scholarly journals Characteristics of morphogenetic responses of Nicotiana langsdorffii on transformation with wild type strains of Agrobacterium in vitro

2007 ◽  
Vol 5 (3) ◽  
pp. 21-24 ◽  
Author(s):  
Tatyana V Matveeva ◽  
Tatiana Yu Pigichka ◽  
Ludmila A Lutova
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Shoot Formation ◽  
Wild Type ◽  
Model Object ◽  
Nicotiana Langsdorffii ◽  
Type Strains ◽  
Morphogenetic Responses ◽  
Leaf Disks

Ability to transformation by wt strains of Agrobacterium tumefaciens (T37, C58, A6) and A. rhizogenes (15834, 8196, A4) was characterized for Nicotiana langsdorffii. It was shown that effectivity of transformation of this species by strains T37, A6,15834, 8196, A4 was lower comparing to the model object N. tabacum. Tumors induced by A. tumefaciens on leaf disks of N. langsdorffii, tend to shoot formation.

scholarly journals Pharmacodynamics of Itraconazole against Aspergillus fumigatus in anIn VitroModel of the Human Alveolus: Perspectives on the Treatment of Triazole-Resistant Infection and Utility of Airway Administration

2012 ◽  
Vol 56 (8) ◽  
pp. 4146-4153 ◽  
Author(s):  
Zaid Al-Nakeeb ◽  
Ajay Sudan ◽  
Adam R. Jeans ◽  
Lea Gregson ◽  
Joanne Goodwin ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Therapeutic Strategies ◽  
Wild Type ◽  
Content Type ◽  
Exposure Response ◽  
Prevention And Treatment ◽  
Resistant Infection ◽  
Resistant Strains ◽  
Type Strains

ABSTRACTItraconazole is used for the prevention and treatment of infections caused byAspergillus fumigatus. An understanding of the pharmacodynamics of itraconazole against wild-type and triazole-resistant strains provides a basis for innovative therapeutic strategies for treatment of infections. Anin vitromodel of the human alveolus was used to define the pharmacodynamics of itraconazole. Galactomannan was used as a biomarker. The effect of systemic and airway administration of itraconazole was assessed, as was a combination of itraconazole administered to the airway and systemically administered 5FC. Systemically administered itraconazole against the wild type induced a concentration-dependent decline in galactomannan in the alveolar and endothelial compartments. No exposure-response relationships were apparent for the L98H, M220T, or G138C mutant. The administration of itraconazole to the airway resulted in comparable exposure-response relationships to those observed with systemic therapy. This was achieved without detectable concentrations of drug within the endothelial compartment. The airway administration of itraconazole resulted in a definite but submaximal effect in the endothelial compartment against the L98H mutant. The administration of 5FC resulted in a concentration-dependent decline in galactomannan in both the alveolar and endothelial compartments. The combination of airway administration of itraconazole and systemically administered 5FC was additive. Systemic administration of itraconazole is ineffective against Cyp51 mutants. The airway administration of itraconazole is effective for the treatment of wild-type strains and appears to have some activity against the L98H mutants. Combination with other agents, such as 5FC, may enable the attainment of near-maximal antifungal activity.

scholarly journals Evaluation of Accessory Gene Regulator (agr) Group and Function in the Proclivity towards Vancomycin Intermediate Resistance in Staphylococcus aureus

2006 ◽  
Vol 51 (3) ◽  
pp. 1089-1091 ◽  
Author(s):  
Brian T. Tsuji ◽  
Michael J. Rybak ◽  
Kerry L. Lau ◽  
George Sakoulas
Keyword(s):  
Staphylococcus Aureus ◽  
Wild Type ◽  
Accessory Gene ◽  
Time Curve ◽  
Unbound Fraction ◽  
Accessory Gene Regulator ◽  
Intermediate Resistance ◽  
And Function ◽  
Type Strains

ABSTRACT Simulated therapeutic vancomycin exposures were evaluated against agr wild-type and knockout Staphylococcus aureus groups I, II, III, and IV using an in vitro pharmacodynamic model. All agr groups developed intermediate resistance to vancomycin after subtherapeutic exposure. The free unbound fraction of the area under the concentration-time curve (fAUC/MIC) required to suppress resistance was fourfold higher (P < 0.001) in agr dysfunctional strains (112 to 169) than that in parent wild-type strains (28).

scholarly journals Agrobacterium tumefaciens Transformation of the Radiation Hypersensitive Arabidopsis thaliana Mutants uvh1 and rad5

1998 ◽  
Vol 11 (11) ◽  
pp. 1136-1141 ◽  
Author(s):  
Jaesung Nam ◽  
Kirankumar S. Mysore ◽  
Stanton B. Gelvin
Keyword(s):  
Arabidopsis Thaliana ◽  
Agrobacterium Tumefaciens ◽  
Transformation Process ◽  
Stable Transformation ◽  
Wild Type ◽  
Dna Integration ◽  
Agrobacterium Tumefaciens Transformation ◽  
Inoculation Assay

The Arabidopsis thaliana mutants uvh1 and rad5, originally identified as radiation hypersensitive, were reported to be deficient in T-DNA integration based on the relative efficiencies of stable transformation and T-DNA transfer. We reassessed these mutants for susceptibility to transformation by Agrobacterium tumefaciens. The mutant rad5 showed a significant reduction in the efficiency of transient as well as stable transformation, compared with its wild-type progenitor. These data indicate that rad5 is blocked at a step in the transformation process prior to T-DNA integration. We additionally found, using both an in vitro root inoculation and an in vivo flower bolt inoculation assay, that the mutant uvh1 is as susceptible to A. tumefaciens-mediated transformation as is its wild-type progenitor, C10.

scholarly journals Mutants of Listeria monocytogenes Defective in In Vitro Invasion and Cell-to-Cell Spreading Still Invade and Proliferate in Hepatocytes of Neutropenic Mice

2000 ◽  
Vol 68 (2) ◽  
pp. 912-914 ◽  
Author(s):  
Rui Appelberg ◽  
Irene S. Leal
Keyword(s):  
Monoclonal Antibody ◽  
Listeria Monocytogenes ◽  
Cell Spreading ◽  
Histologic Examination ◽  
Gene Products ◽  
Wild Type ◽  
In Vitro Invasion ◽  
Parenchymal Cells ◽  
Type Strains

ABSTRACT Listeria monocytogenes mutants defective in theactA gene, the plcB gene, and theinlA and inlB genes were less virulent when injected intravenously into BALB/c mice. The growth of these strains as well as of the virulent wild-type strains was increased by treating mice with a neutrophil-specific depleting monoclonal antibody, RB6-8C5. Histologic examination of the livers of the treated animals showed intrahepatocytic proliferation of the listeriae in all cases. Our data show that more than one pathway exists that allows L. monocytogenes to invade parenchymal cells. One pathway most likely involves the actA and plcB gene products, and a second one probably involves the internalins.

Histological study of organogenesis in vitro from callus cultures of two Nicotiana species

1981 ◽  
Vol 59 (11) ◽  
pp. 1969-1977 ◽  
Author(s):  
V. Nuti Ronchi
Keyword(s):  
Vascular Tissue ◽  
Histological Study ◽  
Parenchyma Cell ◽  
Shoot Formation ◽  
Callus Cultures ◽  
Nicotiana Glauca ◽  
Meristematic Tissue ◽  
Nicotiana Langsdorffii ◽  
Physical And Chemical

The histological events leading to shoot formation in Nicotiana glauca and in the nontumorous Nicotiana glauca × Nicotiana langsdorffii hybrid have been studied. Organized development begins from a single vacuolated parenchyma cell which divides and precociously differentiates tracheidal cells, forming a growth center with nodular structures with xylem in the center and phloem outside. The vascular tissue is precociously separated from the surrounding callus by a layer of cells which are shown to be endodermal by position and by histochemical reactions. Further growth leads to the formation of a mound of meristematic tissue which later forms shoot apical meristems. The sequences of events are discussed in relation to other known systems of regeneration in calluses.The system described could be suitable for evaluating the effects of various physical and chemical agents on the different steps of differentiation.

scholarly journals Mycobacterium tuberculosis Dihydrofolate Reductase Is Not a Target Relevant to the Antitubercular Activity of Isoniazid

2010 ◽  
Vol 54 (9) ◽  
pp. 3776-3782 ◽  
Author(s):  
Feng Wang ◽  
Paras Jain ◽  
Gulcin Gulten ◽  
Zhen Liu ◽  
Yicheng Feng ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Dihydrofolate Reductase ◽  
Fold Increase ◽  
Antitubercular Activity ◽  
Experimental Sample ◽  
Wild Type ◽  
Negative Results ◽  
Sequencing Studies ◽  
Type Strains

ABSTRACT Mycobacterium tuberculosis enoyl-acyl-ACP reductase (InhA) has been demonstrated to be the primary target of isoniazid (INH). Recently, it was postulated that M. tuberculosis dihydrofolate reductase (DHFR) is also a target of INH, based on the findings that a 4R-INH-NADP adduct synthesized from INH by a nonenzymatic approach showed strong inhibition of DHFR in vitro, and overexpression of M. tuberculosis dfrA in M. smegmatis conferred a 2-fold increase of resistance to INH. In the present study, a plasmid expressing M. tuberculosis dfrA was transformed into M. smegmatis and M. tuberculosis strains, respectively. The transformant strains were tested for their resistance to INH. Compared to the wild-type strains, overexpression of dfrA in M. smegmatis and M. tuberculosis did not confer any resistance to INH based on the MIC values. Similar negative results were obtained with 14 other overexpressed proteins that have been proposed to bind some form of INH-NAD(P) adduct. An Escherichia coli cell-based system was designed that allowed coexpression of both M. tuberculosis katG and dfrA genes in the presence of INH. The DHFR protein isolated from the experimental sample was not found bound with any INH-NADP adduct by enzyme inhibition assay and mass spectroscopic analysis. We also used whole-genome sequencing to determine whether polymorphisms in dfrA could be detected in six INH-resistant clinical isolates known to lack mutations in inhA and katG, but no such mutations were found. The dfrA overexpression experiments, together with the biochemical and sequencing studies, conclusively demonstrate that DHFR is not a target relevant to the antitubercular activity of INH.

scholarly journals The Escherichia coli gabDTPC Operon: Specific γ-Aminobutyrate Catabolism and Nonspecific Induction

2002 ◽  
Vol 184 (24) ◽  
pp. 6976-6986 ◽  
Author(s):  
Barbara L. Schneider ◽  
Stephen Ruback ◽  
Alexandros K. Kiupakis ◽  
Hillary Kasbarian ◽  
Christine Pybus ◽  
...  
Keyword(s):  
Nitrogen Source ◽  
Nitrogen Limitation ◽  
Nitrogen Sources ◽  
Wild Type ◽  
Gaba A ◽  
Specific Induction ◽  
Related Compounds ◽  
Type Strains

ABSTRACT Nitrogen limitation induces the nitrogen-regulated (Ntr) response, which includes proteins that assimilate ammonia and scavenge nitrogen. Nitrogen limitation also induces catabolic pathways that degrade four metabolically related compounds: putrescine, arginine, ornithine, and γ-aminobutyrate (GABA). We analyzed the structure, function, and regulation of the gab operon, whose products degrade GABA, a proposed intermediate in putrescine catabolism. We showed that the gabDTPC gene cluster constitutes an operon based partially on coregulation of GabT and GabD activities and the polarity of an insertion in gabT on gabC. A ΔgabDT mutant grew normally on all of the nitrogen sources tested except GABA. The unexpected growth with putrescine resulted from specific induction of gab-independent enzymes. Nac was required for gab transcription in vivo and in vitro. Ntr induction did not require GABA, but various nitrogen sources did not induce enzyme activity equally. A gabC (formerly ygaE) mutant grew faster with GABA and had elevated levels of gab operon products, which suggests that GabC is a repressor. GabC is proposed to reduce nitrogen source-specific modulation of expression. Unlike a wild-type strain, a gabC mutant utilized GABA as a carbon source and such growth required σS. Previous studies showing σS-dependent gab expression in stationary phase involved gabC mutants, which suggests that such expression does not occur in wild-type strains. The seemingly narrow catabolic function of the gab operon is contrasted with the nonspecific (nitrogen source-independent) induction. We propose that the gab operon and the Ntr response itself contribute to putrescine and polyamine homeostasis.

scholarly journals Replication kinetics of a CHIKV Asian strain with 76 aa duplication in the nsP3 HVD, in comparison to the wild-type Asian and ECSA strains

2020 ◽  
Vol 2 (7A) ◽  
Author(s):  
Nurshariza Abdullah ◽  
Hong Wai Tham ◽  
Nafees Abdullah ◽  
Vinod RMT Balasubramaniam ◽  
I-Ching Sam ◽  
...  
Keyword(s):  
Amino Acid ◽  
Preliminary Finding ◽  
Wild Type ◽  
Replication Rate ◽  
Asian Strain ◽  
Genotypic Analysis ◽  
The Indian Ocean ◽  
Kinetics Of ◽  
Type Strains

Introduction: Chikungunya virus (CHIKV) is a mosquito-borne alphavirus which causes fever, rash and polyarthralgia. CHIKV has expanded its circulating regions to the Indian Ocean islands, Europe, Americas and Southeast Asia. Two CHIKV lineages, the ASIAN and ECSA are circulating in Malaysia. In 2009, a CHIKV strain with a 76 amino acid (aa) duplication in its nsP3 hypervariable domain (HVD), identified as CHIKvASIAN09MUM-Dup+ was isolated from a patient co-infected with DENV-2. Indels and duplication have been found in many other alphaviruses, and suggested to play a role in the survivality of the viruses. Objectives: We aim to compare and relate the replication kinetics and virulency in-vitro of CHIKvASIAN09MUM-Dup+ with the wild-type Asian and ECSA strains. Methods & Results: Genotypic analysis was conducted on three CHIKV strains in Malaysia, the CHIKvASIAN06UM-Dup-, CHIKvECSA08UM-Dup- and CHIKvASIAN09MUM-Dup+. We found that CHIKvASIAN09MUM-Dup+ has significant low replication rates in Vero, C6/36 and Rhabdosarcoma cells as compared to the wild-type strains. The highest titers were reached by CHIKvASIAN09MUM-Dup+ in all cells are 6.5 to 6.75 log10 TCID50/mL, which is 100 fold lower compared to the wild-type strains. Conclusion: The significantly low replication rate of Dup+ strain in all the cells, maybe suggestive to be due to co-infection and co-existence with DENV, where the aa duplication may play a role in overcoming competitive suppression. This preliminary finding agrees with reported events, where alphaviruses use insertion, deletion and duplication of amino acid in nsP3 HVD as strategies to influence replication in host, viral virulency, pathogenesis and survivality for evolution adaptation.

scholarly journals SEARCH FOR NEW ANTILEISHMANIAL CHEMOTHERAPEUTICS

2018 ◽  
Vol 10 (1) ◽  
pp. 46
Author(s):  
Nabanita Kar ◽  
Santanu Ghosh ◽  
Leena Kumari ◽  
Shreyasi Chakraborty ◽  
Tanmoy Bera
Keyword(s):  
Betulinic Acid ◽  
Leishmania Donovani ◽  
Antileishmanial Activity ◽  
Gas Chromatography Mass Spectrometry ◽  
Drug Resistant ◽  
Wild Type ◽  
Leaf Oil ◽  
Resistant Strains ◽  
Type Strains

Objective: The objective of this work was to screen a number of compounds for their antileishmanial efficacy and cytotoxicity profiling.Methods: Curry leaf oil, cypress oil and spikenard oil were identified by gas chromatography-mass spectrometry (GC/MS) analysis. Betulinic acid, spikenard oil, cypress oil and curry leaf oil were evaluated for their in vitro antileishmanial activity against Leishmania donovani AG83 wild-type, sodium stibogluconate resistant (SSG-resistant), paromomycin (PMM-resistant) and GE1 field type strains on axenic and cellular amastigote model and compared the results with standard drugs used to treat leishmaniasis.Results: Betulinic acid showed strong antileishmanial activity against wild-type (SI= 192.8), SSG-resistant (SI= 19.3) and GE1 strains (SI= 100), whereas cypress oil has produced highest antileishmanial activity against PMM-resistant strains (SI= 15.09) among all the tested drugs. The data obtained also revealed that cypress oil had the maximum CC50 value of 452.9 μl among all standard and tested drugs.Conclusion: All tested drugs had antileishmanial property but among them, betulinic acid possess strong antileishmanial activity in case of both wild-type and drug-resistant leishmaniasis.

scholarly journals Genetic Barcodes for Improved Environmental Tracking of an Anthrax Simulant

2012 ◽  
Vol 78 (23) ◽  
pp. 8272-8280 ◽  
Author(s):  
Patricia Buckley ◽  
Bryan Rivers ◽  
Sarah Katoski ◽  
Michael H. Kim ◽  
F. Joseph Kragl ◽  
...  
Keyword(s):  
Environmental Fate ◽  
Wild Type ◽  
Risk Models ◽  
Content Type ◽  
Genetic Signatures ◽  
Isogenic Strains ◽  
Type Strains ◽  
Long Term Studies

ABSTRACTThe development of realistic risk models that predict the dissemination, dispersion and persistence of potential biothreat agents have utilized nonpathogenic surrogate organisms such asBacillus atrophaeussubsp.globigiior commercial products such asBacillus thuringiensissubsp.kurstaki. Comparison of results from outdoor tests under different conditions requires the use of genetically identical strains; however, the requirement for isogenic strains limits the ability to compare other desirable properties, such as the behavior in the environment of the same strain prepared using different methods. Finally, current methods do not allow long-term studies of persistence or reaerosolization in test sites where simulants are heavily used or in areas whereB. thuringiensissubsp.kurstakiis applied as a biopesticide. To create a set of genetically heterogeneous yet phenotypically indistinguishable strains so that variables intrinsic to simulations (e.g., sample preparation) can be varied and the strains can be tested under otherwise identical conditions, we have developed a strategy of introducing small genetic signatures (“barcodes”) into neutral regions of the genome. The barcodes are stable over 300 generations and do not impactin vitrogrowth or sporulation. Each barcode contains common and specific tags that allow differentiation of marked strains from wild-type strains and from each other. Each tag is paired with specific real-time PCR assays that facilitate discrimination of barcoded strains from wild-type strains and from each other. These uniquely barcoded strains will be valuable tools for research into the environmental fate of released organisms by providing specific artificial detection signatures.

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