Diversity analysis of Saccharomyces cerevisiae isolated from natural sources by multilocus sequence typing (MLST)

엄유정,손수영,정동현,허문석,김창무,박선영,신우창,이상진,어중혁,김계원,박천석 한국식품과학회 2018 Food Science and Biotechnology Vol.27 No.4

We used multilocus sequence typing (MLST) to analyze the diversity of natural isolates of Saccharomyces cerevisiae, the most important microorganism in alcoholic fermentation. Six loci, ADP1, RPN2, GLN4, ACC1, MET4, and NUP116, in S. cerevisiae genome were selected as MLST markers. To investigate genetic diversity within S. cerevisiae, 42 S. cerevisiae isolated from natural sources in Korea as well as six S. cerevisiae obtained from Genbank and four industrial S. cerevisiae were examined using MLST. Twenty-six polymorphic sites were found in the six loci. Among them, ACC1 had the most genetic variation with eight polymorphic sites. MLST differentiated the 52 strains into three clades. Alcohol fermentation results revealed that S. cerevisiae in Clade III produced less alcohol than those in Clades I and II. These results suggested that MLST is a powerful tool to differentiate S. cerevisiae and can potentially be used to select S. cerevisiae suitable for industrial use.

경기도 식중독에서 분리된 Clostridium perfringens의 유전적 특성 분석

박성희,최옥경,정진아,김운호,이예은,박광희,윤미혜,Park, Sung-Hee,Choi, Ok-Kyung,Jeong, Jin-A,Kim, Woon-Ho,Lee, Yea-Eun,Park, Kwang-Hee,Yoon, Mi-Hye 한국미생물학회 2016 미생물학회지 Vol.52 No.3

질병관리본부에서 2012년 이후 수인성식품매개질환 실험실 진단실무지침에 cpb2 유전자를 포함시킨 후, 2013-2014년 경기도의 C. perfringens에 의한 식중독이 원인불명을 제외하고 가장 많이 발생되었으며, 그 발생률이 2011-2012년에 비해 큰 폭으로 증가하였다. 따라서 경기도내 유행하는 toxinotype을 파악하고, PFGE, MLST를 통해 이들의 분자역학적 연관성을 연구함으로서 C. perfringens에 의한 식중독 발생 시 역학조사 기초자료로 활용하고자 하였다. 2013-2014년 경기도에서 분리된 120주의 C. perfringens 중 cpe 보유균주는 49주, cpb2 보유균주는 71주였다. 발생건별로 살펴보면, cpe 단독발생건은 2건(10주), cpb2 단독발생건은 7건(45주), cpe, cpb2 혼합발생건은 7건(65주)로 cpb2 단독발생과 cpe, cpb2 혼합발생이 대부분을 차지하였다. Toxinotype PCR 결과, 120주 모두 C. perfringens에 의한 식중독의 주요 타입인 A로 밝혀졌다. PFGE 분석 결과, 53.5-100%의 유사도와 75 유형으로 나뉘었다. 65% 이상을 기준으로 했을 때 5가지 그룹으로 나뉘어졌다. A, C, D, E 그룹은 1개의 균주를 제외하고 모두 cpb2 보유균주로 이루어졌고, B 그룹은 1개의 균주를 제외하고 모두 cpe 보유균주로 구성되었다. 2014년 안산상록구 식중독 4주와 2014년 수원 권선구 식중독 3주를 제외하고, 64 cpb2 보유균주들은 대부분 다양한 유전자패턴을 보였다. 41 cpe 보유균주 중 3개의 균주를 제외하고, 2013년 부천원미구, 성남분당구, 2014년 안산상록구, 평택, 김포, 화성 식중독 모두 각각 동일한 유전자 패턴을 보였다. 2013 수원영통구 식중독은 2가지 cpe 유전형 패턴을 보였다. MLST 분석 결과, 크게 P-cpe 및 cpb2 그룹과 C-cpe 그룹으로 나뉘어 졌고, 세세하게 11개의 cluster로 나뉘어졌다. 경기도에서 분리된 31개 균주 중, 16 cpb2 보유균주와 2014-06-03 cpe 보유균주는 1-7 cluster에 속해있었고, 14 cpe 보유균주는 모두 8-11 cluster에 속해있었다. 하나의 cpe 보유균주를 포함하여 cpb2 보유균주들은 P-cpe 그룹과 건강한 사람에서 분리된 cpb2 그룹들 사이에 산재되어 cluster되었고, cpe 보유균주는 C-cpe 그룹에 속해있었다. 2014-06-03주의 cpe gene은 plasmid에 존재하고, 나머지 cpe 보유균주의 cpe gene은 모두 chromosome에 존재함을 추정 할 수 있었다. PFGE 및 MLST 분석 결과, cpe 보유균주에 비해 cpb2 보유균주가 훨씬 다양하고 복잡한 유전자패턴을 나타내며, cpe 유전자 보유균주의 경우 단일 유전자형이거나 유사도가 높은 유전자형으로 이루어져 있음을 알 수 있었다. cpe 보유균주의 경우 집단식중독의 원인균 파악이 용이하였으나, cpb2 보유균주의 경우 2 발생건을 제외하고 역학적인 연관성이 낮음을 확인 할 수 있었다. Clostridium perfringens is both a ubiquitous environmental bacterium and a major cause of human gastrointestinal disease, and C. perfringens food poisoning ranks among the most common gastrointestinal diseases in developed countries. 120 isolates of C. perfringens were obtained from food-poisoning outbreaks in 2013~2014, Gyeonggi-do. Using PCR, all 120 isolates were identified as C. perfringens type A. Of the tested isolates, 49 isolates carried the cpe gene, 71 isolates carried the cpb2 gene. The outbreak cases of cpb2 and cpe /cpb2 genes were 7 and 7, whereas the outbreak cases of cpe-gene were 2. The epidemiological relationship between C. perfringens isolates has previously been investigated chiefly by pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). The genetics relatedness of the isolates raged from 53.5-100% and 75 district PFGE type were observed. The PFGE results revealed a wide genetic diversity among the 64 cpb2 carrying isolates (except 7 isolates), while 46 cpe-carrying isolates (except 3 isolates) showed a high genetic similarity. The MLST analysis revealed that 14 cpe isolates (cpe-chromosomal isolates) belong to a distinct cluster that is significantly distant from all the other cpb2 isolates (cpe-plasmid carrying and cpe-negative isolates). The isolates carrying a cpb2 appear to be rarely related, and are more variable than chromosomal cpe isolates. The results suggest that the cpe-positive outbreak isolates showed close genetic relation, whereas the cpb2-positive isolates revealed a wide genetic diversity.

학업에 어려움을 겪는 대학생의 성격, 동기, 정서, 행동특성과 학업성취도 수준과의 관계

이희원(Heewon Lee),최영진(Youngjin Choi),이미숙(Misook Lee) 한국열린교육학회 2024 열린교육연구 Vol.32 No.2

본 연구는 대학공부에 어려움을 겪는 학부생을 대상으로 학습전략검사(MLST-Ⅱ)를 수행한 뒤 그 결과를 기반으로 학업성취도에 영향을 주는 요인을 분석하기 위하여 수행되었다. 이를 위하여 학습전략검사(MLST-Ⅱ)에 참여한 학부생 789명의 학업성취도 수준에 따라 하, 중하, 중, 중상, 상 등 5가지 집단으로 구분하고 각 집단별 성격, 동기, 정서, 행동영역의 수준과 각 영역에 포함된 요소와 학업성취도 수준과의 관계를 분석하였다. 분석 결과 우울, 불안, 짜증 등의 정서특성이 집중이나 시간관리 등의 행동을 방해하고, 자기 효능감이나 결과 기대, 성실성 등의 성격특성에도 영향을 미치는 것을 확인하였다. 특히 학업성취가 낮은 집단일수록 이들이 겪는 우울, 불안, 짜증 등의 심리적 어려움은 학습동기를 저하시켜서 학업성취도 수준을 낮추는 결과를 초래하였다. 대학생의 학업성취도 수준을 높이기 위해서는 우울, 짜증, 불안의 정서특성 수준을 낮추고 학업동기를 향상시키는 것이 중요한 요인임을 확인하였다. 본 연구 결과는 학업성취도 수준과 관련된 특성과 요소를 고려하여 학업 문제를 해소하는데 도움을 줄 수 있는 구체적인 상담전략의 근거로 활용될 수 있을 것이다. This study was conducted through an MLST-II diagnosis on undergraduate students experiencing academic difficulties with their undergraduate studies, with an aim to identify and analyze the factors that were affecting their academic achievement. For this purpose, the 789 undergraduate students who participated in the MLST-II diagnosis were divided into five groups according to their level of academic achievement: low, low-medium, medium, high-medium, and high. For each group, an analysis was conducted on the levels of personality, motivational, emotional, and behavioral characteristics of the students. The correlation between the sub-characteristics in each area and academic achievement was also analyzed. The results of the analysis confirmed that emotional characteristics such as depression, anxiety, and irritability interfered with behaviors such as concentration and time management, and also had an effect on personality characteristics such as self-efficacy, outcome expectancies, and conscientiousness. In particular, psychological difficulties such as depression, anxiety, and irritability decreased the students’ motivation to learn, more so in groups with low academic achievement, which resulted in a lower level of academic achievement. This confirmed the importance of addressing emotional characteristics, such as depression, anxiety, irritability, and improving academic motivation in order to increase the level of academic achievement of undergraduate students. The results of this study may be used as a basis for utilizing specific counseling strategies that take into consideration characteristics and factors related to academic achievement in order to resolve academic issues.

Wolbachia Sequence Typing in Butterflies Using Pyrosequencing

( Sung Mi Choi ),( Su Kyoung Shin ),( Gil Sang Jeong ),( Ha Na Yi ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.9

Wolbachia is an obligate symbiotic bacteria that is ubiquitous in arthropods, with 25?70% of insect species estimated to be infected. Wolbachia species can interact with their insect hosts in a mutualistic or parasitic manner. Sequence types (ST) of Wolbachia are determined by multilocus sequence typing (MLST) of housekeeping genes. However, there are some limitations to MLST with respect to the generation of clone libraries and the Sanger sequencing method when a host is infected with multiple STs of Wolbachia. To assess the feasibility of massive parallel sequencing, also known as next-generation sequencing, we used pyrosequencing for sequence typing of Wolbachia in butterflies. We collected three species of butterflies (Eurema hecabe, Eurema laeta, and Tongeia fischeri) common to Korea and screened them for Wolbachia STs. We found that T. fischeri was infected with a single ST of Wolbachia, ST41. In contrast, E. hecabe and E. laeta were each infected with two STs of Wolbachia, ST41 and ST40. Our results clearly demonstrate that pyrosequencing-based MLST has a higher sensitivity than cloning and Sanger sequencing methods for the detection of minor alleles. Considering the high prevalence of infection with multiple Wolbachia STs, next-generation sequencing with improved analysis would assist with scaling up approaches to Wolbachia MLST.

임상 검체에서 분리된 Candida albicans의 MLST를 이용한 유전적 변이 특성

김희진 ( Hee-jin Kim ),김상하 ( Sang-ha Kim ),김성현 ( Sunghyun Kim ),유영빈 ( Young-bin Yu ),김영권 ( Young-kwon Kim ) 대한임상검사과학회 2018 대한임상검사과학회지(KJCLS) Vol.50 No.3

본 연구에서는 국내 대전 소재 3차 병원 임상에서 분리된 Candida albicans 40 균주를 대상으로 균주 분리원에 따라 7종류의 housekeeping gene에 대한 염기서열 변이를 확인하고 MLST 분석을 통해 균주간의 계통학적 연관성에 대한 연구를 수행하여 다음과 같은 결과를 얻었다. Phylogenetic tree 분석 결과 sub-cluster 1로 central line blood (2), others (5), sputum (4), urine (7)을 포함해 총 18개가 분류되었으며, sub-cluster 2로는 central line blood (1), others (5), peripheral blood (6), sputum (1), urine (1)을 포함해 총 14개가 분류되어 동일 채취 부위에서 분리된 균주는 유전학적으로 유사성을 가지고 있을 가능성이 있음을 확인하였다. 앞으로 분리지역과 상병 등에 따른 C. albicans 유전자들의 변이 추세에 대한 자료의 축적과 임상 검체에 따른 계통학적 관계를 추정하여 감염병 연구 및 역학적 감시체계 구축에 도움이 될 것으로 생각된다. In this study, multi-locus sequence typing (MLST) analysis of 40 clinically isolated Candida albicans in tertiary hospitals in Daejeon, Korea, confirmed the nucleotide sequence and phylogenetic relationships of the strains collected from different specimen sources. The general variations found in seven different housekeeping genes of C. albicans, collected from urine and sputum, peripheral blood, central line blood, and other specimens, were analyzed. The phylogenetic tree was divided into 18 sub-clusters (1), a central line blood (2), others (5), sputum (1), peripheral blood (6), sputum (1), and urine (1), and the isolates at the same site were confirmed to have genetic similarity. Consequently, genetic similarity and the potential relevance were found in the strains collected from the same specimen sources. MLST analysis of C. albicans suggests that persistent data accumulation of phylogenetic gene variations of C. albicans may help establish infectious disease studies and epidemiological surveillance systems.

Prevalence and Characteristics of Antimicrobial-Resistant Staphylococcus aureus and Methicillin-Resistant Staphylococcus aureus from Retail Meat in Korea

김용훈(Yong Hoon Kim),김한솔(Han Sol Kim),김석환(Seokhwan Kim),김미경(Migyeong Kim),곽효선(Hyo Sun Kwak) 한국축산식품학회 2020 한국축산식품학회지 Vol.40 No.5

This study was to investigate the prevalence and characteristics of antimicrobial-resistant Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) from 4,264 retail meat samples including beef, pork, and chicken in Korea between 2013 and 2018. A broth microdilution antimicrobial susceptibility testing was performed for S. aureus. Molecular typing by multilocus sequence typing (MLST), spa typing, and pulsed-field gel electrophoresis (PFGE), was performed on mecA-positive S. aureus strain. S. aureus was isolated at a rate of 18.2% (777/4,264), of which MRSA comprised 0.7% (29 strains). MLST analysis showed that 11 out of the 29 MRSA isolates were predominantly sequence type (ST) 398 (37.9%). In addition, ST72, ST692, ST188, ST9, and ST630 were identified in the MRSA isolates. The spa typing results were classified into 11 types and showed a high correlation with MLST. The antimicrobial resistance assays revealed that MRSA showed 100% resistance to cefoxitin and penicillin. In addition, resistance to tetracycline (62.1%), clindamycin (55.2%), and erythromycin (55.2%) was relatively high; 27 of the 29 MRSA isolates exhibited multidrug resistance. PFGE analysis of the 18 strains excluding the 11 ST398 strains exhibited a maximum of 100% homology and a minimum of 64.0% homology. Among these, three pairs of isolates showed 100% homology in PFGE; these results were consistent with the MLST and spa typing results. Identification of MRSA at the final consumption stage has potential risks, suggesting that continuous monitoring of retail meat products is required.

충청지역에서 분리된 사람 유래 대장균 및 닭 유래 대장균의 항균제 내성 및 MLST를 이용한 유전형의 분포 조사

김세미 ( Semi Kim ),성지연 ( Ji Youn Sung ),최승구 ( Seung Gu Choi ) 대한임상검사과학회 2015 대한임상검사과학회지(KJCLS) Vol.47 No.2

Antimicrobial resistant bacteria has recently emerged and been disseminated in livestock environments because of excessive use of antimicrobial agents for the therapeutic and growth promotion purposes to food animals. In particular, there is potential for multidrug-resistant bacteria that can be transmitted from animals to mankind. In this study, we investigated the genotypes of E. coli strains isolated from humans and chickens using multi-locus sequence typing (MLST) and antimicrobial resistance patterns by disk diffusion method along with integron study involving antimicrobial resistance mechanisms. From July 2013 to July 2014, E. coli strains isolated from clinical specimens (n=44) and poultry chickens (n=34). ST131 (n=20) was most common in human-derived E. coli. ST752 (n=7) was most common in chicken-derived E. coli, with four isolates each for ST117, ST189, and ST69. Of the 44 E. coli strains isolated from humans, 25 of had a class 1 integron, as opposed to only 11 of 34 strains in the E. coli isolated from chickens. There were differences in genotypes and antimicrobial resistance patterns between the chicken-derived and the human-derived E. coli

Molecular discrimination of <i>Lactobacillus brevis</i> strains isolated from food products in South Korea using multilocus sequence typing

Sharma, Anshul,Kaur, Jasmine,Lee, Sulhee,Park, Young-Seo Elsevier 2017 FOOD SCIENCE AND TECHNOLOGY -ZURICH- Vol.86 No.-

<P><B>Abstract</B></P> <P> <I>Lactobacillus brevis</I> plays an important role in the manufacture of fermented foods. The aim of the present study was to know the genetic relationships among <I>L. brevis</I> isolates using multi-locus sequence typing of seven different housekeeping genes. 13 isolates were collected from different food products of South Korea. The results of the sequence analysis indicated 13 different sequence types (STs), each represented by a single strain. Among the seven loci, a total of 83 polymorphic sites were detected. The number of polymorphic sites varied from 4 (<I>rpoB</I>) to 24 (<I>recA</I>), whereas nucleotide diversity per site among the seven genes varied from 0.00161 (<I>rpoB</I>) to 0.01585 (<I>recA</I>). The number of alleles varied from 2 (<I>dnaK</I>) to 13 (<I>recA</I>). SplitsTree recombination was also performed for all seven loci and concatenated sequences. Phylogenetic analysis divided the 13 strains into three major groups based on their relationships. The minimum spanning tree revealed no clear relationship between the and isolation source or location and <I>L. brevis</I> isolates. This is the first genetic diversity study of <I>L. brevis</I> isolates from South Korea.</P> <P><B>Highlights</B></P> <P> <UL> <LI> An MLST technique was developed for characterization of 13 <I>L. brevis</I> strains from South Korea. </LI> <LI> Seven housekeeping genes were selected and analyzed for MLST. </LI> <LI> A total of 83 polymorphic sites varying from 4 to 24 in each species were identified. </LI> <LI> Thirteen sequence types were generated with allele numbers varying from 2 to 13. </LI> </UL> </P>

대학생의 시간관리전략을 활용한 자기조절학습 및 학습전략 향상 학습컨설팅 사례연구

김동주(Kim Dong Joo) 한국교육심리학회 2023 학교심리와 학습컨설팅 Vol.8 No.1

본 사례는 D여자대학교 학사경고자를 대상으로 하는 학습컨설팅 프로그램에서 대상 학생이 직접 의뢰하여 2021.10.15.-2021.12.5.까지 총 8회기 진행하였다. 학습컨설팅 의뢰사유는 대학생활을 적응적으로 참여하기 위한 학습태도 및 학습전략을 향상하는 것이다. 학습컨설팅 진단도구는 MLST-2 학습전략검사와 CAT 대학적응능력검사를 활용하였다. 학습컨설팅의 목표는 학생의 자기조절학습태도를 수립하여 성적향상과 앞으로의 진로설정에 도움을 주는 것이다. 학습컨설팅 실행은 학습동기와 학습태도 향상을 위한 시간관리전략을 활용였으며, 매 회기 실행결과에 대해 자기반성의 개입방법을 활용하였다. 학습컨설팅 결과 스스로 생활습관을 돌아보는 태도를 함양하게 되면서 시간관리와 자기주도학습태도의 향상이 나타났으며, 학사경고에서 2학기 성적향상장학금 대상 학생으로 선정되었다. 자신의 진로 설정의 목표를 구체화하기 위한 행동 목표를 세우는 태도도 보였다. 본 학습컨설팅 사례는 학사경고 대학생의 자기조절학습태도와 학교적응의 상태를 구체적으로 확인하여 학습컨설팅을 통해 대상 학생의 대학생활적응과 학습태도 함양을 확인한 사례이다. 본 사례는 학사경고대상 학생에게 개인적 상황과 대학 생활 현황을 종합적으로 고려한 학습컨설팅 프로그램이 중요하며, 이들의 적응적인 대학생활과 자기조절학습의 향상을 도모하기 위해 대학 내 주요 센터와 통합적으로 연계하여 지원하는 것이 중요함을 시사하였다. This case is a learning consulting program for academic warnings at D Womens University and was conducted a total of eight times from October 15, 2021 to December 5, 2021. The reason for requesting learning consulting is to improve learning attitudes and learning strategies to adaptively participate in college life. The MLST-2 learning strategy test and CAT university adaptability test were used as the learning consulting diagnostic tools. The goal of learning consulting was to establish students self-regulated learning attitudes and to help them improve their grades and set future careers. The implementation of learning consulting used time management strategies to improve learning motivation and learning attitude. As a result of learning consulting, time management and self-directed learning attitudes improved as they developed a self-reflection attitude to reflect on their lifestyle, and they were selected as students for the second semesters performance improvement scholarship in the academic warning. There was also an attitude of setting an action goal to specify the goal of setting ones career path. This case is It suggested that learning consulting programs that comprehensively consider personal situations and college life are important for academic warnings, and that it is important to support them in integration with major centers in the university to improve their adaptive college life and self-regulated learning.

2007년부터 2015년까지 분리된 반코마이신 내성 Enterococcus faecium 의 MLST 변화 추세

김준,권영인,이위교 대한임상미생물학회 2017 Annals of clinical microbiology Vol.20 No.3

Background: Multilocus sequence typing (MLST) is useful in determining the long-term evolutionary process and minimizes differences in experimental results across individuals and laboratories. It is also useful in determining evolutionary origins and backgrounds of bacterial species. This study carries out MLST analysis on VanA-type vancomycin-resistant Enterococcus faecium isolated from patient specimens in a single university hospital over nine years in order to observe changes in genetic evolution over time. Methods: During the years from 2007 to 2015, 44 clinical isolates of vanA-containing E. faecium were collected from Ajou University Hospital in Korea. Species were identified by the VitekII system (bioMerieux, USA), and antibiotic susceptibility testing was performed by disk diffusion and E-test according to Clinical and Laboratory Standards Institute (CLSI) guidelines. To determine genetic relatedness, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF M/S) was employed. To characterize clonal diversity, MLST analysis was used. Results: All isolates were highly resistant to ampicillin, ciprofloxacin, and vancomycin but showed variable levels of resistance to teicoplanin. The 44 clinical isolates were genetically unrelated according to MALDI-TOF M/S analysis. MLST showed that the clinical isolates harbored 6 sequence types (ST), with ST17 (n=19) being the most common, followed by ST78 (n=13), ST192 (n=6), ST64 (n=4), ST262 (n=1), and ST414 (n=1). Conclusion: The MLST analysis showed that the sequence types of most isolates belonged to clonal complex 17 This is consistent with outbreaks in hospitals. We had single observations for ST262 and ST414, suggesting that they were random occurrences. MLST can be useful for speculating the genetic evolution of VanA-containing E. faecium isolates. (Ann Clin Microbiol 2017;20:-73)