Journal of Microbiology

Volume 47(6); December 2009

Research Support, Non-U.S. Gov't

Isolation, Characterization, and Evaluation of Wild Isolates of Lactobacillus reuteri from Pig Feces: Deog Yong Lee , Yeon-Soo Seo , Nabin Rayamajhi , Mi Lan Kang , Su In Lee , Han Sang Yoo; J. Microbiol. 2009;47(6):663-672. Published online February 4, 2010; DOI: https://doi.org/10.1007/s12275-009-0124-8

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21 Citations

Abstract: Lactic acid bacteria (LAB) are a well-used probiotics for health improvements in both humans and animals. Despite of several benefits, non-host-specific LAB showed poor probiotics effects due to difficulty in colonization and competition with normal flora. Therefore, the feasibility of porcine LAB isolates was evaluated as a probiotics. Ten of 49 Lactobacillus spp. isolates harbored 2~10 kb plasmid DNA. Seven strains were selected based on the safety test, such as hemolytic activity, ammonia, indole, and phenylalanine production. After safety test, five strains were selected again by several tests, such as epithelial adherence, antimicrobial activity, tolerance against acid, bile, heat, and cold-drying, and production of acid and hydrogen peroxide. Then, enzyme profiles (ZYM test) and antibiotics resistance were analyzed for further characterization. Five Lactobacillus reuteri isolates from pig feces were selected by safety and functional tests. The plasmid DNA which was able to develop vector system was detected in the isolates. Together with these approaches, pig-specific Lactobacillus spp. originated from pigs were selected. These strains may be useful tools to develop oral delivery system.

Research Support, U.S. Gov't, Non-P.H.S.

Functional Shifts in Unvegetated, Perhumid, Recently-Deglaciated Soils Do Not Correlate with Shifts in Soil Bacterial Community Composition: Sarah R. Sattin , Cory C. Cleveland , Eran Hood , Sasha C. Reed , Andrew J. King , Steven K. Schmidt , Michael S. Robeson , Nataly Ascarrunz , Diana R. Nemergut; J. Microbiol. 2009;47(6):673-681. Published online February 4, 2010; DOI: https://doi.org/10.1007/s12275-009-0194-7

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73 Citations

Abstract: Past work in recently deglaciated soils demonstrates that microbial communities undergo shifts prior to plant colonization. To date, most studies have focused on relatively ‘long’ chronosequences with the ability to sample plant-free sites over at least 50 years of development. However, some recently deglaciated soils feature rapid plant colonization and questions remain about the relative rate of change in the microbial community in the unvegetated soils of these chronosequences. Thus, we investigated the forelands of the Mendenhall Glacier near Juneau, AK, USA, where plants rapidly establish. We collected unvegetated samples representing soils that had been ice-free for 0, 1, 4, and 8 years. Total nitrogen (N) ranged from 0.00~0.14 mg/g soil, soil organic carbon pools ranged from 0.6~2.3 mg/g soil, and both decreased in concentration between the 0 and 4 yr soils. Biologically available phosphorus (P) and pH underwent similar dynamics. However, both pH and available P increased in the 8 yr soils. Nitrogen fixation was nearly undetectable in the most recently exposed soils, and increased in the 8 yr soils to ~5 ng N fixed/cm2/h, a trend that was matched by the activity of the soil N-cycling enzymes urease and β-1,4-N-acetyl-glucosaminidase. 16S rRNA gene clone libraries revealed no significant differences between the 0 and 8 yr soils; however, 8 yr soils featured the presence of cyanobacteria, a division wholly absent from the 0 yr soils. Taken together, our results suggest that microbes are consuming allochtonous organic matter sources in the most recently exposed soils. Once this carbon source is depleted, a competitive advantage may be ceded to microbes not reliant on in situ nutrient sources.

Research Support, Non-U.S. Gov'ts

Application of Quantitative Real-Time PCR for Enumeration of Total Bacterial, Archaeal, and Yeast Populations in Kimchi: Eun-Jin Park , Ho-Won Chang , Kyoung-Ho Kim , Young-Do Nam , Seong Woon Roh , Jin-Woo Bae; J. Microbiol. 2009;47(6):682-685. Published online February 4, 2010; DOI: https://doi.org/10.1007/s12275-009-0297-1

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Abstract: Kimchi is a Korean traditional fermented food made of brined vegetables, with a variety of spices. Various microorganisms are associated with the kimchi fermentation process. This study was undertaken in order to apply quantitative real-time PCR targeting the 16S and 26S rRNA genes for the investigation of dynamics of bacterial, archaeal, and yeast communities during fermentation of various types of kimchi. Although the total bacterial and archaeal rRNA gene copy numbers increased during kimchi fermentation, the number of yeasts was not significantly altered. In 1 ng of bulk DNA, the mean number of rRNA gene copies for all strains of bacteria was 5.45×106 which was 360 and 50 times greater than those for archaea and yeast, respectively. The total gene copy number for each group of microorganisms differed among the different types of kimchi, although the relative ratios among them were similar. The common dominance of bacteria in the whole microbial communities of various types of kimchi suggests that bacteria play a principal role in the kimchi fermentation process.

Arsenite Oxidation by a Facultative Chemolithotrophic Bacterium SDB1 Isolated from Mine Tailing: Rovimar T. Lugtu , Sung-Chan Choi , Young-Sook Oh; J. Microbiol. 2009;47(6):686-692. Published online February 4, 2010; DOI: https://doi.org/10.1007/s12275-009-0279-3

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18 Citations

Abstract: An arsenite (As[III])-oxidizing bacterium, SDB1, was isolated from mine tailing collected from the Sangdong mine area in Korea and showed chemolithotrophic growth on As[III] and CO2 as the respective electron and carbon sources. SDB1 is Gram-negative, rod-shaped, and belongs to the Sinorhizobium-Ensifer branch of α-Proteobacteria. Growth and As[III] oxidation was enhanced significantly by the presence of yeast extract (0.005%) in minimal salt medium containing 5 mM As[III]; decreasing the doubling time from 9.8 to 2.1 h and increasing the As[III] oxidation rate from 0.014 to 0.349 pmol As[III] oxidized cell-1 h-1. As[III] oxidation nearly stopped at pH around 4 and should be performed at pH 7~8 to be most effective. SDB1 was immobilized in calcium-alginate beads and the oxidation capacity was investigated. Specific As[III] oxidation rates obtained with SDB1 (10.1~33.7 mM As[III] oxidized g-1 dry cell h-1) were 10~16-times higher than those reported previously with a heterotrophic bacterial strain (Simeonova et al., 2005). The stability and reusability of immobilized SDB1 strongly suggested that the immobilized SDB1 cell system can make the As[III] oxidation process technically and economically feasible in practical applications.

Sphingobacterium bambusae sp. nov., Isolated from Soil of Bamboo Plantation: Shengwen Duan , Zhengchu Liu , Xiangyuan Feng , Ke Zheng , Lifeng Cheng; J. Microbiol. 2009;47(6):693-698. Published online February 4, 2010; DOI: https://doi.org/10.1007/s12275-009-0296-2

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24 Citations

Abstract: A Gram-negative, non-motile, non-spore-forming bacterial strain designated IBFC2009T was isolated from soil of a bamboo plantation. The strain could grow at 11°C~39°C, pH 6.0~9.0, and in the presence of 0~5% NaCl. Based on 16S rRNA gene sequence analysis, Strain IBFC2009T belonged to the genus Sphingobacterium and showed the highest sequence similarity of 94.6% (S. composti T5-12T) with the type strains within the genus. The major fatty acids were summed feature 3 (iso-C15:0 2-OH and/or C16:1 ω7c, 34.4%), iso-C15:0 (22.4%), C16:0 3-OH (15.2%), and iso-C17:0 3-OH (12.8%). The G+C content of the genomic DNA was 41.0 mol%. According to the phenotypic and genotypic characteristics, Strain IBFC2009T should represent a novel species of the genus Sphingobacterium, for which the name Sphingobacterium bambusae sp. nov. is proposed. The type strain is IBFC2009T (=CCTCC AB 209162T =KCTC 22814T).

Paenibacillus pini sp. nov., a Cellulolytic Bacterium Isolated from the Rhizosphere of Pine Tree: Byung-Chun Kim , Kang Hyun Lee , Mi Na Kim , Eun-Mi Kim , Sung Ran Min , Hyun Soon Kim , Kee-Sun Shin; J. Microbiol. 2009;47(6):699-704. Published online February 4, 2010; DOI: https://doi.org/10.1007/s12275-009-0343-z

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Abstract: Strain S22T, a novel cellulolytic bacterium was isolated from the rhizosphere of pine trees. This isolate was Gram-reaction positive, motile and rods, and formed terminal or subterminal ellipsoidal spores. S22T represented positive activity for catalase, oxidase, esterase (C4), esterase lipase (C8), β-galactosidase, leucine arylamidase, and hydrolysis of esculin. It contained meso-diaminopimelic acid as the diagnostic diamino acid in the cell-wall. The predominant isoprenoid quinone was menaquinone 7 (MK-7), and the major cellular fatty acids were anteiso-C15:0 (52.9%), iso-C16:0 (11.3%), and iso-C15:0 (10.0%). The DNA G+C content was 43.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that this isolate belonged to the family Paenibacillaceae. S22T exhibited less than 97.0% 16S rRNA gene similarity with all relative type strains in the genus Paenibacillus, and the most closely related strains were Paenibacillus anaericanus MH21T and Paenibacillus ginsengisoli Gsoil 1638T, with equal similarities of 95.8%. This polyphasic evidence suggested that strain S22T should be considered a novel species in the genus Paenibacillus, for which the name, Paenibacillus pini sp. nov., is proposed. The type strain is S22T (=KCTC 13694T =KACC 14198T =JCM 16418T)

Virgibacillus xinjiangensis sp. nov., Isolated from a Salt Lake of Xin-jiang Province in China: Che Ok Jeon , Jeong Myeong Kim , Dong-Jin Park , Li-Hua Xu , Cheng-Lin Jiang , Chang-Jin Kim; J. Microbiol. 2009;47(6):705-709. Published online February 4, 2010; DOI: https://doi.org/10.1007/s12275-009-0107-9

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Abstract: A strictly aerobic Gram-positive, moderately halophilic spore forming bacterium, designated strain SL6-1T, was isolated from a salt lake in Xin-jiang province, China. Growth of strain SL6-1T was observed at NaCl concentrations of 0~20% (w/v) (the optimum being 5~7%, w/v). The peptidoglycan type of strain SL6-1T was A1γ-meso-diaminopimelic acid and its major cellular fatty acids were iso-C14:0 and iso-C16:0 and anteiso-C15:0. The major respiratory isoprenoid quinone was MK-7 and the G+C content of the genomic DNA was 44.5 mol%. The major cellular phospholipids were phosphatidylglycerol and diphosphatidylglycerol. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain SL6-1T formed a phylogenetic lineage within the genus Virgibacillus. Based on 16S rRNA gene sequence similarity, the strain was most closely related to Virgibacillus olivae E308T, Virgibacillus kekensis YIM kkny16T, Virgibacillus marismortui DSM 12325T with 97.1%, 97.1%, and 97.0% gene sequence similarities, respectively and the sequence similarities to other related taxa were less than 96.7%. The DNA relatedness values between strain SL6-1T and V. olivae E308T, V. kekensis YIM kkny16T, V. marismortui DSM 12325T were 16.7%, 51.0%, and 22.8%, respectively. On the basis of physiological, biochemical and phylogenetic properties, strain SL6-1T represents a novel species, for which the name Virgibacillus xinjiangensis sp. nov. is proposed. The type strain is SL6-1T (=KCTC 13128T =DSM 19031T).

Scopulibacillus darangshiensis gen. nov., sp. nov., Isolated from Rock: Soon Dong Lee , Dong Wan Lee; J. Microbiol. 2009;47(6):710-715. Published online February 4, 2010; DOI: https://doi.org/10.1007/s12275-009-0111-0

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Abstract: A novel, Gram-positive bacterium, designated DLS-06T, was isolated from scoria (volcanic ash) under rock on the peak of small mountain (300 m above the sea level; known as Darangshi Oreum) in Jeju, Republic of Korea. The cells of the isolate were aerobic, oxidase-negative, catalase-positive, endospore- forming, non-motile rods. The organism grew at 25~30°C and initial pH 6.1~9.1. A neighbour-joining tree based on 16S rRNA gene sequences showed that the organism was related to members of the family “Sporolactobacillaceae” and related taxa. The phylogenetic neighbours were Pullulanibacillus naganoensis (95.2% 16S rRNA gene sequence similarity), Tuberibacillus calidus (95.0%) and Sporolactobacillus (91.8~94.2%). Levels of 16S rRNA gene sequence similarity of the isolate to representatives of other genera were in the range of 87.2~93.7%. The organism contained meso-diaminopimelic acid as the diagnostic diamino acid in the cell-wall peptidoglycan. The predominant menaquinone was MK-7. The polar lipid profile contained diphosphatidylglycerol, phosphatidylglycerol, an unknown ninhydrin-positive phospholipid, three unknown phospholipids and an unknown lipid. The major fatty acids were anteiso-C15:0 and anteiso-C17:0. The G+C content of the DNA was 50.8 mol%. On the basis of the phenotypic and phylogenetic data presented in this study, this organism represents a novel genus and species in the order Bacillales, for which the name Scopulibacillus darangshiensis gen. nov., sp. nov. is proposed. The type strain is DLS-06T (=DSM 19377T =KCTC 13161T).

Methylobacterium dankookense sp. nov., Isolated from Drinking Water: Si-Won Lee , Hyun-Woo Oh , Kang-Hyun Lee , Tae-Young Ahn; J. Microbiol. 2009;47(6):716-720. Published online February 4, 2010; DOI: https://doi.org/10.1007/s12275-009-0126-6

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Abstract: A pink-pigmented bacterium, designated SW08-7T was isolated from the drinking water of a water purifier. Cells were Gram-negative, rod-shaped, strictly aerobic, and non-spore-forming. It grew optimally at 25°C, pH 6~7. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain SW08-7T belongs to the genus Methylobacterium. The highest 16S rRNA gene sequence similarities were found to Methylobacterium mesophilicum JCM 2829T (96.9%), Methylobacterium brachiatum B0021T (96.9%), Methylobacterium phyllosphaerae CBMB27T (96.6%), Methylobacterium radiotolerans JCM 2831T (96.6%), and Methylobacterium hispanicum GP34T (96.5%). DNA-DNA hybridization experiment revealed low-level (28.5%) of DNA- DNA relatedness between strain SW08-7T and Methylobacterium hispanicum. The genomic DNA G+C content was 68.9 mol% and the major isoprenoid quinone was Q-10. The major cellular fatty acid of strain SW08-7T was C18:1 ω7c (79.8±2.1%). Results of phylogenetic, phenotypic, and biochemical analyses revealed that strain SW08-7T could be classified as representing a novel species of genus Methylobacterium, for which the name Methylobacterium dankookense sp. nov. is proposed. The type strain is SW08-7T (=KCTC 22512T =DSM 22415T).

Journal Article

Symbiotic Relationship between Microbacterium sp. SK0812 and Candida tropicalis SK090404: Seung Won Kang , Bo Young Jeon , Tae Sik Hwang , Doo Hyun Park; J. Microbiol. 2009;47(6):721-727. Published online February 4, 2010; DOI: https://doi.org/10.1007/s12275-009-0146-2

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Abstract: A bacterium growing inside yeast cytoplasm was observed by light microscope without staining. The bacterium was separately stained from yeast cell by a fluorescent dye, 4′,6-diamidino-2-phenylindole (DAPI). The bacterium actively moved inside yeast cytoplasm and propagated in company with the yeast growth. The bacterium was separated from the yeast cytoplasm by selective disruption of yeast cells and the yeast without the intracellular bacterium (YWOB) was obtained by selective inactivation of bacterial cells. The yeast and the intracellular bacterium were identified as Candida tropicalis and Microbacterium sp., respectively. The length of Microbacterium sp. and C. tropicalis measured with SEM image was smaller than 0.5 μm and was larger than 5 μm, respectively. The yeast with the intracellular bacterium (YWIB) grew in a starch-based medium but the YWOB was not C. tropicalis has neither extracellular nor intracellular saccharification enzyme. Glucose was produced from starch by the extracellular crude enzyme (culture fluid) of Microbacterium sp. YWIB produced significantly more ethanol from glucose than YWOB but did not from starch. Conclusively, C. tropicalis is thought to catabolize starch dependent upon Microbacterium sp. growing in its cytoplasm and furnish stable habitat for the Microbacterium sp.

Research Support, Non-U.S. Gov'ts

Proteomic Analysis of Acinetobacter baumannii in Biofilm and Planktonic Growth Mode: Ji-Hyun Shin , Hee-Woo Lee , Sung-Min Kim , Jungmin Kim; J. Microbiol. 2009;47(6):728-735. Published online February 4, 2010; DOI: https://doi.org/10.1007/s12275-009-0158-y

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69 Citations

Abstract: Recently, multidrug-resistant clinical isolates of Acinetobacter baumannii have been found to have a high capacity to form biofilm. It is well known that bacterial cells within biofilms are highly resistant to antibiotics, UV light, acid exposure, dehydration, and phagocytosis in comparison to their planktonic counterparts, which suggests that the cells in a biofilm have altered metabolic activity. To determine which proteins are up-regulated in A. baumannii biofilm cells, we performed a proteomic analysis. A clinical isolate of A. baumannii 1656-2, which was characterized to have a high biofilm forming ability, was cultivated under biofilm and planktonic conditions. Outer membrane enriched A. baumannii 1656-2 proteins were separated by two-dimensional (2-D) gel electrophoresis and the differentially expressed proteins were identified by MALDI-TOF mass spectrometry. The proteins up-regulated or expressed only in biofilm cells of A. baumannii are categorized as follows: (i) proteins processing environmental information such as the outer membrane receptor protein involved in mostly Fe transport, a sensor histidine kinase/response regulator, and diguanylate cyclase (PAS-GGEDF-EAL domain); (ii) proteins involved in metabolism such as NAD- linked malate dehydrogenase, nucleoside-diphosphate sugar epimerase, putative GalE, ProFAR isomerase, and N-acetylmuramoyl-L-alanine amidase; (iii) bacterial antibiotic resistance related proteins; and (iv) proteins related to gene repair such as exodeoxyribonuclease III and GidA. This proteomic analysis provides a fundamental platform for further studies to reveal the role of biofilm in the persistence and tolerance of A. baumannii.

Functional Characterization of the Copper-Transporting P-Type ATPase Gene of Penicillium janthinellum Strain GXCR: Hongmin Lai , Changbin Sun , Huaying Tang , Xianwei Fan , Yili Ma; J. Microbiol. 2009;47(6):736-745. Published online February 4, 2010; DOI: https://doi.org/10.1007/s12275-009-0074-1

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Abstract: Copper (Cu)-transporting P-type ATPase (CTPA) genes have been documented to play an important role in resistance to heavy metals. However, our understanding of roles of CTPA genes of the filamentous fungi was based only on sequence similarity prediction before. In a previous study, we isolated a Penicillum janthinellum strain GXCR of higher tolerance to Cu (200 mM). In this study, we cloned the partial cDNA of CTPA gene, named PcpA, from the strain GXCR. Sequence alignment indicated that the cloned cDNA sequence has the highest identity (94.4%) with a predictive CTPA gene of Aspergillus clavatus. The PcpA- encoded protein, termed PcpA, has classical functional domains of CTPAs, and shows differences from reported CTPAs in some specific sequence motifs and transmembrane regions. Expression of the PcpA was induced by extracellular Cu, cadmium (Cd), and silver (Ag). PcpA RNA interference (RNAi) mutants with a reduced level of PcpA mRNA were more sensitive to Cu, iron, Cd, and Ag than the wild-type (WT) strain GXCR. When grown in the presence of Cu, iron, and Cd, intracellular Cu and iron contents in the PcpA RNAi mutant were significantly (P<0.05) lower than those in the WT; However, intracellular Cd content in the mutant was significantly (P<0.05) higher than that in the WT. Taken together, it can be concluded that the PcpA functions in Cu uptake and homeostasis, iron uptake, and Cd export from the cytosol to the extracytosol.

Hepatitis B Virus Core Interacts with the Host Cell Nucleolar Protein, Nucleophosmin 1: Su Jin Lee , Hee Youn Shim , Antony Hsieh , Ji Young Min , Gu hung Jung; J. Microbiol. 2009;47(6):746-752. Published online February 4, 2010; DOI: https://doi.org/10.1007/s12275-009-2720-z

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21 Citations

Abstract: Hepatitis B virus (HBV) genome replication requires the packaging of viral factors (pregenomic RNA and polymerase) as well as host factors, including heat shock proteins and protein kinase C. Previous reports have suggested that there are several unidentified host factors that affect this encapsidation step. In this study, we identified a new host factor, nucleophosmin (B23) that interacts with the HBV core protein 149 (Cp149). We analyzed this factor using NHS-activated sepharose resin and MALDI-TOF MS. Using the BIAcore analysis system, we were also able to deduce that the B23.1 residues 259-294 were required for the interaction between Cp149 and B23.1 in vitro.

Analysis of a Novel Class 1 Integron Containing Metallo-β-Lactamase Gene VIM-2 in Pseudomonas aeruginosa: Jae Hoon Jeong , Kyeong Seob Shin , Jang Won Lee , Eun Jin Park , Seung-Yeol Son; J. Microbiol. 2009;47(6):753-759. Published online February 4, 2010; DOI: https://doi.org/10.1007/s12275-008-0272-2

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34 Citations

Abstract: Carbapenems such as imipenem are stable to most β-lactamases. Recently, increased numbers of carbapenemase producing Gram-negative bacterial strains have been isolated because of the increased use of cabapenems. In this respect, control of these infectious carbapenemase producing Gram-negative bacteria and understanding their resistance mechanism are becoming more important. These carbapenem-hydrolyzing β-lactamase genes have been reported to exist mostly as gene cassettes in an integron. This implies that antibiotic resistance genes may be transferred to other bacteria via the integron. In the present study, we identified and analyzed an integron containing VIM-2 type metallo-β-lactamase gene in a carbapenemase producing Pseudomonas aeruginosa. In addition, the possibility of resistance spread by integron located in a plasmid was tested. Among glucose non-fermenting Gram-negative bacilli with reduced imipenem susceptibility (MIC≥8 μg/ml) isolated from Korean patients, P. aeruginosa 1082 showed resistance to most β-lactams, cephalosporin, and aminoglycoside. We found that P. aeruginosa 1082 was inhibited by EDTA in EDTA double disk synergy test which means that this strain produces metallo-β-lactamase. Class 1 integron containing blaVIM-2 (carbapenem resistance gene), qacF (quaternary ammonium compound resistance gene), aacA4 (aminoglycoside resistance gene), catB3 (chloramphenicol resistance gene), blaOXA-30 (extended-spectrum β-lactam resistance gene), and aadA1 (aminoglycoside resistance gene) gene cassettes was detected in P. aeruginosa 1082. The size of the integron was 5,246 bp and the structure and arrangement of the integron was a novel one in comparison with other integrons found in other P. aeruginosa. The integron could be transferred to Escherichia coli JM109 from P. aeruginosa 1082 possibly via self-transferable plasmid DNA. The integron and a blaVIM-2 gene were detected in the plasmid DNA of the transconjugants whose imipenem resistance was slightly increased as a result of accepting the integron from the donor strain.

Journal Article

Effects of Methyl Gallate and Gallic Acid on the Production of Inflammatory Mediators Interleukin-6 and Interleukin-8 by Oral Epithelial Cells Stimulated with Fusobacterium nucleatum: Mi-Sun Kang , Hee-Sook Jang , Jong-Suk Oh , Kyu-Ho Yang , Nam-Ki Choi , Hoi-Soon Lim , Seon-Mi Kim; J. Microbiol. 2009;47(6):760-767. Published online February 4, 2010; DOI: https://doi.org/10.1007/s12275-009-0097-7

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Abstract: Interactions between periodontal bacteria and human oral epithelial cells can lead to the activation and expression of a variety of inflammatory mediators in epithelial cells. Fusobacterium nucleatum is a filamentous human pathogen that is strongly associated with periodontal diseases. This study examined the effects of methyl gallate (MG) and gallic acid (GA) on the production of inflammatory mediators, interleukin (IL)-6 and IL-8, by oral epithelial cells stimulated by F. nucleatum. In a real-time reverse transcription-polymerase chain reaction and an enzyme-linked immunosorbent assay, live F. nucleatum induced high levels of gene expression and protein release of IL-6 and IL-8. The effects of MG and GA were examined by treating KB oral epithelial cells with MG and GA and stimulating them with F. nucleatum. MG and GA inhibited significantly the increases in the IL-6 and IL-8 gene and protein levels in a dose- dependent manner. These compounds also inhibited the growth of F. nucleatum. No visible effects of MG and GA on the adhesion and invasion of KB cells by F. nucleatum were observed. In conclusion, both MG and GA inhibit IL-6 and IL-8 production from F. nucleatum-activated KB cells.

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