• 대한임상검사과학회지
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• 제52권2호
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• pp.136-142
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• 2020

세균의 항균제 내성율은 지난 몇십년 동안 지속적으로 상승하였으며 mobile genetic elements를 통한 항균제내성인자들의 전파는 다제내성세균의 출현 및 확산을 가중시켰다. 본연구에서는 임상검체에서 분리된 aminoglycoside에 비감수성 대장균 33주를 대상으로 mobile genetic elements를 통해 전파될 수 있는 aminoglycoside 내성인자를 조사하였다. 16S ribosomal RNA methyltransferases (RMTases)와 aminoglycoside-modifying enzyme (AME)유전자가 PCR과 DNA 염기서열분석을 통해 검출되었다. 그 결과 aac(3')-II 유전자(54.5%)를 포함하고 있는 균주가 제일 많았으며 그 다음으로 aph(3')-Ia 유전자(18.2%)가 많았고 aac(6')-Ib 유전자(15.2%)를 포함하는 균주도 있었다. RMTase 유전자는 본 연구에서는 검출되지 않았다. aac(3')-II 유전자를 포함하고 있는 18균주 중 17균주가 gentamicin에 내성을 보였으며 이중 16균주는 tobramycin에도 내성을 보였다. aac(6')-Ib 유전자를 포함하고 있는 5균주는 모두 tobramycin에 내성을 보였다. 본 연구에서 AME 유전자를 획득하는 것은 사람에서 분리된 대장균이 aminoglycoside에 내성을 나타내는 중요한 기전 중 하나임이 확인되었다. 사람으로부터 분리된 세균을 대상으로 지속적으로 항균제 내성인자를 조사하는 것은 내성세균의 확산을 막는데 필요할 것으로 사료된다.

• Fisheries and Aquatic Sciences
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• 제12권3호
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• pp.171-178
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• 2009

The Perciformes include approximately 40% of all bony fishes and are the largest order of vertebrates. This order includes some of the most economically relevant marine fishes, particularly the red seabream, black seabream and rock bream. A 409 bp fragment of the cytochrome b (cyt b) gene and 403 bp and 518 bp fragments of ribosomal RNA (12S and 16S rRNA, respectively) were sequenced from five populations of natural and cultured red seabreams, natural black seabream, and natural and cultured rock breams. The mitochondrial DNA sequences were utilized for the genetic identification and population structural analyses of these three species. Phylogenetic relationships of intra- and inter-species were elucidated using three types of molecular genetic markers from three species of the order Perciformes in Korea. We noted no significant differences in the intra-specific variation of the cyt b and rRNA genes in each population however, inter-specific divergences were greater than intra-specific variation. Inter-specific variation was induced more by transition than transversion type in the cyt b and rRNA genes. The cyt b gene and rRNA genes make it possible to determine the inter-species divergence. The rRNA genes have more conserved sequences than the cyt b gene. Therefore, these genes are expected to prove useful among species belonging to the different genera or families.

• Journal of Microbiology and Biotechnology
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• 제20권5호
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• pp.853-861
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• 2010

High substrate costs decrease the profitability of polyhydroxyalkanoates (PHAs) production, and thus low-cost carbon substrates coming from agricultural and industrial residuals are tested for the production of these biopolymers. Among them, crude glycerol, formed as a by-product during biodiesel production, seems to be the most promising source of carbon. The object of this study was to characterize the mixed population responsible for the conversion of crude glycerol into PHAs by cultivation-dependent and -independent methods. Enrichment of the microbial community was monitored by applying the Ribosomal Intergenic Spacer Analysis (RISA), and the identification of community members was based on 16S rRNA gene sequencing of cultivable species. Molecular analysis revealed that mixed populations consisted of microorganisms affiliated with four bacterial lineages: ${\alpha}$, ${\gamma}$-Proteobacteria, Actinobacteria, and Bacteroides. Among these, three Pseudomonas strains and Rhodobacter sp. possessed genes coding for polyhydroxyalkanoates synthase. Comparative analysis revealed that most of the microorganisms detected by direct molecular analysis were obtained by the traditional culturing method.

• 생명과학회지
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• 제17권1호
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• pp.162-165
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• 2007

Brown Ring Disease (BRD) is a bacterial disease caused by Vibrio tapetis which affects cultured clam Ruditapes philippinarum and causes heavy economic losses on Atlantic coasts of france, Spain and England. In this study, to evaluate the effective detection of the pathogen, specific primer set based on 16S ribosomal RNA (rRNA) sequences designed for rapid detection of V. tapetis. Polymerase chain reaction (PCR) with this primer set produced the specific band for each V. tapetis. The length of PCR product using designed primer set of Vbts-F and Vbts-R was about 400 bp. Therefore, these primers will be provided with a basic tool for rapid detection of V. tapetis in the various cases such as examination of imported aquatic products, diagnosis of aquatic organisms, and etc.

• 한국임상수의학회지
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• 제32권2호
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• pp.191-195
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• 2015

7년령, 중성화 수컷 고양이가 무기력과 식욕부진으로 내원하였다. 실험실 검사는 말초혈액 호중구에서 중등도의 퇴행성 변화, free 및 total thyroxine의 농도 감소 및 혈액배양에서 세균증식이 관찰되었다. 16S ribosomal RNA 및 heat shock protein 60 유전자 검사 결과 세균은 Enterobacter cloacae로 확인되었다. 항생제 최소억제농도 평가결과 16개 항생제에 대한 다약제 내성이 관찰되었다. 중합효소연쇄반응 및 시퀀싱 결과 $bla_{TEM-1}$, $bla_{CTX-M-15}$ 및 플라스미드 유래 $bla_{ACT-1}$ 유전자에 대한 양성 반응이 관찰되었으며, 결과적으로 확인된 세균이 광범위 beta-lactamase 및 ampC beta-lactamase를 합성하는 플라스미드를 보유한 것을 확인하였다. 환자는 1개월 간 항생제와 levothyroxine 치료를 받은 후 증상이 호전되었고, 치료 후 갑상선 기능검사와 혈액배양 결과 이상소견은 소실되었다. 이 증례는 고양이의 지역사회획득 다약제내성 E. cloacae에 의한 정상 갑상샘 질환 증후군의 첫 예이다. 신속한 진단과정과 적절한 항생제 선택에 의해 이환된 고양이는 패혈증으로부터 회복되었다.

• International Journal of Oral Biology
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• 제42권3호
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• pp.143-147
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• 2017

In a previous study, Peptoniphilus mikwangii was isolated from the human oral cavity as a new species. The purpose of this study was to develop P. mikwangii-specific PCR primers. The PCR primers were designed, based on the nucleotide sequence of 16S ribosomal RNA (16S rDNA). The specificity of the primers was tested using genomic DNAs of 3 strains of P. mikwangii and 27 strains (27 species) of non-P. mikwangii bacteria. The sensitivity of primers sensitivity was determined using PCR, with serial dilutions of the purified genomic DNAs (4 ng to 4 fg) of P. mikwangii KCOM $1628^T$. The data showed that P. mikwangii-specific qPCR primers (B134-F11/B134-R1 & B134-F5/B134-R5) could detect only P. mikwangii strains, and 400 fg or 40 fg of P. mikwangii genome DNA. These results suggest that PCR primers are useful in detecting P. mikwangii from the oral cavity.

• 생명과학회지
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• 제15권3호
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• pp.479-485
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• 2005

2002년 2월부터 2005년 2월까지 성인 및 소아 호홉기질환자 994명의 상기도 도말물에서 M. pneumoniae 균주를 분리하고, 분리 균주의 ciprofloxacin, ofloxacin, minecline, tetracycline, sparfloxacin, josamycin, erythromycin에 대한 감수성 검사를 실시하였으며, 분리된 균주의 235 rRNA domain II와 V에서 erythromycin저항성 변이가 일어났는가를 PCR과 유전자 염기서열분석으로 erythromycin에 감수성인 M. pneumonine균주의 염기서열과 비교분석하여 확인하였다. 호흡기질환자에서 M. pneumoniae의 분리율은 123/994$(12.4\%)$이었으며, 분리된 M. pneumoniae 균주의 minocycline, sparfloxacin, tetracycline, ciprofloxacin, ofloxacin, josamycin, erythromycin MIC 범위는 각각 $0.015\~0.25,\;0.06\~0.5,\;0.06\~0.5,\;0.25\~0.5,\;0.25\~0.5,\;0.015\~8.0,\;0.015\~8.0{\mu}m$이었다. 분리 동정된 M. pneumoniae 균주 중에서 erythromycin에 저항성인 균주가 60주$(48.8\%)$였으며, 모두가 ribosomal protein L4 영역과 23S rRNA domain V에 내성변이가 일어났으며, 이 중 2균주는 23S rRNA domain II에도 변이가 일어난 균주도 있었다. 국내에서 분리되는 M. pneumoniae균주의 $48\%$가 erytomycin에 저항성인 균주이므로 앞으로 이 균에 의한 폐렴의 치료에 주의가 요구된다.

• Journal of Microbiology and Biotechnology
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• 제11권6호
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• pp.1046-1054
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• 2001

Bioleaching is the process in which insoluble metal sulfide is oxidized by specialized iron- and/or sulfur-oxidizing lithotrophic bacteria in acidic, metal-rich environments. Most of these processes are carried out by the genus Thiobacillus. Three novel Thiobacillus strains (Thiobacillus thiooxidans AZ11, Thiobacillus thiooxidans MET, and thiobacillus thiooxidans TAS) associated with bioleaching have been isolated from soil and sludge (Korean patent No. 1999-0073060 for T. thiooxidans AZ11, Korean patent No. 1999-0005798 for T. thiooxidans MET, and Korean patent No. 1999-0073059 for T. thiooxidans TAS). A partial sequence of 16S ribosomal RNA gene (16S rDNA) and the entire sequence of 16S/23S intergenic spacer region (ISR) were determined in the three above novel strains and in Thiobacillus ferrooxidans ATCC19859 as a reference strain. When phylogenetic analysis was performed based on G+C contents and sequence alignments, T. ferroxidans ATCC19859 was found to be closely related to previously registered T. ferrooxidans strains in a monophyletic manner, while the three novel T. thiooxidans strains were classified in a paraphyletic manner. Close examination on the base composition of 16S/23S ISR revealed that the 5\` part (nucleotide residues 21-200) was specific for the genus Thiobacillus. On the other end, the 3\` part (nucleotide residues 201-520) showed specificity in T. ferrooxidans strains, but not in T. thiooxidans strains. These results suggest that the proximal and distal halves of 16S/23S could be used as a genetic marker for the identification of the genus Thiobacillus and the species T. ferrooxidans, respectively.

• Journal of Veterinary Science
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• 제22권3호
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• pp.37.1-37.14
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• 2021

Background: Ticks are one of the most common external parasites in dogs, and are associated with the transmission of a number of major zoonoses, which result in serious harm to human health and even death. Also, the increasing number of pet dogs and pet owners in China has caused concern regarding human tick-borne illnesses. Accordingly, studies are needed to gain a complete understanding of the bacterial composition and diversity of the ticks that parasitize dogs. Objectives: To date, there have been relatively few reports on the analysis of the bacterial community structure and diversity in ticks that parasitize dogs. The objective of this study was to investigate the microbial composition and diversity of parasitic ticks of dogs, and assessed the effect of tick sex and geographical region on the bacterial composition in two tick genera collected from dogs in China. Methods: A total of 178 whole ticks were subjected to a 16S ribosomal RNA (rRNA) next generation sequencing analysis. The Illumina MiSeq platform targeting the V3-V4 region of the 16S rRNA gene was used to characterize the bacterial communities of the collected ticks. Sequence analysis and taxonomic assignment were performed using QIIME 2 and the GreenGene database, respectively. After clustering the sequences into taxonomic units, the sequences were quality-filtered and rarefied. Results: After pooling 24 tick samples, we identified a total of 2,081 operational taxonomic units, which were assigned to 23 phyla and 328 genera, revealing a diverse bacterial community profile. The high, moderate and low prevalent taxa include 46, 101, and 182 genera, respectively. Among them, dominant taxa include environmental bacterial genera, such as Psychrobacter and Burkholderia. Additionally, some known tick-associated endosymbionts were also detected, including Coxiella, Rickettsia, and Ricketssiella. Also, the potentially pathogenic genera Staphylococcus and Pseudomonas were detected in the tick pools. Moreover, our preliminary study found that the differences in microbial communities are more dependent on the sampling location than tick sex in the tick specimens collected from dogs. Conclusions: The findings of this study support the need for future research on the microbial population present in ticks collected from dogs in China.

• Journal of Microbiology and Biotechnology
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• 제15권6호
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• pp.1240-1249
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• 2005

Saccharomyces cerevisiae KNU5377 has potential as an industrial strain that can ferment wasted paper for fuel ethanol at $40^{\circ}C$ [15, 16]. To understand the characteristics of the strain, genome-wide expression was performed using DNA microarray technology. We compared the homology of the DNA microarray between genomic DNAs of S. cerevisiae KNU5377 and a control strain, S. cerevisiae S288C. Approximately $97\%$ of the genes in S. cerevisiae KNU5377 were identified with those of the reference strain. YHR053c (CUP1), YLR155c (ASP3), and YDR038c (ENA5) showed lower homology than those of S. cerevisiae S288C. In particular, the differences in the regions of YHR053c and YLR155c were confirmed by Southern hybridization, but did not with that of the region of YDR038c. The expression level of mRNA in S. cerevisiae KNU5377 and S288C was also compared: the 550 ORFs of S. cerevisiae KNU5377 showed more than two-fold higher intensity than those of S. cerevisiae S288C. Among the 550 ORFs, 59 ORFs belonged to the groups of ribosomal proteins and mitochondrial ribosomal proteins, and 200 ORFs belonged to the group of cellular organization. DIP5 and GAP1 were the most highly expressed genes. These results suggest that upregulated DIP5 and GAP 1 might take the place of ASP3 and, additionally, the sensitivity against copper might be contributable to the lowest expression level of copper-binding metallothioneins encoded by CUP 1a (YHR053c) and CUP1b (YHR055c) in S. cerevisiae KNU5377.