Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
1.
BMJ Open ; 14(3): e080023, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38531581

RESUMO

OBJECTIVE: To identify and describe evidence on brief emergency department (ED)-delivered behavioural and care process interventions among patients presenting with suicide attempt or acute ideation, substance overdose or psychosis. DESIGN: We employed a scoping review design and searched multiple data sources, clinical trial registries and references lists through March 2023. We included English-language trials and rigorously designed observational studies. In alignment with scoping review guidelines, we did not assess the quality of included studies or rate the strength of evidence of intervention effectiveness. POPULATION: Our population of interest was adults presenting to the ED with suicidality (eg, attempt or acute ideation), any substance overdose or acute psychosis from a primary mental health condition. INTERVENTION: We included studies of brief behavioural or care process interventions delivered in the ED. OUTCOME MEASURES: Health outcomes (eg, symptom reduction), healthcare utilisation and harms. RESULTS: Our search identified 2034 potentially relevant articles. We included 40 studies: 3 systematic reviews and 39 primary studies. Most studies (n=34) examined ED interventions in patients with suicide attempt or suicidal ideation, while eight studies examined interventions in patients with opioid overdose. No studies examined ED interventions in patients with acute psychosis. Most suicide prevention studies reported that brief psychological, psychosocial or screening and triage interventions reduce suicide and suicide attempt following an ED visit. Most clinical trial interventions were multicomponent and included at least one follow-up. All substance overdose studies focused on opioids. These studies often contained medication and referral or consultation components. Multiple studies reported increases in substance use disorder treatment utilisation; evidence on repeat overdose events was limited. CONCLUSIONS: A wide range of multicomponent ED-delivered behavioural health interventions for suicidality and opioid use disorder show short-term improvement on primary outcomes such as suicide reattempt. Few studies on non-opioid substances and psychosis are available.


Assuntos
Overdose de Drogas , Transtornos Psicóticos , Adulto , Humanos , Saúde Mental , Transtornos Psicóticos/terapia , Tentativa de Suicídio/psicologia , Prevenção do Suicídio , Ideação Suicida , Serviço Hospitalar de Emergência
2.
J Community Psychol ; 51(7): 2592-2617, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37088990

RESUMO

The purpose of this scoping review is to map the extent of the current research on how to best structure questions asking respondents to self-identify their sexual orientation and gender identity and to ascertain what further issues about measurement need to be explored. Using the Arksey and O'Malley framework for scoping reviews, 52 articles describing primary research about how to structure sexual orientation and gender identity (SOGI) questions, published in the years 2000-2021, were identified and analyzed. The domain of sexuality being asked about (e.g., self-label vs. behavior) needs to be clarified, and gender identity should be asked through a multipart item differentiating current identity from the sex assigned at birth. The terms used in the response options should be defined and may vary based on the study population or context. Contrary to expectations given the wide range of question formats currently being used in the field, there is considerable consensus around the basic tenets for structuring questions designed to assess SOGI dimensions.


Assuntos
Identidade de Gênero , Minorias Sexuais e de Gênero , Recém-Nascido , Humanos , Feminino , Masculino , Comportamento Sexual
3.
Genome Med ; 14(1): 37, 2022 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-35379360

RESUMO

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.


Assuntos
Carbapenêmicos , Transferência Genética Horizontal , Antibacterianos/farmacologia , Carbapenêmicos/farmacologia , Humanos , Plasmídeos/genética , Estudos Prospectivos
4.
Gen Hosp Psychiatry ; 66: 89-95, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32750604

RESUMO

The COVID-19 pandemic has dramatically transformed the U.S. healthcare landscape. Within psychiatry, a sudden relaxing of insurance and regulatory barriers during the month of March 2020 enabled clinicians practicing in a wide range of settings to quickly adopt virtual care in order to provide critical ongoing mental health supports to both existing and new patients struggling with the pandemic's impact. In this article, we briefly review the extensive literature supporting the effectiveness of telepsychiatry relative to in-person mental health care, and describe how payment and regulatory challenges were the primary barriers preventing more widespread adoption of this treatment modality prior to COVID-19. We then review key changes that were implemented at the federal, state, professional, and insurance levels over a one-month period that helped usher in an unprecedented transformation in psychiatric care delivery, from mostly in-person to mostly virtual. Early quality improvement data regarding virtual visit volumes and clinical insights from our outpatient psychiatry department located within a large, urban, tertiary care academic medical center reflect both the opportunities and challenges of virtual care for patients and providers. Notable benefits have included robust clinical volumes despite social distancing mandates, reduced logistical barrieres to care for many patients, and decreased no-show rates. Finally, we provide clinical suggestions for optimizing telepsychiatry based on our experience, make a call for advocacy to continue the reduced insurance and regulatory restrictions affecting telepsychiatry even once this public health crisis has passed, and pose research questions that can help guide optimal utilization of telepsychiatry as mainstay or adjunct of outpatient psychiatric treatment now and in the future.


Assuntos
Assistência Ambulatorial/organização & administração , Infecções por Coronavirus , Transtornos Mentais , Serviços de Saúde Mental/organização & administração , Pandemias , Pneumonia Viral , Psiquiatria/organização & administração , Telemedicina/organização & administração , COVID-19 , Humanos , Transtornos Mentais/diagnóstico , Transtornos Mentais/terapia
5.
Nat Microbiol ; 4(6): 964-971, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30911128

RESUMO

The human microbiome, described as an accessory organ because of the crucial functions it provides, is composed of species that are uniquely found in humans1,2. Yet, surprisingly little is known about the impact of routine interpersonal contacts in shaping microbiome composition. In a relatively 'closed' cohort of 287 people from the Fiji Islands, where common barriers to bacterial transmission are absent, we examine putative bacterial transmission in individuals' gut and oral microbiomes using strain-level data from both core single-nucleotide polymorphisms and flexible genomic regions. We find a weak signal of transmission, defined by the inferred sharing of genotypes, across many organisms that, in aggregate, reveals strong transmission patterns, most notably within households and between spouses. We were unable to determine the directionality of transmission nor whether it was direct. We further find that women harbour strains more closely related to those harboured by their familial and social contacts than men, and that transmission patterns of oral-associated and gut-associated microbiota need not be the same. Using strain-level data alone, we are able to confidently predict a subset of spouses, highlighting the role of shared susceptibilities, behaviours or social interactions that distinguish specific links in the social network.


Assuntos
Família , Microbiota , Rede Social , Bactérias/genética , Feminino , Fiji , Microbioma Gastrointestinal/genética , Genômica , Genótipo , Especificidade de Hospedeiro , Humanos , Sequências Repetitivas Dispersas , Masculino , Microbiota/genética , Polimorfismo de Nucleotídeo Único
6.
Elife ; 52016 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-27892853

RESUMO

The germline genome of the binucleated ciliate Tetrahymena thermophila undergoes programmed chromosome breakage and massive DNA elimination to generate the somatic genome. Here, we present a complete sequence assembly of the germline genome and analyze multiple features of its structure and its relationship to the somatic genome, shedding light on the mechanisms of genome rearrangement as well as the evolutionary history of this remarkable germline/soma differentiation. Our results strengthen the notion that a complex, dynamic, and ongoing interplay between mobile DNA elements and the host genome have shaped Tetrahymena chromosome structure, locally and globally. Non-standard outcomes of rearrangement events, including the generation of short-lived somatic chromosomes and excision of DNA interrupting protein-coding regions, may represent novel forms of developmental gene regulation. We also compare Tetrahymena's germline/soma differentiation to that of other characterized ciliates, illustrating the wide diversity of adaptations that have occurred within this phylum.


Assuntos
Rearranjo Gênico , Genoma de Protozoário , Tetrahymena thermophila/genética , Análise de Sequência de DNA
8.
BMC Genomics ; 17: 550, 2016 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-27495311

RESUMO

BACKGROUND: Pichia pastoris has emerged as an important alternative host for producing recombinant biopharmaceuticals, owing to its high cultivation density, low host cell protein burden, and the development of strains with humanized glycosylation. Despite its demonstrated utility, relatively little strain engineering has been performed to improve Pichia, due in part to the limited number and inconsistent frameworks of reported genomes and transcriptomes. Furthermore, the co-mingling of genomic, transcriptomic and fermentation data collected about Komagataella pastoris and Komagataella phaffii, the two strains co-branded as Pichia, has generated confusion about host performance for these genetically distinct species. Generation of comparative high-quality genomes and transcriptomes will enable meaningful comparisons between the organisms, and potentially inform distinct biotechnological utilies for each species. RESULTS: Here, we present a comprehensive and standardized comparative analysis of the genomic features of the three most commonly used strains comprising the tradename Pichia: K. pastoris wild-type, K. phaffii wild-type, and K. phaffii GS115. We used a combination of long-read (PacBio) and short-read (Illumina) sequencing technologies to achieve over 1000X coverage of each genome. Construction of individual genomes was then performed using as few as seven individual contigs to create gap-free assemblies. We found substantial syntenic rearrangements between the species and characterized a linear plasmid present in K. phaffii. Comparative analyses between K. phaffii genomes enabled the characterization of the mutational landscape of the GS115 strain. We identified and examined 35 non-synonomous coding mutations present in GS115, many of which are likely to impact strain performance. Additionally, we investigated transcriptomic profiles of gene expression for both species during cultivation on various carbon sources. We observed that the most highly transcribed genes in both organisms were consistently highly expressed in all three carbon sources examined. We also observed selective expression of certain genes in each carbon source, including many sequences not previously reported as promoters for expression of heterologous proteins in yeasts. CONCLUSIONS: Our studies establish a foundation for understanding critical relationships between genome structure, cultivation conditions and gene expression. The resources we report here will inform and facilitate rational, organism-wide strain engineering for improved utility as a host for protein production.


Assuntos
Perfilação da Expressão Gênica , Genômica , Pichia/genética , Processamento Alternativo , DNA Fúngico/genética , Anotação de Sequência Molecular , Mutação , Pichia/crescimento & desenvolvimento , Pichia/metabolismo , Especificidade da Espécie
9.
PLoS Med ; 12(9): e1001880, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26418737

RESUMO

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.


Assuntos
Antituberculosos/farmacologia , Tuberculose Extensivamente Resistente a Medicamentos/genética , Genoma Bacteriano , Mycobacterium tuberculosis/genética , Adulto , Surtos de Doenças , Tuberculose Extensivamente Resistente a Medicamentos/tratamento farmacológico , Tuberculose Extensivamente Resistente a Medicamentos/epidemiologia , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Mutação , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/isolamento & purificação , Análise de Sequência de DNA , África do Sul/epidemiologia
10.
PLoS One ; 9(11): e112963, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25409509

RESUMO

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.


Assuntos
Bactérias/genética , Variação Genética , Análise de Sequência de DNA/métodos , Software , Algoritmos , Bactérias/classificação , Genoma Bacteriano , Dados de Sequência Molecular
11.
Genome Announc ; 2(5)2014 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-25212613

RESUMO

Draft genome sequences of seven enterohepatic Helicobacter species, H. bilis, H. canadensis, H. canis, H. cinaedi, H. winghamensis, H. pullorum, and H. macacae, are presented. These isolates were obtained from clinical patients and a nonhuman primate. Due to potential zoonotic risks, we characterized antibiotic resistance markers and Helicobacter virulence factors.

12.
PLoS One ; 8(6): e67511, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23825666

RESUMO

Listeria monocytogenes, a foodborne bacterial pathogen, is comprised of four phylogenetic lineages that vary with regard to their serotypes and distribution among sources. In order to characterize lineage-specific genomic diversity within L. monocytogenes, we sequenced the genomes of eight strains from several lineages and serotypes, and characterized the accessory genome, which was hypothesized to contribute to phenotypic differences across lineages. The eight L. monocytogenes genomes sequenced range in size from 2.85-3.14 Mb, encode 2,822-3,187 genes, and include the first publicly available sequenced representatives of serotypes 1/2c, 3a and 4c. Mapping of the distribution of accessory genes revealed two distinct regions of the L. monocytogenes chromosome: an accessory-rich region in the first 65° adjacent to the origin of replication and a more stable region in the remaining 295°. This pattern of genome organization is distinct from that of related bacteria Staphylococcus aureus and Bacillus cereus. The accessory genome of all lineages is enriched for cell surface-related genes and phosphotransferase systems, and transcriptional regulators, highlighting the selective pressures faced by contemporary strains from their hosts, other microbes, and their environment. Phylogenetic analysis of O-antigen genes and gene clusters predicts that serotype 4 was ancestral in L. monocytogenes and serotype 1/2 associated gene clusters were putatively introduced through horizontal gene transfer in the ancestral population of L. monocytogenes lineage I and II.


Assuntos
Evolução Molecular , Genoma Bacteriano/genética , Listeria monocytogenes/genética , Sequência Conservada , Transferência Genética Horizontal , Genômica , Listeria monocytogenes/fisiologia , Listeria monocytogenes/virologia , Antígenos O/genética , Fosfotransferases/genética , Filogenia , Prófagos/fisiologia
13.
PLoS Genet ; 9(6): e1003272, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23785293

RESUMO

Oomycetes in the class Saprolegniomycetidae of the Eukaryotic kingdom Stramenopila have evolved as severe pathogens of amphibians, crustaceans, fish and insects, resulting in major losses in aquaculture and damage to aquatic ecosystems. We have sequenced the 63 Mb genome of the fresh water fish pathogen, Saprolegnia parasitica. Approximately 1/3 of the assembled genome exhibits loss of heterozygosity, indicating an efficient mechanism for revealing new variation. Comparison of S. parasitica with plant pathogenic oomycetes suggests that during evolution the host cellular environment has driven distinct patterns of gene expansion and loss in the genomes of plant and animal pathogens. S. parasitica possesses one of the largest repertoires of proteases (270) among eukaryotes that are deployed in waves at different points during infection as determined from RNA-Seq data. In contrast, despite being capable of living saprotrophically, parasitism has led to loss of inorganic nitrogen and sulfur assimilation pathways, strikingly similar to losses in obligate plant pathogenic oomycetes and fungi. The large gene families that are hallmarks of plant pathogenic oomycetes such as Phytophthora appear to be lacking in S. parasitica, including those encoding RXLR effectors, Crinkler's, and Necrosis Inducing-Like Proteins (NLP). S. parasitica also has a very large kinome of 543 kinases, 10% of which is induced upon infection. Moreover, S. parasitica encodes several genes typical of animals or animal-pathogens and lacking from other oomycetes, including disintegrins and galactose-binding lectins, whose expression and evolutionary origins implicate horizontal gene transfer in the evolution of animal pathogenesis in S. parasitica.


Assuntos
Transferência Genética Horizontal , Interações Hospedeiro-Parasita/genética , Oomicetos/genética , Saprolegnia/genética , Virulência/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Evolução Molecular , Peixes/genética , Peixes/parasitologia , Genoma , Oomicetos/classificação , Oomicetos/patogenicidade , Filogenia , Plantas/parasitologia , Saprolegnia/classificação , Saprolegnia/patogenicidade
14.
Evolution ; 66(11): 3519-33, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23106715

RESUMO

Parallels have been drawn between the evolution of nonrecombining regions in fungal mating-type chromosomes and animal and plant sex chromosomes, particularly regarding the stages of recombination cessation forming evolutionary strata of allelic divergence. Currently, evidence and explanations for recombination cessation in fungi are sparse, and the presence of evolutionary strata has been examined in a minimal number of fungal taxa. Here, the basidiomycete genus Microbotryum was used to determine the history of recombination cessation for loci on the mating-type chromosomes. Ancestry of linkage with mating type for 13 loci was assessed across 20 species by a phylogenetic method. No locus was found to exhibit trans-specific polymorphism for alternate alleles as old as the mating pheromone receptor, indicating that ages of linkage to mating type varied among the loci. The ordering of loci in the ancestry of linkage to mating type does not agree with their previously proposed assignments to evolutionary strata. This study suggests that processes capable of influencing divergence between alternate alleles may act at loci in the nonrecombining regions (e.g., gene conversion) and encourages further work to dissect the evolutionary processes acting upon genomic regions that determine mating compatibility.


Assuntos
Basidiomycota/genética , Evolução Molecular , Proteínas Fúngicas/genética , Genes Fúngicos Tipo Acasalamento , Receptores de Feromônios/genética , Alelos , Basidiomycota/fisiologia , DNA Complementar/análise , DNA Fúngico/análise , Proteínas Fúngicas/metabolismo , Ligação Genética , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Polimorfismo Genético , Receptores de Feromônios/metabolismo , Recombinação Genética , Análise de Sequência de DNA , Especificidade da Espécie
15.
Genome Res ; 22(11): 2241-9, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22800726

RESUMO

Eliminating the bacterial cloning step has been a major factor in the vastly improved efficiency of massively parallel sequencing approaches. However, this also has made it a technical challenge to produce the modern equivalent of the Fosmid- or BAC-end sequences that were crucial for assembling and analyzing complex genomes during the Sanger-based sequencing era. To close this technology gap, we developed Fosill, a method for converting Fosmids to Illumina-compatible jumping libraries. We constructed Fosmid libraries in vectors with Illumina primer sequences and specific nicking sites flanking the cloning site. Our family of pFosill vectors allows multiplex Fosmid cloning of end-tagged genomic fragments without physical size selection and is compatible with standard and multiplex paired-end Illumina sequencing. To excise the bulk of each cloned insert, we introduced two nicks in the vector, translated them into the inserts, and cleaved them. Recircularization of the vector via coligation of insert termini followed by inverse PCR generates a jumping library for paired-end sequencing with 101-base reads. The yield of unique Fosmid-sized jumps is sufficiently high, and the background of short, incorrectly spaced and chimeric artifacts sufficiently low, to enable applications such as mapping of structural variation and scaffolding of de novo assemblies. We demonstrate the power of Fosill to map genome rearrangements in a cancer cell line and identified three fusion genes that were corroborated by RNA-seq data. Our Fosill-powered assembly of the mouse genome has an N50 scaffold length of 17.0 Mb, rivaling the connectivity (16.9 Mb) of the Sanger-sequencing based draft assembly.


Assuntos
Escherichia coli/genética , Vetores Genéticos/genética , Genoma Bacteriano , Genoma Fúngico , Biblioteca Genômica , Schizosaccharomyces/genética , Análise de Sequência de DNA/métodos , Animais , Rearranjo Gênico , Camundongos , Camundongos Endogâmicos C57BL
16.
Genome Res ; 22(11): 2270-7, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22829535

RESUMO

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.


Assuntos
Bactérias/genética , Genoma Bacteriano , Biblioteca Genômica , Análise de Sequência de DNA/métodos , Algoritmos
17.
PLoS Pathog ; 8(3): e1002529, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22412369

RESUMO

Deep sequencing technologies have the potential to transform the study of highly variable viral pathogens by providing a rapid and cost-effective approach to sensitively characterize rapidly evolving viral quasispecies. Here, we report on a high-throughput whole HIV-1 genome deep sequencing platform that combines 454 pyrosequencing with novel assembly and variant detection algorithms. In one subject we combined these genetic data with detailed immunological analyses to comprehensively evaluate viral evolution and immune escape during the acute phase of HIV-1 infection. The majority of early, low frequency mutations represented viral adaptation to host CD8+ T cell responses, evidence of strong immune selection pressure occurring during the early decline from peak viremia. CD8+ T cell responses capable of recognizing these low frequency escape variants coincided with the selection and evolution of more effective secondary HLA-anchor escape mutations. Frequent, and in some cases rapid, reversion of transmitted mutations was also observed across the viral genome. When located within restricted CD8 epitopes these low frequency reverting mutations were sufficient to prime de novo responses to these epitopes, again illustrating the capacity of the immune response to recognize and respond to low frequency variants. More importantly, rapid viral escape from the most immunodominant CD8+ T cell responses coincided with plateauing of the initial viral load decline in this subject, suggestive of a potential link between maintenance of effective, dominant CD8 responses and the degree of early viremia reduction. We conclude that the early control of HIV-1 replication by immunodominant CD8+ T cell responses may be substantially influenced by rapid, low frequency viral adaptations not detected by conventional sequencing approaches, which warrants further investigation. These data support the critical need for vaccine-induced CD8+ T cell responses to target more highly constrained regions of the virus in order to ensure the maintenance of immunodominant CD8 responses and the sustained decline of early viremia.


Assuntos
Genoma Viral/genética , Estudo de Associação Genômica Ampla , Infecções por HIV/virologia , HIV-1/genética , Evasão da Resposta Imune/imunologia , Linfócitos T CD8-Positivos/imunologia , Variação Genética , Variação Estrutural do Genoma , Infecções por HIV/imunologia , Infecções por HIV/prevenção & controle , HIV-1/imunologia , HIV-1/patogenicidade , Humanos , Evasão da Resposta Imune/genética , Análise de Sequência com Séries de Oligonucleotídeos , RNA Viral/análise , Análise de Sequência de RNA , Vacinas Virais/imunologia
18.
Science ; 332(6032): 930-6, 2011 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-21511999

RESUMO

The fission yeast clade--comprising Schizosaccharomyces pombe, S. octosporus, S. cryophilus, and S. japonicus--occupies the basal branch of Ascomycete fungi and is an important model of eukaryote biology. A comparative annotation of these genomes identified a near extinction of transposons and the associated innovation of transposon-free centromeres. Expression analysis established that meiotic genes are subject to antisense transcription during vegetative growth, which suggests a mechanism for their tight regulation. In addition, trans-acting regulators control new genes within the context of expanded functional modules for meiosis and stress response. Differences in gene content and regulation also explain why, unlike the budding yeast of Saccharomycotina, fission yeasts cannot use ethanol as a primary carbon source. These analyses elucidate the genome structure and gene regulation of fission yeast and provide tools for investigation across the Schizosaccharomyces clade.


Assuntos
Genoma Fúngico , Schizosaccharomyces/genética , Centrômero/genética , Centrômero/fisiologia , Centrômero/ultraestrutura , Elementos de DNA Transponíveis , Evolução Molecular , Perfilação da Expressão Gênica , Regulação Fúngica da Expressão Gênica , Genes Fúngicos Tipo Acasalamento , Genômica , Glucose/metabolismo , Meiose , Anotação de Sequência Molecular , Dados de Sequência Molecular , Filogenia , RNA Antissenso/genética , RNA Fúngico/genética , RNA Interferente Pequeno/genética , RNA não Traduzido/genética , Elementos Reguladores de Transcrição , Schizosaccharomyces/crescimento & desenvolvimento , Schizosaccharomyces/metabolismo , Proteínas de Schizosaccharomyces pombe/genética , Proteínas de Schizosaccharomyces pombe/metabolismo , Análise de Sequência de DNA , Especificidade da Espécie , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transcrição Gênica
19.
J Bacteriol ; 193(6): 1485-6, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21183675

RESUMO

Bacteria are the primary food source of choanoflagellates, the closest known relatives of animals. Studying signaling interactions between the Gram-negative Bacteroidetes bacterium Algoriphagus sp. PR1 and its predator, the choanoflagellate Salpingoeca rosetta, provides a promising avenue for testing hypotheses regarding the involvement of bacteria in animal evolution. Here we announce the complete genome sequence of Algoriphagus sp. PR1 and initial findings from its annotation.


Assuntos
Bacteroidetes/genética , DNA Bacteriano/química , DNA Bacteriano/genética , Genoma Bacteriano , Coanoflagelados/fisiologia , Dados de Sequência Molecular , Análise de Sequência de DNA
20.
PLoS One ; 5(2): e9083, 2010 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-20140207

RESUMO

BACKGROUND: Bacterial viruses (phages) play a critical role in shaping microbial populations as they influence both host mortality and horizontal gene transfer. As such, they have a significant impact on local and global ecosystem function and human health. Despite their importance, little is known about the genomic diversity harbored in phages, as methods to capture complete phage genomes have been hampered by the lack of knowledge about the target genomes, and difficulties in generating sufficient quantities of genomic DNA for sequencing. Of the approximately 550 phage genomes currently available in the public domain, fewer than 5% are marine phage. METHODOLOGY/PRINCIPAL FINDINGS: To advance the study of phage biology through comparative genomic approaches we used marine cyanophage as a model system. We compared DNA preparation methodologies (DNA extraction directly from either phage lysates or CsCl purified phage particles), and sequencing strategies that utilize either Sanger sequencing of a linker amplification shotgun library (LASL) or of a whole genome shotgun library (WGSL), or 454 pyrosequencing methods. We demonstrate that genomic DNA sample preparation directly from a phage lysate, combined with 454 pyrosequencing, is best suited for phage genome sequencing at scale, as this method is capable of capturing complete continuous genomes with high accuracy. In addition, we describe an automated annotation informatics pipeline that delivers high-quality annotation and yields few false positives and negatives in ORF calling. CONCLUSIONS/SIGNIFICANCE: These DNA preparation, sequencing and annotation strategies enable a high-throughput approach to the burgeoning field of phage genomics.


Assuntos
Bacteriófagos/genética , DNA Viral/genética , Genoma Viral/genética , Análise de Sequência de DNA/métodos , Biologia Computacional/métodos , DNA Viral/química , DNA Viral/metabolismo , Desoxirribonucleases/metabolismo , Dados de Sequência Molecular , Fases de Leitura Aberta/genética , Prochlorococcus/virologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...