RESUMO
To isolate Bacillus velezensis mutants with improved antifungal activity for use in the biological control of phytopathogenic fungi, wild-type Bacillus velezensis KRF-001 producing iturin, surfactin, and fengycin was irradiated by ultraviolet (UV) rays. The in vitro and in vivo antifungal activities of UV mutants and characterization of the cyclic lipopeptides produced by a selected mutant were examined. A mutant strain yielding high levels of iturin showed over 2-fold higher antifungal activity than the wild-type against Fusarium oxysporum. A potent suppressive effect of the mutant was also observed on spore germination of Botrytis cinerea, the causative agent of cucumber gray mold, at different butanol extract concentrations. Further analysis of the mutant by real-time PCR and high-performance liquid chromatography revealed increased expression of iturin and surfactin biosynthesis genes as well as enhanced production of iturin and surfactin metabolites. However, the amounts of fengycin obtained from the mutant strain BSM54 were significantly lesser than those of iturin and surfactin. Particularly, iturin A production by the mutant was 3.5-fold higher than that of the wild-type, suggesting that the higher antifungal activity of the mutant against F. oxysporum resulted from the increased expression of biosynthesis genes associated with iturin production. The commercial greenhouse experiment using soil naturally infested with Sclerotinia sclerotiorum (sclerotinia rot) and F. oxysporum (fusarium wilt) showed that the mutant strain reduced sclerotinia rot and fusarium wilt diseases (P = 0.05) more effectively than the wild-type and commercially available product Cillus® in Korea. These results suggest that the mutant with high iturin yield is a potential candidate for the development of a biological control agent in agriculture.
Assuntos
Antifúngicos/isolamento & purificação , Bacillus/isolamento & purificação , Peptídeos Cíclicos/metabolismo , Ascomicetos/crescimento & desenvolvimento , Bacillus/metabolismo , Botrytis/crescimento & desenvolvimento , Fusarium/crescimento & desenvolvimento , Lipopeptídeos/metabolismo , República da CoreiaRESUMO
Bacillus subtilis subsp. krictiensis ATCC55079 produces the cyclic lipopeptide antibiotics iturin A-F as well as several surfactins. Here, we analyzed and characterized the biosynthetic genes associated with iturin and surfactin production in this strain. We aligned the sequences of each iturin and surfactin synthetase ORF obtained from a genomic library screen and next generation sequencing. The resulting 37,249-bp and 37,645-bp sequences associated with iturin and surfactin production, respectively, contained several ORFs that are predicted to encode proteins involved in iturin and surfactin biosynthesis. These ORFs showed higher sequence homologies with the respective iturin and surfactin synthetase genes of B. methylotrophicus CAU B946 than with those of B. subtilis RB14 and B. subtilis ATCC6633. Moreover, comparative analysis of the secondary metabolites produced by the wild-type and surfactin-less mutant (with a spectinomycin resistance cassette inserted into the srfAB gene within the putative surfactin gene region) strains demonstrated that the mutant strain showed significantly higher antifungal activity against Fusarium oxysporum than the wild-type strain. In addition, the wild-type strain-specific surfactin high performance liquid chromatography (HPLC) peaks were not observed in the surfactin-less mutant strain. In contrast, the iturin A peak detected by HPLC and liquid chromatography-mass spectrometry (LC/MS) in the surfactin-less mutant strain was 30% greater than that in the wild-type strain. These results suggested that the gene cluster we identified is involved in surfactin biosynthesis, and the biosynthetic pathways for iturin and surfactin in Bacillus strains producing both iturin and surfactin may utilize a common pathway.
Assuntos
Bacillus subtilis/genética , Genes Bacterianos , Peptídeos Cíclicos/biossíntese , Bacillus subtilis/enzimologia , Cromatografia Líquida de Alta Pressão , Clonagem Molecular , Espectrometria de Massas , Fases de Leitura AbertaRESUMO
In many pathogenic Gram-negative bacteria, such as Salmonella, Escherichia coli, Yersinia and Chlamydia spp., which cause diseases in humans, the type III secretion system (TTSS) is an important virulence factor that translocates effector proteins into the cytosol of host cells. Thus, the TTSS is a good target for antibacterial agents. Here we used a hemolysis assay to search for TTSS inhibitors and found that a compound from Magnolia obovata called obovatol blocks the TTSS of Salmonella. Obovatol showed potent inhibitory activity (IC50=19.8 µM) against the TTSS-related hemolysis of Salmonella, which was not due to a reduction of bacterial growth. Instead, the compound inhibited bacterial motility, TTSS-related mRNA expression and effector protein secretion. These data demonstrate the inhibitory effect of obovatol on the Salmonella TTSS and suggest that it could be useful for the prevention and supplementary treatment of bacterial infections.
Assuntos
Compostos de Bifenilo/farmacologia , Magnolia/química , Éteres Fenílicos/farmacologia , Salmonella/patogenicidade , Sistemas de Secreção Tipo III/efeitos dos fármacos , Antibacterianos/administração & dosagem , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Compostos de Bifenilo/administração & dosagem , Compostos de Bifenilo/isolamento & purificação , Hemólise/efeitos dos fármacos , Concentração Inibidora 50 , Éteres Fenílicos/administração & dosagem , Éteres Fenílicos/isolamento & purificaçãoRESUMO
Two dimeric sesquiterpenes were separated from Chloranthus japonicus Sieb. and identified as shizukaols C and F. They exhibited potent antifungal activities (MICs = 4-16 µg/ml) in vitro against various plant pathogenic fungi (Pythium ultimum, Phytophthora infestans, Botrytis cinerea, Colletotrichum lagenarium, Alternaria kikuchiana, and Magnaporthe grisea). Shizukaol C showed 88% and 91% protective activities in the greenhouse against Puccinia recondita (wheat leaf rust) and Phytophthora infestans (tomato late blight), respectively, at 100 µg/ml; shizukaol F exhibited 93% antifungal activity against Puccinia recondita at the same concentration. Therefore, these compounds might serve as interesting candidates for effective antifungal agents.
Assuntos
Antifúngicos/farmacologia , Fungos/efeitos dos fármacos , Magnoliopsida/química , Sesquiterpenos/farmacologia , Antifúngicos/química , Antifúngicos/isolamento & purificação , Fungicidas Industriais/isolamento & purificação , Fungicidas Industriais/farmacologia , Medicina Tradicional Chinesa , Testes de Sensibilidade Microbiana , Phytophthora infestans/efeitos dos fármacos , Doenças das Plantas/prevenção & controle , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Sesquiterpenos/química , Sesquiterpenos/isolamento & purificaçãoRESUMO
In order to discover plant-derived signaling pathway inhibitors with antifungal properties, a two-component screening system utilizing the calcineurin and Hog1 mitogen-activated protein kinase pathways responsible for the virulence networks of Cryptococcus neoformans was employed, owing to the counter-regulatory actions of these pathways. Of the 1,000 plant extracts tested, two bioactive compounds from Miliusa sinensis were found to act specifically on the calcineurin pathway of C. neoformans. These compounds, identified as pashanone and 5-hydroxy-6,7-dimethoxyflavanone, exhibited potent antifungal activities against various human pathogenic fungi with minimum inhibitory concentration values ranging from 4.0 to >128 µg/ml.
Assuntos
Annonaceae/química , Antifúngicos/farmacologia , Calcineurina/metabolismo , Flavonoides/farmacologia , Redes e Vias Metabólicas/efeitos dos fármacos , Antifúngicos/química , Antifúngicos/isolamento & purificação , Flavonoides/química , Flavonoides/isolamento & purificação , Testes de Sensibilidade Microbiana , Extratos Vegetais/químicaRESUMO
To identify plant-derived cell signaling inhibitors with antifungal properties, a twocomponent screening system using both wild-type Cryptococcus neoformans and a calcineurin mutant was employed owing to their counter-regulatory actions on the Hog1 mitogenactivated protein kinase and calcineurin pathways. Of the 2,000 plant extracts evaluated, a single bioactive compound from M. obovata Thunb. was found to act specifically on the calcineurin pathway of C. neoformans. This compound was identified as magnoloside A, and had potent antifungal activities against various Cryptococcus strains with minimum inhibitory concentration values ranging from 1.0 to 4.0 µg/ml.
Assuntos
Antifúngicos/metabolismo , Produtos Biológicos/metabolismo , Inibidores de Calcineurina/metabolismo , Cryptococcus neoformans/efeitos dos fármacos , Glicosídeos/metabolismo , Magnolia/química , Extratos Vegetais/metabolismo , Antifúngicos/isolamento & purificação , Produtos Biológicos/isolamento & purificação , Inibidores de Calcineurina/isolamento & purificação , Cryptococcus neoformans/enzimologia , Avaliação Pré-Clínica de Medicamentos , Glicosídeos/isolamento & purificação , Testes de Sensibilidade Microbiana , Extratos Vegetais/isolamento & purificaçãoRESUMO
In this study we explored the mode of action of KR-72, a 9-O-butyl-13-(4-isopropylbenzyl)berberine derivative previously shown to exhibit potent antifungal activity against a variety of human fungal pathogens. The DNA microarray data revealed that KR-72 treatment significantly changed the transcription profiles of C. neoformans, affecting the expression of more than 2,000 genes. Genes involved in translation and transcription were mostly upregulated, whereas those involved in the cytoskeleton, intracellular trafficking, and lipid metabolism were downregulated. KR-72 also exhibited a strong synergistic effect with the antifungal agent FK506. KR-72 treatment regulated the expression of several essential genes, including ECM16, NOP14, HSP10 and MGE1, which are required for C. neoformans growth. The KR-72-mediated induction of MGE1 also likely reduced the viability of C. neoformans by impairing cell cycle or the DNA repair system. In conclusion, KR-72 showed antifungal activity by modulating diverse biological processes through a mode of action distinct from those of clinically available antifungal drugs such as polyene and azole drugs.
Assuntos
Antifúngicos/farmacologia , Alcaloides de Berberina/farmacologia , Cryptococcus neoformans/efeitos dos fármacos , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Expressão Gênica/efeitos dos fármacos , Cryptococcus neoformans/genética , Análise de Sequência com Séries de OligonucleotídeosRESUMO
In order to discover and develop novel signaling inhibitors from plants, a screening system was established targeting the two-component system of Cryptococcus neoformans by using the wild type and a calcineurin mutant of C. neoformans, based on the counter-regulatory action of high-osmolarity glycerol (Hog1) mitogen-activated protein kinase and the calcineurin pathways in C. neoformans. Among 10,000 plant extracts, that from Harrisonia abyssinica Oliv. exhibited the most potent inhibitory activity against C. neoformans var. grubii H99 with fludioxonil. Bioassay-guided fractionation was used to isolate two bioactive compounds from H. abyssinica, and these compounds were identified as chebulagic acid and chebulanin using spectroscopic methods. These compounds specifically inhibited the calcineurin pathway in C. neoformans. Moreover, they exhibited potent antifungal activities against various human pathogenic fungi with minimum inhibitory concentrations ranging from 0.25 to over 64 µg/ml.
Assuntos
Benzopiranos/metabolismo , Calcineurina/metabolismo , Cryptococcus neoformans/enzimologia , Inibidores Enzimáticos/metabolismo , Glucosídeos/metabolismo , Taninos Hidrolisáveis/metabolismo , Simaroubaceae/química , Antifúngicos/isolamento & purificação , Antifúngicos/metabolismo , Benzopiranos/isolamento & purificação , Bioensaio/métodos , Cryptococcus neoformans/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos/métodos , Inibidores Enzimáticos/isolamento & purificação , Glucosídeos/isolamento & purificação , Taninos Hidrolisáveis/isolamento & purificação , Análise EspectralRESUMO
Two strains of Gram-staining-negative, rod-shaped bacteria that were motile by gliding, N7d-4(T) and B4a-b5, were isolated during a study of culturable bacteria in soil cultivated with potatoes. These isolates grew at 15-37 °C and at pH 6.5-7.0. The major cellular fatty acids were summed feature 3 (iso-C15â:â0 2-OH and/or C16â:â1ω7c), anteiso-C15â:â0, iso-C15â:â0, iso-C17â:â0 3-OH and iso-C17â:â1ω9c. The major polar lipids were phosphatidyl-N-methylethanolamine and phosphatidylethanolamine. The strains contained d-18â:â0 and d-19â:â0 sphingosines. The DNA G+C contents of strains N7d-4(T) and B4a-b5 were 48.5 and 46.9 mol% (HPLC), respectively. A phylogenetic analysis based on 16S rRNA gene sequences showed that strains N7d-4(T) and B4a-b5 were affiliated with Pedobacter species in the family Sphingobacteriaceae. Strains N7d-4(T) and B4a-b5 shared 99.9â% sequence similarity, and the most closely related Pedobacter type strains were Pedobacter composti TR6-06(T) (96.5 and 96.7â% sequence similarity, respectively), P. oryzae N7(T) (95.4 and 95.6â%) and P. caeni LMG 22862(T) (94.0 and 94.4â%). Phenotypic data and phylogenetic inference clearly distinguished the two isolates from other Pedobacter species. Based on these data, the isolates are considered to represent a novel species of the genus Pedobacter, for which the name Pedobacter luteus sp. nov. is proposed. The type strain is N7d-4(T) (â=âKCTC 22699(T) â=âDSM 22385(T)).
Assuntos
Pedobacter/classificação , Filogenia , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/análise , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Pedobacter/genética , Pedobacter/isolamento & purificação , Fosfatidiletanolaminas/análise , RNA Ribossômico 16S/genética , República da Coreia , Análise de Sequência de DNA , Solanum tuberosum/microbiologia , Esfingolipídeos/análise , Vitamina K 2/análogos & derivados , Vitamina K 2/análiseRESUMO
Two novel, Gram-positive, motile, coccal bacteria, strains L1b-b9(T) and B5a-b5, were isolated from a potato cultivation field in Ochang, Korea. These isolates grew at 10-45°C, pH 5.0-10.0, and in the presence of 8% (w/v) NaCl. The diagnostic diamino acid in the cell-wall peptidoglycan was meso-diaminopimelic acid. The major menaquinone was MK-8(H(4)) and the main cellular fatty acids were iso-C(14:0), iso-C(15:0), and anteiso-C(15:0). Polar lipids in strain L1b-b9(T) consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, and an unknown glyco-amino lipid. The G+C content of genomic DNA was 73.6 mol%. A phylogenetic analysis based on 16S rRNA gene sequences showed that strains L1b-b9(T) and B5a-b5 shared 99.36% similarity and formed a robust clade with the type species of the genus Phycicoccus. Strain L1b-b9(T) is related most closely to Phycicoccus cremeus V2M29(T) (97.52% 16S rRNA gene sequence similarity). On the basis of phylogenetic characteristics, the name Phycicoccus ochangensis sp. nov. is proposed for strain LIb-b9(T) (=KCTC 19695(T) [corrected] =JCM 17595(T)).
Assuntos
Actinomycetales/isolamento & purificação , Microbiologia do Solo , Actinomycetales/classificação , Actinomycetales/genética , Actinomycetales/metabolismo , Ácidos Graxos/metabolismo , Dados de Sequência Molecular , Filogenia , Cloreto de Sódio/metabolismo , Solanum tuberosum/crescimento & desenvolvimento , Solanum tuberosum/microbiologiaRESUMO
To investigate the possibility of horizontal gene transfer between agricultural microorganisms and soil microorganisms in the environment, Bacillus subtilis KB producing iturin and the PGPR recombinant strain Pseudomonas fluorescens MX1 were used as model microorganisms. The soil samples of cucumber or tomato plants cultivated in pots and the greenhouse for a six month period were investigated by PCR, real-time PCR, Southern hybridization, and terminal restriction fragment length polymorphism (T-RFLP) fingerprinting. Our data from Southern blotting and TRFLP patterns suggest that the model bacteria do not give significant impacts on the other bacteria in the pots and greenhouse during cultivation.
Assuntos
Bacillus subtilis/genética , Bactérias/genética , Cucumis sativus/microbiologia , Transferência Genética Horizontal , Pseudomonas fluorescens/genética , Solanum lycopersicum/microbiologia , Bactérias/classificação , Bactérias/isolamento & purificação , Microbiologia do SoloRESUMO
Most Arabidopsis ecotypes display tolerance to the Tobacco ringspot virus (TRSV), but a subset of Arabidopsis ecotypes, including Estland (Est), develop lethal systemic necrosis (LSN), which differs from the localized hypersensitive responses (HRs) or systemic acquired resistance (SAR) characteristic of incompatible reactions. Neither viral replication nor the systemic movement of TRSV was restricted in tolerant or sensitive Arabidopsis ecotypes; therefore, the LSN phenotype shown in the sensitive ecotypes might not be due to viral accumulation. In the present study, we identified the Est TTR1 gene (tolerance to Tobacco ringspot virus 1) encoding a TIR-NBS-LRR protein that controls the ecotype-dependent tolerant/sensitive phenotypes by a map-based cloning method. The tolerant Col-0 ecotype Arabidopsis transformed with the sensitive Est TTR1 allele developed an LSN phenotype upon TRSV infection, suggesting that the Est TTR1 allele is dominant over the tolerant ttr1 allele of Col-0. Multiple sequence alignments of 10 tolerant ecotypes from those of eight sensitive ecotypes showed that 10 LRR amino acid polymorphisms were consistently distributed across the TTR1/ttr1 alleles. Site-directed mutagenesis of these amino acids in the LRR region revealed that two sites, L956S and K1124Q, completely abolished the LSN phenotype. VIGS study revealed that TTR1 is dependent on SGT1, rather than EDS1. The LSN phenotype by TTR1 was shown to be transferred to Nicotiana benthamiana, demonstrating functional conservation of TTR1 across plant families, which are involved in SGT-dependent defense responses, rather than EDS1-dependent signaling pathways.
Assuntos
Arabidopsis/genética , Arabidopsis/virologia , Nepovirus/fisiologia , Doenças das Plantas/virologia , Sequência de Aminoácidos , Arabidopsis/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Inativação Gênica , Genes Virais , Dados de Sequência Molecular , Nepovirus/genética , Nepovirus/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Replicação ViralRESUMO
The environmental release of genetically engineered microorganisms (GEMs) to improve agriculture or remediate environmental hazards has raised concern over the fate of the organisms and their engineered genes. To detect the microorganisms released into the environment at the molecular level, Bacillus subtilis KB producing iturin and Pseudomonas fluorescens MX1 carrying the moc (mannityl opine catabolism) region from the Agrobacterium tumefaciens were employed as model microorganisms. Using specific fusion primers and the TaqMan probes, qualitative and quantitative detections of the model organisms by PCR and real-time PCR were conducted employing a small-scale soil-core device and pots during the six month period. The data indicate that the model bacteria can be easily detected by qualitative and quantitative methods in the test systems employed, and they do not give significant impacts on the other bacteria in soils on the Southern blotting analysis, although long-term observation may be needed.
Assuntos
Bacillus subtilis/genética , Proteínas de Bactérias/genética , Engenharia Genética , Pseudomonas fluorescens/genética , Microbiologia do Solo , Solo/análise , Agrobacterium tumefaciens/enzimologia , Agrobacterium tumefaciens/genética , Bacillus subtilis/isolamento & purificação , Bacillus subtilis/metabolismo , Proteínas de Bactérias/metabolismo , Sequência de Bases , Dados de Sequência Molecular , Pseudomonas fluorescens/isolamento & purificação , Pseudomonas fluorescens/metabolismoRESUMO
By replacing the methyl group of 13-(4-isopropylbenzyl)berberine 2 with various acyl, alkyl, and benzyl groups via the demethylated intermediate, 13-(4-isopropylbenzyl)berberrubine 4, a novel series of 9-O-alkyl-13-(4-isopropylbenzyl)berberine derivatives was synthesized and examined for antifungal activities against various human pathogenic fungi. The introduction of various alkyl groups led to enhanced antifungal activity but that of acyl groups resulted in decrease of the activity. Among them, 9-O-butyl-13-(4-isopropylbenzyl)berberine 6d exhibited the most potent antifungal activities against Cryptococcus neoformans, Candida species (MIC=0.25-1 µg/ml), and Aspergillus species (MIC=2-4 µg/ml). The compound was found to be relatively safe up to 900 mg/kg in oral administration to mice.
Assuntos
Antifúngicos/síntese química , Antifúngicos/farmacologia , Berberina/síntese química , Berberina/farmacologia , Animais , Antifúngicos/química , Aspergillus/efeitos dos fármacos , Berberina/química , Candida/efeitos dos fármacos , Cryptococcus neoformans/efeitos dos fármacos , Camundongos , Testes de Sensibilidade MicrobianaRESUMO
To examine the possibility of horizontal gene transfer between transgenic potatoes and microorganisms in potato fields, the gene flow from transgenic potatoes containing nucleoside diphosphate kinase 2 (NDPK2) gene to microorganisms in soils was investigated. The soil samples collected from the potato fields from March to October in 2007 were examined by PCR, Southern hybridization, and AFLP fingerprinting. The NDPK2 gene from soil genomic DNAs was not detected by both PCR and Southern hybridization, indicating that gene-transfer did not occur in the potato fields. In addition, no discrepancy was found in pathogenicity and noticeable changes for the appearance of variants of Phytophthora infestans in each generation when serial inoculations and the analysis of genomic DNAs by AFLP was conducted. Thus, these data suggest that transgenic potatoes do not give significant impacts on the communities of soil microorganisms and the emergence of variants although continued research efforts may be necessary to make a decisive conclusion.
Assuntos
Transferência Genética Horizontal , Phytophthora infestans/genética , Plantas Geneticamente Modificadas/genética , Solanum tuberosum/genética , Variação Genética , Núcleosídeo-Difosfato Quinase/genética , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/parasitologia , Solo/parasitologia , Solanum tuberosum/enzimologia , Solanum tuberosum/parasitologiaRESUMO
The novel intracellular GH10 xylanase (iXylC) gene (1023-bp) of Cohnella laeviribosi HY-21 encoded a protein consisting of 340 amino acids with a deduced molecular mass of 39,330Da and a calculated pI of 5.81. The primary structure of iXylC was 70% identical to that of Geobacillus sp. GH10 enzyme (GenBank accession number: EDV78425). Xylanolytic activity of the His-tagged iXylC overproduced in Escherichiacoli BL21 was stimulated by 2.2-fold in the presence of 0.5% non-ionic detergents. iXylC produced a mixture of xylooligosaccharides (xylobiose to xylooctaose) from xylotriose and xylotetraose used as the hydrolytic substrate. In addition, it exhibited considerable cleavage activities for p-nitrophenylxylopyranoside (PNP-xylopyranoside) and PNP-cellobioside, indicating that iXylC is a unique GH10 enzyme. The hydrolytic activity (57.8IUmL(-1)) of iXylC toward PNP-xylopyranoside increased to 8.3-fold by W217A and W315A mutations, while mutations of W133A, W295A, and W303A abolished the hydrolytic activity of the enzyme.
Assuntos
Endo-1,4-beta-Xilanases/biossíntese , Endo-1,4-beta-Xilanases/genética , Mutagênese Sítio-Dirigida/métodos , Paenibacillus/fisiologia , Triptofano/genética , Catálise , Engenharia de Proteínas/métodos , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Especificidade por SubstratoRESUMO
OBJECTIVE: Mycobacterial involvement of the esophagus is rare. Similar abnormal lesions of the esophagus may be confused with esophageal cancer and deep fungal infections. We studied the clinical features, endoscopic findings, the role of histopathology, and the outcome of antituberculosis treatment in patients with esophageal tuberculosis. METHODS: A single center based, retrospective study was performed. We reviewed the clinical and pathological records of patients with esophageal tuberculosis that were clinically diagnosed from 1997 to 2006. RESULTS: Esophageal tuberculosis, confirmed by histology, was found in six patients. Five patients presented with local symptoms. The mean number of endoscopic sessions for a diagnosis was 1.8 sessions (range 1-3). For the histopathology, caseous necrosis was found in four patients but positive acid fast bacilli stains and tuberculosis-polymerase chain reaction were not detected. Patients diagnosed with esophageal tuberculosis tolerated medical therapy and responded well. CONCLUSION: Because esophageal tuberculosis presents with various, diverse clinical features, and endoscopic findings, it is difficult to diagnose at one session of endoscopy. However, esophageal tuberculosis should be considered in the differential diagnosis if ulcerative lesions were found in the mid esophagus.
Assuntos
Doenças do Esôfago/diagnóstico , Esofagoscopia , Esôfago/patologia , Tuberculose Gastrointestinal/diagnóstico , Úlcera/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto JovemRESUMO
In order to monitor the possibility of horizontal gene transfer between transgenic rice and microorganisms in paddy rice field, the gene flow from bifunctional fusion (TPSP) rice containing trehalose-6-phosphate synthase and phosphatase to microorganisms in soils was investigated. The soil samples collected every month from the paddy rice field during June, 2004 to March, 2006 were investigated by multiplex PCR, Southern hybridization, and amplified fragment length polymorphism (AFLP). The TPSP gene from soil genomics DNAs was not detected by PCR. Soil genomic DNAs were not shown its homologies on the Southern blotting data, indicating that gene-transfer did not occur during the last two years in paddy rice field. In addition, the AFLP band patterns produced by both soil genomic DNAs extracted from transgenic and non-transgenic rice field appeared similar to each other when analyzed by NTSYSpc program. Thus, these data suggest that transgenic rice does not give a significant impact on the communities of soil microorganisms although long-term observation may be needed.
Assuntos
Transferência Genética Horizontal , Glucosiltransferases/genética , Oryza/genética , Proteínas de Plantas/genética , Microbiologia do Solo , Solo/análise , Glucosiltransferases/metabolismo , Oryza/enzimologia , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/enzimologia , Plantas Geneticamente Modificadas/genéticaRESUMO
The gene encoding a novel modular xylanase from Cellulosimicrobium sp. strain HY-13 was identified and expressed in Escherichia coli, and its truncated gene product was characterized. The enzyme consisted of three distinct functional domains, an N-terminal catalytic GH10 domain, a fibronectin type 3 domain, and C-terminal carbohydrate-binding module 2.
Assuntos
Actinomycetales/enzimologia , Oligoquetos/microbiologia , Xilosidases/metabolismo , Actinomycetales/genética , Sequência de Aminoácidos , Animais , Endo-1,4-beta-Xilanases/química , Endo-1,4-beta-Xilanases/genética , Endo-1,4-beta-Xilanases/metabolismo , Fibronectinas/química , Intestinos/microbiologia , Dados de Sequência Molecular , Ligação Proteica , Estrutura Terciária de Proteína , Alinhamento de Sequência , Especificidade por Substrato/genética , Xilosidases/química , Xilosidases/genéticaRESUMO
An antifungal compound was isolated from methanol extracts of stems and roots of Chloranthus henryi Hemsl. using ethyl acetate extraction and various chromatographic techniques. On the basis of spectroscopic analyses including mass and various NMR, the structure of the compound was identified as a dimeric sesquiterpene, CHE-23C. The compound showed potent antifungal activities (MICs = 1-32 microg/mL) in vitro against various phytopathogenic fungi such as Alternaria kikuchiana , Botrytis cinerea , Colletotrichum lagenarium , Magnaporthe grisea , Pythium ultimum , and Phytophthora infestans . In particular, it exhibited 91 and 100% disease-control activity in vivo against tomato late blight (P. infestans) and wheat leaf rust ( Puccinia recondita ) at concentrations of 33 and 100 microg/mL, respectively. The disease-control activity of this compound was stronger than that of the commercially available fungicide chlorothalonil, but weaker than that of dimethomorph. Therefore, the compound might serve as an interesting lead to develop effective antifungal agents.