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31.
Paulo A. Zaini Leonardo De La Fuente Harvey C. Hoch & Thomas J. Burr 《FEMS microbiology letters》2009,295(1):129-134
Xylella fastidiosa is able to form biofilms within xylem vessels of many economically important crops. Vessel blockage is believed to be a major contributor to disease development caused by this bacterium. This report shows that Vitis riparia xylem sap increases growth rate and induces a characteristic biofilm architecture as compared with biofilms formed in PD2 and PW media. In addition, stable cultures could be maintained, frozen and reestablished in xylem sap. These findings are important as xylem sap provides a natural medium that facilitates the identification of virulence determinants of Pierce's disease. 相似文献
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Reza?Kachuei Mohammad Hossein?Yadegari?Email author Sasan?Rezaie Abdolamir?Allameh Naser?Safaie Farideh?Zaini Fatemeh?Khanezad?Yazdi 《Annals of microbiology》2009,59(2):383
Wheat is the most important cereal produced in Iran. A mycological survey was carried out for the first time, on the stored wheat samples in Tehran, East Azarbayejan and Mazandaran provinces in 2007. Exogenous and endogenous fungi, were isolated by the method of flotation with Malachite green agar (MGA 0.25) and Freeze blotter techniques respectively. In this study, 46 species belonging to 23 different genera were isolated.Cladosporium spp. (57.1–89.2%) andAlternaria spp. (82.4–100%) species were the predominant fungal species identified as endogenous mycoflora. The predominant exogenous fungi werePenicillium spp. (78.4–92.8%) andAspergillus spp. (71.4–85.7%) species.Fusarium proliferatum was the most prevalent species ofFusarium isolates.Aspergillus niger (39.4%) andAspergillus flavus (36.7%) were the predominantAspergillus species identified as exogenous mycoflora.Aspergillus flavus (26.6%) was the predominantAspergillus species identified as endogenous mycoflora. Flotation method with MGA 0.25 recommended for isolating of hyaline fungi from wheat cereals. In this study one isolate fromFusarium species was isolated on the basis of morphology and ribosomal internal transcribed spacer classified asFusarium langsethiae but on the basis of partial translation elongation factor-1alpha gene grouped withFusarium sporotrichioides. To our knowledge, this is the first report aboutF. cf.langsethiae in Iran and Asia. 相似文献
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Sugijanto Kartosentono Sinar Suryawati Gunawan Indrayanto Noor Cholies Zaini 《Biotechnology letters》2002,24(9):687-690
Cell suspension cultures of Agave amaniensis and Costus speciosus were grown in media containing Cd2 + up to 25 and 20 mg l–1, respectively, and Pb2+ up to 40 mg l–1. The cultures hyper-accumulated Cd2+ up to 900 and 530 g g–1 and Pb2+ up to 1390 and 1170 g g–1 dry wt. in their respective biomasses. Increasing Pb2+ up to 30 mg l–1 increased the biomass production and total sitosterol content of Costus speciosus by up to 1.7- and 1.3-fold, respectively. 相似文献
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Juhas M Power PM Harding RM Ferguson DJ Dimopoulou ID Elamin AR Mohd-Zain Z Hood DW Adegbola R Erwin A Smith A Munson RS Harrison A Mansfield L Bentley S Crook DW 《Genome biology》2007,8(11):R237-14
Background
A major part of horizontal gene transfer that contributes to the diversification and adaptation of bacteria is facilitated by genomic islands. The evolution of these islands is poorly understood. Some progress was made with the identification of a set of phylogenetically related genomic islands among the Proteobacteria, recognized from the investigation of the evolutionary origins of a Haemophilus influenzae antibiotic resistance island, namely ICEHin1056. More clarity comes from this comparative analysis of seven complete sequences of the ICEHin1056 genomic island subfamily.Results
These genomic islands have core and accessory genes in approximately equal proportion, with none demonstrating recent acquisition from other islands. The number of variable sites within core genes is similar to that found in the host bacteria. Furthermore, the GC content of the core genes is similar to that of the host bacteria (38% to 40%). Most of the core gene content is formed by the syntenic type IV secretion system dependent conjugative module and replicative module. GC content and lack of variable sites indicate that the antibiotic resistance genes were acquired relatively recently. An analysis of conjugation efficiency and antibiotic susceptibility demonstrates that phenotypic expression of genomic island-borne genes differs between different hosts.Conclusion
Genomic islands of the ICEHin1056 subfamily have a longstanding relationship with H. influenzae and H. parainfluenzae and are co-evolving as semi-autonomous genomes within the 'supragenomes' of their host species. They have promoted bacterial diversity and adaptation through becoming efficient vectors of antibiotic resistance by the recent acquisition of antibiotic resistance transposons. 相似文献35.
Andrographis paniculata (Burm.f) Nees is one of the most popular and important medicinal plant of the Orient, and South East Asia. It finds mention
in various forms in Indian, Chinese, Malay, Thai, Unani, and Japanese systems of medicine. The plant exhibits anti-cancer,
anti-inflammatory, anti-diabetic, anti-hypertensive, anti-venom, cholestatic, hepatoprotective, anti-thrombotic, anti-retroviral,
anti-microbial, anti-pyretic, anti-malarial, anti-oxidant, immunomodulatory, and cardioprotective effects. The major active
principles contributing to biological activity are diterpene lactones, but flavonoids, xanthones and caffeic acid derivatives
also contribute to anti-oxidant, anti-proliferative, anti-atherosclerotic, and anti-malarial effects. As a result of its wide
spectrum of pharmacological activity, almost impeccable safety profile, being a widely cultivated medicinal plant, we have
collected and compiled various facets of this plant. Extensive datamining of the phytochemistry and pharmacology of Andrographis paniculata revealed more than 50 diterpene lactones, 30 flavonoids, 8 quinic acid derivatives, and 4 xanthones. This review contains
information on around 80 isolated compounds, out of which more than half of the compounds have no reported pharmacological
activity. Though there are some good reviews available on Andrographis paniculata, the authors of the earlier reviews focused on one or two aspects of the plant and none have attempted to integrate the available
information on this plant. This provided us the much needed impetus, warranting a full-fledged and complete review on Andrographis paniculata, one of the most popular and important Oriental medicinal plant. 相似文献
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Luciana Cursino Dusit Athinuwat Kelly R. Patel Cheryl D. Galvani Paulo A. Zaini Yaxin Li Leonardo De La Fuente Harvey C. Hoch Thomas J. Burr Patricia Mowery 《PloS one》2015,10(3)
Xylella fastidiosa is an important phytopathogenic bacterium that causes many serious plant diseases including Pierce’s disease of grapevines. X. fastidiosa is thought to induce disease by colonizing and clogging xylem vessels through the formation of cell aggregates and bacterial biofilms. Here we examine the role in X. fastidiosa virulence of an uncharacterized gene, PD1671, annotated as a two-component response regulator with potential GGDEF and EAL domains. GGDEF domains are found in c-di-GMP diguanylate cyclases while EAL domains are found in phosphodiesterases, and these domains are for c-di-GMP production and turnover, respectively. Functional analysis of the PD1671 gene revealed that it affected multiple X. fastidiosa virulence-related phenotypes. A Tn5 PD1671 mutant had a hypervirulent phenotype in grapevines presumably due to enhanced expression of gum genes leading to increased exopolysaccharide levels that resulted in elevated biofilm formation. Interestingly, the PD1671 mutant also had decreased motility in vitro but did not show a reduced distribution in grapevines following inoculation. Given these responses, the putative PD1671 protein may be a negative regulator of X. fastidiosa virulence. 相似文献
37.
Mirza M Pang MF Zaini MA Haiko P Tammela T Alitalo K Philipson L Fuxe J Sollerbrant K 《PloS one》2012,7(5):e37523
The coxsackie- and adenovirus receptor (CAR) is a cell adhesion molecule predominantly associated with epithelial tight junctions in adult tissues. CAR is also expressed in cardiomyocytes and essential for heart development up to embryonic day 11.5, but not thereafter. CAR is not expressed in vascular endothelial cells but was recently detected in neonatal lymphatic vessels, suggesting that CAR could play a role in the development of the lymphatic system. To address this, we generated mice carrying a conditional deletion of the CAR gene (Cxadr) and knocked out CAR in the mouse embryo at different time points during post-cardiac development. Deletion of Cxadr from E12.5, but not from E13.5, resulted in subcutaneous edema, hemorrhage and embryonic death. Subcutaneous lymphatic vessels were dilated and structurally abnormal with gaps and holes present at lymphatic endothelial cell-cell junctions. Furthermore, lymphatic vessels were filled with erythrocytes showing a defect in the separation between the blood and lymphatic systems. Regionally, erythrocytes leaked out into the interstitium from leaky lymphatic vessels explaining the hemorrhage detected in CAR-deficient mouse embryos. The results show that CAR plays an essential role in development of the lymphatic vasculature in the mouse embryo by promoting appropriate formation of lymphatic endothelial cell-cell junctions. 相似文献
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DNA microarray-based genome comparison of a pathogenic and a nonpathogenic strain of Xylella fastidiosa delineates genes important for bacterial virulence
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Koide T Zaini PA Moreira LM Vêncio RZ Matsukuma AY Durham AM Teixeira DC El-Dorry H Monteiro PB da Silva AC Verjovski-Almeida S da Silva AM Gomes SL 《Journal of bacteriology》2004,186(16):5442-5449
Xylella fastidiosa is a phytopathogenic bacterium that causes serious diseases in a wide range of economically important crops. Despite extensive comparative analyses of genome sequences of Xylella pathogenic strains from different plant hosts, nonpathogenic strains have not been studied. In this report, we show that X. fastidiosa strain J1a12, associated with citrus variegated chlorosis (CVC), is nonpathogenic when injected into citrus and tobacco plants. Furthermore, a DNA microarray-based comparison of J1a12 with 9a5c, a CVC strain that is highly pathogenic and had its genome completely sequenced, revealed that 14 coding sequences of strain 9a5c are absent or highly divergent in strain J1a12. Among them, we found an arginase and a fimbrial adhesin precursor of type III pilus, which were confirmed to be absent in the nonpathogenic strain by PCR and DNA sequencing. The absence of arginase can be correlated to the inability of J1a12 to multiply in host plants. This enzyme has been recently shown to act as a bacterial survival mechanism by down-regulating host nitric oxide production. The lack of the adhesin precursor gene is in accordance with the less aggregated phenotype observed for J1a12 cells growing in vitro. Thus, the absence of both genes can be associated with the failure of the J1a12 strain to establish and spread in citrus and tobacco plants. These results provide the first detailed comparison between a nonpathogenic strain and a pathogenic strain of X. fastidiosa, constituting an important step towards understanding the molecular basis of the disease. 相似文献