• 한국축산식품학회지
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• 제24권1호
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• pp.8-14
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• 2004

가축의 개체식별은 일반적으로 암호화된 코드를 부여한 이표를 활용하고 있으며 또한 생체에서 친자확인 검증을 위해 개체 혈액형 등이 활용되어 왔다. 그러나 생체 상태에서의 완벽한 개체 확인을 위한 수단으로 최근 유전자감식 기법이 널리 활용되고 있다. 이때 사용되는 유전자 표지는 소의 품종에 따라 매우 다양하게 발현되어 개체 확인 정확도를 높이기 위해 한우 집단에서 대상 유전자 표지의 유전자형 발현 양상을 분석하여 최적의 표지 유전자 표지를 설정하는 것이 필요하다. 따라서 본 연구는 한우의 원산지 추적 및 개체식별 검증 시스템에서 절절히 사용할 수 있도록 생체 유전자 감식기법에 소요되는 유전자 표지(genetic marker)를 개발하기 위해 수행되었다. 공시재료로는 후보 유전자 표지의 광범위한 한우집단 발현특성의 분석을 위해 국가 후대검정 집단 740두를 활용하였으며 도축되기 전 단계의 생축에서 분석된 유전자형과 도축 후 유통과정에서 분석된 유전자형을 이용한 개체 확인 여부의 검증을 위해 국내 브랜드한우 농가로부터 출하된 4두를 분석에 공시하였다. 후보 유전자 표지는 염색체 1번과 14번에서 확인되어 보고된 16종의 초위성체 DNA의 염기서열 정보를 이용하였다. 한우집단에서 나타난 각각의 대상 유전자 표지의 유전자형 분석결과를 보면 대립유전자는 최소 3개에서 최대 12였으며 이형접합체 발현율은 0.022∼0.824였다. 유효대립유전자수는 각각의 대상 유전자마다 3∼7의 범위를 보였으며 이들 중 6개의 유전자 표지를 설정하여 개체 확인을 실시할 경우 100%에 가까운 정확도가 나타난 것으로 추정되었다.

• 한국축산식품학회지
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• 제38권5호
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• pp.851-865
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• 2018

This study investigated the prevalence of Listeria monocytogenes in slaughterhouses, and determined serovars and genotypes, and antibiotic resistance of the isolates obtained from slaughterhouses and humans in Korea. Two hundred ninety samples were collected from feces (n=136), carcasses [n=140 (cattle: n=61, swine: n=79)], and washing water (n=14) in nine slaughterhouses. Eleven human isolates were obtained from hospitals and the Korea Center for Disease Control and Prevention. Listeria monocytogenes was enriched and identified, using polymerase chain reaction (PCR) and 16S rRNA sequencing. Serovars and presence of virulence genes were determined, and genetic correlations among the isolates were evaluated by the restriction digest patterns of AscI. Antibiotic resistance of L. monocytogenes isolates were examined against 12 different antibiotics. Of 290 slaughterhouse samples, 15 (5.17%) carcass samples were L. monocytogenes positive. Most L. monocytogenes isolates possessed all the virulence genes, while polymorphisms in the actA gene were found between carcass and human isolates. Serovars 1/2a (33.3%) and 1/2b (46.7%) were the most frequent in carcass isolates. Genetic correlations among the isolates from carcass and clinical isolates were grouped within serotypes, but there were low geographical correlations. Most L. monocytogenes isolates were antibiotic resistant, and some strains showed resistance to more than four antibiotics. These results indicate that L. monocytogenes are isolated from carcass and human in Korea, and they showed high risk serotypes and antibiotic resistance. Therefore, intensive attentions are necessary to be aware for the risk of L. monocytogenes in Korea.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제12권3호
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• pp.183-191
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• 2006

생물학 분야에서 유전자에 대한 연구가 활발하게 이루어지면서 유전자에 대한 정보 구축 및 통합에 대한 필요성이 대두 되었다. 그 결과 Gene Ontology Consortium은 W3C에서 제정한 온톨로지 기술언어인 OWL로 유전자에 대한 정보와 분류를 담고 있는 Gene Ontology를 구축하였다. 하지만 Gene Ontology를 위한 기존의 브라우저들은 키워드, 트리, 그래프 기반의 단순 검색만을 지원할 뿐 다양한 관계를 고려한 고급 정보 검색이 불가능하다. 본 논문은 실제 생물학 연구를 수행하는 사용자들이 Gene Ontology를 효과적이고 편리하게 사용할 수 있도록 하기 위해 다양한 온톨로지 검색 기법을 통합적으로 지원하는 방법을 제안하였다. 또한 질의어 입력대신 검색 중에 손쉽게 질의를 생성하는 기법과 생성된 질의를 SeRQL 질의로 변환하는 기법을 제안함으로써 온톨로지에서 지원하는 질의어에 독립적으로 손쉽게 질의를 생성하고 고급정보를 얻을 수 있도록 하였다. 그리고 이렇게 구축한 GO Guide 브라우저를 통해 Gene Ontology의 방대한 정보를 효과적으로 이용할 수 있음을 확인하였다.

• 대한수의학회지
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• 제60권3호
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• pp.173-177
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• 2020

Edible offal is easily contaminated by Escherichia coli (E. coli) and fluoroquinolone (FQ)-resistant E. coli is considered a serious public health problem, thus, this study investigated the genetic characteristics of FQ-resistant E. coli from edible offal. A total of 22 FQ-resistant E. coli isolates were tested. A double mutation in each gyrA and parC led the highest MIC. Four (18.2%) isolates carried plasmid-mediated quinolone resistance genes. The fimH, eaeA, escV, astA, and iucC genes were confirmed. Seventeen isolates (77.3%) were positive for plasmid replicons. The isolates showed high genetic heterogeneity based on pulsed-field gel electrophoresis patterns.

• 대한수의학회지
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• 제51권2호
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• pp.107-115
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• 2011

Theileria (T.) buffeli (formerly T. sergenti/T. orientalis) is the major hemo-protozoan distributed in the Far East Asian countries such as Korea, China and Japan. It is responsible for the clinical symptoms of anorexia, ateliosis, anemia, fever and icterus. It also causes abortion and sudden death under severe cases, resulting in economic losses for many livestock farms. The objective of this study was to analyze the genetic diversity of the major surface protein (Msp) gene in T. buffeli in Holstein in Korea, and we characterized the association of the diversification of the Msp gene and its relationship with the pathogenicity of Theileria. For this, complete blood counts and Theileria PCR sequence analysis were performed from 57 Holstein in Jeju Island. A total of 26 PCR positive Holstein (16 anemic and 10 non-anemic) were then randomly selected based on 18s rRNA sequence typing of the Theileria Msp gene. The DNA sequence of the T. buffeli Msp gene in Holstein showed 99.0%, 99.2%, 99.9%, 99.5%, 98.7%, 98.4% and 98.4% homology with T. sergenti, Theileria spp., T. sergenti, Theileria spp., Theileria spp., Theileria spp. and Theileria spp., respectively. The result showed a genetic variation of 57.7% (type I), 3.8% (type II), 15.4% (type III), 7.7% (type IV), 13.5% (type V) and 1.9% (type VI). Type I is the most frequent type in both anemic and non-anemic Holstein while type II was found in only non-anemic Holstein. This results of our study help confirm the diversity of Msp gene types and demonstrate that the gene type distribution of Msp genes varies among Theileria-infected Holstein in Jeju Island.

• Annals of Laboratory Medicine
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• 제38권6호
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• pp.545-554
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• 2018

Background: The increasing morbidity and mortality rates associated with Acinetobacter baumannii are due to the emergence of drug resistance and the limited treatment options. We compared characteristics of colistin-resistant Acinetobacter baumannii (CR-AB) clinical isolates recovered from patients with and without prior colistin treatment. We assessed whether prior colistin treatment affects the resistance mechanism of CR-AB isolates, mortality rates, and clinical characteristics. Additionally, a proper method for identifying CR-AB was determined. Methods: We collected 36 non-duplicate CR-AB clinical isolates resistant to colistin. Antimicrobial susceptibility testing, Sanger sequencing analysis, molecular typing, lipid A structure analysis, and in vitro synergy testing were performed. Eleven colistin-susceptible AB isolates were used as controls. Results: Despite no differences in clinical characteristics between patients with and without prior colistin treatment, resistance-causing genetic mutations were more frequent in isolates from colistin-treated patients. Distinct mutations were overlooked via the Sanger sequencing method, perhaps because of a masking effect by the colistin-susceptible AB subpopulation of CR-AB isolates lacking genetic mutations. However, modified lipid A analysis revealed colistin resistance peaks, despite the population heterogeneity, and peak levels were significantly different between the groups. Conclusions: Although prior colistin use did not induce clinical or susceptibility differences, we demonstrated that identification of CR-AB by sequencing is insufficient. We propose that population heterogeneity has a masking effect, especially in colistin non-treated patients; therefore, accurate testing methods reflecting physiological alterations of the bacteria, such as phosphoethanolamine-modified lipid A identification by matrix-assisted laser desorption ionization-time of flight, should be employed.

• 한국균학회지
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• 제49권4호
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• pp.455-467
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• 2021

Macrofungi are valuable resources as novel drug candidates, new biomaterials, and edible materials. Recently, genetic approaches pertaining to macrofungi have been continuously growing for their identification, molecular breeding, and genetic engineering. However, purification and amplification of fungal DNA is challenging because of the rigid cell wall and presence of PCR inhibitory metabolites. Here, we established a direct PCR method to provide a rapid and efficient method for PCR-grade macrofungal DNA preparation applicable to both conventional PCR and real-time PCR. We first optimized the procedure of lysis and PCR using the mycelia of Lentinula edodes, one of the most widely consumed macrofungal species. Lysates prepared by neutralizing with (NH₄)₂SO₄ after heating the mycelia in a mixture of TE buffer and KOH at 65℃ for 10 min showed successful amplification in both conventional and real-time PCR. Moreover, the addition of bovine serum albumin to the PCR mixture enhanced the amplification in conventional PCR. Using this method, we successfully amplified not only internal transcribed spacer fragments but also low-copy genes ranging in length from 500 to 3,000 bp. Next, we applied this method to 62 different species (54 genera) of macrofungi, including edible mushrooms, such as Pleurotus ostreatus, and medicinal mushrooms such as Cordyceps militaris. It was found that our method is widely applicable to both ascomycetes and basidiomycetes. We expect that our method will contribute to accelerating PCR-based approaches, such as molecular identification, DNA marker typing, gene cloning, and transformant screening, in macrofungal studies.

• 환경생물
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• 제29권4호
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• pp.286-295
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• 2011

Bacteria resistant to various antibiotics have recently become an issue of the utmost importance. Resistant strains are not uncommon, even in municipal drinking water sources. The health threat posed by resistant, pathogenic bacteria has serious ramifications for both public health and agriculture. In this study, we isolated antibiotic resistant bacteria from water samples from the Han River, Korea, which is contaminated by the wastewater from many industrial complexes, hospitals, agricultural and animal husbandry estates, and from wastewater treatment facilities. We determined the degrees of resistance to various antibiotics exhibited by the isolated strains. The similarities between the isolated $E.$ $coli$ strains were examined, using the pulsed field gel electrophoresis and multilocus sequence typing, in order to trace their origins and to explore the syntechnic adaptations and pathogenicity of the various strains and relate these to their genetic sequence. A total of 25 $E.$ $coli$ strains were isolated from six stations along the Han River. All the 25 strains exhibited resistance to ampicillin. We also investigated resistance to amoxicillin, clavulanic acid, cefazolin, cofoxitin, cefotaxime, cefpodoxime, ceftriaxone, cefepime, nalidixic acid, aztreonam, ciprofloxacin, streptomycin, gentamicin, chloramphenicol and imipenem. Based on the ESBL detection, 14 strains belonged to the ESBL producing strains. The number of the clonal complex producing strains was 5 among the 14 isolated strains. The 5 strains were included in the 168, 23, 38, 469, 156 clonal complex, respectively. The rest 9 strains were not included in the clonal complex, but showed independent STs.

• 생물정신의학
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• 제1권1호
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• pp.79-87
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• 1994

For the purpose of evaluating the human leukocyte antigen(HLA) disease-association with bipolar disorder, HLA class I and class II allelic frequencies were assessed in 37 bipolar patients and were compared to the data from normal population. HLA class 1 typing was performed with microlymphocytotoxicity method while class II(DRB1) genotyping with reverse dot blot hybridization and sandwich method. Statistical analysis consisted of relative risk, Haldane's modified relative risk, Fisher's exact test and Bonferoni's corrected P. The results were as follows : 1) Bipolar patients showed increased allelic frequency of HLA A3 which has statistical significance. 2) Allelic frequencies of HLA B7, B14 and B54 were higher, while those of B51 and B55 were lower in bipolar patients, but they were not statistically significant. 3) Both of increased frequencies of DR2 in bipolar patients and DR15 in normal controls had statistical significance. The results of the present study suggested that some of HLA allelic types might be associated with bipolar disorder. To clarify the genetic influence of HLA to bipolar disorder, we should do consecutive study of bipolar disorder with new information about HLA system including alleles.

• 한국미생물·생명공학회지
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• 제48권3호
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• pp.389-398
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• 2020

The prevalence of carbapenem-resistant Enterobacteriaceae (CRE) is increasing globally, resulting in high mortality rates. Although CRE is a relatively recent problem in Korea (the first case was not diagnosed until 2010), it is responsible for serious morbidities at an alarming rate. In this study, we carried out a molecular genetic analysis to determine the incidence of CRE and carbapenemase-producing Enterobacteriaceae (CPE) at a general hospital in Korea between August 2017 and August 2019. Forty strains of CPE were isolated from various clinical specimens and analyzed via antimicrobial susceptibility testing, polymerase chain reaction to detect β-lactamase genes, deoxyribonucleic acid sequencing, multilocus sequence typing, curing testing, and conjugal transfer of plasmids. The results demonstrated that all 40 isolates were multidrug-resistant. The fluoroquinolone susceptibility test showed that 75% of the Enterobacteriaceae isolates were resistant to ciprofloxacin, whereas 72.5% were resistant to trimethoprim-sulfamethoxazole. Further, conjugation accounted for 57.5% of all resistant plasmid transfer events, which is 4.3-fold higher than that observed in 2010 by Frost et al. Finally, the high detection rate of transposon Tn4401 was associated with the rapid diffusion and evolution of CPE. Our results highlight the rapid emergence of extensively drugresistant strains in Korea and emphasize the need for employing urgent control measures and protocols at the national level.