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Yorki S, Shea T, Cuomo CA, Walker BJ, LaRocque RC, Manson AL, Earl AM, Worby CJ. Comparison of long- and short-read metagenomic assembly for low-abundance species and resistance genes. Brief Bioinform 2023; 24:bbad050. [PMID: 36804804 PMCID: PMC10025444 DOI: 10.1093/bib/bbad050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 01/13/2023] [Accepted: 01/26/2023] [Indexed: 02/23/2023] Open
Abstract
Recent technological and computational advances have made metagenomic assembly a viable approach to achieving high-resolution views of complex microbial communities. In previous benchmarking, short-read (SR) metagenomic assemblers had the highest accuracy, long-read (LR) assemblers generated the most contiguous sequences and hybrid (HY) assemblers balanced length and accuracy. However, no assessments have specifically compared the performance of these assemblers on low-abundance species, which include clinically relevant organisms in the gut. We generated semi-synthetic LR and SR datasets by spiking small and increasing amounts of Escherichia coli isolate reads into fecal metagenomes and, using different assemblers, examined E. coli contigs and the presence of antibiotic resistance genes (ARGs). For ARG assembly, although SR assemblers recovered more ARGs with high accuracy, even at low coverages, LR assemblies allowed for the placement of ARGs within longer, E. coli-specific contigs, thus pinpointing their taxonomic origin. HY assemblies identified resistance genes with high accuracy and had lower contiguity than LR assemblies. Each assembler type's strengths were maintained even when our isolate was spiked in with a competing strain, which fragmented and reduced the accuracy of all assemblies. For strain characterization and determining gene context, LR assembly is optimal, while for base-accurate gene identification, SR assemblers outperform other options. HY assembly offers contiguity and base accuracy, but requires generating data on multiple platforms, and may suffer high misassembly rates when strain diversity exists. Our results highlight the trade-offs associated with each approach for recovering low-abundance taxa, and that the optimal approach is goal-dependent.
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Affiliation(s)
- Sosie Yorki
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Terrance Shea
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Christina A Cuomo
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Bruce J Walker
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Applied Invention, LLC, Cambridge, MA, USA
| | - Regina C LaRocque
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA
| | - Abigail L Manson
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Ashlee M Earl
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Colin J Worby
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA, USA
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2
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Salamzade R, Manson AL, Walker BJ, Brennan-Krohn T, Worby CJ, Ma P, He LL, Shea TP, Qu J, Chapman SB, Howe W, Young SK, Wurster JI, Delaney ML, Kanjilal S, Onderdonk AB, Bittencourt CE, Gussin GM, Kim D, Peterson EM, Ferraro MJ, Hooper DC, Shenoy ES, Cuomo CA, Cosimi LA, Huang SS, Kirby JE, Pierce VM, Bhattacharyya RP, Earl AM. Inter-species geographic signatures for tracing horizontal gene transfer and long-term persistence of carbapenem resistance. Genome Med 2022; 14:37. [PMID: 35379360 PMCID: PMC8981930 DOI: 10.1186/s13073-022-01040-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 03/22/2022] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Carbapenem-resistant Enterobacterales (CRE) are an urgent global health threat. Inferring the dynamics of local CRE dissemination is currently limited by our inability to confidently trace the spread of resistance determinants to unrelated bacterial hosts. Whole-genome sequence comparison is useful for identifying CRE clonal transmission and outbreaks, but high-frequency horizontal gene transfer (HGT) of carbapenem resistance genes and subsequent genome rearrangement complicate tracing the local persistence and mobilization of these genes across organisms. METHODS To overcome this limitation, we developed a new approach to identify recent HGT of large, near-identical plasmid segments across species boundaries, which also allowed us to overcome technical challenges with genome assembly. We applied this to complete and near-complete genome assemblies to examine the local spread of CRE in a systematic, prospective collection of all CRE, as well as time- and species-matched carbapenem-susceptible Enterobacterales, isolated from patients from four US hospitals over nearly 5 years. RESULTS Our CRE collection comprised a diverse range of species, lineages, and carbapenem resistance mechanisms, many of which were encoded on a variety of promiscuous plasmid types. We found and quantified rearrangement, persistence, and repeated transfer of plasmid segments, including those harboring carbapenemases, between organisms over multiple years. Some plasmid segments were found to be strongly associated with specific locales, thus representing geographic signatures that make it possible to trace recent and localized HGT events. Functional analysis of these signatures revealed genes commonly found in plasmids of nosocomial pathogens, such as functions required for plasmid retention and spread, as well survival against a variety of antibiotic and antiseptics common to the hospital environment. CONCLUSIONS Collectively, the framework we developed provides a clearer, high-resolution picture of the epidemiology of antibiotic resistance importation, spread, and persistence in patients and healthcare networks.
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Affiliation(s)
- Rauf Salamzade
- grid.66859.340000 0004 0546 1623Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142 USA ,grid.14003.360000 0001 2167 3675Present Address: Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, WI 53706 USA
| | - Abigail L. Manson
- grid.66859.340000 0004 0546 1623Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142 USA
| | - Bruce J. Walker
- grid.66859.340000 0004 0546 1623Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142 USA ,Applied Invention, Cambridge, MA 02139 USA
| | - Thea Brennan-Krohn
- grid.239395.70000 0000 9011 8547Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215 USA
| | - Colin J. Worby
- grid.66859.340000 0004 0546 1623Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142 USA
| | - Peijun Ma
- grid.66859.340000 0004 0546 1623Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142 USA
| | - Lorrie L. He
- grid.66859.340000 0004 0546 1623Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142 USA
| | - Terrance P. Shea
- grid.66859.340000 0004 0546 1623Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142 USA
| | - James Qu
- grid.66859.340000 0004 0546 1623Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142 USA
| | - Sinéad B. Chapman
- grid.66859.340000 0004 0546 1623Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142 USA
| | - Whitney Howe
- grid.66859.340000 0004 0546 1623Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142 USA
| | - Sarah K. Young
- grid.66859.340000 0004 0546 1623Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142 USA
| | - Jenna I. Wurster
- grid.38142.3c000000041936754XDepartment of Ophthalmology, Department of Microbiology, Harvard Medical School and Massachusetts Eye and Ear Infirmary, 240 Charles St., Boston, MA 02114 USA
| | - Mary L. Delaney
- grid.38142.3c000000041936754XDivision of Infectious Disease, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115 USA
| | - Sanjat Kanjilal
- grid.38142.3c000000041936754XDivision of Infectious Disease, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115 USA ,grid.38142.3c000000041936754XDepartment of Population Medicine, Harvard Medical School and Harvard Pilgrim Healthcare Institute, Boston, MA 02215 USA
| | - Andrew B. Onderdonk
- grid.38142.3c000000041936754XDivision of Infectious Disease, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115 USA
| | - Cassiana E. Bittencourt
- grid.266093.80000 0001 0668 7243Department of Pathology and Laboratory Medicine, University of California Irvine School of Medicine, Orange, CA 92868 USA
| | - Gabrielle M. Gussin
- grid.266093.80000 0001 0668 7243Division of Infectious Diseases, University of California Irvine School of Medicine, Irvine, CA 92617 USA
| | - Diane Kim
- grid.266093.80000 0001 0668 7243Division of Infectious Diseases, University of California Irvine School of Medicine, Irvine, CA 92617 USA
| | - Ellena M. Peterson
- grid.266093.80000 0001 0668 7243Department of Pathology and Laboratory Medicine, University of California Irvine School of Medicine, Orange, CA 92868 USA
| | - Mary Jane Ferraro
- grid.32224.350000 0004 0386 9924Massachusetts General Hospital, Boston, MA 02114 USA
| | - David C. Hooper
- grid.32224.350000 0004 0386 9924Massachusetts General Hospital, Boston, MA 02114 USA
| | - Erica S. Shenoy
- grid.32224.350000 0004 0386 9924Massachusetts General Hospital, Boston, MA 02114 USA
| | - Christina A. Cuomo
- grid.66859.340000 0004 0546 1623Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142 USA
| | - Lisa A. Cosimi
- grid.66859.340000 0004 0546 1623Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142 USA ,grid.38142.3c000000041936754XDivision of Infectious Disease, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115 USA
| | - Susan S. Huang
- grid.266093.80000 0001 0668 7243Division of Infectious Diseases, University of California Irvine School of Medicine, Irvine, CA 92617 USA
| | - James E. Kirby
- grid.239395.70000 0000 9011 8547Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215 USA
| | - Virginia M. Pierce
- grid.32224.350000 0004 0386 9924Massachusetts General Hospital, Boston, MA 02114 USA
| | - Roby P. Bhattacharyya
- grid.66859.340000 0004 0546 1623Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142 USA ,grid.32224.350000 0004 0386 9924Massachusetts General Hospital, Boston, MA 02114 USA
| | - Ashlee M. Earl
- grid.66859.340000 0004 0546 1623Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, MA 02142 USA
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van Dijk LR, Walker BJ, Straub TJ, Worby CJ, Grote A, Schreiber HL, Anyansi C, Pickering AJ, Hultgren SJ, Manson AL, Abeel T, Earl AM. StrainGE: a toolkit to track and characterize low-abundance strains in complex microbial communities. Genome Biol 2022; 23:74. [PMID: 35255937 PMCID: PMC8900328 DOI: 10.1186/s13059-022-02630-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 02/09/2022] [Indexed: 01/21/2023] Open
Abstract
Human-associated microbial communities comprise not only complex mixtures of bacterial species, but also mixtures of conspecific strains, the implications of which are mostly unknown since strain level dynamics are underexplored due to the difficulties of studying them. We introduce the Strain Genome Explorer (StrainGE) toolkit, which deconvolves strain mixtures and characterizes component strains at the nucleotide level from short-read metagenomic sequencing with higher sensitivity and resolution than other tools. StrainGE is able to identify strains at 0.1x coverage and detect variants for multiple conspecific strains within a sample from coverages as low as 0.5x.
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Affiliation(s)
- Lucas R. van Dijk
- grid.66859.340000 0004 0546 1623Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA 02142 USA ,grid.5292.c0000 0001 2097 4740Delft Bioinformatics Lab, Delft University of Technology, Van Mourik Broekmanweg 6, Delft, 2628 XE The Netherlands
| | - Bruce J. Walker
- grid.66859.340000 0004 0546 1623Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA 02142 USA ,Applied Invention, Cambridge, MA USA
| | - Timothy J. Straub
- grid.66859.340000 0004 0546 1623Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA 02142 USA ,grid.38142.3c000000041936754XDepartment of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA 02115 USA
| | - Colin J. Worby
- grid.66859.340000 0004 0546 1623Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA 02142 USA
| | - Alexandra Grote
- grid.66859.340000 0004 0546 1623Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA 02142 USA
| | - Henry L. Schreiber
- grid.4367.60000 0001 2355 7002Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110 USA ,grid.4367.60000 0001 2355 7002Center for Women’s Infectious Disease Research (CWIDR), Washington University School of Medicine, St. Louis, MO 63110 USA
| | - Christine Anyansi
- grid.5292.c0000 0001 2097 4740Delft Bioinformatics Lab, Delft University of Technology, Van Mourik Broekmanweg 6, Delft, 2628 XE The Netherlands
| | - Amy J. Pickering
- grid.47840.3f0000 0001 2181 7878Department of Civil and Environmental Engineering, University of California, Berkeley, Berkeley, CA 94720 USA ,grid.429997.80000 0004 1936 7531Stuart B. Levy Center for Integrated Management of Antimicrobial Resistance (Levy CIMAR), Tufts University, Boston, MA USA
| | - Scott J. Hultgren
- grid.4367.60000 0001 2355 7002Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110 USA ,grid.4367.60000 0001 2355 7002Center for Women’s Infectious Disease Research (CWIDR), Washington University School of Medicine, St. Louis, MO 63110 USA
| | - Abigail L. Manson
- grid.66859.340000 0004 0546 1623Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA 02142 USA
| | - Thomas Abeel
- grid.66859.340000 0004 0546 1623Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA 02142 USA ,grid.5292.c0000 0001 2097 4740Delft Bioinformatics Lab, Delft University of Technology, Van Mourik Broekmanweg 6, Delft, 2628 XE The Netherlands
| | - Ashlee M. Earl
- grid.66859.340000 0004 0546 1623Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA 02142 USA
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4
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Straub TJ, Chou WC, Manson AL, Schreiber HL, Walker BJ, Desjardins CA, Chapman SB, Kaspar KL, Kahsai OJ, Traylor E, Dodson KW, Hullar MAJ, Hultgren SJ, Khoo C, Earl AM. Limited effects of long-term daily cranberry consumption on the gut microbiome in a placebo-controlled study of women with recurrent urinary tract infections. BMC Microbiol 2021; 21:53. [PMID: 33596852 PMCID: PMC7890861 DOI: 10.1186/s12866-021-02106-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 01/28/2021] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Urinary tract infections (UTIs) affect 15 million women each year in the United States, with > 20% experiencing frequent recurrent UTIs. A recent placebo-controlled clinical trial found a 39% reduction in UTI symptoms among recurrent UTI sufferers who consumed a daily cranberry beverage for 24 weeks. Using metagenomic sequencing of stool from a subset of these trial participants, we assessed the impact of cranberry consumption on the gut microbiota, a reservoir for UTI-causing pathogens such as Escherichia coli, which causes > 80% of UTIs. RESULTS The overall taxonomic composition, community diversity, carriage of functional pathways and gene families, and relative abundances of the vast majority of observed bacterial taxa, including E. coli, were not changed significantly by cranberry consumption. However, one unnamed Flavonifractor species (OTU41), which represented ≤1% of the overall metagenome, was significantly less abundant in cranberry consumers compared to placebo at trial completion. Given Flavonifractor's association with negative human health effects, we sought to determine OTU41 characteristic genes that may explain its differential abundance and/or relationship to key host functions. Using comparative genomic and metagenomic techniques, we identified genes in OTU41 related to transport and metabolism of various compounds, including tryptophan and cobalamin, which have been shown to play roles in host-microbe interactions. CONCLUSION While our results indicated that cranberry juice consumption had little impact on global measures of the microbiome, we found one unnamed Flavonifractor species differed significantly between study arms. This suggests further studies are needed to assess the role of cranberry consumption and Flavonifractor in health and wellbeing in the context of recurrent UTI. TRIAL REGISTRATION Clinical trial registration number: ClinicalTrials.gov NCT01776021 .
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Affiliation(s)
- Timothy J Straub
- Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA, 02142, USA
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Wen-Chi Chou
- Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA, 02142, USA
| | - Abigail L Manson
- Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA, 02142, USA
| | - Henry L Schreiber
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
- Center for Women's Infectious Disease Research, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Bruce J Walker
- Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA, 02142, USA
| | - Christopher A Desjardins
- Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA, 02142, USA
| | - Sinéad B Chapman
- Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA, 02142, USA
| | | | - Orsalem J Kahsai
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Elizabeth Traylor
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Karen W Dodson
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
- Center for Women's Infectious Disease Research, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Meredith A J Hullar
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Scott J Hultgren
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
- Center for Women's Infectious Disease Research, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | | | - Ashlee M Earl
- Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA, 02142, USA.
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5
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Anyansi C, Keo A, Walker BJ, Straub TJ, Manson AL, Earl AM, Abeel T. QuantTB - a method to classify mixed Mycobacterium tuberculosis infections within whole genome sequencing data. BMC Genomics 2020; 21:80. [PMID: 31992201 PMCID: PMC6986090 DOI: 10.1186/s12864-020-6486-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 01/13/2020] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Mixed infections of Mycobacterium tuberculosis and antibiotic heteroresistance continue to complicate tuberculosis (TB) diagnosis and treatment. Detection of mixed infections has been limited to molecular genotyping techniques, which lack the sensitivity and resolution to accurately estimate the multiplicity of TB infections. In contrast, whole genome sequencing offers sensitive views of the genetic differences between strains of M. tuberculosis within a sample. Although metagenomic tools exist to classify strains in a metagenomic sample, most tools have been developed for more divergent species, and therefore cannot provide the sensitivity required to disentangle strains within closely related bacterial species such as M. tuberculosis. Here we present QuantTB, a method to identify and quantify individual M. tuberculosis strains in whole genome sequencing data. QuantTB uses SNP markers to determine the combination of strains that best explain the allelic variation observed in a sample. QuantTB outputs a list of identified strains, their corresponding relative abundances, and a list of drugs for which resistance-conferring mutations (or heteroresistance) have been predicted within the sample. RESULTS We show that QuantTB has a high degree of resolution and is capable of differentiating communities differing by less than 25 SNPs and identifying strains down to 1× coverage. Using simulated data, we found QuantTB outperformed other metagenomic strain identification tools at detecting strains and quantifying strain multiplicity. In a real-world scenario, using a dataset of 50 paired clinical isolates from a study of patients with either reinfections or relapses, we found that QuantTB could detect mixed infections and reinfections at rates concordant with a manually curated approach. CONCLUSION QuantTB can determine infection multiplicity, identify hetero-resistance patterns, enable differentiation between relapse and re-infection, and clarify transmission events across seemingly unrelated patients - even in low-coverage (1×) samples. QuantTB outperforms existing tools and promises to serve as a valuable resource for both clinicians and researchers working with clinical TB samples.
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Affiliation(s)
- Christine Anyansi
- Delft Bioinformatics Lab, Delft University of Technology, Van Mourik Broekmanweg 6, Delft, 2628XE, The Netherlands.,Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, 415 Main Street, Cambridge, MA, 02142, USA
| | - Arlin Keo
- Delft Bioinformatics Lab, Delft University of Technology, Van Mourik Broekmanweg 6, Delft, 2628XE, The Netherlands
| | - Bruce J Walker
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, 415 Main Street, Cambridge, MA, 02142, USA.,Applied Invention, LLC, 486 Green Street, Cambridge, MA, 02139, USA
| | - Timothy J Straub
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, 415 Main Street, Cambridge, MA, 02142, USA.,Department of Immunology and Infectious Disease, Harvard T.H. Chan School of Public Health, 677 Huntington Avenue, Boston, MA, 02115, USA
| | - Abigail L Manson
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, 415 Main Street, Cambridge, MA, 02142, USA
| | - Ashlee M Earl
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, 415 Main Street, Cambridge, MA, 02142, USA
| | - Thomas Abeel
- Delft Bioinformatics Lab, Delft University of Technology, Van Mourik Broekmanweg 6, Delft, 2628XE, The Netherlands. .,Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, 415 Main Street, Cambridge, MA, 02142, USA.
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6
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Bhattacharyya R, Pironti A, Walker BJ, Manson A, Pierce V, Ferraro MJ, Shenoy E, Hooper DC, Earl A. 1202. Multimodal Sequencing of a Clonal Case Cluster of Carbapenem-Resistant Citrobacter Reveals Unexpectedly Rapid Dynamics of KPC3-Containing Plasmids. Open Forum Infect Dis 2018. [PMCID: PMC6252548 DOI: 10.1093/ofid/ofy210.1035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Background Carbapenem-resistant Enterobacteriaceae (CRE) are a major public health threat. We report four clonally related Citrobacter freundii isolates harboring the blaKPC-3 carbapenemase in April–May 2017 that are nearly identical to a strain from 2014 at the same institution. Despite differing by ≤5 single nucleotide polymorphisms (SNPs), these isolates exhibited dramatic differences in carbapenemase plasmid architecture. Methods We sequenced four carbapenem-resistant C. freundii isolates from 2017 and compared them with an ongoing CRE surveillance project at our institution. SNPs were identified from Illumina MiSeq data aligned to a reference genome using the variant caller Pilon. Plasmids were assembled from Illumina and Oxford Nanopore sequencing data using Unicycler. Results The four 2017 isolates differed from one another by 0–5 chromosomal SNPs; two were identical. With one exception, these isolates differed by >38,000 SNPs from 25 C. freundii isolates sequenced from 2013 to 2017 at the same institution for CRE surveillance. The exception was a 2014 isolate that differed by 13–16 SNPs from each 2017 isolate, with 13 SNPs common to all four. Each C. freundii isolate harbored wild-type blaKPC-3. Despite the close relationship among the 2017 cluster, the plasmids harboring the blaKPC-3 genes differed dramatically: the carbapenemase occurred in one of the two different plasmids, with rearrangements between these plasmids across isolates. The related 2014 isolate harbored both plasmids, each with a separate copy of blaKPC-3. No transmission chains were found between any of the affected patients. Conclusion WGS confirmed clonality among four contemporaneous blaKPC-3-containing C. freundii isolates, and marked similarity with a 2014 isolate, within an institution. That only 13–16 SNPs varied between the 2014 and 2017 isolates suggests durable persistence of the blaKPC-3 gene within this lineage in a hospital ecosystem. The plasmids harboring these carbapenemase genes proved remarkably plastic, with plasmid loss and rearrangements occurring on the same time scale as two to three chromosomal point mutations. Combining short and long-read sequencing in a case cluster uniquely revealed unexpectedly rapid dynamics of carbapenemase plasmids, providing critical insight into their manner of spread. Disclosures M. J. Ferraro, SeLux Diagnostics: Scientific Advisor and Shareholder, Consulting fee. D. C. Hooper, SeLux Diagnostics: Scientific Advisor, Consulting fee.
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Affiliation(s)
- Roby Bhattacharyya
- Department of Medicine, Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts
- Infectious Disease and Microbiome Program, Broad Institute, Cambridge, Massachusetts
| | | | | | | | - Virginia Pierce
- Pathology and Pediatrics, Massachusetts General Hospital, MassGeneral Hospital for Children, Harvard Medical School, Boston, Massachusetts
| | | | - Erica Shenoy
- Infection Control Unit, Massachusetts General Hospital, Boston, Massachusetts
| | - David C Hooper
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts
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7
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Desjardins CA, Cohen KA, Munsamy V, Abeel T, Maharaj K, Walker BJ, Shea TP, Almeida DV, Manson AL, Salazar A, Padayatchi N, O'Donnell MR, Mlisana KP, Wortman J, Birren BW, Grosset J, Earl AM, Pym AS. Genomic and functional analyses of Mycobacterium tuberculosis strains implicate ald in D-cycloserine resistance. Nat Genet 2016; 48:544-51. [PMID: 27064254 PMCID: PMC4848111 DOI: 10.1038/ng.3548] [Citation(s) in RCA: 121] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2015] [Accepted: 03/18/2016] [Indexed: 12/19/2022]
Abstract
A more complete understanding of the genetic basis of drug resistance in Mycobacterium tuberculosis is critical for prompt diagnosis and optimal treatment, particularly for toxic second-line drugs such as D-cycloserine. Here we used the whole-genome sequences from 498 strains of M. tuberculosis to identify new resistance-conferring genotypes. By combining association and correlated evolution tests with strategies for amplifying signal from rare variants, we found that loss-of-function mutations in ald (Rv2780), encoding L-alanine dehydrogenase, were associated with unexplained drug resistance. Convergent evolution of this loss of function was observed exclusively among multidrug-resistant strains. Drug susceptibility testing established that ald loss of function conferred resistance to D-cycloserine, and susceptibility to the drug was partially restored by complementation of ald. Clinical strains with mutations in ald and alr exhibited increased resistance to D-cycloserine when cultured in vitro. Incorporation of D-cycloserine resistance in novel molecular diagnostics could allow for targeted use of this toxic drug among patients with susceptible infections.
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Affiliation(s)
| | - Keira A Cohen
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Division of Pulmonary and Critical Care Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
- KwaZulu-Natal Research Institute for TB and HIV (K-RITH), Durban, South Africa
| | - Vanisha Munsamy
- KwaZulu-Natal Research Institute for TB and HIV (K-RITH), Durban, South Africa
| | - Thomas Abeel
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Delft Bioinformatics Laboratory, Delft University of Technology, Delft, the Netherlands
| | - Kashmeel Maharaj
- KwaZulu-Natal Research Institute for TB and HIV (K-RITH), Durban, South Africa
| | - Bruce J Walker
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Terrance P Shea
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Deepak V Almeida
- KwaZulu-Natal Research Institute for TB and HIV (K-RITH), Durban, South Africa
- Center for Tuberculosis Research, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Abigail L Manson
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Alex Salazar
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
- Delft Bioinformatics Laboratory, Delft University of Technology, Delft, the Netherlands
| | - Nesri Padayatchi
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), Durban, South Africa
| | - Max R O'Donnell
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), Durban, South Africa
- Division of Pulmonary, Allergy, and Critical Care Medicine, Columbia University College of Physicians and Surgeons, New York, New York, USA
- Department of Epidemiology, Columbia Mailman School of Public Health, New York, New York, USA
| | - Koleka P Mlisana
- School of Laboratory Medicine and Medical Sciences, University of KwaZulu-Natal, Durban, South Africa
- National Health Laboratory Service, Durban, South Africa
| | - Jennifer Wortman
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Bruce W Birren
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Jacques Grosset
- KwaZulu-Natal Research Institute for TB and HIV (K-RITH), Durban, South Africa
- Center for Tuberculosis Research, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Ashlee M Earl
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Alexander S Pym
- KwaZulu-Natal Research Institute for TB and HIV (K-RITH), Durban, South Africa
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Cohen KA, Abeel T, Manson McGuire A, Desjardins CA, Munsamy V, Shea TP, Walker BJ, Bantubani N, Almeida DV, Alvarado L, Chapman SB, Mvelase NR, Duffy EY, Fitzgerald MG, Govender P, Gujja S, Hamilton S, Howarth C, Larimer JD, Maharaj K, Pearson MD, Priest ME, Zeng Q, Padayatchi N, Grosset J, Young SK, Wortman J, Mlisana KP, O'Donnell MR, Birren BW, Bishai WR, Pym AS, Earl AM. Evolution of Extensively Drug-Resistant Tuberculosis over Four Decades: Whole Genome Sequencing and Dating Analysis of Mycobacterium tuberculosis Isolates from KwaZulu-Natal. PLoS Med 2015; 12:e1001880. [PMID: 26418737 PMCID: PMC4587932 DOI: 10.1371/journal.pmed.1001880] [Citation(s) in RCA: 186] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 08/20/2015] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND The continued advance of antibiotic resistance threatens the treatment and control of many infectious diseases. This is exemplified by the largest global outbreak of extensively drug-resistant (XDR) tuberculosis (TB) identified in Tugela Ferry, KwaZulu-Natal, South Africa, in 2005 that continues today. It is unclear whether the emergence of XDR-TB in KwaZulu-Natal was due to recent inadequacies in TB control in conjunction with HIV or other factors. Understanding the origins of drug resistance in this fatal outbreak of XDR will inform the control and prevention of drug-resistant TB in other settings. In this study, we used whole genome sequencing and dating analysis to determine if XDR-TB had emerged recently or had ancient antecedents. METHODS AND FINDINGS We performed whole genome sequencing and drug susceptibility testing on 337 clinical isolates of Mycobacterium tuberculosis collected in KwaZulu-Natal from 2008 to 2013, in addition to three historical isolates, collected from patients in the same province and including an isolate from the 2005 Tugela Ferry XDR outbreak, a multidrug-resistant (MDR) isolate from 1994, and a pansusceptible isolate from 1995. We utilized an array of whole genome comparative techniques to assess the relatedness among strains, to establish the order of acquisition of drug resistance mutations, including the timing of acquisitions leading to XDR-TB in the LAM4 spoligotype, and to calculate the number of independent evolutionary emergences of MDR and XDR. Our sequencing and analysis revealed a 50-member clone of XDR M. tuberculosis that was highly related to the Tugela Ferry XDR outbreak strain. We estimated that mutations conferring isoniazid and streptomycin resistance in this clone were acquired 50 y prior to the Tugela Ferry outbreak (katG S315T [isoniazid]; gidB 130 bp deletion [streptomycin]; 1957 [95% highest posterior density (HPD): 1937-1971]), with the subsequent emergence of MDR and XDR occurring 20 y (rpoB L452P [rifampicin]; pncA 1 bp insertion [pyrazinamide]; 1984 [95% HPD: 1974-1992]) and 10 y (rpoB D435G [rifampicin]; rrs 1400 [kanamycin]; gyrA A90V [ofloxacin]; 1995 [95% HPD: 1988-1999]) prior to the outbreak, respectively. We observed frequent de novo evolution of MDR and XDR, with 56 and nine independent evolutionary events, respectively. Isoniazid resistance evolved before rifampicin resistance 46 times, whereas rifampicin resistance evolved prior to isoniazid only twice. We identified additional putative compensatory mutations to rifampicin in this dataset. One major limitation of this study is that the conclusions with respect to ordering and timing of acquisition of mutations may not represent universal patterns of drug resistance emergence in other areas of the globe. CONCLUSIONS In the first whole genome-based analysis of the emergence of drug resistance among clinical isolates of M. tuberculosis, we show that the ancestral precursor of the LAM4 XDR outbreak strain in Tugela Ferry gained mutations to first-line drugs at the beginning of the antibiotic era. Subsequent accumulation of stepwise resistance mutations, occurring over decades and prior to the explosion of HIV in this region, yielded MDR and XDR, permitting the emergence of compensatory mutations. Our results suggest that drug-resistant strains circulating today reflect not only vulnerabilities of current TB control efforts but also those that date back 50 y. In drug-resistant TB, isoniazid resistance was overwhelmingly the initial resistance mutation to be acquired, which would not be detected by current rapid molecular diagnostics employed in South Africa that assess only rifampicin resistance.
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Affiliation(s)
- Keira A. Cohen
- Division of Pulmonary and Critical Care Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- KwaZulu-Natal Research Institute for TB and HIV (K-RITH), Durban, South Africa
| | - Thomas Abeel
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
- Delft Bioinformatics Lab, Delft University of Technology, Delft, The Netherlands
| | | | | | - Vanisha Munsamy
- KwaZulu-Natal Research Institute for TB and HIV (K-RITH), Durban, South Africa
| | - Terrance P. Shea
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Bruce J. Walker
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | | | - Deepak V. Almeida
- KwaZulu-Natal Research Institute for TB and HIV (K-RITH), Durban, South Africa
- Center for Tuberculosis Research, Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
| | - Lucia Alvarado
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Sinéad B. Chapman
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Nomonde R. Mvelase
- School of Laboratory Medicine and Medical Sciences, University of KwaZulu-Natal, Durban, South Africa
- National Health Laboratory Service, Durban, South Africa
| | - Eamon Y. Duffy
- KwaZulu-Natal Research Institute for TB and HIV (K-RITH), Durban, South Africa
| | - Michael G. Fitzgerald
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Pamla Govender
- KwaZulu-Natal Research Institute for TB and HIV (K-RITH), Durban, South Africa
| | - Sharvari Gujja
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Susanna Hamilton
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Clinton Howarth
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Jeffrey D. Larimer
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Kashmeel Maharaj
- KwaZulu-Natal Research Institute for TB and HIV (K-RITH), Durban, South Africa
| | - Matthew D. Pearson
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Margaret E. Priest
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Qiandong Zeng
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Nesri Padayatchi
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), Durban, South Africa
| | - Jacques Grosset
- KwaZulu-Natal Research Institute for TB and HIV (K-RITH), Durban, South Africa
- Center for Tuberculosis Research, Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
| | - Sarah K. Young
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Jennifer Wortman
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Koleka P. Mlisana
- School of Laboratory Medicine and Medical Sciences, University of KwaZulu-Natal, Durban, South Africa
- National Health Laboratory Service, Durban, South Africa
| | - Max R. O'Donnell
- Centre for the AIDS Programme of Research in South Africa (CAPRISA), Durban, South Africa
- Division of Pulmonary, Allergy, and Critical Care Medicine, Columbia University College of Physicians and Surgeons, New York, United States of America
- Department of Epidemiology, Columbia Mailman School of Public Health, New York, United States of America
| | - Bruce W. Birren
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - William R. Bishai
- Center for Tuberculosis Research, Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
| | - Alexander S. Pym
- KwaZulu-Natal Research Institute for TB and HIV (K-RITH), Durban, South Africa
- * E-mail: (ASP); (AME)
| | - Ashlee M. Earl
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
- * E-mail: (ASP); (AME)
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Cohen KA, Abeel T, McGuire AM, Desjardins CA, Munsamy V, Shea TP, Walker BJ, Bantubani N, Almeida DV, Alvarado L, Chapman S, Mvelase NR, Duffy EY, Fitzgerald MG, Govender P, Gujja S, Hamilton S, Howarth C, Larimer JD, Maharaj K, Pearson MD, Priest ME, Zeng Q, Padayatchi N, Grosset J, Young SK, Wortman J, Mlisana KP, O’Donnell MR, Birren BW, Bishai WR, Pym AS, Earl AM. Evolution of extensively drug-resistant tuberculosis over four decades revealed by whole genome sequencing of Mycobacterium tuberculosis from KwaZulu-Natal, South Africa. Int J Mycobacteriol 2015. [DOI: 10.1016/j.ijmyco.2014.11.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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10
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Walker BJ, Abeel T, Shea T, Priest M, Abouelliel A, Sakthikumar S, Cuomo CA, Zeng Q, Wortman J, Young SK, Earl AM. Pilon: an integrated tool for comprehensive microbial variant detection and genome assembly improvement. PLoS One 2014; 9:e112963. [PMID: 25409509 PMCID: PMC4237348 DOI: 10.1371/journal.pone.0112963] [Citation(s) in RCA: 5091] [Impact Index Per Article: 509.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Accepted: 10/16/2014] [Indexed: 02/06/2023] Open
Abstract
Advances in modern sequencing technologies allow us to generate sufficient data to analyze hundreds of bacterial genomes from a single machine in a single day. This potential for sequencing massive numbers of genomes calls for fully automated methods to produce high-quality assemblies and variant calls. We introduce Pilon, a fully automated, all-in-one tool for correcting draft assemblies and calling sequence variants of multiple sizes, including very large insertions and deletions. Pilon works with many types of sequence data, but is particularly strong when supplied with paired end data from two Illumina libraries with small e.g., 180 bp and large e.g., 3–5 Kb inserts. Pilon significantly improves draft genome assemblies by correcting bases, fixing mis-assemblies and filling gaps. For both haploid and diploid genomes, Pilon produces more contiguous genomes with fewer errors, enabling identification of more biologically relevant genes. Furthermore, Pilon identifies small variants with high accuracy as compared to state-of-the-art tools and is unique in its ability to accurately identify large sequence variants including duplications and resolve large insertions. Pilon is being used to improve the assemblies of thousands of new genomes and to identify variants from thousands of clinically relevant bacterial strains. Pilon is freely available as open source software.
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Affiliation(s)
- Bruce J. Walker
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
- * E-mail: (BJW); (AME)
| | - Thomas Abeel
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
- VIB Department of Plant Systems Biology, Ghent University, Ghent, Belgium
| | - Terrance Shea
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Margaret Priest
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Amr Abouelliel
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Sharadha Sakthikumar
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Christina A. Cuomo
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Qiandong Zeng
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Jennifer Wortman
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Sarah K. Young
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Ashlee M. Earl
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
- * E-mail: (BJW); (AME)
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Bhatt AS, Freeman SS, Herrera AF, Pedamallu CS, Gevers D, Duke F, Jung J, Michaud M, Walker BJ, Young S, Earl AM, Kostic AD, Ojesina AI, Hasserjian R, Ballen KK, Chen YB, Hobbs G, Antin JH, Soiffer RJ, Baden LR, Garrett WS, Hornick JL, Marty FM, Meyerson M. Sequence-based discovery of Bradyrhizobium enterica in cord colitis syndrome. N Engl J Med 2013; 369:517-28. [PMID: 23924002 PMCID: PMC3889161 DOI: 10.1056/nejmoa1211115] [Citation(s) in RCA: 134] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND Immunosuppression is associated with a variety of idiopathic clinical syndromes that may have infectious causes. It has been hypothesized that the cord colitis syndrome, a complication of umbilical-cord hematopoietic stem-cell transplantation, is infectious in origin. METHODS We performed shotgun DNA sequencing on four archived, paraffin-embedded endoscopic colon-biopsy specimens obtained from two patients with cord colitis. Computational subtraction of human and known microbial sequences and assembly of residual sequences into a bacterial draft genome were performed. We used polymerase-chain-reaction (PCR) assays and fluorescence in situ hybridization to determine whether the corresponding bacterium was present in additional patients and controls. RESULTS DNA sequencing of the biopsy specimens revealed more than 2.5 million sequencing reads that did not match known organisms. These sequences were computationally assembled into a 7.65-Mb draft genome showing a high degree of homology with genomes of bacteria in the bradyrhizobium genus. The corresponding newly discovered bacterium was provisionally named Bradyrhizobium enterica. PCR identified B. enterica nucleotide sequences in biopsy specimens from all three additional patients with cord colitis whose samples were tested, whereas B. enterica sequences were absent in samples obtained from healthy controls and patients with colon cancer or graft-versus-host disease. CONCLUSIONS We assembled a novel bacterial draft genome from the direct sequencing of tissue specimens from patients with cord colitis. Association of these sequences with cord colitis suggests that B. enterica may be an opportunistic human pathogen. (Funded by the National Cancer Institute and others.)
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Affiliation(s)
- Ami S Bhatt
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
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12
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Ribeiro FJ, Przybylski D, Yin S, Sharpe T, Gnerre S, Abouelleil A, Berlin AM, Montmayeur A, Shea TP, Walker BJ, Young SK, Russ C, Nusbaum C, MacCallum I, Jaffe DB. Finished bacterial genomes from shotgun sequence data. Genome Res 2012; 22:2270-7. [PMID: 22829535 PMCID: PMC3483556 DOI: 10.1101/gr.141515.112] [Citation(s) in RCA: 160] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Exceptionally accurate genome reference sequences have proven to be of great value to microbial researchers. Thus, to date, about 1800 bacterial genome assemblies have been “finished” at great expense with the aid of manual laboratory and computational processes that typically iterate over a period of months or even years. By applying a new laboratory design and new assembly algorithm to 16 samples, we demonstrate that assemblies exceeding finished quality can be obtained from whole-genome shotgun data and automated computation. Cost and time requirements are thus dramatically reduced.
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13
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Walker B, Wharry S, Hamilton RJ, Martin SL, Healy A, Walker BJ. Asymmetric preference of serine proteases toward phosphonate and phosphinate esters. Biochem Biophys Res Commun 2000; 276:1235-9. [PMID: 11027616 DOI: 10.1006/bbrc.2000.3597] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have previously reported the asymmetric synthesis of (alpha-aminoalkyl) diphenylphosphonate and phosphinate derivatives designed as inhibitors of chymotrypsin- and elastase-like proteases. This paper reports the first kinetic evaluation of individual epimers of the (alpha-aminoalkyl) diphenylphosphonates as inactivators of chymotrypsin, cathepsin G and neutrophil elastase (HNE). Results show that the (R)-epimers consistently function as more potent irreversible inactivators of their respective target proteases than the corresponding (S)-epimers. Additionally, phosphinate analogues were found to be consistently superior to their diphenylphosphonate counterparts. For example, Cbz. Phe(P)(OPh)-(CH(2))(2)-CO(2)Et inactivates cathepsin G approximately 45-fold more rapidly (k(i)/K(i) = 1.2 x 10(5) M(-1). min(-1)) than the analogous Cbz.Phe(P)(OPh)(2) (2.6 x 10(3) M(-1). min(-1)). Similarly, Cbz.Val(P)(OPh)-(CH(2))(2)-CO(2)Et was found to inactivate HNE some 3-fold more efficiently than Cbz.Val(P)(OPh)(2) (6.5 x 10(3) and 2.0 x 10(3) M(-1). min(-1), respectively).
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Affiliation(s)
- B Walker
- Division of Biomedicinal Chemistry, School of Pharmacy, Medical Biology Centre, 97 Lisburn Road, Belfast, Northern Ireland, BT9 7BL, United Kingdom
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Hamilton R, Walker B, Walker BJ. Synthesis and proteinase inhibitory properties of diphenyl phosphonate analogues of aspartic and glutamic acids. Bioorg Med Chem Lett 1998; 8:1655-60. [PMID: 9873408 DOI: 10.1016/s0960-894x(98)00272-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The synthesis of diphenyl phosphonate analogues of aspartic and glutamic acid, and their inhibitory activity against S. aureus V8 protease and granzyme B, is described. The study has revealed difficulties with protecting group compatibility in the synthesis of these analogues. Two analogues, Acetyl. AspP (OPh)2 and Acetyl.GluP (OPh)2 were found to function as irreversible inactivators of V8 proteinase, yet exhibit no activity against granzyme B.
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Affiliation(s)
- R Hamilton
- School of Chemistry, Queen's University of Belfast, Northern Ireland
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Abstract
Administration of terfenadine (Seldane) immediately after a high fat breakfast slightly affects the rate but not the extent of absorption relative to fasting administration. Mean peak levels of the active metabolite were increased by 13 per cent but delayed by 0.9 h while AUC was virtually the same as when terfenadine was administered while fasting. Changes in rate of absorption may be due to delayed gastric emptying and more rapid terfenadine solubilization. In any case, these rate differences are unlikely to be clinically important in the absence of differences in extent of absorption.
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Affiliation(s)
- M G Eller
- Marion Merrell Dow Inc., Cincinnati, OH 45215
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16
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Abstract
The pharmacokinetics of the terfenadine active metabolite, metabolite I, was examined in ten healthy elderly adults and ten younger adults after single-dose oral administration of 120-mg terfenadine. All subjects successfully completed the study without reporting sedation or other adverse events. Absorption was rapid in both the young and elderly. The mean Cmax was the same for both groups, 501 ng/mL, and occurred at 2.3 hours in the young subjects and 2.5 hours in elderly subjects. However, the apparent clearance was reduced by about 25% in the elderly. After correcting clearance for bodyweight, this difference was not statistically significant.
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Affiliation(s)
- M G Eller
- Drug Metabolism Department, Marion Merrell Dow Inc., Cincinnati, OH 45215-6300
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Newby LM, White L, DiBartolomeis SM, Walker BJ, Dowse HB, Ringo JM, Khuda N, Jackson FR. Mutational analysis of the Drosophila miniature-dusky (m-dy) locus: effects on cell size and circadian rhythms. Genetics 1991; 128:571-82. [PMID: 1908397 PMCID: PMC1204531 DOI: 10.1093/genetics/128.3.571] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
A mutational analysis has been performed to explore the function of the Drosophila melanogaster miniature-dusky (m-dy) locus. Mutations at this locus affect wing development, fertility and behavior. The genetic characterization of 13 different mutations suggests that m and dy variants are alleles of a single complex gene. All of these mutations alter wing size, apparently by reducing the volume of individual epidermal cells of the developing wing. In m mutants, epidermal cell boundaries persist in the mature wing, whereas they normally degenerate 1-2 hr after eclosion in wild-type or dy flies. This has permitted the direct visualization of cell size differences among several m mutants. Mutations at the m-dy locus also affect behavioral processes. Three out of nine dy alleles (dyn1, dyn3 and dyn4) lengthen the circadian period of the activity and eclosion rhythms by approximately 1.5 hr. In contrast, m mutants have normal circadian periods, but an abnormally large percentage of individuals express aperiodic bouts of activity. These behavior genetic studies also indicate that an existing "rhythm" mutation known as Andante is an allele of the m-dy locus. The differential effects of certain m-dy mutations on wing and behavioral phenotypes suggest that separable domains of function exist within this locus.
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Affiliation(s)
- L M Newby
- Neurobiology Group, Worcester Foundation for Experimental Biology, Shrewsbury, Massachusetts 01545
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Walker BJ, Lang JF, Okerholm RA. Quantitative analysis of dicyclomine in human plasma by capillary gas chromatography and nitrogen-selective detection. J Chromatogr 1987; 416:150-3. [PMID: 3597632 DOI: 10.1016/0378-4347(87)80496-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Abstract
Intravenous infusion of somatostatin in six water loaded normal human subjects produced a prompt reduction in urine flow accompanied by a rise in urine osmolality and a decrease in free water clearance. Plasma AVP levels did not change. Somatostatin would seem to exert an antidiuretic effect directly on the kidney.
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Abstract
The possibility of using electroimmunoassay as a technique for assessing microalbuminuria in the diabetic population has been studied. The method was found to be precise (given inter-batch coefficients of variation of 5.7% and 5.8% at levels of 16 mg/l and 23 mg/l respectively), showed adequate sensitivity, and produced results which correlated well (r = 0.971) with these obtained from a routine radioimmunoassay procedure. It is concluded that electroimmunoassay provides a reliable alternative to more sophisticated techniques in the non-specialized laboratory dealing with only moderate numbers of specimens.
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Okerholm RA, Weiner DL, Hook RH, Walker BJ, Leeson GA, Biedenbach SA, Cawein MJ, Dusebout TD, Wright GJ, Myers M, Schindler V, Cook CE. Bioavailability of terfenadine in man. Biopharm Drug Dispos 1981; 2:185-90. [PMID: 6113858 DOI: 10.1002/bdd.2510020211] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Fourteen normal male subjects were given either 60mg or 180mg of terfenadine suspension in a randomized two-way crossover study. Peak plasma concentrations of 1.544 +/- 0.726 (mean +/- S.D.) ng ml-1 were obtained in 0.786 h following the 60 mg dose and displayed an AUC or 11.864 +/- 3.369 ng h ml-1. Whereas peak plasma concentrations of 4.519 +/- 2.002 ng ml-1 in 1.071 +/- 0.514 h were obtained following the 180 mg dose. The AUC following the 180 mg dose was 44.341 +/- 22.041 ng h ml-1. When 60 mg of 14C terfenadine was given to six additional subjects, the peak plasma concentrations of 351 +/- 43 ng equivalents per ml were obtained in 1.67 +/- 0.41 h and the AUC was 2297.71 +/- 310.85 ng-equivalents h ml-1. This indicates that approximately 99.5 per cent of the terfenadine related material that is absorbed undergoes biotransformation. Urinary excretion of 14C accounted for 39.89 +/- 5.29 per cent of the dose while 60.58 +/- 2.44 per cent of the dose was recovered in the feces in twelve days. Thin-layer chromatographic (TLC) examination of fecal extracts showed only a trace of material chromatographing with terfenadine. This may indicate that the 14C present in the feces is not due to lack of absorption.
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Walker BJ. Nursing care to assess and prevent common cardiovascular problems. Nurs Clin North Am 1975; 10:43-8. [PMID: 1038629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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