• Title/Summary/Keyword: ErmE

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Functional Role of Peptide Segment Containing 1-25 Amino Acids in N-terminal End Region of ErmSF (ErmSF에서 특이적으로 발견되는 N-terminal end region에 존재하는 1-25번째 아미노산을 함유하는 peptide segment의 효소 활성에서의 역할)

  • Jin, Hyung-Jong
    • Korean Journal of Microbiology
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    • v.42 no.3
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    • pp.165-171
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    • 2006
  • ERM proteins transfer the methyl group to $A_{2058}$ in 23S rRNA to confer the resistance to MLS (macrolide-lincosamide-streptogramin B) antibiotics on microorganism ranging from antibiotic producers to pathogens. To define the functional role of peptide segment encompassing amino acid residues 1 to 25 in NTER (N-terminal end region) of ErmSF, one of the ERM proteins, DNA fragment encoding mutant protein deprived of that peptide was cloned and overexpressed in E. coli to obtain a purified soluble form protein to the apparent homogeneity in the yield of 12.65 mg per liter of culture. The in vitro activity of mutant protein was found to be 85% compared to wild type ErmSF, suggesting that this peptide interact with substrate to affect the enzyme activity. This diminished activity of mutant protein caused the delayed expression of antibiotic resistance in vivo, that at fIrst cells expressing mutant protein showed the retarded growth due to the antibiotic action but with time cells inhibited by antibiotic gradually recovered the viability to exert the resistance to the same extent as those with wild type protein.

Nucleotide Sequence and Properties of Macrolide-Lincosamide-Streptogramin B Resistance Gene from Staphylococcus aureus DH1 (Staphylococcus aureus DH1에서 분리된 Macrolide-Lincosamide-Streptogramin B 계열 항생물질에 대한 저항성 인자의 특성과 염기서열)

  • 권동현;박승문;윤권상;변우현
    • Korean Journal of Microbiology
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    • v.28 no.1
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    • pp.27-34
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    • 1990
  • Two macrolide-lincosamide-streptogramin B (MLS) antibiotic resistance genes, one expressed inducibly and the other expressed constitutively were recognized from a single Staphylococcus aureus DH1 strain. The inducible MLS resistance gene was isolated and cloned from the R-plasmid pDE1(7.4kb) and the constitutive gene was from chromosomal DNA. Base sequence of the inducible MLS resistance gene (1.2kb) was determined and found as same that of pE194. The restriction map of the cloned constitutive MLS resistance gene was compared with that of the inducible gene. Two genes have same restriction map except leader region. In the constitutive gene there is no leader region which is doing major role in inducible expression.

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Detection of Antibiotic Resistance and Resistance Genes in Enterococci Isolated from Sucuk, a Traditional Turkish Dry-Fermented Sausage

  • Demirgul, Furkan;Tuncer, Yasin
    • Food Science of Animal Resources
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    • v.37 no.5
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    • pp.670-681
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    • 2017
  • The aim of this study was to isolate enterococci in Sucuk, a traditional Turkish dry-fermented sausage and to analyze isolates for their biodiversity, antibiotic resistance patterns and the presence of some antibiotic resistance genes. A total of 60 enterococci strains were isolated from 20 sucuk samples manufactured without using a starter culture and they were identified as E. faecium (73.3%), E. faecalis (11.7%), E. hirae (8.3%), E. durans (3.3%), E. mundtii (1.7%) and E. thailandicus (1.7%). Most of the strains were found resistant to rifampin (51.67%) followed by ciprofloxacin (38.33%), nitrofurantoin (33.33%) and erythromycin (21.67%). All strains were found susceptible to ampicillin. Only E. faecium FYE4 and FYE60 strains displayed susceptibility to all antibiotics. Other strains showed different resistance patterns to antibiotics. E. faecalis was found more resistant to antibiotics than other species. Most of the strains (61.7%) displayed resistance from between two and eight antibiotics. The ermB, ermC, gyrA, tetM, tetL and vanA genes were detected in some strains. A lack of correlation between genotypic and phenotypic analysis for some strains was detected. The results of this study indicated that Sucuk manufactured without using a starter culture is a reservoir of multiple antibiotic resistant enterococci. Consequently, Sucuk is a potential reservoir for the transmission of antibiotic resistance genes from animals to humans.

Fillers in the Hong Kong Corpus of Spoken English (HKCSE)

  • Seto, Andy
    • Asia Pacific Journal of Corpus Research
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    • v.2 no.1
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    • pp.13-22
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    • 2021
  • The present study employed an analytical framework that is characterised by a synthesis of quantitative and qualitative analyses with a specially designed computer software SpeechActConc to examine speech acts in business communication. The naturally occurring data from the audio recordings and the prosodic transcriptions of the business sub-corpora of the HKCSE (prosodic) are manually annotated with a speech act taxonomy for finding out the frequency of fillers, the co-occurring patterns of fillers with other speech acts, and the linguistic realisations of fillers. The discoursal function of fillers to sustain the discourse or to hold the floor has diverse linguistic realisations, ranging from a sound (e.g. 'uhuh') and a word (e.g. 'well') to sounds (e.g. 'um er') and words, namely phrase ('sort of') and clause (e.g. 'you know'). Some are even combinations of sound(s) and word(s) (e.g. 'and um', 'yes er um', 'sort of erm'). Among the top five frequent linguistic realisations of fillers, 'er' and 'um' are the most common ones found in all the six genres with relatively higher percentages of occurrence. The remaining more frequent realisations consist of clause ('you know'), word ('yeah') and sound ('erm'). These common forms are syntactically simpler than the less frequent realisations found in the genres. The co-occurring patterns of fillers and other speech acts are diverse. The more common co-occurring speech acts with fillers include informing and answering. The findings show that fillers are not only frequently used by speakers in spontaneous conversation but also mostly represented in sounds or non-linguistic realisations.

Design and Evaluation of a User Tag-based Retrieval Model for Electronic Journals within Electronic Resource Management Systems (전자자원관리시스템의 이용자 태그 기반의 전자저널 검색 모형 설계 및 평가에 관한 연구)

  • Kang, Jeong-Won;Kim, Hyun-Hee
    • Journal of the Korean Society for Library and Information Science
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    • v.43 no.4
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    • pp.241-264
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    • 2009
  • The study proposed an electronic journal retrieval model to be used to improve the retrieval efficiency of e-journals. To do this, firstly, we reviewed the literature on users' information behavior and on ERM (Electronic Resource Management) systems. Secondly, we conducted an e-mail survey of 96 participants (professors and graduate students) to find out about their information behavior on how to access, use and evaluate electronic resources as well as scientific information. Thirdly, we administered case studies on two ERMSs, Ex Libris' Verde and Innovative's Millennium. The proposed model will be operated within ERM systems and it enables to the supply of both system- and user-based services by combining taxonomy-based ERM systems with tag folksonomy. The model is unique in that it includes not only the automatic tagging functions that can be performed using log files but also the tag management functions including grouping similar or related tags.

Effects of the Bee Venom on Human Gastric Adenocarcinoma Cell Lines (봉독이 위암 세포주에 미치는 효과)

  • Heo, Gyeong;Kim, Myung Ho;Lim, Seong Woo
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.27 no.1
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    • pp.92-98
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    • 2013
  • Bee Venom(below BV) has been used in alternative medicine to treat the diseases, such as pain diseases. BV contains a variety of peptides, including melittin, apamin, adolapin, MCD peptide, enzymes(i.e. PLA2), amines(i.e. histamine and epinephrine), and nonpeptide components. The two main components of BV are melittin and PLA2. The cell cytotoxic effects through the activation of PLA2 by melittin have been suggested to be the critical mechanism for the depress of cancer cell. Melittin and PLA2 have been reported to induce apoptosis and to possess anti-cancer effects and neurite outgrowth in PC12 cells. Analysis of proliferation was confirmed by MTT assay. BV decreased cell number through dose- and duration-dependent manner and these effects are apparent at a concentration of 3 ${\mu}g/ml$. To observe which signaling molecules will be activated by BV, phosphorylation of ERK, p38 MAPK, JNK and ERM were examined by Western blot analysis. To study the long term effect of BV in human gastric adenocarcinoma cell lines, the image of cells treated with BV for 4 days were obtained. BV was shown to exhibit anti-cancer activity in human gastric adenocarcinoma cell lines at a broad range of concentrations of 3 ${\mu}g/ml$. ERK, p38 MAPK and JNK were found to increase in BV treated cells. However, ERM which known to be involved in the cell death, was gradually decreased to 30minutes after addition 3 ${\mu}g/ml$ of BV. These results provide a possible BV-induced inhibitory signal for cancer proliferation that is initiated by the decrease in ERM activity. Moreover, it is likely that the activation of ERK, p38 MAPK and JNK are required for the BV-induced inhibition of cancer proliferation.

Improvement of Natamycin Production by Cholesterol Oxidase Overexpression in Streptomyces gilvosporeus

  • Wang, Miao;Wang, Shaohua;Zong, Gongli;Hou, Zhongwen;Liu, Fei;Liao, D. Joshua;Zhu, Xiqiang
    • Journal of Microbiology and Biotechnology
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    • v.26 no.2
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    • pp.241-247
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    • 2016
  • Natamycin is a widely used antifungal antibiotic. For natamycin biosynthesis, the gene pimE encodes cholesterol oxidase, which acts as a signalling protein. To confirm the positive effect of the gene pimE on natamycin biosynthesis, an additional copy of the gene pimE was inserted into the genome of Streptomyces gilvosporeus 712 under the control of the ermE* promoter (permE*) using intergeneric conjugation. Overexpression of the target protein engendered 72% and 81% increases in the natamycin production and cell productivity, respectively, compared with the control strain. Further improvement in the antibiotic production was achieved in a 1 L fermenter to 7.0 g/l, which was a 153% improvement after 120 h cultivation. Exconjugants highly expressing pimE and pimM were constructed to investigate the effects of both genes on the increase of natamycin production. However, the co-effect of pimE and pimM did not enhance the antibiotic production obviously, compared with the exconjugants highly expressing pimE only. These results suggest not only a new application of cholesterol oxidase but also a useful strategy to genetically engineer natamycin production.

Expression Profiles of Streptomyces Doxorubicin Biosynthetic Gene Cluster Using DNA Microarray System (DNA Microarray 시스템을 이용한 방선균 독소루비신 생합성 유전자군의 발현패턴 분석)

  • Kang Seung-Hoon;Kim Myung-Gun;Park Hyun-Joo;Kim Eung-Soo
    • KSBB Journal
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    • v.20 no.3
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    • pp.220-227
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    • 2005
  • Doxorubicin is an anthracycline-family polyketide compound with a very potent anti-cancer activity, typically produced by Streptomyces peucetius. To understand the potential target biosynthetic genes critical for the doxorubicin everproduction, a doxorubicin-specific DNA microarray chip was fabricated and applied to reveal the growth-phase-dependent expression profiles of biosynthetic genes from two doxorubicin-overproducing strains along with the wild-type strain. Two doxorubicin-overproducing 5. peucetius strains were generated via over-expression of a dnrl (a doxorubicin-specific positive regulatory gene) and a doxA (a gene involved in the conversion from daunorubicin to doxorubicin) using a streptomycetes high expression vector containing a strong ermE promoter. Each doxorubicin-overproducing strain was quantitatively compared with the wild-type doxorubicin producer based on the growth-phase-dependent doxorubicin productivity as well as doxorubicin biosynthetic gene expression profiles. The doxorubicin-specific DNA microarray chip data revealed the early-and-steady expressions of the doxorubicin-specific regulatory gene (dnrl), the doxorubicin resistance genes (drrA, drrB, drrC), and the doxorubicin deoxysugar biosynthetic gene (dnmL) are critical for the doxorubicin overproduction in S. peucetius. These results provide that the relationship between the growth-phase-dependent doxorubicin productivity and the doxorubicin biosynthetic gene expression profiles should lead us a rational design of molecular genetic strain improvement strategy.

A Study on Implementation of the Integrated Electronic Resource Management System for Digital Librarian (디지털도서관 정보관리자를 위한 전자정보자원관리시스템 구축 연구)

  • Han Jong-Yup;Cho Hyun-Yang;Ki Myong-Jong
    • Journal of the Korean Society for Library and Information Science
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    • v.40 no.3
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    • pp.263-287
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    • 2006
  • With the rapid and broad changes of information media and information environment the traditional libraries have been evolving into the digital libraries. An analysis for the Planning and realization of the electronic resource management system was carried out to establish the various electronic resources in the digital library, the first in Korea. The study targeted from electronic journals, web-based databases, e-books, and to open access resources. The focus of the analysis lies in the Providing practical integrated electronic resource management for digital librarian based on the framework of effective Electronic Resource Management Initiative(ERMI) of Digital Library Federation(DLF) with network and electronic resource description. The analyses included life-cycle, subscription models, coverages. types of information provider for electronic resources. and system organization for implementation of electronic resource management system.

Analysis of Genotype and Phenotype of Erythromycin Resistance in Enterococci spp. Isolated from Raw Milk Samples (원유시료에서 분리한 장구균의 에리스로마이신 내성 유전자형 및 표현형 분석)

  • Lee, Hye-In;Jung, Jae-Hyuk;Lee, Sang-Jin;Choi, Sung-Sook
    • Korean Journal of Microbiology
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    • v.46 no.2
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    • pp.148-151
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    • 2010
  • The aim of this study was to investigate the erythromycin resistance patterns of Enterococci sp. present in cow milk. A total 110 erythromycin resistant Enterococci were isolated from milk samples; E. faecalis (n=101), E. avium (n=7), and E. durans (n=2). The minimum inhibitory concentration of erythromycin against 110 Enterococci were determined. The 66.3% of Entercocci (n=73) showed high level resistance (${\geq}64$ mg/ml). Among 110 isolates, 86.3% (n=95) showed $cMLS_B$ phenotype and 13.6% (n=15) showed $iMLS_B$ The aim of this study was to investigate the erythromycin resistance patterns of Enterococci sp. present in cow milk. A total 110 erythromycin resistant Enterococci were isolated from milk samples; E. faecalis (n=101), E. avium (n=7), and E. durans (n=2). The minimum inhibitory concentration of erythromycin against 110 Enterococci were determined. The 66.3% of Entercocci (n=73) showed high level resistance (${\geq}64$ mg/ml). Among 110 isolates, 86.3% (n=95) showed $cMLS_B$ phenotype and 13.6% (n=15) showed $iMLS_B$ phenotype. All of isolates have erm(B) determinant, 75.45% (n=83) have mef(A) an efflux system determinant. The majority of Enetrcococci isolated from raw milk samples in northern area of Gyeonggi-Do showed high level of resistance to erythromycin.