• BMB Reports
• /
• 제50권2호
• /
• pp.55-57
• /
• 2017

Toll-like receptor 4 (TLR4) together with MD2, one of the key pattern recognition receptors for a pathogen-associated molecular pattern, activates innate immunity by recognizing lipopolysaccharide (LPS) of Gram-negative bacteria. Although LBP and CD14 catalyze LPS transfer to the TLR4/MD2 complex, the detail mechanisms underlying this dynamic LPS transfer remain elusive. Using negative-stain electron microscopy, we visualized the dynamic intermediate complexes during LPS transfer-LBP/LPS micelles and ternary CD14/LBP/LPS micelle complexes. We also reconstituted the entire cascade of LPS transfer to TLR4/MD2 in a total internal reflection fluorescence (TIRF) microscope for a single molecule fluorescence analysis. These analyses reveal longitudinal LBP binding to the surface of LPS micelles and multi-round binding/unbinding of CD14 to single LBP/LPS micelles via key charged residues on LBP and CD14. Finally, we reveal that a single LPS molecule bound to CD14 is transferred to TLR4/MD2 in a TLR4-dependent manner. These discoveries, which clarify the molecular mechanism of dynamic LPS transfer to TLR4/MD2 via LBP and CD14, provide novel insights into the initiation of innate immune responses.

• 한국의류산업학회지
• /
• 제8권5호
• /
• pp.571-576
• /
• 2006

피부관리실을 방문한 서른명의 얼굴 여드름 부위로부터 30주의 P. acnes를 분리하였다. 이들 균 주들을 형태학적, 생화학적 특징 등을 조사하여 P. acnes로 동정하였으며, 분리된 균 주들간의 생화학적특징은 유의한 차이를 나타내지 않았다. 생물학적 균 주 분류(biotyping)한 결과 comedone을 나타내는 여드름증상으로부터 23주의 biotype I, 구진(papule) 여드름증상으로부터 1주의 biotype II, 구진과 농포의 여드름증상으로부터 5주의 biotype III, 구진(papule) 여드름증상으로부터 1주의 biotype IV가 각각 분리되었으며, biotype V형의 균 주는 분리되지 않았다.

• Mycobiology
• /
• 제37권1호
• /
• pp.62-66
• /
• 2009

The internal stipe necrosis of cultivated mushrooms (Agaricus bisporus) is caused by the bacterium Ewingella americana, a species of the Enterobacteriaceae. Recently, Ewingella americana was isolated from cultivated white button mushrooms in Korea evidencing symptoms of internal stipe browning. Its symptoms are visible only at harvest, and appear as a variable browning reaction in the center of the stipes. From these lesions, we isolated one bacterial strain (designated CH4). Inoculation of the bacterial isolate into mushroom sporocarps yielded the characteristic browning symptoms that were distinguishable from those of the bacterial soft rot that is well known to mushroom growers. The results of Gram stain, flagellal staining, and biochemical tests identified these isolates as E. americana. This was verified by pathogenicity, physiological and biochemical characteristics, and the results of an analysis of the 16S rRNA gene sequences and the fatty acids profile. This is the first report of the isolation of E. americana from cultivated white button mushrooms in Korea.

• Archives of Plastic Surgery
• /
• 제42권1호
• /
• pp.68-72
• /
• 2015

For recent years, use of autologous fat injection has increased significantly in facial contouring surgery. Along with such increase in use, complications like atypical mycoplasma infection have been also on the increasing trend. The authors report two cases of Mycobacterium chelonae infection that occurred after autologous fat injection. Patients were treated as infection that resistant to common antibiotics and results were negative to routine culture and Gram staining. Acid-fast bacillus stain, polymerase chain reaction (PCR) test and mycobacterial cultures were conducted for diagnosis under suspicion of atypical mycoplasma infection. Then, combination antibiotics therapy, surgical treatment, and steroid injection were performed for treatment. Both patients were diagnosed with Mycobacterium chelonae in PCR test. They were positive to mycobacterial cultures. Combination antibiotics therapy was repeated to improvement of symptom. However, they could not be free from side effects such as deformation in facial contour, scar and pigmentation even after full recovery. When chronic wound infections after autologous fat injection, we must suspect atypical or mycobacterial infection and conduct examinations for a early diagnosis and proper antibiotic therapy that is effective to the nontuberculous mycobacteria.

• Journal of Species Research
• /
• 제9권4호
• /
• pp.325-338
• /
• 2020

The animal gut is filled with highly diverse microbes associated with host metabolism, physiology, and pathology. However, numerous animal gut microbes have not been cultured or reported. We isolated various bacterial species using culture-dependent approaches during a comprehensive investigation of endangered endemic vertebrate species in the Republic of Korea. A total of 18 unrecorded bacterial species were isolated from the feces of an Oriental stork (Ciconia boyciana), and from the intestinal tracts of a cobitid fish (Kichulchoia multifasciata) and a Korean splendid dace (Coreoleuciscus splendidus). Based on a phylogenetic analysis of 16S rRNA gene sequences, we discovered species belonging to the phyla Actinobacteria (eight species), Firmicutes (seven species), Proteobacteria (two species), and Bacteroidetes (one species). Based on their high 16S rRNA gene sequence similarities (>98.7%) and formation of monophyletic clades with type species, each species was classified into an independent and predefined bacterial species. Gram-stain reaction, colony and cell morphology, basic biochemical characteristics, isolation source, and NIBR IDs for each species are described in the species description section.

• Journal of Species Research
• /
• 제9권4호
• /
• pp.339-345
• /
• 2020

The Earth contains billions of microbial species, although the vast majority cannot be cultured in laboratories and are thus considered unidentified and uncharacterized. Extremophiles are microorganisms that thrive in extreme conditions, including temperature, salinity, and pH. Extremophilic microorganisms have provided important insights for biological, metabolic, and evolutionary studies. Between 2017 and 2019, as part of a comprehensive investigation to identify bacterial species in Korea, eight bacterial strains were isolated from marine and non-marine environments in Jeju Island. These strains were cultured under extreme salinity or pH conditions. Phylogenetic analysis using 16S ribosomal RNA(rRNA) gene sequencing indicated that all eight strains belonged to the phyla Gammaproteobacteria, Bacilli, and Alphaproteobacteria. Based on their high 16S rRNA gene sequence similarities(>98.7%) and the formation of strong monophyletic clades with their closest related species, all isolated strains were considered as an unrecorded strain, previously unidentified species. Gram stain reaction, culture conditions, colony and cell morphology, biochemical characteristics, isolation source, and National Institute of Biological Resources(NIBR) IDs are described in this article. The characterization of these unrecorded strains provides information on microorganisms living in Korea.

• 한국동물위생학회지
• /
• 제19권2호
• /
• pp.115-125
• /
• 1996

A total of 315 microorgainisms were isolated from 256 pneumonic lung samples of pig in abattoirs of northern Chungnam area during February to November 1994, and Identified 97 strains as Pusteurella multocida, 89 strains as Staphylococcus spp, 54 strains as Streptococcus spp, 22 strains as Mycoplasma spp, 21 strains as Escherichia coli, 18 strains as Haemophilus parsuis, 11 strains as Corymebacteroi, pyogenes, and 3 strains as Acrinobacillus spp by Gram's and Dienes stain, and biological properties test Involved API system. After that, they were examined anti biotic susceptibility for ampicillin(AM), cephalothin(CF), chloramphenicol(CP), erythromycin(EM), kanamycin(KM), gentamicin(GM), neomycin(NM), penicillin(PC), streptomycin(SM), tetracycline(TE), tiamulin(TIA), tylosin(TYL), methicillin(DP), colistin(CL) and trimet hoprim(SXT). In antibiotics susceptibility test, 293 isolates except Mycoplasma spp 22 strain were highly susceptible to DF(79.2%) and AM(76.2%), but resistant to PC(14.0%), NM(19.5%) and KM (23.2%) The multiple drug resistant patterns were noted in most isolates, whereas only 7 isolates resistant to single drugs.

• Journal of Microbiology and Biotechnology
• /
• 제27권7호
• /
• pp.1300-1305
• /
• 2017

A rod shaped, aerobic, Gram-stain-negative, and motile bacterium, strain $AR2^T$, was isolated from a water sample of Yeongsan river, Republic of Korea. Strain $AR2^T$ clustered closely with the members of the genus Chitinimonas and showed the highest 16S rRNA gene sequence similarity with Chitinimonas prasina $LY03^T$ (96.4%), Chitinimonas viridis $HMD2169^T$ (96.4%), Chitinimonas taiwanensis $cf^T$ (96.2%), and Chitinimonas koreensis $R2A43-10^T$ (94.2%). The predominant fatty acids of strain $AR2^T$ were identified to be summed feature 3 (comprising $C_{16:1}{\omega}7c$ and/or $C_{16:1}{\omega}6c$), $C_{16:0}$, and $C_{10:0}3-OH$. Diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine were found to be the major polar lipids. The genomic DNA G+C content was 60.4 mol%. Based on the polyphasic characterization, the isolated strain $AR2^T$ is described as a representative of a novel species in the genus Chitinimonas, for which the name Chitinimonas naiadis sp. nov. (type strain =$AR2^T$ =KCTC $42755^T$ =JCM $31504^T$) is proposed.

• Journal of Yeungnam Medical Science
• /
• 제8권1호
• /
• pp.231-237
• /
• 1991

Actinomycosis is a chronic suppurative and granulomatous bacterial infection characterized by contiguous spread, abcess formation and sinus tract formation. There are four clinical forms according to the lesional site, as 1) cervicofacial, 2) thoracic, 3) abdominal, and 4) disseminated form. Recently, we experienced a case of 54 year-old patient with left mandibular actinomycosis. The pathognomonic findings of actinomycosis is sulfur granule with multiple filaments in Gram-stain and the treatment of actinomycosis is surgical excision of mass or sinus tract with massive antibiotics(esp. Penicillin) therapy for 6 to 12 months.

• Journal of Species Research
• /
• 제9권1호
• /
• pp.35-45
• /
• 2020

In 2016 and 2017, as part of a comprehensive investigation to identify the prokaryotic species in Korea, a total of 12 bacterial strains were isolated from the gastrointestinal tract and/or fecal samples of four endangered species, including reptile, bird, and marine and terrestrial mammals. Phylogenetic analysis with the 16S rRNA gene sequence was used to assign these strains to the phyla, Firmicutes, Actinobacteria or Proteobacteria. Furthermore, most of the strains Firmicutes belonged to the order Lactobacillales. Interestingly, 12 of the isolated strains have not been previously reported from the Korean Peninsula. Also, based on their high 16S rRNA gene sequence similarities(>98.7%) and formation of strong monophyletic clades with the closest type species, each isolated strain of isolates was assigned to an independent, predefined bacterial species. Gram-stain reaction, colony and cell morphology, biochemical characteristics, isolation source, and NIBR IDs are described in the species description section.