scholarly journals Effect of Nutritional Determinants and TonB on the Natural Transformation of Riemerella anatipestifer

2021 ◽  
Vol 12 ◽  
Author(s):  
Li Zhang ◽  
Li Huang ◽  
Mi Huang ◽  
Mengying Wang ◽  
Dekang Zhu ◽  
...  
Keyword(s):  
Natural Transformation ◽  
Iron Acquisition ◽  
Vitamin B1 ◽  
Underlying Mechanism ◽  
Iron Chelator ◽  
Transformation Frequency ◽  
Nutritional Factors ◽  
Riemerella Anatipestifer ◽  
The Family ◽  
Competent Bacterium

Riemerella anatipestifer is a gram-negative bacterium that is the first naturally competent bacterium identified in the family Flavobacteriaceae. However, the determinants that influence the natural transformation and the underlying mechanism remain unknown. In this study, we evaluated the effects of various nutritional factors of the GCB medium [glucose, L-glutamine, vitamin B1, Fe (NO3)3, NaCl, phosphate, and peptone], on the natural transformation of R. anatipestifer ATCC 11845. Among the assayed nutrients, peptone and phosphate affected the natural transformation of R. anatipestifer ATCC 11845, and the transformation frequency was significantly decreased when phosphate or peptone was removed from the GCB medium. When the iron chelator 2,2′-dipyridyl (Dip) was added, the transformation frequency was decreased by approximately 100-fold and restored gradually when Fe (NO3)3 was added, suggesting that the natural transformation of R. anatipestifer ATCC 11845 requires iron. Given the importance of TonB in nutrient transportation, we further identified whether TonB is involved in the natural transformation of R. anatipestifer ATCC 11845. Mutation of tonBA or tonBB, but not tbfA, was shown to inhibit the natural transformation of R. anatipestifer ATCC 11845 in the GCB medium. In parallel, it was shown that the tonBB mutant, but not the tonBA mutant, decreased iron acquisition in the GCB medium. This result suggested that the tonBB mutant affects the natural transformation frequency due to the deficiency of iron utilization.

scholarly journals Use of Natural Transformation To Establish an Easy Knockout Method in Riemerella anatipestifer

2017 ◽  
Vol 83 (9) ◽  
Author(s):  
MaFeng Liu ◽  
Li Zhang ◽  
Li Huang ◽  
Francis Biville ◽  
DeKang Zhu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Natural Transformation ◽  
Genetic Manipulation ◽  
Gene Knockout ◽  
Targeted Mutagenesis ◽  
Chromosomal Dna ◽  
Content Type ◽  
Riemerella Anatipestifer ◽  
The Family ◽  
First Time

ABSTRACT Riemerella anatipestifer is a member of the family Flavobacteriaceae and a major causative agent of duck serositis. Little is known about its genetics and pathogenesis. Several bacteria are competent for natural transformation; however, whether R. anatipestifer is also competent for natural transformation has not been investigated. Here, we showed that R. anatipestifer strain ATCC 11845 can uptake the chromosomal DNA of R. anatipestifer strain RA-CH-1 in all growth phases. Subsequently, a natural transformation-based knockout method was established for R. anatipestifer ATCC 11845. Targeted mutagenesis gave transformation frequencies of ∼10−5 transformants. Competition assay experiments showed that R. anatipestifer ATCC 11845 preferentially took up its own DNA rather than heterogeneous DNA, such as Escherichia coli DNA. Transformation was less efficient with the shuttle plasmid pLMF03 (transformation frequencies of ∼10−9 transformants). However, the efficiency of transformation was increased approximately 100-fold using pLMF03 derivatives containing R. anatipestifer DNA fragments (transformation frequencies of ∼10−7 transformants). Finally, we found that the R. anatipestifer RA-CH-1 strain was also naturally transformable, suggesting that natural competence is widely applicable for this species. The findings described here provide important tools for the genetic manipulation of R. anatipestifer. IMPORTANCE Riemerella anatipestifer is an important duck pathogen that belongs to the family Flavobacteriaceae. At least 21 different serotypes have been identified. Genetic diversity has been demonstrated among these serotypes. The genetic and pathogenic mechanisms of R. anatipestifer remain largely unknown because no genetic tools are available for this bacterium. At present, natural transformation has been found in some bacteria but not in R. anatipestifer. For the first time, we showed that natural transformation occurred in R. anatipestifer ATCC 11845 and R. anatipestifer RA-CH-1. Then, we established an easy gene knockout method in R. anatipestifer based on natural transformation. This information is important for further studies of the genetic diversity and pathogenesis in R. anatipestifer.

scholarly journals Identification of the Natural Transformation Genes in Riemerella anatipestifer by Random Transposon Mutagenesis

2021 ◽  
Vol 12 ◽  
Author(s):  
Li Huang ◽  
Mafeng Liu ◽  
Aparna Viswanathan Ammanath ◽  
Dekang Zhu ◽  
Renyong Jia ◽  
...  
Keyword(s):  
Unknown Function ◽  
Natural Transformation ◽  
Transposon Mutagenesis ◽  
Transformation Frequency ◽  
Mutant Library ◽  
Negative Bacterium ◽  
Gram Negative ◽  
Riemerella Anatipestifer ◽  
Insertion Mutants

In our previous study, it was shown that Riemerella anatipestifer, a Gram-negative bacterium, is naturally competent, but the genes involved in the process of natural transformation remain largely unknown. In this study, a random transposon mutant library was constructed using the R. anatipestifer ATCC11845 strain to screen for the genes involved in natural transformation. Among the 3000 insertion mutants, nine mutants had completely lost the ability of natural transformation, and 14 mutants showed a significant decrease in natural transformation frequency. We found that the genes RA0C_RS04920, RA0C_RS04915, RA0C_RS02645, RA0C_RS04895, RA0C_RS05130, RA0C_RS05105, RA0C_RS09020, and RA0C_RS04870 are essential for the occurrence of natural transformation in R. anatipestifer ATCC11845. In particular, RA0C_RS04895, RA0C_RS05130, RA0C_RS05105, and RA0C_RS04870 were putatively annotated as ComEC, DprA, ComF, and RecA proteins, respectively, in the NCBI database. However, RA0C_RS02645, RA0C_RS04920, RA0C_RS04915, and RA0C_RS09020 were annotated as proteins with unknown function, with no homology to any well-characterized natural transformation machinery proteins. The homologs of these proteins are mainly distributed in the members of Flavobacteriaceae. Taken together, our results suggest that R. anatipestifer encodes a unique natural transformation machinery.

scholarly journals Comparison between Pseudomonas aeruginosa siderophores and desferrioxamine for iron acquisition from ferritin

2010 ◽  
Vol 4 (4) ◽  
pp. 631-635 ◽  
Author(s):  
Somporn Srifuengfung ◽  
Susan Assanasen ◽  
Malulee Tuntawiroon ◽  
Sumonrat Meejanpetch
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Iron Acquisition ◽  
Iron Chelator ◽  
Dialysis Membrane ◽  
In Vitro Experiment ◽  
Iron Mobilization ◽  
Ph Values ◽  
Minimum Medium ◽  
Stimulation Of

Abstract Background: Siderophore is an iron chelator produced by microorganism. Pseudomonas aeruginosa produces two siderophores (pyoverdin and pyochelin). Desferrioxamine is a siderophore used in thalassemia patients to treat an iron overload of vital organs. Objective: Compare the ability of pyoverdin, pyochelin, and desferrioxamine for iron mobilization from ferritin. Materials and Methods: In vitro experiment, the ability of P. aeruginosa siderophores and desferrioxamine for iron mobilization from ferritin was compared by using a dialysis membrane assay at pH values of 7.4 and 6.0. Stimulation of P. aeruginosa PAO1 growth by all siderophores was studied in glucose minimum medium. Results: All three compounds were capable of iron mobilization at both pHs. At pH 6.0, the most effectiveness compound was desferrioxamine (31.6%), followed by pyoverdin (21.5%) and pyochelin (13.7%) compared on weight basis, each at 10 μg/mL. At equimolar concentration, their activities were desferrioxamine (38.5±1.2%), followed by pyoverdin (32.0±4.8%) and pyochelin (26.7±1.9%), respectively. Conclusion: The most effective compound in iron mobilization from ferritin was desferrioxamine, followed by pyoverdin and pyochelin respectively.

The role of TonB-dependent receptor TbdR1 in Riemerella anatipestifer in iron acquisition and virulence

2013 ◽  
Vol 167 (3-4) ◽  
pp. 713-718 ◽  
Author(s):  
Fengying Lu ◽  
Shuang Miao ◽  
Jing Tu ◽  
Xintao Ni ◽  
Linlin Xing ◽  
...  
Keyword(s):  
Iron Acquisition ◽  
Riemerella Anatipestifer

scholarly journals Nitric oxide–mediated regulation of ferroportin-1 controls macrophage iron homeostasis and immune function in Salmonella infection

2013 ◽  
Vol 210 (5) ◽  
pp. 855-873 ◽  
Author(s):  
Manfred Nairz ◽  
Ulrike Schleicher ◽  
Andrea Schroll ◽  
Thomas Sonnweber ◽  
Igor Theurl ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Iron Homeostasis ◽  
Molecular Mechanisms ◽  
Iron Acquisition ◽  
Iron Chelator ◽  
Related Factor ◽  
Cellular Iron ◽  
Splenic Macrophages ◽  
Ferroportin 1 ◽  
Pathogen Control

Nitric oxide (NO) generated by inducible NO synthase 2 (NOS2) affects cellular iron homeostasis, but the underlying molecular mechanisms and implications for NOS2-dependent pathogen control are incompletely understood. In this study, we found that NO up-regulated the expression of ferroportin-1 (Fpn1), the major cellular iron exporter, in mouse and human cells. Nos2−/− macrophages displayed increased iron content due to reduced Fpn1 expression and allowed for an enhanced iron acquisition by the intracellular bacterium Salmonella typhimurium. Nos2 gene disruption or inhibition of NOS2 activity led to an accumulation of iron in the spleen and splenic macrophages. Lack of NO formation resulted in impaired nuclear factor erythroid 2-related factor-2 (Nrf2) expression, resulting in reduced Fpn1 transcription and diminished cellular iron egress. After infection of Nos2−/− macrophages or mice with S. typhimurium, the increased iron accumulation was paralleled by a reduced cytokine (TNF, IL-12, and IFN-γ) expression and impaired pathogen control, all of which were restored upon administration of the iron chelator deferasirox or hyperexpression of Fpn1 or Nrf2. Thus, the accumulation of iron in Nos2−/− macrophages counteracts a proinflammatory host immune response, and the protective effect of NO appears to partially result from its ability to prevent iron overload in macrophages

scholarly journals Genome Sequence of a Novel Soil Actinomycete, Protaetiibacter sp. Strain SSC-01

2021 ◽  
Vol 10 (5) ◽  
Author(s):  
Huiquan Duan ◽  
Chamil E. Fernando ◽  
Scott S. Crupper ◽  
Stephen D. Fields
Keyword(s):  
Genome Sequence ◽  
Soil Bacteria ◽  
Iron Acquisition ◽  
Xylose Metabolism ◽  
Important Group ◽  
Putative Species ◽  
The Family ◽  
Soil Actinomycete

ABSTRACT The family Microbacteriaceae represents a diverse and important group of soil bacteria in the phylum Actinobacteria. Here, we report the genome sequence of a soil Microbacteriaceae strain, Protaetiibacter sp. strain SSC-01, the second putative species of the genus. Iron acquisition and xylose metabolism are central pathways identified in the annotated genome.

scholarly journals Medicinal Values of Tomato (Lycopersicon esculentum Mill. –Solanaceae)

2021 ◽  
Vol 9 (3) ◽  
pp. 166-168
Author(s):  
Pushpa Karna Mallick
Keyword(s):  
Antioxidant Activity ◽  
Lycopersicon Esculentum ◽  
Cell Damage ◽  
Soluble Sugars ◽  
Antioxidant Properties ◽  
Vitamin B1 ◽  
Flowering Plant ◽  
Mineral Salts ◽  
Blood Constituents ◽  
The Family

Lycopersicon esculentum is a flowering plant of the family Solanaceae. The common name for this plant is tomato. Tomatoes are a good source of lycopene which is a main pigment found in it and responsible for red colour. The lycopene provides antioxidant properties and helps to prevent cell damage. Tomatoes also prevent the adverse effects of lead in the blood constituents. Tomatoes are used in different ways such as raw or cooked, in many dishes, sauces, salads, pickles, puree, paste, juice, sun- dried and drink. Tomato fruits content ninety four percent water, citric acid, malic acid, soluble sugars, vitamin, vitamin B1, B2, vitamin A, and many mineral salts etc. High levels of lycopene which contain in tomatoes are used in facial cleanser. Flavonoids like flavonols which is present in tomatoes are rich in antioxidant activity and can help our body ward off every day toxins. Flavonoides such as flavonols present in tomatoes are rich in antioxidant activity and   can help our body ward off every day toxins Flavonoides directly associated with human dietary ingredients, play a great role in diseases prevention and shows versatile health benefits. Int. J. Appl. Sci. Biotechnol. Vol 9(3): 166-168.

Literature review: nutritional factors influencing academic achievement in school age children

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Pattaneeya Prangthip ◽  
Yee Mon Soe ◽  
Jean Faulan Signar
Keyword(s):  
Transition Period ◽  
Economic Status ◽  
Eating Behaviour ◽  
School Age Children ◽  
Nutritional Factors ◽  
Adolescent Students ◽  
Balanced Diet ◽  
The Family ◽  
Knowledge And Attitude

Abstract Background and objective Adolescence is a transition period involving tremendous physical, psychological and cognitive growth. For appropriate growth of adolescents in these aspects, a correct quantity and quality of nourishment is required, as a lack of such nourishment among adolescents can lead to various degrees of malnutrition, which may have implications on their health as well as their academic achievements. Materials and methods This review examines the research topics around factors that influence the nutritional status of adolescent students which can affect their academic performance. Results Some of the vital factors include knowledge and attitude about nutrition, eating behaviour, physical activity, socio-economic status of the family, the surrounding environment at school and home, the frequency and timing of meals, nutritional contents and amount of food intake. Conclusion Students who consume a balanced diet perform better in exams, show better behaviour as well as attendance at school and get their assigned tasks done more thoroughly compared with those who do not consume a balanced diet.

scholarly journals An Electrocatalytic Screen-Printed Amperometric Sensor for the Selective Measurement of Thiamine (Vitamin B1) in Food Supplements

Biosensors ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 98 ◽  
Author(s):  
Amy Smart ◽  
Kelly L. Westmacott ◽  
Adrian Crew ◽  
Olena Doran ◽  
John P. Hart
Keyword(s):  
Limit Of Detection ◽  
Vitamin B1 ◽  
Underlying Mechanism ◽  
Food Supplements ◽  
Screen Printed Carbon Electrode ◽  
Thiolate Anion ◽  
Analytical Response ◽  
Operating Potential ◽  
Response Current ◽  
Screen Printed

An electrocatalytic screen-printed sensor has been investigated for the measurement of the biologically important biomolecule vitamin B1 (thiamine) for the first time in food supplements. Under basic conditions, the vitamin was converted to its electrochemically active thiolate anion species. It was shown that an electrocatalytic oxidation reaction occurred with the screen-printed carbon electrode containing the mediator cobalt phthalocyanine (CoPC-SPCE). This had the advantage of producing an analytical response current at an operating potential of 0 V vs. Ag/AgCl compared to +0.34 V obtained with plain SPCEs. This resulted in improved selectivity and limit of detection. Detailed studies on the underlying mechanism occurring with the sensor are reported in this paper. A linear response was obtained between 0.1 and 20 µg mL−1, which was suitable for the quantification of the vitamin in two commercial products containing vitamin B1. The mean recovery for a multivitamin tablet with a declared content of 5 mg was 101% (coefficient of variation (CV) of 9.6%). A multivitamin drink, which had a much lower concentration of vitamin B1 (0.22 mg/100 mL), gave a mean recovery of 93.3% (CV 7.2%). These results indicate that our sensor holds promise for quality control of food supplements and other food types.

The siderophore-mediated iron acquisition systems of Acinetobacter baumannii ATCC 19606 and Vibrio anguillarum 775 are structurally and functionally related

Microbiology ◽  
2004 ◽  
Vol 150 (11) ◽  
pp. 3657-3667 ◽  
Author(s):  
Caleb W. Dorsey ◽  
Andrew P. Tomaras ◽  
Pamela L. Connerly ◽  
Marcelo E. Tolmasky ◽  
Jorge H. Crosa ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Insertional Mutagenesis ◽  
Iron Acquisition ◽  
Vibrio Anguillarum ◽  
Structural Similarity ◽  
Iron Chelator ◽  
Transport Systems ◽  
Nucleotide Sequence Analysis ◽  
Bacterial Strains ◽  
Gene Encoding

The Acinetobacter baumannii type strain, ATCC 19606, secretes acinetobactin, a catechol siderophore highly related to the iron chelator anguibactin produced by the fish pathogen Vibrio anguillarum (Listonella anguillarum). This paper reports the initial characterization of the genes and gene products involved in the acinetobactin-mediated iron-acquisition process. Insertional mutagenesis resulted in the isolation of several derivatives whose ability to grow in medium containing the iron chelator 2,2′-dipyridyl was affected. One of the insertions disrupted a gene encoding a predicted outer-membrane protein, named BauA, highly similar to FatA, the receptor for ferric anguibactin. Immunological relatedness of BauA with FatA was confirmed by Western blot analysis. Another transposon insertion was mapped to a gene encoding a protein highly similar to FatD, the permease component of the anguibactin transport system. Further DNA sequencing and nucleotide sequence analysis revealed that these A. baumannii 19606 genes are part of a polycistronic locus that contains the bauDCEBA ORFs. While the translation products of bauD, -C, -B and -A are highly related to the V. anguillarum FatDCBA iron-transport proteins, the product of bauE is related to the ATPase component of Gram-positive ATP-binding cassette (ABC) transport systems. This entire locus is flanked by genes encoding predicted proteins related to AngU and AngN, V. anguillarum proteins required for the biosynthesis of anguibactin. These protein similarities, as well as the structural similarity of anguibactin and acinetobactin, suggested that these two siderophores could be utilized by both bacterial strains, a possibility that was confirmed by siderophore utilization bioassays. Taken together, these results demonstrate that these pathogens, which cause serious infections in unrelated hosts, express very similar siderophore-mediated iron-acquisition systems.

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