scholarly journals Identification of Regulatory Genes and Metabolic Processes Important for Alginate Biosynthesis in Azotobacter vinelandii by Screening of a Transposon Insertion Mutant Library

2020 ◽  
Vol 7 ◽  
Author(s):  
Mali Mærk ◽  
Øyvind M. Jakobsen ◽  
Håvard Sletta ◽  
Geir Klinkenberg ◽  
Anne Tøndervik ◽  
...  
Keyword(s):  
Azotobacter Vinelandii ◽  
Regulatory Genes ◽  
Insertion Mutant ◽  
Mutant Library ◽  
Metabolic Processes ◽  
Transposon Insertion ◽  
Alginate Biosynthesis

scholarly journals Genes Contributing to Staphylococcus aureus Fitness in Abscess- and Infection-Related Ecologies

mBio ◽  
2014 ◽  
Vol 5 (5) ◽  
Author(s):  
Michael D. Valentino ◽  
Lucy Foulston ◽  
Ama Sadaka ◽  
Veronica N. Kos ◽  
Regis A. Villet ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
New Drugs ◽  
Insertion Mutant ◽  
Mutant Library ◽  
Entire Genome ◽  
Antibiotic Resistant ◽  
Content Type ◽  
Transposon Insertion ◽  
Genes Encoding ◽  
Novel Targets

ABSTRACTStaphylococcus aureusis a leading cause of both community- and hospital-acquired infections that are increasingly antibiotic resistant. The emergence ofS. aureusresistance to even last-line antibiotics heightens the need for the development of new drugs with novel targets. We generated a highly saturated transposon insertion mutant library in the genome ofS. aureusand used Tn-seq analysis to probe the entire genome, with unprecedented resolution and sensitivity, for genes of importance in infection. We further identified genes contributing to fitness in various infected compartments (blood and ocular fluids) and compared them to genes required for growth in rich medium. This resulted in the identification of 426 genes that were important forS. aureusfitness during growth in infection models, including 71 genes that could be considered essential for survival specifically during infection. These findings highlight novel as well as previously known genes encoding virulence traits and metabolic pathways important forS. aureusproliferation at sites of infection, which may represent new therapeutic targets.IMPORTANCEStaphylococcus aureuscontinues to be a leading cause of antibiotic-resistant community and nosocomial infection. With the bacterium’s acquisition of resistance to methicillin and, more recently, vancomycin, the need for the development of new drugs with novel targets is urgent. Applying a highly saturated Tn-seq mutant library to analyze fitness and growth requirements in a murine abscess and in various infection-relevant fluids, we identifiedS. aureustraits that enable it to survive and proliferate during infection. This identifies potential new targeting opportunities for the development of novel therapeutics.

scholarly journals Comprehensive MALDI-TOF Biotyping of the Non-Redundant Harvard Pseudomonas aeruginosa PA14 Transposon Insertion Mutant Library

PLoS ONE ◽  
2015 ◽  
Vol 10 (2) ◽  
pp. e0117144 ◽  
Author(s):  
Tonio Oumeraci ◽  
Vanessa Jensen ◽  
Steven R. Talbot ◽  
Winfried Hofmann ◽  
Markus Kostrzewa ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Insertion Mutant ◽  
Mutant Library ◽  
Maldi Tof ◽  
Transposon Insertion

scholarly journals Generation of comprehensive transposon insertion mutant library for the model archaeon, Haloferax volcanii, and its use for gene discovery

BMC Biology ◽  
2014 ◽  
Vol 12 (1) ◽  
Author(s):  
Saija Kiljunen ◽  
Maria I Pajunen ◽  
Kieran Dilks ◽  
Stefanie Storf ◽  
Mechthild Pohlschroder ◽  
...  
Keyword(s):  
Gene Discovery ◽  
Haloferax Volcanii ◽  
Insertion Mutant ◽  
Mutant Library ◽  
Transposon Insertion

scholarly journals Generation of comprehensive transposon insertion mutant library for the model archaeon, Haloferax volcanii , and its use for gene discovery

BMC Biology ◽  
2014 ◽  
Vol 12 (1) ◽  
pp. 103 ◽  
Author(s):  
Saija Kiljunen ◽  
Maria I Pajunen ◽  
Kieran Dilks ◽  
Stefanie Storf ◽  
Mecky Pohlschroder ◽  
...  
Keyword(s):  
Gene Discovery ◽  
Haloferax Volcanii ◽  
Insertion Mutant ◽  
Mutant Library ◽  
Transposon Insertion

scholarly journals The algT Gene of Pseudomonas syringae pv. glycinea andNew Insights into the Transcriptional Organization of thealgT-muc Gene Cluster

2006 ◽  
Vol 188 (23) ◽  
pp. 8013-8021 ◽  
Author(s):  
Alexander Schenk ◽  
Michael Berger ◽  
Lisa M. Keith ◽  
Carol L. Bender ◽  
Georgi Muskhelishvili ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Pseudomonas Syringae ◽  
Azotobacter Vinelandii ◽  
Regulatory Gene ◽  
In Planta ◽  
Phytopathogenic Bacterium ◽  
Reverse Transcription Pcr ◽  
Alginate Production ◽  
Alginate Biosynthesis

ABSTRACT The phytopathogenic bacterium Pseudomonas syringae pv. glycinea infects soybean plants and causes bacterial blight. In addition to P. syringae, the human pathogen Pseudomonas aeruginosa and the soil bacterium Azotobacter vinelandii produce the exopolysaccharide alginate, a copolymer of d-mannuronic and l-guluronic acids. Alginate production in P. syringae has been associated with increased fitness and virulence in planta. Alginate biosynthesis is tightly controlled by proteins encoded by the algT-muc regulatory gene cluster in P. aeruginosa and A. vinelandii. These genes encode the alternative sigma factor AlgT (σ22), its anti-sigma factors MucA and MucB, MucC, a protein with a controversial function that is absent in P. syringae, and MucD, a periplasmic serine protease and homolog of HtrA in Escherichia coli. We compared an alginate-deficient algT mutant of P. syringae pv. glycinea with an alginate-producing derivative in which algT is intact. The alginate-producing derivative grew significantly slower in vitro growth but showed increased epiphytic fitness and better symptom development in planta. Evaluation of expression levels for algT, mucA, mucB, mucD, and algD, which encodes an alginate biosynthesis gene, showed that mucD transcription is not dependent on AlgT in P. syringae in vitro. Promoter mapping using primer extension experiments confirmed this finding. Results of reverse transcription-PCR demonstrated that algT, mucA, and mucB are cotranscribed as an operon in P. syringae. Northern blot analysis revealed that mucD was expressed as a 1.75-kb monocistronic mRNA in P. syringae.

scholarly journals Genetic Determinants Involved in the Susceptibility of Pseudomonas aeruginosa to β-Lactam Antibiotics

2010 ◽  
Vol 54 (10) ◽  
pp. 4159-4167 ◽  
Author(s):  
Carolina Alvarez-Ortega ◽  
Irith Wiegand ◽  
Jorge Olivares ◽  
Robert E. W. Hancock ◽  
José Luis Martínez
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Detailed Analysis ◽  
Barrier Function ◽  
Mechanisms Of Action ◽  
Mutant Library ◽  
Genetic Determinants ◽  
Intrinsic Resistance ◽  
Resistance Phenotype ◽  
Mixed Phenotype ◽  
Alginate Biosynthesis

ABSTRACT The resistome of P. aeruginosa for three β-lactam antibiotics, namely, ceftazidime, imipenem, and meropenem, was deciphered by screening a comprehensive PA14 mutant library for mutants with increased or reduced susceptibility to these antimicrobials. Confirmation of the phenotypes of all selected mutants was performed by Etest. Of the total of 78 confirmed mutants, 41 demonstrated a reduced susceptibility phenotype and 37 a supersusceptibility (i.e., altered intrinsic resistance) phenotype, with 6 mutants demonstrating a mixed phenotype, depending on the antibiotic. Only three mutants demonstrated reduced (PA0908) or increased (glnK and ftsK) susceptibility to all three antibiotics. Overall, the mutant profiles of susceptibility suggested distinct mechanisms of action and resistance for the three antibiotics despite their similar structures. More detailed analysis indicated important roles for novel and known β-lactamase regulatory genes, for genes with likely involvement in barrier function, and for a range of regulators of alginate biosynthesis.

scholarly journals The Striking Flower-in-Flower Phenotype of Arabidopsis thaliana Nossen (No-0) is Caused by a Novel LEAFY Allele

Plants ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 599 ◽  
Author(s):  
Anne Mohrholz ◽  
Hequan Sun ◽  
Nina Glöckner ◽  
Sabine Hummel ◽  
Üner Kolukisaoglu ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Dna Binding ◽  
Insertion Mutant ◽  
Transposon Insertion ◽  
Lateral Shoots ◽  
Target Dna ◽  
Axillary Meristems ◽  
Leafy Gene ◽  
Two Phases ◽  
Mutant Flower

The transition to reproduction is a crucial step in the life cycle of any organism. In Arabidopsis thaliana the establishment of reproductive growth can be divided into two phases: Firstly, cauline leaves with axillary meristems are formed and internode elongation begins. Secondly, lateral meristems develop into flowers with defined organs. Floral shoots are usually determinate and suppress the development of lateral shoots. Here, we describe a transposon insertion mutant in the Nossen accession with defects in floral development and growth. Most strikingly is the outgrowth of stems from the axillary bracts of the primary flower carrying secondary flowers. Therefore, we named this mutant flower-in-flower (fif). However, the transposon insertion in the annotated gene is not the cause for the fif phenotype. By means of classical and genome sequencing-based mapping, the mutation responsible for the fif phenotype was found to be in the LEAFY gene. The mutation, a G-to-A exchange in the second exon of LEAFY, creates a novel lfy allele and results in a cysteine-to-tyrosine exchange in the α1-helix of LEAFY’s DNA-binding domain. This exchange abolishes target DNA-binding, whereas subcellular localization and homomerization are not affected. To explain the strong fif phenotype against these molecular findings, several hypotheses are discussed.

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