Kristian Fog Nielsen

Dr. Kristian Fog Nielsen


Research Focus & Metrics

Academic Career Length

25Years (2002-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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9 August 2016 in Nature Biotechnology
Verified
Journal Article
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MWMingxun Wang
Mingxun Wang
JCJeremy J Carver
Jeremy J Carver
VPVanessa Phelan
Vanessa Phelan
LSLaura Sanchez
Laura Sanchez
NGNeha Garg
Neha Garg
NBNuno Bandeira
Nuno Bandeira
GNPS is an open-access community-curated analysis platform for sharing natural product mass spectrometry data that enables continuous, automatic reanalysis of deposited 'living' data sets. The potential of the diverse chemistries present in natural products (NP) for biotechnology and medicine remains untapped because NP databases are not searchable with raw data and the NP community has no way to share data other than in published papers. Although mass spectrometry (MS) techniques are well-suited to high-throughput characterization of NP, there is a pressing need for an infrastructure to enable sharing and curation of data. We present Global Natural Products Social Molecular Networking (GNPS; http://gnps.ucsd.edu ), an open-access knowledge base for community-wide organization and sharing of raw, processed or identified tandem mass (MS/MS) spectrometry data. In GNPS, crowdsourced curation of freely available community-wide reference MS libraries will underpin improved annotations. Data-driven social-networking should facilitate identification of spectra and foster collaborations. We also introduce the concept of 'living data' through continuous reanalysis of deposited data.

1 May 2012 in Antimicrobial Agents and Chemotherapy
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TJTim Holm Jakobsen
Tim Holm Jakobsen
MGMaria van Gennip
Maria van Gennip
RPRichard Kerry Phipps
Richard Kerry Phipps
MSMeenakshi Sundaram Shanmugham
Meenakshi Sundaram Shanmugham
LHLouise Dahl Hultqvist
Louise Dahl Hultqvist
MGMichael Givskov
Michael Givskov
In relation to emerging multiresistant bacteria, development of antimicrobials and new treatment strategies of infections should be expected to become a high-priority research area. Quorum sensing (QS), a communication system used by pathogenic bacteria likePseudomonas aeruginosato synchronize the expression of specific genes involved in pathogenicity, is a possible drug target. Previousin vitroandin vivostudies revealed a significant inhibition ofP. aeruginosaQS by crude garlic extract. By bioassay-guided fractionation of garlic extracts, we determined the primary QS inhibitor present in garlic to be ajoene, a sulfur-containing compound with potential as an antipathogenic drug. By comprehensivein vitroandin vivostudies, the effect of synthetic ajoene towardP. aeruginosawas elucidated. DNA microarray studies of ajoene-treatedP. aeruginosacultures revealed a concentration-dependent attenuation of a few but central QS-controlled virulence factors, including rhamnolipid. Furthermore, ajoene treatment ofin vitrobiofilms demonstrated a clear synergistic, antimicrobial effect with tobramycin on biofilm killing and a cease in lytic necrosis of polymorphonuclear leukocytes. Furthermore, in a mouse model of pulmonary infection, a significant clearing of infectingP. aeruginosawas detected in ajoene-treated mice compared to a nontreated control group. This study adds to the list of examples demonstrating the potential of QS-interfering compounds in the treatment of bacterial infections.


4 May 2011 in Genome Research
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MAMikael Rørdam Andersen
Mikael Rørdam Andersen
MSMargarita P. Salazar
Margarita P. Salazar
PSPeter J. Schaap
Peter J. Schaap
PVPeter J.I. van de Vondervoort
Peter J.I. van de Vondervoort
DCDavid Culley
David Culley
SBScott Baker
Scott Baker
The filamentous fungusAspergillus nigerexhibits great diversity in its phenotype. It is found globally, both as marine and terrestrial strains, produces both organic acids and hydrolytic enzymes in high amounts, and some isolates exhibit pathogenicity. Although the genome of an industrial enzyme-producingA. nigerstrain (CBS 513.88) has already been sequenced, the versatility and diversity of this species compel additional exploration. We therefore undertook whole-genome sequencing of the acidogenicA. nigerwild-type strain (ATCC 1015) and produced a genome sequence of very high quality. Only 15 gaps are present in the sequence, and half the telomeric regions have been elucidated. Moreover, sequence information from ATCC 1015 was used to improve the genome sequence of CBS 513.88. Chromosome-level comparisons uncovered several genome rearrangements, deletions, a clear case of strain-specific horizontal gene transfer, and identification of 0.8 Mb of novel sequence. Single nucleotide polymorphisms per kilobase (SNPs/kb) between the two strains were found to be exceptionally high (average: 7.8, maximum: 160 SNPs/kb). High variation within the species was confirmed with exo-metabolite profiling and phylogenetics. Detailed lists of alleles were generated, and genotypic differences were observed to accumulate in metabolic pathways essential to acid production and protein synthesis. A transcriptome analysis supported up-regulation of genes associated with biosynthesis of amino acids that are abundant in glucoamylase A, tRNA-synthases, and protein transporters in the protein producing CBS 513.88 strain. Our results and data sets from this integrative systems biology analysis resulted in a snapshot of fungal evolution and will support further optimization of cell factories based on filamentous fungi.

12 August 2015 in Toxins
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Antonio Gallo GalloAntonio Gallo Gallo
Antonio Gallo Gallo
Gianluca GiubertiGianluca Giuberti
Gianluca Giuberti
JFJens Frisvad
Jens Frisvad
Terenzio BertuzziTerenzio Bertuzzi
Terenzio Bertuzzi
KNKristian Fog Nielsen
Kristian Fog Nielsen
Ruminant diets include cereals, protein feeds, their by-products as well as hay and grass, grass/legume, whole-crop maize, small grain or sorghum silages. Furthermore, ruminants are annually or seasonally fed with grazed forage in many parts of the World. All these forages could be contaminated by several exometabolites of mycotoxigenic fungi that increase and diversify the risk of mycotoxin exposure in ruminants compared to swine and poultry that have less varied diets. Evidence suggests the greatest exposure for ruminants to some regulated mycotoxins (aflatoxins, trichothecenes, ochratoxin A, fumonisins and zearalenone) and to many other secondary metabolites produced by different species of Alternaria spp. (e.g., AAL toxins, alternariols, tenuazonic acid or 4Z-infectopyrone), Aspergillus flavus (e.g., kojic acid, cyclopiazonic acid or β-nitropropionic acid), Aspergillus fuminatus (e.g., gliotoxin, agroclavine, festuclavines or fumagillin), Penicillium roqueforti and P. paneum (e.g., mycophenolic acid, roquefortines, PR toxin or marcfortines) or Monascus ruber (citrinin and monacolins) could be mainly related to forage contamination. This review includes the knowledge of mycotoxin occurrence reported in the last 15 years, with special emphasis on mycotoxins detected in forages, and animal toxicological issues due to their ingestion. Strategies for preventing the problem of mycotoxin feed contamination under farm conditions are discussed.

16 September 2009 in Analytical and Bioanalytical Chemistry
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Journal Article
Closed access
KNKristian Fog Nielsen
Kristian Fog Nielsen
JMJesper Mølgaard Mogensen
Jesper Mølgaard Mogensen
MJMaria Johansen
Maria Johansen
TLThomas Ostenfeld Larsen
Thomas Ostenfeld Larsen
JFJens Frisvad
Jens Frisvad