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1.
Gut ; 71(7): 1266-1276, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-34389621

RESUMEN

OBJECTIVE: Gastric cancer (GC) is a leading cause of cancer-related mortality. Although microbes besides Helicobacter pylori may also contribute to gastric carcinogenesis, wild-type germ-free (GF) mouse models investigating the role of human gastric microbiota in the process are not yet available. We aimed to evaluate the histopathological features of GF mouse stomachs transplanted with gastric microbiota from patients with different gastric disease states and their relationships with the microbiota. DESIGN: Microbiota profiles in corpus and antrum tissues and gastric fluid from 12 patients with gastric dysplasia or GC were analysed. Thereafter, biopsied corpus and antrum tissues and gastric fluid from patients (n=15 and n=12, respectively) with chronic superficial gastritis, intestinal metaplasia or GC were inoculated into 42 GF C57BL/6 mice. The gastric microbiota was analysed by amplicon sequencing. Histopathological features of mouse stomachs were analysed immunohistochemically at 1 month after inoculation. An independent set of an additional 15 GF mice was also analysed at 1 year. RESULTS: The microbial community structures of patients with dysplasia or GC in the corpus and antrum were similar. The gastric microbiota from patients with intestinal metaplasia or GC selectively colonised the mouse stomachs and induced premalignant lesions: loss of parietal cells and increases in inflammation foci, in F4/80 and Ki-67 expression, and in CD44v9/GSII lectin expression. Marked dysplastic changes were noted at 1 year post inoculation. CONCLUSION: Major histopathological features of premalignant changes are reproducible in GF mice transplanted with gastric microbiota from patients with intestinal metaplasia or GC. Our results suggest that GF mice are useful for analysing the causality of associations reported in human gastric microbiome studies.


Asunto(s)
Infecciones por Helicobacter , Helicobacter pylori , Microbiota , Neoplasias Gástricas , Animales , Mucosa Gástrica/metabolismo , Infecciones por Helicobacter/patología , Humanos , Hiperplasia/patología , Metaplasia/patología , Ratones , Ratones Endogámicos C57BL , Neoplasias Gástricas/patología
2.
Microb Cell Fact ; 21(1): 125, 2022 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-35729580

RESUMEN

BACKGROUND: Generally, bacteria have a circular genome with a single replication origin for each replicon, whereas archaea and eukaryotes can have multiple replication origins in a single chromosome. In Escherichia coli, bidirectional DNA replication is initiated at the origin of replication (oriC) and arrested by the 10 termination sites (terA-J). RESULTS: We constructed E. coli derivatives with additional or ectopic replication origins, which demonstrate the relationship between DNA replication and cell physiology. The cultures of E. coli derivatives with multiple replication origins contained an increased fraction of replicating chromosomes and the cells varied in size. Without the original oriC, E. coli derivatives with double ectopic replication origins manifested impaired growth irrespective of growth conditions and enhanced cell size, and exhibited excessive and asynchronous replication initiation. The generation time of an E. coli strain with three replication origins decreased in a minimal medium supplemented with glucose as the sole carbon source. As well as cell growth, the introduction of additional replication origins promoted increased biomass production. CONCLUSIONS: Balanced cell growth and physiological stability of E. coli under rapid growth condition are affected by changes in the position and number of replication origins. Additionally, we show that, for the first time to our knowledge, the introduction of replication initiation sites to the chromosome promotes cell growth and increases protein production.


Asunto(s)
Cromosomas Bacterianos , Escherichia coli , Biomasa , Cromosomas Bacterianos/genética , Replicación del ADN , ADN Bacteriano/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Origen de Réplica
3.
Proc Natl Acad Sci U S A ; 116(36): 18031-18040, 2019 09 03.
Artículo en Inglés | MEDLINE | ID: mdl-31427506

RESUMEN

Upon invading target cells, multifunctional autoprocessing repeats-in-toxin (MARTX) toxins secreted by bacterial pathogens release their disease-related modularly structured effector domains. However, it is unclear how a diverse repertoire of effector domains within these toxins are processed and activated. Here, we report that Makes caterpillars floppy-like effector (MCF)-containing MARTX toxins require ubiquitous ADP-ribosylation factor (ARF) proteins for processing and activation of intermediate effector modules, which localize in different subcellular compartments following limited processing of holo effector modules by the internal cysteine protease. Effector domains structured tandemly with MCF in intermediate modules become disengaged and fully activated by MCF, which aggressively interacts with ARF proteins present at the same location as intermediate modules and is converted allosterically into a catalytically competent protease. MCF-mediated effector processing leads ultimately to severe virulence in mice via an MCF-mediated ARF switching mechanism across subcellular compartments. This work provides insight into how bacteria take advantage of host systems to induce systemic pathogenicity.


Asunto(s)
Factores de Ribosilacion-ADP , ADP-Ribosilación , Toxinas Bacterianas , Vibrio vulnificus , Factores de Ribosilacion-ADP/química , Factores de Ribosilacion-ADP/metabolismo , Animales , Toxinas Bacterianas/química , Toxinas Bacterianas/metabolismo , Células HEK293 , Células HeLa , Humanos , Ratones , Dominios Proteicos , Vibrio vulnificus/genética , Vibrio vulnificus/metabolismo , Vibrio vulnificus/patogenicidad
4.
Int J Syst Evol Microbiol ; 71(10)2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34596509

RESUMEN

A bacterial strain, designated TCH3-2T, was isolated from the rhizosphere of tomato plant grown at Dong-A University Agricultural Experiment Station, Republic of Korea. The strain was Gram-stain-negative, obligate aerobic, orange yellow-coloured, motile by gliding and short rod-shaped. Strain TCH3-2 T only grew on 1/2 tryptic soy agar and Luria-Bertani agar among the media tested, with optimum growth at 28 °C and pH 7. Salt of 1 % NaCl was necessary to support the growth of TCH3-2T. Strain TCH3-2T produced flexirubin-type pigments. The predominant cellular fatty acids were iso-C15 : 0 (55.6 %), iso-C17 : 0 3-OH (17.9 %), summed feature 9 (comprising C16 : 0 10-methyl and/or iso-C17 : 1 ω9c; 10.5 %), iso-C15 : 0 3-OH (4.8 %) and anteiso-C15 : 0 (2.3 %). The major menaquinone was menaquinone-6 and the major polar lipids were phosphatidylethanolamine, five unknown aminolipids and three unknown lipids. Phylogenetic analysis based on 16S rRNA sequences indicated that TCH3-2T was closely related to Flavobacterium ummariense DS-12T (95.16 %), Flavobacterium marinum SW105T (95.14 %) and Flavobacterium viscosus YIM 102796T (94.54 %). The draft genome of TCH3-2T comprised ca. 2.8 Mb with a G+C content of 34.61 mol%. The average nucleotide identity and digital DNA-DNA hybridization values between TCH3-2T and closely related Flavobacterium species showed that it belongs to a distinct species. Furthermore, the results of morphological, physiological and biochemical tests allowed further phenotypic differentiation of TCH3-2T from its closest relatives. Thus, chemotaxonomic characteristics together with phylogenetic affiliation illustrate that TCH3-2T represents a novel species of the genus Flavobacterium, for which the name Flavobacterium dauae sp. nov. (type strain TCH3-2T=KACC 19054T=JCM 34025T) is proposed.


Asunto(s)
Flavobacterium , Filogenia , Rizosfera , Microbiología del Suelo , Solanum lycopersicum , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Ácidos Grasos/química , Flavobacterium/clasificación , Flavobacterium/aislamiento & purificación , Solanum lycopersicum/microbiología , Hibridación de Ácido Nucleico , Fosfolípidos/química , Pigmentación , ARN Ribosómico 16S/genética , República de Corea , Análisis de Secuencia de ADN , Vitamina K 2/análogos & derivados , Vitamina K 2/química
5.
Plant Dis ; 105(4): 1143-1152, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32931384

RESUMEN

Erwinia amylovora is a plant-pathogenic bacterium that causes fire blight disease in Rosaceae plants. Since fire blight is highly contagious and results in serious losses once introduced, it is regulated as a quarantine disease. Recently, for the first time in East Asia, fire blight emerged in Korea with strains of E. amylovora being isolated from lesions of infected trees. Five of those strains were selected and subjected to whole-genome shotgun sequencing. Each strain had two circular replicons, a 3.8-Mb chromosome and a 28-kb plasmid. The genome sequences were compared with those of other E. amylovora strains isolated from different hosts or geographical regions. Genome synteny was analyzed and sequence variations including nucleotide substitutions, inversions, insertions, and deletions were detected. Analysis of the population genomic structure revealed that the five strains form a distinct structural group. Phylogenomic analysis was performed to infer the evolutionary relationships among E. amylovora strains, which indicated that the Korean isolates, all descended from a common ancestor, are closely related to a lineage of North American strains. These results provide useful information for understanding the genomic dynamics of E. amylovora strains including those in Korea, developing genetic markers for surveillance of the pathogen or diagnosis of the disease, and eventually developing measures to eradicate it.


Asunto(s)
Erwinia amylovora , Brotes de Enfermedades , Erwinia amylovora/genética , Asia Oriental , Enfermedades de las Plantas , República de Corea
6.
Nucleic Acids Res ; 45(9): 5285-5293, 2017 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-28379538

RESUMEN

Escherichia coli BL21(DE3) has long served as a model organism for scientific research, as well as a workhorse for biotechnology. Here we present the most current genome annotation of E. coli BL21(DE3) based on the transcriptome structure of the strain that was determined for the first time. The genome was annotated using multiple automated pipelines and compared to the current genome annotation of the closely related strain, E. coli K-12. High-resolution tiling array data of E. coli BL21(DE3) from several different stages of cell growth in rich and minimal media were analyzed to characterize the transcriptome structure and to provide supporting evidence for open reading frames. This new integrated analysis of the genomic and transcriptomic structure of E. coli BL21(DE3) has led to the correction of translation initiation sites for 88 coding DNA sequences and provided updated information for most genes. Additionally, 37 putative genes and 66 putative non-coding RNAs were also identified. The panoramic landscape of the genome and transcriptome of E. coli BL21(DE3) revealed here will allow us to better understand the fundamental biology of the strain and also advance biotechnological applications in industry.


Asunto(s)
Escherichia coli/genética , Genoma Bacteriano , Genómica , Transcriptoma/genética , Medios de Cultivo/farmacología , Escherichia coli/efectos de los fármacos , Escherichia coli/crecimiento & desarrollo , Perfilación de la Expresión Génica , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Anotación de Secuencia Molecular , Sistemas de Lectura Abierta/genética , ARN no Traducido/genética
7.
Gastroenterology ; 152(8): 1998-2010, 2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-28246016

RESUMEN

BACKGROUND & AIMS: Obesity and metabolic syndrome have been associated with alterations to the intestinal microbiota. However, few studies examined the effects of obesity on the intestinal immune system. We investigated changes in subsets of intestinal CD4+ T-helper (TH) cells with obesity and the effects of gut-tropic TH17 cells in mice on a high-fat diet (HFD). METHODS: We isolated immune cells from small intestine and adipose tissue of C57BL/6 mice fed a normal chow diet or a HFD for 10 weeks and analyzed the cells by flow cytometry. Mice fed a vitamin A-deficient HFD were compared with mice fed a vitamin A-sufficient HFD. Obese RAG1-deficient mice were given injections of only regulatory T cells or a combination of regulatory T cells and TH17 cells (wild type or deficient in integrin ß7 subunit or interleukin 17 [IL17]). Mice were examined for weight gain, fat mass, fatty liver, glucose tolerance, and insulin resistance. Fecal samples were collected before and after T cell transfer and analyzed for microbiota composition by metagenomic DNA sequencing and quantitative polymerase chain reaction. RESULTS: Mice placed on a HFD became obese, which affected the distribution of small intestinal CD4+ TH cells. Intestinal tissues from obese mice had significant reductions in the proportion of TH17 cells but increased proportion of TH1 cells, compared with intestinal tissues from nonobese mice. Depletion of vitamin A in obese mice further reduced the proportion of TH17 cells in small intestine; this reduction correlated with more weight gain and worsening of glucose intolerance and insulin resistance. Adoptive transfer of in vitro-differentiated gut-tropic TH17 cells to obese mice reduced these metabolic defects, which required the integrin ß7 subunit and IL17. Delivery of TH17 cells to intestines of mice led to expansion of commensal microbes associated with leanness. CONCLUSIONS: In mice, intestinal TH17 cells contribute to development of a microbiota that maintains metabolic homeostasis, via IL17. Gut-homing TH17 cells might be used to reduce metabolic disorders in obese individuals.


Asunto(s)
Traslado Adoptivo , Inmunidad Mucosa , Resistencia a la Insulina , Intestino Delgado/inmunología , Síndrome Metabólico/prevención & control , Obesidad/prevención & control , Células Th17/trasplante , Animales , Células Cultivadas , Dieta Alta en Grasa , Modelos Animales de Enfermedad , Heces/microbiología , Microbioma Gastrointestinal/inmunología , Genotipo , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Interacciones Huésped-Patógeno , Cadenas beta de Integrinas/genética , Cadenas beta de Integrinas/metabolismo , Interleucina-17/deficiencia , Interleucina-17/genética , Intestino Delgado/metabolismo , Intestino Delgado/microbiología , Masculino , Síndrome Metabólico/genética , Síndrome Metabólico/inmunología , Síndrome Metabólico/microbiología , Ratones Endogámicos C57BL , Ratones Noqueados , Obesidad/genética , Obesidad/inmunología , Obesidad/microbiología , Fenotipo , Células Th17/inmunología , Células Th17/microbiología , Factores de Tiempo , Deficiencia de Vitamina A/complicaciones
8.
Nucleic Acids Res ; 43(Database issue): D624-30, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25336619

RESUMEN

Pathogenicity is a complex multifactorial process confounded by the concerted activity of genetic regions associated with virulence and/or resistance determinants. Pathogenicity islands (PAIs) and resistance islands (REIs) are key to the evolution of pathogens and appear to play complimentary roles in the process of bacterial infection. While PAIs promote disease development, REIs give a fitness advantage to the host against multiple antimicrobial agents. The Pathogenicity Island Database (PAIDB, http://www.paidb.re.kr) has been the only database dedicated to providing comprehensive information on all reported PAIs and candidate PAIs in prokaryotic genomes. In this study, we present PAIDB v2.0, whose functionality is extended to incorporate REIs. PAIDB v2.0 contains 223 types of PAIs with 1331 accessions, and 88 types of REIs with 108 accessions. With an improved detection scheme, 2673 prokaryotic genomes were analyzed to locate candidate PAIs and REIs. With additional quantitative and qualitative advancements in database content and detection accuracy, PAIDB will continue to facilitate pathogenomic studies of both pathogenic and non-pathogenic organisms.


Asunto(s)
Bases de Datos de Ácidos Nucleicos , Islas Genómicas , Farmacorresistencia Microbiana/genética , Genoma Microbiano , Internet , Virulencia/genética
9.
BMC Gastroenterol ; 16: 28, 2016 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-26922889

RESUMEN

BACKGROUND: Intestinal microbiota play an important role in maintaining the homeostasis of the host immune system. To analyze the alteration of the intestinal microbial community structure in Korean Crohn's disease (CD) patients, we performed a comparative metagenomic analysis between healthy people and CD patients using fecal samples and mucosal tissues of ileocecal valve. METHODS: 16S rRNA genes from fecal samples or mucosal tissues of 35 CD patients and 15 healthy controls (HC) were amplified using a universal primer set and sequenced with GS FLX Titanium. The microbial composition and diversity of each sample were analyzed with the mothur pipeline, and the association between microbial community and clinical characteristics of the patients were investigated. RESULTS: The contribution of bacterial groups to the intestinal microbial composition differed between CD and HC, especially in fecal samples. Global structure and individual bacterial abundance of intestinal microbial community were different between feces and ileocecal tissues in HC. In CD patients with active stage, relative abundances of Gammaproteobacteria and Fusobacteria were higher in both fecal and mucosal tissue samples. Moreover, the intestinal microbial community structure was altered by anti-tumor necrosis factor (anti-TNF) treatment. CONCLUSIONS: Our 16S rRNA sequence data demonstrate intestinal dysbiosis at the community level in Korean CD patients, which is similar to alterations of the intestinal microbial community seen in the western counterparts. Clinical disease activity and anti-TNF treatment might affect the intestinal microbial community structure in CD patients.


Asunto(s)
Enfermedad de Crohn/microbiología , ADN Ribosómico/genética , Disbiosis/microbiología , Microbioma Gastrointestinal/genética , ARN Ribosómico 16S/genética , Acidobacteria/genética , Actinobacteria/genética , Adulto , Antiinflamatorios no Esteroideos/uso terapéutico , Pueblo Asiatico , Azatioprina/uso terapéutico , Bacteroidetes/genética , Estudios de Casos y Controles , Enfermedad de Crohn/tratamiento farmacológico , Enfermedad de Crohn/etnología , Disbiosis/etnología , Heces/microbiología , Femenino , Firmicutes/genética , Fusobacterias/genética , Gammaproteobacteria/genética , Fármacos Gastrointestinales/uso terapéutico , Humanos , Inmunosupresores/uso terapéutico , Infliximab/uso terapéutico , Mucosa Intestinal/microbiología , Masculino , Mesalamina/uso terapéutico , Prednisolona/uso terapéutico , Proteobacteria/genética , República de Corea , Análisis de Secuencia de ADN , Análisis de Secuencia de ARN , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores
10.
Nature ; 461(7268): 1243-7, 2009 Oct 29.
Artículo en Inglés | MEDLINE | ID: mdl-19838166

RESUMEN

The relationship between rates of genomic evolution and organismal adaptation remains uncertain, despite considerable interest. The feasibility of obtaining genome sequences from experimentally evolving populations offers the opportunity to investigate this relationship with new precision. Here we sequence genomes sampled through 40,000 generations from a laboratory population of Escherichia coli. Although adaptation decelerated sharply, genomic evolution was nearly constant for 20,000 generations. Such clock-like regularity is usually viewed as the signature of neutral evolution, but several lines of evidence indicate that almost all of these mutations were beneficial. This same population later evolved an elevated mutation rate and accumulated hundreds of additional mutations dominated by a neutral signature. Thus, the coupling between genomic and adaptive evolution is complex and can be counterintuitive even in a constant environment. In particular, beneficial substitutions were surprisingly uniform over time, whereas neutral substitutions were highly variable.


Asunto(s)
Adaptación Fisiológica , Escherichia coli/genética , Evolución Molecular , Genoma Bacteriano/genética , Análisis Mutacional de ADN , Escherichia coli/crecimiento & desarrollo , Aptitud Genética , Modelos Genéticos , Mutación , Selección Genética , Factores de Tiempo
11.
J Ind Microbiol Biotechnol ; 42(6): 915-24, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25838237

RESUMEN

Overexpression of phosphoenolpyruvate carboxykinase (PCK) was reported to cause the harboring of higher intracellular ATP concentration in Escherichia coli, accompanied with a slower growth rate. For systematic determination of the relationship between the artificial increase of ATP and growth retardation, PCKWT enzyme was directly evolved in vitro and further overexpressed. The evolved PCK67 showed a 60% greater catalytic efficiency than that of PCKWT. Consequently, the PCK67-overexpressing E. coli showed the highest ATP concentration at the log phase of 1.45 µmol/gcell, with the slowest growth rate of 0.66 h(-1), while the PCKWT-overexpressing cells displayed 1.00 µmol/gcell ATP concentration with the growth rate of 0.84 h(-1) and the control had 0.28 µmol/gcell with 1.03 h(-1). To find a plausible reason, PCK-overexpressing cells in a steady state during chemostat growth were applied to monitor intracellular reactive oxygen species (ROS). Higher amount of intracellular ROS were observed as the ATP levels increased. To confirm the hypothesis of slower growth rate without perturbation of the carbon flux by PCK-overexpression, phototrophic Gloeobacter rhodopsin (GR) was expressed. The GR-expressing strain under illumination harbored 81% more ATP concentration along with 82% higher ROS, with a 54% slower maximum growth rate than the control, while both the GR-expressing strain under dark and dicarboxylate transporter (a control membrane protein)-expressing strain showed a lower ATP and increased ROS, and slower growth rate. Regardless of carbon flux changes, the artificial ATP increase was related to the ROS increase and it was reciprocally correlated to the maximum growth rate. To verify that the accumulated intracellular ROS were responsible for the growth retardation, glutathione was added to the medium to reduce the ROS. As a result, the growth retardation was restored by the addition of 0.1 mM glutathione. Anaerobic culture even enabled the artificial ATP-increased E. coli to grow faster than control. Collectively, it was concluded that artificial ATP increases inhibit the growth of E. coli due to the overproduction of ROS.


Asunto(s)
Adenosina Trifosfato/metabolismo , Escherichia coli/crecimiento & desarrollo , Escherichia coli/metabolismo , Anaerobiosis , Biocatálisis/efectos de los fármacos , Ciclo del Carbono , Cianobacterias/genética , Cianobacterias/metabolismo , Transportadores de Ácidos Dicarboxílicos/metabolismo , Escherichia coli/citología , Escherichia coli/efectos de los fármacos , Glutatión/metabolismo , Glutatión/farmacología , Fosfoenolpiruvato Carboxilasa/genética , Fosfoenolpiruvato Carboxilasa/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Rodopsina/metabolismo
12.
Int J Syst Evol Microbiol ; 64(Pt 11): 3760-3767, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25122614

RESUMEN

Four Gram-stain-negative, aerobic, rod-shaped bacterial strains, MM-124, MM-126, NB-68 and NB-77, were isolated from the coastal seawater or a region with a bloom of sea sparkle around Geoje island in Korea. The sequence similarity values of the 16S rRNA gene between the isolates and Sulfitobacter mediterraneus DSM 12244(T) ranged from 97.7 to 98.2%, and phylogenetic relationships suggested that they belong to a phylogenetic branch that includes the genera Sulfitobacter and Roseobacter. The isoprenoid quinone of all three novel strains was ubiquinone-10 and the major fatty acid was cis-vaccenic acid, as in other species of the genus Sulfitobacter. However, there were several differences in the morphological, physiological and biochemical characteristics among the four strains and the reference species of the genus Sulfitobacter. Moreover, the average nucleotide identity values between the three sequenced isolates and the reference strains were below 76.33, indicating that genomic variation exists between the isolates and reference strains. Chemotaxonomic characteristics together with phylogenetic affiliations and genomic distances illustrate that strains MM-124, NB-68 and NB-77 represent novel species of the genus Sulfitobacter, for which the names Sulfitobacter geojensis sp. nov. (type strain MM-124(T) =KCTC 32124(T) =JCM 18835(T)), Sulfitobacter noctilucae sp. nov. (type strain NB-68(T) =KCTC 32122(T) =JCM 18833(T)) and Sulfitobacter noctilucicola sp. nov. (type strain NB-77(T) =KCTC 32123(T) =JCM 18834(T)) are proposed.


Asunto(s)
Filogenia , Rhodobacteraceae/clasificación , Agua de Mar/microbiología , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Ácidos Oléicos/química , ARN Ribosómico 16S/genética , República de Corea , Rhodobacteraceae/genética , Rhodobacteraceae/aislamiento & purificación , Análisis de Secuencia de ADN , Ubiquinona/análogos & derivados , Ubiquinona/química
13.
Helicobacter ; 19(6): 407-16, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25052961

RESUMEN

BACKGROUND: Helicobacter pylori (H. pylori) infection plays an important role in the early stage of cancer development. However, various bacteria that promote the synthesis of reactive oxygen and nitrogen species may be involved in the later stages. We aimed to determine the microbial composition of gastric mucosa from the patients with chronic gastritis, intestinal metaplasia, and gastric cancer using 454 GS FLX Titanium. METHODS: Gastric mucosal biopsy samples were collected from 31 patients during endoscopy. After the extraction of genomic DNA, variable region V5 of the 16S rRNA gene was amplified. PCR products were sequenced using 454 high-throughput sequencer. The composition, diversity, and richness of microbial communities were compared between three groups. RESULTS: The composition of H. pylori-containing Epsilonproteobacteria class appeared to be the most prevalent, but the relative increase in the Bacilli class in the gastric cancer group was noticed, resulting in a significant difference compared with the chronic gastritis group. By analyzing the Helicobacter-dominant group at a family level, the relative abundance of Helicobacteraceae family was significantly lower in the gastric cancer group compared with chronic gastritis and intestinal metaplasia groups, while the relative abundance of Streptococcaceae family significantly increased. In a UPGMA clustering of Helicobacter-dominant group based on UniFrac distance, the chronic gastritis group and gastric cancer group were clearly separated, while the intestinal metaplasia group was distributed in between the two groups. The evenness and diversity of gastric microbiota in the gastric cancer group was increased compared with other groups. CONCLUSIONS: In Helicobacter predominant patients, the microbial compositions of gastric mucosa from gastric cancer patients are significantly different to chronic gastritis and intestinal metaplasia patients. These alterations of gastric microbial composition may play an important, as-yet-undetermined role in gastric carcinogenesis of Helicobacter predominant patients.


Asunto(s)
Bacterias/aislamiento & purificación , Mucosa Gástrica/microbiología , Gastritis/microbiología , Enfermedades Intestinales/microbiología , Microbiota , Adulto , Anciano , Bacterias/clasificación , Bacterias/genética , Técnicas de Tipificación Bacteriana , Biodiversidad , Femenino , Infecciones por Helicobacter/microbiología , Helicobacter pylori/genética , Helicobacter pylori/aislamiento & purificación , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Enfermedades Intestinales/patología , Masculino , Metaplasia/microbiología , Persona de Mediana Edad , Estudios Prospectivos , Neoplasias Gástricas/microbiología
14.
ISME J ; 2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-38952008

RESUMEN

Microbial interactions impact the functioning of microbial communities. However, microbial interactions within host-associated communities remains poorly understood. Here, we report that the beneficiary rhizobacterium Niallia sp. RD1 requires the helper Pseudomonas putida H3 for bacterial growth and beneficial interactions with the plant host. In the absence of the helper H3 strain, the Niallia sp. RD1 strain exhibited weak respiration and elongated cell morphology without forming bacterial colonies. A transposon mutant of H3 in a gene encoding succinate-semialdehyde dehydrogenase displayed much attenuated support of RD1 colony formation. Through subsequent addition of succinate to the media, we found that succinate serves as a public good that supports RD1 growth. Comparative genome analysis highlighted that RD1 lacked the gene for sufficient succinate, suggesting its evolution as a beneficiary of succinate biosynthesis. The syntrophic interaction between RD1 and H3 efficiently protected tomato plants from bacterial wilt and promoted the tomato growth. The addition of succinate to the medium restored complex II-dependent respiration in RD1 and facilitated the cultivation of various bacterial isolates from the rhizosphere. Taken together, we delineate energy auxotrophic beneficiaries ubiquitous in the microbial community, and these beneficiaries could benefit host plants with the aid of helpers in the rhizosphere.

15.
Anal Chem ; 85(12): 5892-9, 2013 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-23581968

RESUMEN

High-throughput growth phenotyping is receiving great attention for establishing the genotype-phenotype map of sequenced organisms owing to the ready availability of complete genome sequences. To date, microbial growth phenotypes have been investigated mostly by the conventional method of batch cultivation using test tubes, Erlenmeyer flasks, or the recently available microwell plates. However, the current batch cultivation methods are time- and labor-intensive and often fail to consider sophisticated environmental changes. The implementation of batch cultures at the nanoliter scale has been difficult because of the quick evaporation of the culture medium inside the reactors. Here, we report a microfluidic system that allows independent cell cultures in evaporation-free multiplex nanoliter reactors under different culture conditions to assess the behavior of cells. The design allows three experimental replicates for each of eight culture environments in a single run. We demonstrate the versatility of the device by performing growth curve experiments with Escherichia coli and microbiological assays of antibiotics against the opportunistic pathogen Pseudomonas aeruginosa. Our study highlights that the microfluidic system can effectively replace the traditional batch culture methods with nanoliter volumes of bacterial cultivations, and it may be therefore promising for high-throughput growth phenotyping as well as for single-cell analyses.


Asunto(s)
Técnicas de Cultivo Celular por Lotes/métodos , Reactores Biológicos , Escherichia coli/fisiología , Nanotecnología/métodos , Fenotipo , Pseudomonas aeruginosa/fisiología
16.
J Virol ; 86(18): 9708-20, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22740391

RESUMEN

Efficient genetic modification of herpesviruses such as Kaposi's sarcoma-associated herpesvirus (KSHV) has come to rely on bacterial artificial chromosome (BAC) technology. In order to facilitate this approach, we generated a new KSHV BAC clone, called BAC16, derived from the rKSHV.219 virus, which stems from KSHV and Epstein-Barr virus-coinfected JSC1 primary effusion lymphoma (PEL) cells. Restriction enzyme and complete sequencing data demonstrate that the KSHV of JSC1 PEL cells showed a minimal level of sequence variation across the entire viral genome compared to the complete genomic sequence of other KSHV strains. BAC16 not only stably propagated in both Escherichia coli and mammalian cells without apparent genetic rearrangements, but also was capable of robustly producing infectious virions (∼5 × 10(7)/ml). We also demonstrated the utility of BAC16 by generating deletion mutants of either the K3 or K5 genes, whose products are E3 ligases of the membrane-associated RING-CH (MARCH) family. While previous studies have shown that individual expression of either K3 or K5 results in efficient downregulation of the surface expression of major histocompatibility complex class I (MHC-I) molecules, we found that K5, but not K3, was the primary factor critical for the downregulation of MHC-I surface expression during KSHV lytic reactivation or following de novo infection. The data presented here demonstrate the utility of BAC16 for the generation and characterization of KSHV knockout and mutant recombinants and further emphasize the importance of functional analysis of viral genes in the context of the KSHV genome besides the study of individual gene expression.


Asunto(s)
Cromosomas Artificiales Bacterianos/genética , Herpesvirus Humano 8/genética , Animales , Secuencia de Bases , Línea Celular Tumoral , Chlorocebus aethiops , Clonación Molecular , ADN Viral/genética , Escherichia coli/genética , Eliminación de Gen , Regulación Viral de la Expresión Génica , Genoma Viral , Herpesvirus Humano 8/patogenicidad , Herpesvirus Humano 8/fisiología , Antígenos de Histocompatibilidad Clase I/metabolismo , Interacciones Huésped-Patógeno , Humanos , Proteínas Inmediatas-Precoces/genética , Proteínas Inmediatas-Precoces/fisiología , Linfoma de Efusión Primaria/virología , Datos de Secuencia Molecular , Mutación , Plásmidos/genética , Células Vero , Proteínas Virales/genética , Proteínas Virales/fisiología
17.
Eukaryot Cell ; 11(12): 1584-5, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23193140

RESUMEN

Kluyveromyces marxianus is a thermotolerant yeast that has been explored for potential use in biotechnological applications, such as production of biofuels, single-cell proteins, enzymes, and other heterologous proteins. Here, we present the high-quality draft of the 10.9-Mb genome of K. marxianus var. marxianus KCTC 17555 (= CBS 6556 = ATCC 26548).


Asunto(s)
Genoma Fúngico , Kluyveromyces/genética , Secuencia de Bases , Bases de Datos Genéticas , Datos de Secuencia Molecular
18.
Plant Pathol J ; 39(6): 584-591, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38081318

RESUMEN

Active plant immune response involving programmed cell death called the hypersensitive response (HR) is elicited by microbial effectors delivered through the type III secretion system (T3SS). The marine bacterium Hahella chejuensis contains two T3SSs that are similar to those of animal pathogens, but it was able to elicit HR-like cell death in the land plant Nicotiana benthamiana. The cell death was comparable with the transcriptional patterns of H. chejuensis T3SS-1 genes, was mediated by SGT1, a general regulator of plant resistance, and was suppressed by AvrPto1, a type III-secreted effector of a plant pathogen that inhibits HR. Thus, type III-secreted effectors of a marine bacterium are capable of inducing the nonhost HR in a land plant it has never encountered before. This suggests that plants may have evolved to cope with a potential threat posed by alien pathogen effectors. Our work documents an exceptional case of nonhost HR and provides an expanded perspective for studying plant nonhost resistance.

19.
J Bacteriol ; 194(24): 6961-2, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23209220

RESUMEN

Here, we present the high-quality draft genome sequence of the agar-degrading marine gammaproteobacterium Alteromonadaceae sp. strain G7, which was isolated from coastal seawater to be utilized as a bioresource for production of agar-derived biofuels. The 3.91-Mb genome contains a number of genes encoding algal polysaccharide-degrading enzymes such as agarases and sulfatases.


Asunto(s)
Alteromonadaceae/genética , Genoma Bacteriano , Agar/metabolismo , Alteromonadaceae/aislamiento & purificación , Alteromonadaceae/metabolismo , Composición de Base , Secuencia de Bases , ADN Bacteriano/genética , Glicósido Hidrolasas/genética , Datos de Secuencia Molecular , Plásmidos , Agua de Mar/microbiología , Análisis de Secuencia de ADN , Sulfatasas/genética
20.
J Bacteriol ; 194(23): 6649-50, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23144399

RESUMEN

Burkholderia pyrrocinia CH-67 was isolated from forest soil as a biocontrol agent to be utilized in agriculture. Here, we report the 8.05-Mb draft genome sequence of this bacterium. Its genome contains genes involved in biosynthesis of secondary metabolites and plant growth promotion, which may contribute to probiotic effects on plants.


Asunto(s)
Burkholderia/genética , ADN Bacteriano/química , ADN Bacteriano/genética , Genoma Bacteriano , Análisis de Secuencia de ADN , Antifúngicos/metabolismo , Vías Biosintéticas/genética , Burkholderia/aislamiento & purificación , Burkholderia/metabolismo , Datos de Secuencia Molecular , Plantas , Probióticos , Microbiología del Suelo , Árboles
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