutically active compounds (PhACs) have become an environmental havoc in last few decades with reported cases of antibiotic resistant bacteria (ARB) and antibiotic resistant genes (ARGs), lethal effects over aquatic organisms, interference in natural decomposition of organic matter, reduced diversity of microbial communities in different environmental compartments, inhibition of growth of microbes resulting in reduced rate of nutrient cycling, hormonal imbalance in exposed organisms etc. Owing to their potential towards bioaccumulation and persistent nature, these compounds have longer residence time and activity in environment. The conventional technologies of wastewater treatment have got poor efficiency towards removal/degradation of PhACs and therefore, modern techniques with efficient, cost-effective and environment-friendly operation need to be explored. Advanced oxidation processes (AOPs) like Photocatalysis, Fenton oxidation, Ozonation etc. are some of the promising, viable and sustainable options for degradation of PhACs. Although energy/chemical or both are essentially required for AOPs, these methods target complete degradation/mineralization of persistent pollutants resulting in no residual toxicity. Considering the high efficiency towards degradation, non-toxic nature, universal viability and acceptability, AOPs have become a promising option for effective treatment of chemicals with persistent nature.

• 한국미생물·생명공학회지
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• 제10권3호
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• pp.171-175
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• 1982

항균 활성이 대체로 상승되었으나 Sarcina maginata의 경우는 약간 감소되었다. $\beta$-lactam 항생 물질인 penicillin G.Na와 ampicillin.Na도 인삼 saponin의 첨가로 항균 활성이 상승되었으나 Serratia 속 세균은 penicillin G.Na의 항균활성에 일정한 효과를 나타내지 않았다. 인삼 saponin 의 첨가에 의한 항생 물질들의 항균 활성의 변화는 Gram양성 세균 및 Gram음성 세균에 대해 일정하지 않은 상승 작용 혹은 길항작용과 같은 비특이성을 나타내었다. 세균의 약제 내성 현상도 인삼 saponin자 항생물질의 투여로 배제될 수 있을 것으로 사료되었다.

• 미생물학회지
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• 제42권1호
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• pp.59-61
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• 2006

먹물버섯의 하나인 Coprinellus congregatus를 대상으로 유전자의 도입을 위한 형질전환실험에서 원형질체를 생성하지 않고 분열자 (oidium)를 사용하는 방법을 확립하였다. 분열자는 20일 이상된 CKMM 한천배지에서 생성되며, 이를 밤샘배양으로 발아를 촉진시킨 상태에서 전기천공방법으로 항생물질 basta에 대한 형질전환을 수행한 결과 10-20 형질전환체/${\mu}g$ DNA의 수율로 형질전환체를 확보할 수 있었다. 이 형질전환체들은 도입된 벡터가 염색체 상에 삽입되어 유전적으로 안정된 상태를 유지하였다.

• The Plant Pathology Journal
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• 제28권1호
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• pp.1-9
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• 2012

In this study, 200 isolates of fluorescent pseudomonads were isolated from different fields of East and West Azarbaijan and Ardebil provinces of Iran. These bacterial isolates were screened on the basis of a dual culture assay, the presence of known antibiotic genes, and their ability to successfully colonize roots and to promote plant growth. Twelve isolates exhibited 30% or more inhibition of mycelia growth of $P.$ $drechsleri$. Genes encoding production of the antibiotics 2,4-diacetylphloroglucinol, phenazine-1-carboxylic acid, and pyoluteorin were detected in some strains but none of the strains possessed the coding gene for production of antibiotic pyrrolnitrin. In an $in$ $vitro$ test for root colonization, the population density on roots of plants treated with most of the above strains was more than 6 $\log_{10}$ CFU $g^{-1}$ roots, with a maximum of 7.99 $\log_{10}$ CFU $g^{-1}$ roots for strain 58A. Most of the strains promoted significant plant growth in comparison to non-treated controls. In green house studies, the percentage of healthy plants in pots treated with strains 58A and 8B was 90.8% and 88.7%, respectively. The difference between these treatments and treatment with the fungicide metalaxyl was not significant.

• 대한수의학회지
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• 제47권1호
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• pp.67-75
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• 2007

Environmental mastitis has increased particularly in well-managed or low somatic cell countherds that have successfully controled contagious pathogens. Major pathogens of environmental mastitisare Escherichia coli (E. coli) and Streptococcus uberis. The present study was conducted to investigate1,865 quaters of 241 Korean dairy farms from 2001 to 2004. Prevalence of major gram-negative bacteriaisolated from mastitis milk were E. coli (22.7%) and Enterobacter spp. (16.3%) in coliforms and Pseudomoassp. (10.3%) and Serratia spp. (7.9%) in non-coliforms. The results on antibiotic susceptibility by agardifusion test against these pathogens were 86.7% in piperaciliin, 94.6% in cefepime, 85.5% in amikacin,87.7% in gentamicin and so on. In contrast, the susceptibility against ampicillin (41.9%), cephalothin (9.9%),streptomycin (39.9%) and tetracycline (46.7%) appeared to be below 50%. Gram-negative bacteria showed(96.8%). Acording to year, distribution of high $256{\sim}64{\mu}g/ml$ on cephalothin get increased, but the othersare diferent. These findings demonstrate that major gram-negative bacteria were E. coli and Enterobacterspp. isolates, and often encountered the diverse antibiotic resistant patterns.

• Journal of Microbiology and Biotechnology
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• 제11권1호
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• pp.1-6
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• 2001

Ten strains of plasmid-harboring Bifidobacterium sp. were isolated from the feces of adults and children, and named as Bifidobacterium sp. GE1-GE8, ST, and SH5. These plasmids were categorized into three homologous groups (pKJ50-homologous, pKJ36-homologous, and non-homologous groups) according to Southern hybridization patterns using the formerly characterized bifidobacterial plasmids, pKJ50 and pKJ36, as probes. nine strains harboring the plasmids were shown to accumulate single-stranded DNA as a replication intermediate, based on the S1 nuclease treatment and Southern hybridization. These results suggest that the strains replicate by a rolling circle mechanism. Minimal inhibitory concentrations (MIC) of the isolated bifidobacteria against several antibiotics were determined. Two strains, GE2 and GE3, showed relatively high MiC values against tetracycline ($793.6{\mu}g/ml$) and erythromycin ($153.6{\mu}g/ml$), respectively. The tetracycline resistance of GE2 disappeared when the resident plasmid of GE2 was cured by ethidium bromide. These results show that pKJ36-homologous and pKJ50-homologous plasmids are prevalent among various Bifidobacterium strains and some Bifidobacterium plasmids appear to code for antibiotic resistance.

• 약학회지
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• 제57권2호
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• pp.132-138
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• 2013

Acinetobacter baumannii is gram-negative bacilli that can be widely found in environments. Recently, A. baumannii emerged as a serious nosocomial infection. A total of 92 A. baumannii were isolated from hospitalized patients in Seoul, Korea, between December 2010 and April 2011. Antimicrobial susceptibility testing was investigated using CLSI agar dilution methods. Tigecycline non-susceptible A. baumannii isolates were investigated by repetitive extragenic palindromic sequence-based PCR (rep-PCR). Pulsed-field gel electrophoresis was performed to determine the epidemiological relationships. All clinical isolates showed high-level resistance to the most commonly used antibiotics: Ciprofloxacin (87.0%), Ampicillin/sulbactam (82.6%), Cefotaxime (81.5%), Ceftazidime (80.4%). Moreover, 50.0% of these isolates were non-susceptible to tigecycline. When evaluated by RAPD analysis, generated distinct band ranging in size from 1kb to 8k band varying from 4 to 10 bands. Stricter surveillance and more rapid detection are essential to prevent the spread of multi drug resistant A. baumannii.