• Asian-Australasian Journal of Animal Sciences
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• 제20권2호
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• pp.283-294
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• 2007

Conventional culture-based methods of enumerating rumen microorganisms (bacteria, archaea, protozoa, and fungi) are being rapidly replaced by nucleic acid-based techniques which can be used to characterise complex microbial communities without incubation. The foundation of these techniques is 16S/18S rDNA sequence analysis which has provided a phylogenetically based classification scheme for enumeration and identification of microbial community members. While these analyses are very informative for determining the composition of the microbial community and monitoring changes in population size, they can only infer function based on these observations. The next step in functional analysis of the ecosystem is to measure how specific and, or, predominant members of the ecosystem are operating and interacting with other groups. It is also apparent that techniques which optimise the analysis of complex microbial communities rather than the detection of single organisms will need to address the issues of high throughput analysis using many primers/probes in a single sample. Nearly all the molecular ecological techniques are dependant upon the efficient extraction of high quality DNA/RNA representing the diversity of ruminal microbial communities. Recent reviews and technical manuals written on the subject of molecular microbial ecology of animals provide a broad perspective of the variety of techniques available and their potential application in the field of animal science which is beyond the scope of this treatise. This paper will focus on nucleic acid based molecular methods which have recently been developed for studying major functional groups (cellulolytic bacteria, protozoa, fungi and methanogens) of microorganisms that are important in nutritional studies, as well as, novel methods for studying microbial diversity and function from a genomics perspective.

• 한국균학회지
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• 제51권4호
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• pp.491-504
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• 2023

To explore fungal diversity in orchard soil where fire-blighted apple trees are buried, we collected soil samples from apple orchards in Chungju, Korea. Fungal isolates were obtained from DG18 agar and identified at the species level based on morphological features and phylogenetic analyses. The colony characteristics and microstructures were examined using a light microscope and a scanning electron microscope after culturing on potato dextrose agar (PDA), malt extract agar (MEA), Czapek yeast agar (CYA), and oatmeal agar (OA) The PCR-amplified products of the ITS1-5.8S-ITS2 region and 28S large subunit of the nuclear ribosomal RNA gene, as well as partial sequences of the β-tubulin, calmodulin, and translation elongation factor 1-α genes were sequenced and analyzed phylogenetically. Seven previously unknown fungal species were explored in Korea. All samples, including Aspergillus aureolatus, Botryotrichum atrogriseum, Dactylonectria novozelandica, Fusarium denticulatum, Paecilomyces tabacinus, Sarcopodium tibetense and Talaromyces stollii, had ascomycetes. Herein, we report their descriptions and features.

• Asian-Australasian Journal of Animal Sciences
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• 제18권4호
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• pp.483-489
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• 2005

To understand the molecular mechanisms that regulate intramuscular fat deposition and its release, cDNA clones expressed in adipose tissues of Korean cattle were identified by differential screening from adipose tissue cDNA library. By partial nucleotide sequencing of 486 clones and a search for sequence similarity in NCBI nucleotide databases, 245 clones revealed unique clones. By a functional grouping of the clones, 14% of the clones were categorized to metabolism and enzyme-related group (stearoyl CoA desaturase, lactate dehydrogenase, fatty acid synthase, ATP citrate lyase, lipoprotein lipase, acetyl CoA synthetase, etc), and 6% to signal transduction/cell cycle-related group (C/EBP, cAMP-regulated phosphoprotein, calmodulin, cyclin G1, cyclin H, etc), and 4% to cytoskeleton and extracellular matrix components (vimentin, ankyrin 2, gelosin, syntenin, talin, prefoldin 5). The obtained 245 clones will be useful to study lipid metabolism and signal transduction pathway in adipose tissues and to study obesity in human. Some clones were subjected to full-sequencing containing open reading frame. The cDNA clone of bovine homolog of human prefoldin 5 gene had a total length of 959 nucleotides coding for 139 amino acids. Comparison of the deduced amino acid sequences of bovine prefoldin 5 with those of human and mouse showed over 95% identity. The cDNA clone of bovine homolog of human ubiquitin-like/S30 ribosomal fusion protein gene had a total length of 484 nucleotides coding for 133 amino acids. Comparison of the deduced amino acid sequences of bovine ubiquitin-like/S30 ribosomal fusion protein gene with those of human, rat and mouse showed over 97% identity. The cDNA clone of bovine homolog of human proteolipid protein 2 mRNA had a total length of 928 nucleotides coding for 152 amino acids. Comparison of the deduced amino acid sequences of bovine proteolipid protein 2 with those of human and mouse showed 87.5% similarity. The cDNA clone of bovine homolog of rat thymosin beta 4 had a total length of 602 nucleotides coding for 44 amino acids. Comparison of the deduced amino acid sequences of bovine thymosin beta 4 gene with those of human, mouse and rat showed 93.1% similarity. The cDNA clone of bovine homolog of human myotrophin mRNA had a total length of 790 nucleotides coding for 118 amino acids. Comparison of the deduced amino acid sequences of bovine myotrophin gene with those of human, mouse and rat showed 83.9% similarity. The functional role of these clones in adipose tissues needs to be established.

• 생명과학회지
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• 제18권12호
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• pp.1771-1774
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• 2008

콩나물은 우리나라에서 오래 전부터 재배하여 온 채소로서 그 기호성이 매우 높으며 영양학적으로 우수하나 일부 열악한 재배환경으로 콩나물의 부패문제가 자주 발생해 왔다. 따라서 본 연구는 시중의 부패된 콩나물로부터 다양한 병원균을 분리함과 동시에 재래콩 유전자원으로부터 시중의 콩나물 부패병에 강한 품종을 탐색하고 선발된 내병성 계통의 생육특성을 조사하였다. 분리된 콩나물 부패균들 중 병원성이 강한 콩나물 부패균인 Pseudomonas sp. SN239을 분리하고 16S rRNA 염기서열을 동정한 결과 P. putita, P. plecoglossicida, P. monteilii 및 P. mevalonii와 근연관계를 보였으나 완전히 일치하지는 않았으므로 Pseudomonas sp. SN239는 새로이 동정된 콩나물 부패균으로 여겨진다. 또한 재래콩 194계통에 콩나물 부패병균 Pseudomonas sp. SN239을 접종하여 저항성을 검정한 결과, 이병성 계통은 심하게 부패되었으나 한국 고유계통 YNPCS3-19는 병원성이 없었으며 또한 지속적으로 생육하였다. 그러므로 부패균 저항성 계통 YNPCS3-19는 부패균 저항성 품종 육성에도 활용 가치가 크다고 판단된다.

• Parasites, Hosts and Diseases
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• 제52권3호
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• pp.299-304
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• 2014

This study aimed to identify the assemblages (or subassemblages) of Giardia duodenalis by using normal or nested PCR based on 4 genetic loci: glutamate dehydrogenase (gdh), triose phosphate isomerase (tpi), ${\beta}$-giardin (bg), and small subunit ribosomal DNA (18S rRNA) genes. For this work, a total of 216 dogs' fecal samples were collected in Guangdong, China. The phylogenetic trees were constructed with MEGA5.2 by using the neighbor-joining method. Results showed that 9.7% (21/216) samples were found to be positive; moreover, 10 samples were single infection (7 isolates assemblage A, 2 isolates assemblage C, and 1 isolate assemblage D) and 11 samples were mixed infections where assemblage A was predominant, which was potentially zoonotic. These findings showed that most of the dogs in Guangdong were infected or mixed-infected with assemblage A, and multi-locus sequence typing could be the best selection for the genotype analysis of dog-derived Giardia isolates.

• Parasites, Hosts and Diseases
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• 제41권4호
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• pp.181-188
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• 2003

A new species of Acanthamoeba was isolated from a freshwater fish in Korea and tentatively named Acanthamoeba sp. YM-4 (Korean isolate YM-4). The trophozoites were $11.0-23.0{\;}{\mu\textrm{m}}$ in length and had hyaline filamentous projections. Cysts were similar to those of A. culbertsoni and A. royreba, which were previously designated as Acanthamoeba group III. Acanthamoeba YM-4 can survive at $40^{\circ}C$, and its generation time was 19.6 hr, which was longer than that of A. culbertsoni. In terms of the in vitro cytotoxicity of lysates, Acanthamoeba YM-4 was weaker than A. culbertsoni, but stronger than A. polyphaga. On the basis of the mortality of experimentally infected mice, Acanthamoeba YM-4 was found to be highly virulent. The isoenzymes profile of Acanthamoeba YM-4 was similar to that of A. royreba. An anti-Acanthamoeba YM-4 monoclonal antibody, McAY7, was found to react only with Acanthamoeba YM-4, and not with A. culbertsoni. Random amplified polymorphic DNA marker analysis and RFLP analysis of mitochondrial DNA and of 18S small subunit ribosomal RNA, placed Acanthamoeba YM-4 in a separate cluster on the basis of phylogenetic distances. Thus the Acanthamoeba Korean isolate YM-4 was identified as a new species, and assigned as Acanthamoeba sohi.

• Parasites, Hosts and Diseases
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• 제62권1호
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• pp.139-144
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• 2024

Acanthamoeba infection is associated with keratitis in humans; however, its association with keratitis in dogs remains unclear. To investigate this possibility, we collected 171 conjunctival swab samples from dogs with eye-related diseases (65 with keratitis and 106 without keratitis) at Chungbuk National University Veterinary Teaching Hospital, Korea, from August 2021 to September 2022. Polymerase chain reaction identified 9 samples (5.3%) as Acanthamoeba positive; of these, 3 were from dogs with keratitis (4.6%) and 6 were from dogs without keratitis (5.7%). Our results indicated no significant association between Acanthamoeba infection and keratitis, season, sex, or age. All Acanthamoeba organisms found in this study had the genotype T4, according to 18S ribosomal RNA analysis. Acanthamoeba infection in dogs might have only a limited association with keratitis.

• 미생물학회지
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• 제55권1호
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• pp.69-73
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• 2019

향장원료 개선을 위한 미생물 탐색 실험을 통하여 Marinobacter salarius HL2708#2을 제주도의 용암 해수 환경에서 분리하였다. 균주 HL278#2의 완전한 게놈 서열을 분석하였으며, 원형 염색체는 4,304,603 bp이고 57.21% G+C이고 플라스미드는 244,163 bp이고 53.14% G+C였다. 4,180개의 단백질 코딩서열이 과 49개의 tRNA와 18개의 rRNA 유전자와 함께 확인되었다. 균주 HL2708# 2의 게놈은 알콜, 말토덱스트린/전분 및 단당류 대사 유전자를 보유하고 있었다. 호염성 및 중금속 저항성을 담당하는 유전자와 방향족 및 알칸 계열 탄화수소를 대사하는 유전자를 가지고 있는 것으로 분석되었다. Marinobacter salarius가 질산염 및 아질산염 환원능력이 없다고 알려져 있는 것과 달리, HL2708#2 균주는 질산염/아질산염 환원 효소, 질산염/질산염 운반체 및 질산염 모노 옥시게나제를 가지고 있는 것으로 보아 세포 체외의 니트로알켄을 활용할 수 있는 능력을 가진 것으로 사료된다.

• 한국임상수의학회지
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• 제31권3호
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• pp.194-198
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• 2014

Methicillin 내성 포도상구균은 전세계적으로 사람과 동물에서 중요한 병인체로 주목 받고 있다. 본 연구는 국내 말과 말을 취급하는 사람에서의 methicillin 내성 포도상구균 발생현황을 조사하고자 실시하였다. 국내 경주마 목장에 소재하는 총 195두의 말과 18명의 말을 취급하는 사람(8명의 수의사, 7명의 말 관리사, 3명의 동물병원 직원)을 대상으로 하였다. 면봉을 이용하여 한쪽 비강에서 시료를 채취하여 세균수송배지에 보관 후 5% 양 혈액배지에서 $37^{\circ}C$ 3일간 배양하여 포도상구균 존재여부를 확인하였다. 포도상구균은 16S rRNA 유전자 분석을 실시하여 동정하였으며, 동정된 포도상구균은 coagulase 검사를 실시하였다. Methicillin 저항성을 확인하기 위하여 oxacillin 디스크 검사와 함께 mecA 유전자 존재를 PCR을 통하여 확인하였다. 검사를 실시하였던 말 195두 중 64두가 포도상구균으로 동정되었으며, 이중 29두(44.6%)가 methicillin 내성 포도상구균으로 확인되었다. 말을 취급하는 18명 중 14명의 시료에서 포도상구균이 동정되었으며, 이중 12명(85.7%)의 시료에서 methicillin에 내성을 가지고 있는 포도상구균으로 확인되었다. 말과 사람에서 동정된 모든 methicillin 내성 포도상구균은 coagulase 음성으로 확인되었다. 또한 항생제의 사용기간이 긴 개체에서 사용기간이 짧았던 개체군보다 methicillin 내성 포도상구균이 높은 것으로 나타났다(p = 0.002). 본 연구결과는 사람과 말 사이에서 인수공통전파가 일어날 수 있음을 시사한다.

• Parasites, Hosts and Diseases
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• 제53권1호
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• pp.119-124
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• 2015

The objective of this study was to genetically characterize isolates of Giardia duodenalis and to determine if zoonotic potential of G. duodenalis could be found in stray cats from urban and suburban environments in Guangzhou, China. Among 102 fresh fecal samples of stray cats, 30 samples were collected in Baiyun district (urban) and 72 in Conghua district (suburban). G. duodenalis specimens were examined using light microscopy, then the positive specimens were subjected to PCR amplification and subsequent sequencing at 4 loci such as glutamate dehydrogenase (gdh), triose phosphate isomerase (tpi), ${\beta}$-giardin (bg), and small subunit ribosomal RNA (18S rRNA) genes. The phylogenetic trees were constructed using obtained sequences by MEGA5.2 software. Results show that 9.8% (10/102) feline fecal samples were found to be positive by microscopy, 10% (3/30) in Baiyun district and 9.7% (7/72) in Conghua district. Among the 10 positive samples, 9 were single infection (8 isolates, assemblage A; 1 isolate, assemblage F) and 1 sample was mixed infection with assemblages A and C. Based on tpi, gdh, and bg genes, all sequences of assemblage A showed complete homology with AI except for 1 isolate (CHC83). These findings not only confirmed the occurrence of G. duodenalis in stray cats, but also showed that zoonotic assemblage A was found for the first time in stray cats living in urban and suburban environments in China.