scholarly journals Natural Transformation of Riemerella columbina and Its Determinants

2021 ◽  
Vol 12 ◽  
Author(s):  
Li Huang ◽  
Mafeng Liu ◽  
Dekang Zhu ◽  
Li Xie ◽  
Mi Huang ◽  
...  
Keyword(s):  
Genomic Dna ◽  
Natural Transformation ◽  
Divalent Cations ◽  
Transformation Frequency ◽  
Logarithmic Phase ◽  
Growth Phases ◽  
Competition Assay ◽  
Natural Competence ◽  
Flavobacterium Johnsoniae ◽  
First Time

In a previous study, it was shown that Riemerella anatipestifer, a member of Flavobacteriaceae, is naturally competent. However, whether natural competence is universal in Flavobacteriaceae remains unknown. In this study, it was shown for the first time that Riemerella columbina was naturally competent in the laboratory condition; however, Flavobacterium johnsoniae was not naturally competent under the same conditions. The competence of R. columbina was maintained throughout the growth phases, and the transformation frequency was highest during the logarithmic phase. A competition assay revealed that R. columbina preferentially took up its own genomic DNA over heterologous DNA. The natural transformation frequency of R. columbina was significantly increased in GCB medium without peptone or phosphate. Furthermore, natural transformation of R. columbina was inhibited by 0.5 mM EDTA, but could be restored by the addition of CaCl2, MgCl2, ZnCl2, and MnCl2, suggesting that these divalent cations promote the natural transformation of R. columbina. Overall, this study revealed that natural competence is not universal in Flavobacteriaceae members and triggering of competence differs from species to species.

scholarly journals Involvement of the Histone-Like Nucleoid Structuring Protein (H-NS) in Acinetobacter baumannii’s Natural Transformation

Pathogens ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1083
Author(s):  
Casin Le ◽  
Camila Pimentel ◽  
Marisel R. Tuttobene ◽  
Tomás Subils ◽  
Jenny Escalante ◽  
...  
Keyword(s):  
Wild Type Strain ◽  
Natural Transformation ◽  
Regulatory Elements ◽  
Transformation Frequency ◽  
Wild Type ◽  
Natural Competence ◽  
Expression Levels ◽  
Expression Of Genes ◽  
Foreign Dna

Most Acinetobacter baumannii strains are naturally competent. Although some information is available about factors that enhance or reduce the frequency of the transformation of this bacterium, the regulatory elements and mechanisms are barely understood. In this article, we describe studies on the role of the histone-like nucleoid structuring protein, H-NS, in the regulation of the expression of genes related to natural competency and the ability to uptake foreign DNA. The expression levels of the natural transformation-related genes pilA, pilT, pilQ, comEA, comEC, comF, and drpA significantly increased in a Δhns derivative of A. baumannii A118. The complementation of the mutant with a recombinant plasmid harboring hns restored the expression levels of six of these genes (pilT remained expressed at high levels) to those of the wild-type strain. The transformation frequency of the A. baumannii A118 Δhns strain was significantly higher than that of the wild-type. Similar, albeit not identical, there were consequences when hns was deleted from the hypervirulent A. baumannii AB5075 strain. In the AB5075 complemented strain, the reduction in gene expression in a few cases was not so pronounced that it reached wild-type levels, and the expression of comEA was enhanced further. In conclusion, the expression of all seven transformation-related genes was enhanced after deleting hns in A. baumannii A118 and AB5075, and these modifications were accompanied by an increase in the cells’ transformability. The results highlight a role of H-NS in A. baumannii’s natural competence.

Cloning of taxane 2α-O-benzoyltransferase (TBT) genomic DNA from Taxus

Biologia ◽  
2006 ◽  
Vol 61 (3) ◽  
Author(s):  
Dongli Zhao ◽  
Le Li ◽  
Qian Wang ◽  
Guoyin Kai ◽  
Xiang Wang ◽  
...  
Keyword(s):  
Genomic Dna ◽  
Cdna Sequence ◽  
Gene Diversity ◽  
Genomic Sequences ◽  
Taxus Yunnanensis ◽  
Sequence Encoding ◽  
First Time

AbstractBased on the cDNA sequence encoding taxane 2α-O-benzoyltransferase (TBT) from Taxus yunnanensis (Gen-Bank Accession No.: AY970522), genomic sequences of TBTs from T. yunnanensis (TyTBT) and T. cuspidata (TcuTBT) were cloned for the first time. They both contain only one intron. The finding that the introns of TyTBT and TcuTBT are more diverse than their exons implies that the gene diversity is more within introns than within exons, which may be important for keeping the functions of the genes.

Aureobasidium pullulans Gene from Egypt

2021 ◽  
Vol 8 (1) ◽  
pp. 6-10
Author(s):  
Hani Moubasher ◽  
Salwa S Wahsh ◽  
Nabil Abo El-Kassem ◽  
Refaat Ali
Keyword(s):  
Molecular Mass ◽  
Genomic Dna ◽  
Aureobasidium Pullulans ◽  
Hypothetical Protein ◽  
Significant Alignment ◽  
First Time

Sequancing of pullulanase from the fungus Aureobasidium pullulans isolated from Egypt soil; Genomic DNA of pullulanase was determined for the first time using PCR, according to Baser program, Pullulanase nucleotide collection from Aureobasidium pullulans was blasted which showed similarity using NCBI significant alignment with Aureobasidium namibiae CBS 147.97 hypothetical protein partial mRNA and 46 % with Aureobasidium pullulans JQ624241 and AF470619; Identified sequenced fragment was 2051 bp. and G+C content is 50.5% with molecular mass 63 KDa.

scholarly journals Serum Albumin and Ca2+Are Natural Competence Inducers in the Human Pathogen Acinetobacter baumannii

2016 ◽  
Vol 60 (8) ◽  
pp. 4920-4929 ◽  
Author(s):  
German Matias Traglia ◽  
Brettni Quinn ◽  
Sareda T. J. Schramm ◽  
Alfonso Soler-Bistue ◽  
Maria Soledad Ramirez
Keyword(s):  
Acinetobacter Baumannii ◽  
Natural Transformation ◽  
Hospital Environment ◽  
Human Pathogen ◽  
Nosocomial Pathogen ◽  
Natural Competence ◽  
Exogenous Dna ◽  
Content Type ◽  
Resistance Determinants ◽  
Main Protein

ABSTRACTThe increasing frequency of bacteria showing antimicrobial resistance (AMR) raises the menace of entering into a postantibiotic era. Horizontal gene transfer (HGT) is one of the prime reasons for AMR acquisition.Acinetobacter baumanniiis a nosocomial pathogen with outstanding abilities to survive in the hospital environment and to acquire resistance determinants. Its capacity to incorporate exogenous DNA is a major source of AMR genes; however, few studies have addressed this subject. The transformation machinery as well as the factors that induce natural competence inA. baumanniiare unknown. In this study, we demonstrate that naturally competent strain A118 increases its natural transformation frequency upon the addition of Ca2+or albumin. We show thatcomEAandpilQare involved in this process since their expression levels are increased upon the addition of these compounds. An unspecific protein, like casein, does not reproduce this effect, showing that albumin's effect is specific. Our work describes the first specific inducers of natural competence inA. baumannii. Overall, our results suggest that the main protein in blood enhances HGT inA. baumannii, contributing to the increase of AMR in this threatening human pathogen.

scholarly journals Genetic study of motor functions in Drosophila melanogaster

2012 ◽  
Vol 10 (1) ◽  
pp. 51-61 ◽  
Author(s):  
Sergey A Fedotov ◽  
Julia V Bragina ◽  
Nataliya G Besedina ◽  
Larisa V Danilenkova ◽  
Elena A Kamysheva ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Motor Activity ◽  
Genomic Dna ◽  
Molecular Mechanisms ◽  
Central Pattern Generators ◽  
Courtship Song ◽  
P Element ◽  
Rhythmic Motor ◽  
Pattern Generators ◽  
First Time

To investigate molecular mechanisms of central pattern generators (CPG s) functioning, we carried out a screening of collection of Drosophila P-insertional mutants for strong deviations in locomotion and courtship song. In 21 mutants, the site of the P-insertion was localized by sequencing of the fragments of genomic DNA flanking the P-element. Bioinformational analysis revealed a list of candidate genes, potential players in development and functioning of CPG s. Possible involvement of certain identified genes in rhythmic motor activity is suggested for the first time (CG15630, Map205).

Characterization of transport mechanisms and determinants critical for Na+-dependent Pisymport of the PiT family paralogs human PiT1 and PiT2

2006 ◽  
Vol 291 (6) ◽  
pp. C1377-C1387 ◽  
Author(s):  
Pernille Bøttger ◽  
Susanne E. Hede ◽  
Morten Grunnet ◽  
Boy Høyer ◽  
Dan A. Klærke ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Divalent Cations ◽  
Maximal Activity ◽  
Xenopus Laevis Oocytes ◽  
Transport Function ◽  
Knockout Mutant ◽  
Uptake Medium ◽  
The Impact ◽  
First Time

The general phosphate need in mammalian cells is accommodated by members of the Pitransport (PiT) family ( SLC20), which use either Na+or H+to mediate inorganic phosphate (Pi) symport. The mammalian PiT paralogs PiT1 and PiT2 are Na+-dependent Pi(NaPi) transporters and are exploited by a group of retroviruses for cell entry. Human PiT1 and PiT2 were characterized by expression in Xenopus laevis oocytes with32Pias a traceable Pisource. For PiT1, the Michaelis-Menten constant for Piwas determined as 322.5 ± 124.5 μM. PiT2 was analyzed for the first time and showed positive cooperativity in Piuptake with a half-maximal activity constant for Piof 163.5 ± 39.8 μM. PiT1- and PiT2-mediated Na+-dependent Piuptake functions were not significantly affected by acidic and alkaline pH and displayed similar Na+dependency patterns. However, only PiT2 was capable of Na+-independent Pitransport at acidic pH. Study of the impact of divalent cations Ca2+and Mg2+revealed that Ca2+was important, but not critical, for NaPitransport function of PiT proteins. To gain insight into the NaPicotransport function, we analyzed PiT2 and a PiT2 Pitransport knockout mutant using22Na+as a traceable Na+source. Na+was transported by PiT2 even without Piin the uptake medium and also when Pitransport function was knocked out. This is the first time decoupling of Pifrom Na+transport has been demonstrated for a PiT family member. Moreover, the results imply that putative transmembrane amino acids E55and E575are responsible for linking Piimport to Na+transport in PiT2.

scholarly journals Pseudomonas aeruginosa Requires the DNA-Specific Endonuclease EndA To Degrade Extracellular Genomic DNA To Disperse from the Biofilm

2019 ◽  
Vol 201 (18) ◽  
Author(s):  
Kathryn E. Cherny ◽  
Karin Sauer
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Genomic Dna ◽  
Early Stage ◽  
Content Type ◽  
Biofilm Dispersion ◽  
Biofilm Structure ◽  
First Time ◽  
Biofilm Matrix ◽  
Dispersed Cells

ABSTRACT The dispersion of biofilms is an active process resulting in the release of planktonic cells from the biofilm structure. While much is known about the process of dispersion cue perception and the subsequent modulation of the c-di-GMP pool, little is known about subsequent events resulting in the release of cells from the biofilm. Given that dispersion coincides with void formation and an overall erosion of the biofilm structure, we asked whether dispersion involves degradation of the biofilm matrix. Here, we focused on extracellular genomic DNA (eDNA) due to its almost universal presence in the matrix of biofilm-forming species. We identified two probable nucleases, endA and eddB, and eddA encoding a phosphatase that were significantly increased in transcript abundance in dispersed cells. However, only inactivation of endA but not eddA or eddB impaired dispersion by Pseudomonas aeruginosa biofilms in response to glutamate and nitric oxide (NO). Heterologously produced EndA was found to be secreted and active in degrading genomic DNA. While endA inactivation had little effect on biofilm formation and the presence of eDNA in biofilms, eDNA degradation upon induction of dispersion was impaired. In contrast, induction of endA expression coincided with eDNA degradation and resulted in biofilm dispersion. Thus, released cells demonstrated a hyperattaching phenotype but remained as resistant to tobramycin as biofilm cells from which they egress, indicating EndA-dispersed cells adopted some but not all of the phenotypes associated with dispersed cells. Our findings indicate for the first time a role of DNase EndA in dispersion and suggest weakening of the biofilm matrix is a requisite for biofilm dispersion. IMPORTANCE The finding that exposure to DNase I impairs biofilm formation or leads to the dispersal of early stage biofilms has led to the realization of extracellular genomic DNA (eDNA) as a structural component of the biofilm matrix. However, little is known about the contribution of intrinsic DNases to the weakening of the biofilm matrix and dispersion of established biofilms. Here, we demonstrate for the first time that nucleases are induced in dispersed Pseudomonas aeruginosa cells and are essential to the dispersion response and that degradation of matrix eDNA by endogenously produced/secreted EndA is required for P. aeruginosa biofilm dispersion. Our findings suggest that dispersing cells mediate their active release from the biofilm matrix via the induction of nucleases.

scholarly journals Natural Transformation of Gallibacterium anatis

2012 ◽  
Vol 78 (14) ◽  
pp. 4914-4922 ◽  
Author(s):  
Bodil M. Kristensen ◽  
Sunita Sinha ◽  
John D. Boyce ◽  
Anders M. Bojesen ◽  
Joshua C. Mell ◽  
...  
Keyword(s):  
Bioinformatics Analysis ◽  
Natural Transformation ◽  
Genetic Manipulation ◽  
Targeted Mutagenesis ◽  
Chromosomal Dna ◽  
Natural Competence ◽  
Content Type ◽  
Transformation Procedure ◽  
High Transformation ◽  
Dna Types

ABSTRACTGallibacterium anatisis a pathogen of poultry. Very little is known about its genetics and pathogenesis. To enable the study of gene function inG. anatis, we have established methods for transformation and targeted mutagenesis. The genusGallibacteriumbelongs to thePasteurellaceae, a group with several naturally transformable members, includingHaemophilus influenzae. Bioinformatics analysis identifiedG. anatishomologs of theH. influenzaecompetence genes, and natural competence was induced inG. anatisby the procedure established forH. influenzae: transfer from rich medium to the starvation medium M-IV. This procedure gave reproducibly high transformation frequencies withG. anatischromosomal DNA and with linearized plasmid DNA carryingG. anatissequences. Both DNA types integrated into theG. anatischromosome by homologous recombination. Targeted mutagenesis gave transformation frequencies of >2 × 10−4transformants CFU−1. Transformation was also efficient with circular plasmid containing noG. anatisDNA; this resulted in the establishment of a self-replicating plasmid. Nine diverseG. anatisstrains were found to be naturally transformable by this procedure, suggesting that natural competence is common and the M-IV transformation procedure widely applicable for this species. TheG. anatisgenome is only slightly enriched for the uptake signal sequences identified in other pasteurellaceaen genomes, butG. anatisdid preferentially take up its own DNA over that ofEscherichia coli. Transformation by electroporation was not effective for chromosomal integration but could be used to introduce self-replicating plasmids. The findings described here provide important tools for the genetic manipulation ofG. anatis.

scholarly journals Influence of Cation Exchange on the 27Al-NMR Spectra of Zeolites

2003 ◽  
Vol 217 (12) ◽  
pp. 1613-1626 ◽  
Author(s):  
W. Masierak ◽  
T. Emmler ◽  
Gerd Buntkowsky ◽  
A. Gutsze
Keyword(s):  
Cation Exchange ◽  
Nmr Spectra ◽  
Structural Changes ◽  
Divalent Cations ◽  
Second Order ◽  
Quadrupolar Coupling ◽  
Frame Work ◽  
Ion Radius ◽  
First Time

AbstractThe influence of cation exchange on the 27Al-NMR spectra of NaA-zeolites has been studied by 27Al-MAS- and MQ-MAS-Solid State-NMR. From the 27Al-spectra a characterization of the different Al sites in the A zeolites according to their chemical environment and the structural changes on the aluminosilicate network caused by the cation exchange are obtained. It is found that the exchange with cations with smaller ion-radius cause stronger distortions of the 27Al-NMR-spectra than exchange with larger cations like Ba2+. Employing MQ-MAS spectroscopy these distortions are revealed as second order quadrupolar effects for the smaller cations and as a combination of chemical shift and second order quadrupolar interaction for the Ba cation. These changes of the quadrupolar coupling are interpreted numerically via calculations of the lowering of the symmetry of the EFG tensor. Finally it is found that the exchange with divalent cations leads to distortions of the zeolitic framework and the formation of an extra-framework aluminum. To the best of our knowledge this is for the first time that evidence for the production of extra frame work aluminum by pure cation exchange without any thermal treatment has been found in type A zeolites.

First molecular detection and characterization of Sarcocystis infection in naturally infected buffaloes, Brazil

2020 ◽  
Author(s):  
Luiza Pires Portella ◽  
Fagner D'ambroso Fernandes ◽  
Camila Encarnação Minuzzi ◽  
Juliana Felipetto Cargnelutti ◽  
Luis Fernando Vilani de Pelegrini ◽  
...  
Keyword(s):  
Microscopic Examination ◽  
Genomic Dna ◽  
Molecular Detection ◽  
Natural Infection ◽  
Sarcocystis Species ◽  
Sarcocystis Spp ◽  
The World ◽  
First Time ◽  
Pathogenic Effects

Sarcocystosis is a disease caused by varying Sarcocystis species infecting humans and animals. It is commonly found in ruminants causing pathogenic effects. Although the distribution of Sarcocystis can be found all over the world, the species infecting buffaloes in Brazil is still unknown. Through this study, we aim to estimate the molecular prevalence of natural infection with Sarcocystis spp. in buffaloes using molecular identification. In addition, phylogenetic analyzes were used for the first time to identify the different species of this protozoan infecting buffalo in the south of the country. Heart samples from 80 buffaloes were subjected to microscopic examination, followed by molecular analysis. Microcysts were present in 19/80 (23,75%) of the samples. Genomic DNA was extracted from the 19 isolates, all there were amplified DNA in the primer used in the study. Six readable sequences were obtained after sequencing of the samples in both the directions. In the present study all the sequenced samples indicated were of Sarcocystis levinei.

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