Publications by authors named "Richa Agarwala"

Article Synopsis
  • - Whole-genome sequencing helps public health agencies link food poisoning cases to the same source of contamination, but most cases are sporadic and often go uninvestigated.
  • - Researchers analyze specific bacterial pathogens by looking at small mutations in their DNA to understand patterns in contamination events and infection susceptibility, particularly highlighting that younger age groups are more vulnerable.
  • - Many contamination episodes last a long time, with 50% of cases linked to clusters persisting for nearly 3 years, often involving contaminated food that affects people across multiple states, rather than just issues with infant formula.
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Article Synopsis
  • * A study of bacterial isolates reveals that younger individuals are more susceptible to infections, with significant regional variations in serovar prevalence across the U.S.
  • * Many contamination episodes leading to illness last a long time, with 50% of cases linked to clusters persisting for nearly three years, and infants are often infected through cross-contamination rather than contaminated formula.
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Searching vast and rapidly growing nucleotide content in resources, such as runs in the Sequence Read Archive and assemblies for whole-genome shotgun sequencing projects in GenBank, is currently impractical for most researchers. Here we present Pebblescout, a tool that navigates such content by providing indexing and search capabilities. Indexing uses dense sampling of the sequences in the resource.

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Candida auris is a newly emerged multidrug-resistant fungus capable of causing invasive infections with high mortality. Despite intense efforts to understand how this pathogen rapidly emerged and spread worldwide, its environmental reservoirs are poorly understood. Here, we present a collaborative effort between the U.

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Abstract: This multiagency report developed by the Interagency Collaboration for Genomics for Food and Feed Safety provides an overview of the use of and transition to whole genome sequencing (WGS) technology for detection and characterization of pathogens transmitted commonly by food and for identification of their sources. We describe foodborne pathogen analysis, investigation, and harmonization efforts among the following federal agencies: National Institutes of Health; Department of Health and Human Services, Centers for Disease Control and Prevention (CDC) and U.S.

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Background: Illumina is the dominant sequencing technology at this time. Short length, short insert size, some systematic biases, and low-level carryover contamination in Illumina reads continue to make assembly of repeated regions a challenging problem. Some applications also require finding multiple well supported variants for assembled regions.

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Background: Alignment of sequence reads generated by next-generation sequencing is an integral part of most pipelines analyzing next-generation sequencing data. A number of tools designed to quickly align a large volume of sequences are already available. However, most existing tools lack explicit guarantees about their output.

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The National Center for Biotechnology Information (NCBI) provides a large suite of online resources for biological information and data, including the GenBank® nucleic acid sequence database and the PubMed database of citations and abstracts published in life science journals. The Entrez system provides search and retrieval operations for most of these data from 38 distinct databases. The E-utilities serve as the programming interface for the Entrez system.

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Article Synopsis
  • SKESA is a DeBruijn graph-based assembler specifically designed for creating assemblies from microbial genome reads sequenced with Illumina technology.
  • It outperforms other assemblers like SPAdes and MegaHit by delivering high-quality, contiguous sequences while being fast and consistent across multiple assembly runs.
  • SKESA has been utilized for over 272,000 read sets in the NCBI Sequence Read Archive and is available for real-time pathogen detection; its source code can be accessed for free on GitHub.
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Article Synopsis
  • Advances in genome-scale analysis programs are allowing for faster and more efficient determination of evolutionary relationships, essential for public health epidemiology, yet require comprehensive validation datasets.
  • Four documented foodborne pathogen events were identified that align with phylogenomic analyses, leading to the creation of benchmark datasets that are publicly accessible for validation of these methods.
  • The developed benchmark datasets encompass major foodborne bacterial pathogens and provide a standardized approach to facilitate comparisons of different phylogenomic pipelines in outbreak surveillance and research.
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Pseudomonas fluorescens is a well-known plant growth-promoting rhizobacterium (PGPR). We report here the first whole-genome sequence of PGPR P. fluorescens evaluated in Colombian banana plants.

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Campylobacter coli, along with Campylobacter jejuni, is a major agent of gastroenteritis and acute enterocolitis in humans. We report the whole-genome sequences of two multidrug-resistance C. coli strains, isolated from the Colombian poultry chain.

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Campylobacter coli is considered one of the main causes of food-borne illness worldwide. We report here the whole-genome sequence of multidrug-resistant Campylobacter coli strain COL B1-266, isolated from the Colombian poultry chain. The genome sequences encode genes for a variety of antimicrobial resistance genes, including aminoglycosides, β-lactams, lincosamides, fluoroquinolones, and tetracyclines.

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Background: Xiphophorus fishes are represented by 26 live-bearing species of tropical fish that express many attributes (e.g., viviparity, genetic and phenotypic variation, ecological adaptation, varied sexual developmental mechanisms, ability to produce fertile interspecies hybrids) that have made attractive research models for over 85 years.

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Bacillus amyloliquefaciens is an important plant growth-promoting rhizobacterium (PGPR). We report the first whole-genome sequence of PGPR Bacillus amyloliquefaciens evaluated in Colombian banana plants. The genome sequences encode genes involved in plant growth and defense, including bacteriocins, ribosomally synthesized antibacterial peptides, in addition to genes that provide resistance to toxic compounds.

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Salmonella enterica is a pathogen of significant public health importance that is frequently associated with foodborne illness. We report the whole-genome sequences of four multidrug-resistant Salmonella enterica serovar Paratyphi B and Heidelberg strains, isolated from the Colombian poultry chain. The isolates contain a variety of antimicrobial resistance genes for aminoglycosides, β-lactams, fluoroquinolones, sulfonamides, tetracycline, and trimethoprim.

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Background & Aims: Small intestinal carcinoids are rare and difficult to diagnose and patients often present with advanced incurable disease. Although the disease occurs sporadically, there have been reports of family clusters. Hereditary small intestinal carcinoid has not been recognized and genetic factors have not been identified.

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A complete reference assembly is essential for accurately interpreting individual genomes and associating variation with phenotypes. While the current human reference genome sequence is of very high quality, gaps and misassemblies remain due to biological and technical complexities. Large repetitive sequences and complex allelic diversity are the two main drivers of assembly error.

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Background: BLAST is a commonly-used software package for comparing a query sequence to a database of known sequences; in this study, we focus on protein sequences. Position-specific-iterated BLAST (PSI-BLAST) iteratively searches a protein sequence database, using the matches in round i to construct a position-specific score matrix (PSSM) for searching the database in round i + 1. Biegert and Söding developed Context-sensitive BLAST (CS-BLAST), which combines information from searching the sequence database with information derived from a library of short protein profiles to achieve better homology detection than PSI-BLAST, which builds its PSSMs from scratch.

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We recently reported autosomal recessive fetal-onset neuroaxonal dystrophy (FNAD) in a large family of dogs that is not caused by mutation in the PLA2G6 locus (Fyfe et al., J Comp Neurol 518:3771-3784, 2010). Here, we report a genome-wide linkage analysis using 333 microsatellite markers to map canine FNAD to the telomeric end of chromosome 2.

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The regions encoding the coordinately regulated Th2 cytokines IL5, IL4 and IL13 are located on chromosomes 5 of man and 11 of mouse. They have been intensively studied because these interleukins have protective roles in helminth infections, but may lead to detrimental effects such as allergy, asthma, and fibrosis in lung and liver. We added to previous studies by comparing sequences of syntenic regions on chromosome 3 of the rabbit (Oryctolagus cuniculus) genome OryCun 2.

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Background: Because they are a closed founder population, the Old Order Amish (OOA) of Lancaster County have been the subject of many medical genetics studies. We constructed four versions of Anabaptist Genealogy Database (AGDB) using three sources of genealogies and multiple updates. In addition, we developed PedHunter, a suite of query software that can solve pedigree-related problems automatically and systematically.

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