Biomedical subjects

David Ussery

Publications and source records attributed to David Ussery.

5 recordsLinked to original sources

PubMed2025

Rapid assessment of clinical severity for salmonellosis cases via protein family domain analysis and machine learning.

Salmonella is a common pathogen, infecting more than a million people yearly. Rapid assessment of clinical case severity is essential for improving patient outcomes and optimizing healthcare resources. Advancements in genome sequencing technologies have enabled the analysis of bacterial genomes from many clinical cases, opening up new opportunities for precise and timely diagnosis. This study proposes a genome-based framework for identifying critical Salmonella cases before the onset of critical symptoms and facilitating early medical intervention. By leveraging protein family (Pfam) domains as the representation for genomic data, the complex genetic profiles of Salmonella cases are simplified into interpretable features. The severity levels of cases were investigated through rigorous data analysis, resulting in a set of 70 Pfam domains that could be potentially used as biomarkers. Machine Learning was employed to assess the predictive power of the curated Pfam biomarkers, achieving high accuracy (~93%) in sorting cases into critical, moderate, and mild categories. The results demonstrate the efficacy of the proposed approach. This framework highlights the potential of using bacterial genomic data in clinical decision-making, opening the window for timely personalized interventions for Salmonella infection management.

Domains of unknown function (DUFs)↗

PubMed2006

The genomic code: inferring Vibrionaceae niche specialization.

The Vibrionaceae show a wide range of niche specialization, from free-living forms to those attached to biotic and abiotic surfaces, from symbionts to pathogens and from estuarine inhabitants to deep-sea piezophiles. The existence of complete genome sequences for closely related species from varied aquatic niches makes this group an excellent case study for genome comparison.

Animals↗

PubMed2003

Analysis of two large functionally uncharacterized regions in the Methanopyrus kandleri AV19 genome.

BACKGROUND: For most sequenced prokaryotic genomes, about a third of the protein coding genes annotated are "orphan proteins", that is, they lack homology to known proteins. These hypothetical genes are typically short and randomly scattered throughout the genome. This trend is seen for most of the bacterial and archaeal genomes published to date. RESULTS: In contrast we have found that a large fraction of the genes coding for such orphan proteins in the Methanopyrus kandleri AV19 genome occur within two large regions. These genes have no known homologs except from other M. kandleri genes. However, analysis of their lengths, codon usage, and Ribosomal Binding Site (RBS) sequences shows that they are most likely true protein coding genes and not random open reading frames. CONCLUSIONS: Although these regions can be considered as candidates for massive lateral gene transfer, our bioinformatics analysis suggests that this is not the case. We predict many of the organism specific proteins to be transmembrane and belong to protein families that are non-randomly distributed between the regions. Consistent with this, we suggest that the two regions are most likely unrelated, and that they may be integrated plasmids.

Amino Acids↗

PubMed2002

Bias of purine stretches in sequenced chromosomes.

We examined more than 700 DNA sequences (full length chromosomes and plasmids) for stretches of purines (R) or pyrimidines (Y) and alternating YR stretches; such regions will likely adopt structures which are different from the canonical B-form. Since one turn of the DNA helix is roughly 10 bp, we measured the fraction of each genome which contains purine (or pyrimidine) tracts of lengths of 10 bp or longer (hereafter referred to as 'purine tracts'), as well as stretches of alternating pyrimidines/purine (pyr/pur tracts') of the same length. Using this criteria, a random sequence would be expected to contain 1.0% of purine tracts and also 1.0% of the alternating pyr/pur tracts. In the vast majority of cases, there are more purine tracts than would be expected from a random sequence, with an average of 3.5%, significantly larger than the expectation value. The fraction of the chromosomes containing pyr/pur tracts was slightly less than expected, with an average of 0.8%. One of the most surprising findings is a clear difference in the length distributions of the regions studied between prokaryotes and eukaryotes. Whereas short-range correlations can explain the length distributions in prokaryotes, in eukaryotes there is an abundance of long stretches of purines or alternating purine/pyrimidine tracts, which cannot be explained in this way; these sequences are likely to play an important role in eukaryotic chromosome organisation.

Animals↗

PubMed2002

Evaluation of potential regulatory elements identified as DNase I hypersensitive sites in the CFTR gene.

The cystic fibrosis transmembrane conductance regulator (CFTR) gene shows a complex pattern of expression, with temporal and spatial regulation that is not accounted for by elements in the promoter. One approach to identifying the regulatory elements for CFTR is the mapping of DNase I hypersensitive sites (DHS) within the locus. We previously identified at least 12 clusters of DHS across the CFTR gene and here further evaluate DHS in introns 2, 3, 10, 16, 17a, 18, 20 and 21 to assess their functional importance in regulation of CFTR gene expression. Transient transfections of enhan- cer/reporter constructs containing the DHS regions showed that those in introns 20 and 21 augmented the activity of the CFTR promoter. Structural analysis of the DNA sequence at the DHS suggested that only the one intron 21 might be caused by inherent DNA structures. Cell specificity of the DHS suggested a role for the DHS in introns 2 and 18 in CFTR expression in some pancreatic duct cells. Finally, regulatory elements at the DHS in introns 10 and 18 may contribute to upregulation of CFTR gene transcription by forskolin and mitomycin C, respectively. These data support a model of regulation of expression of the CFTR gene in which multiple elements contribute to tightly co-ordinated expression in vivo.

Cystic Fibrosis Transmembrane Conductance Regulato↗