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1.
JAMA ; 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38709541

RESUMO

This study examines substances identified during testing of counterfeit prescription pills seized by law enforcement in Rhode Island from 2017 to 2022.

3.
Curr Biol ; 33(12): 2515-2527.e6, 2023 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-37295427

RESUMO

Eastern equine encephalitis virus (EEEV) causes a rare but severe disease in horses and humans and is maintained in an enzootic transmission cycle between songbirds and Culiseta melanura mosquitoes. In 2019, the largest EEEV outbreak in the United States for more than 50 years occurred, centered in the Northeast. To explore the dynamics of the outbreak, we sequenced 80 isolates of EEEV and combined them with existing genomic data. We found that, similar to previous years, cases were driven by multiple independent but short-lived virus introductions into the Northeast from Florida. Once in the Northeast, we found that Massachusetts was important for regional spread. We found no evidence of any changes in viral, human, or bird factors which would explain the increase in cases in 2019, although the ecology of EEEV is complex and further data is required to explore these in more detail. By using detailed mosquito surveillance data collected by Massachusetts and Connecticut, however, we found that the abundance of Cs. melanura was exceptionally high in 2019, as was the EEEV infection rate. We employed these mosquito data to build a negative binomial regression model and applied it to estimate early season risks of human or horse cases. We found that the month of first detection of EEEV in mosquito surveillance data and vector index (abundance multiplied by infection rate) were predictive of cases later in the season. We therefore highlight the importance of mosquito surveillance programs as an integral part of public health and disease control.


Assuntos
Culicidae , Vírus da Encefalite Equina do Leste , Encefalomielite Equina , Aves Canoras , Animais , Cavalos , Humanos , Vírus da Encefalite Equina do Leste/genética , Mosquitos Vetores , Encefalomielite Equina/epidemiologia , Encefalomielite Equina/veterinária , Massachusetts/epidemiologia , Surtos de Doenças/veterinária
4.
medRxiv ; 2023 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-36945576

RESUMO

Eastern equine encephalitis virus (EEEV) causes a rare but severe disease in horses and humans, and is maintained in an enzootic transmission cycle between songbirds and Culiseta melanura mosquitoes. In 2019, the largest EEEV outbreak in the United States for more than 50 years occurred, centered in the Northeast. To explore the dynamics of the outbreak, we sequenced 80 isolates of EEEV and combined them with existing genomic data. We found that, like previous years, cases were driven by frequent short-lived virus introductions into the Northeast from Florida. Once in the Northeast, we found that Massachusetts was important for regional spread. We found no evidence of any changes in viral, human, or bird factors which would explain the increase in cases in 2019. By using detailed mosquito surveillance data collected by Massachusetts and Connecticut, however, we found that the abundance of Cs. melanura was exceptionally high in 2019, as was the EEEV infection rate. We employed these mosquito data to build a negative binomial regression model and applied it to estimate early season risks of human or horse cases. We found that the month of first detection of EEEV in mosquito surveillance data and vector index (abundance multiplied by infection rate) were predictive of cases later in the season. We therefore highlight the importance of mosquito surveillance programs as an integral part of public health and disease control.

5.
Science ; 378(6619): 560-565, 2022 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-36264825

RESUMO

Monkeypox is a viral zoonotic disease endemic in Central and West Africa. In May 2022, dozens of non-endemic countries reported hundreds of monkeypox cases, most with no epidemiological link to Africa. We identified two lineages of monkeypox virus (MPXV) among two 2021 and seven 2022 US monkeypox cases: the major 2022 outbreak variant called B.1 and a minor contemporaneously sampled variant called A.2. Analyses of mutations among these two variants revealed an extreme preference for GA-to-AA mutations indicative of human APOBEC3 cytosine deaminase activity among Clade IIb MPXV (previously West African, Nigeria) sampled since 2017. Such mutations were not enriched within other MPXV clades. These findings suggest that APOBEC3 editing may be a recurrent and a dominant driver of MPXV evolution within the current outbreak.


Assuntos
Desaminases APOBEC , Interações Hospedeiro-Patógeno , Monkeypox virus , Mpox , Edição de RNA , Humanos , Mpox/enzimologia , Mpox/virologia , Monkeypox virus/genética , Monkeypox virus/isolamento & purificação , Nigéria/epidemiologia , Estados Unidos/epidemiologia , Mutação , Evolução Molecular , Desaminases APOBEC/metabolismo , Adenosina/genética , Citidina/genética
6.
MMWR Morb Mortal Wkly Rep ; 71(23): 764-769, 2022 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-35679181

RESUMO

On May 17, 2022, the Massachusetts Department of Public Health (MDPH) Laboratory Response Network (LRN) laboratory confirmed the presence of orthopoxvirus DNA via real-time polymerase chain reaction (PCR) from lesion swabs obtained from a Massachusetts resident. Orthopoxviruses include Monkeypox virus, the causative agent of monkeypox. Subsequent real-time PCR testing at CDC on May 18 confirmed that the patient was infected with the West African clade of Monkeypox virus. Since then, confirmed cases* have been reported by nine states. In addition, 28 countries and territories,† none of which has endemic monkeypox, have reported laboratory-confirmed cases. On May 17, CDC, in coordination with state and local jurisdictions, initiated an emergency response to identify, monitor, and investigate additional monkeypox cases in the United States. This response has included releasing a Health Alert Network (HAN) Health Advisory, developing interim public health and clinical recommendations, releasing guidance for LRN testing, hosting clinician and public health partner outreach calls, disseminating health communication messages to the public, developing protocols for use and release of medical countermeasures, and facilitating delivery of vaccine postexposure prophylaxis (PEP) and antivirals that have been stockpiled by the U.S. government for preparedness and response purposes. On May 19, a call center was established to provide guidance to states for the evaluation of possible cases of monkeypox, including recommendations for clinical diagnosis and orthopoxvirus testing. The call center also gathers information about possible cases to identify interjurisdictional linkages. As of May 31, this investigation has identified 17§ cases in the United States; most cases (16) were diagnosed in persons who identify as gay, bisexual, or men who have sex with men (MSM). Ongoing investigation suggests person-to-person community transmission, and CDC urges health departments, clinicians, and the public to remain vigilant, institute appropriate infection prevention and control measures, and notify public health authorities of suspected cases to reduce disease spread. Public health authorities are identifying cases and conducting investigations to determine possible sources and prevent further spread. This activity was reviewed by CDC and conducted consistent with applicable federal law and CDC policy.¶.


Assuntos
Malária , Mpox , Minorias Sexuais e de Gênero , Surtos de Doenças , Homossexualidade Masculina , Humanos , Malária/diagnóstico , Masculino , Mpox/diagnóstico , Mpox/epidemiologia , Vigilância da População , Viagem , Estados Unidos/epidemiologia
7.
Cell Rep Med ; 3(4): 100583, 2022 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-35480627

RESUMO

The SARS-CoV-2 Delta variant rose to dominance in mid-2021, likely propelled by an estimated 40%-80% increased transmissibility over Alpha. To investigate if this ostensible difference in transmissibility is uniform across populations, we partner with public health programs from all six states in New England in the United States. We compare logistic growth rates during each variant's respective emergence period, finding that Delta emerged 1.37-2.63 times faster than Alpha (range across states). We compute variant-specific effective reproductive numbers, estimating that Delta is 63%-167% more transmissible than Alpha (range across states). Finally, we estimate that Delta infections generate on average 6.2 (95% CI 3.1-10.9) times more viral RNA copies per milliliter than Alpha infections during their respective emergence. Overall, our evidence suggests that Delta's enhanced transmissibility can be attributed to its innate ability to increase infectiousness, but its epidemiological dynamics may vary depending on underlying population attributes and sequencing data availability.


Assuntos
COVID-19 , SARS-CoV-2 , COVID-19/epidemiologia , Humanos , New England/epidemiologia , Saúde Pública , SARS-CoV-2/genética
8.
Nat Med ; 28(5): 1083-1094, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35130561

RESUMO

The coronavirus disease 2019 (COVID-19) pandemic has demonstrated a clear need for high-throughput, multiplexed and sensitive assays for detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other respiratory viruses and their emerging variants. Here, we present a cost-effective virus and variant detection platform, called microfluidic Combinatorial Arrayed Reactions for Multiplexed Evaluation of Nucleic acids (mCARMEN), which combines CRISPR-based diagnostics and microfluidics with a streamlined workflow for clinical use. We developed the mCARMEN respiratory virus panel to test for up to 21 viruses, including SARS-CoV-2, other coronaviruses and both influenza strains, and demonstrated its diagnostic-grade performance on 525 patient specimens in an academic setting and 166 specimens in a clinical setting. We further developed an mCARMEN panel to enable the identification of 6 SARS-CoV-2 variant lineages, including Delta and Omicron, and evaluated it on 2,088 patient specimens with near-perfect concordance to sequencing-based variant classification. Lastly, we implemented a combined Cas13 and Cas12 approach that enables quantitative measurement of SARS-CoV-2 and influenza A viral copies in samples. The mCARMEN platform enables high-throughput surveillance of multiple viruses and variants simultaneously, enabling rapid detection of SARS-CoV-2 variants.


Assuntos
COVID-19 , Influenza Humana , COVID-19/diagnóstico , Humanos , Microfluídica , SARS-CoV-2/genética
9.
medRxiv ; 2021 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-34642698

RESUMO

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta variant quickly rose to dominance in mid-2021, displacing other variants, including Alpha. Studies using data from the United Kingdom and India estimated that Delta was 40-80% more transmissible than Alpha, allowing Delta to become the globally dominant variant. However, it was unclear if the ostensible difference in relative transmissibility was due mostly to innate properties of Delta's infectiousness or differences in the study populations. To investigate, we formed a partnership with SARS-CoV-2 genomic surveillance programs from all six New England US states. By comparing logistic growth rates, we found that Delta emerged 37-163% faster than Alpha in early 2021 (37% Massachusetts, 75% New Hampshire, 95% Maine, 98% Rhode Island, 151% Connecticut, and 163% Vermont). We next computed variant-specific effective reproductive numbers and estimated that Delta was 58-120% more transmissible than Alpha across New England (58% New Hampshire, 68% Massachusetts, 76% Connecticut, 85% Rhode Island, 98% Maine, and 120% Vermont). Finally, using RT-PCR data, we estimated that Delta infections generate on average ∼6 times more viral RNA copies per mL than Alpha infections. Overall, our evidence indicates that Delta's enhanced transmissibility could be attributed to its innate ability to increase infectiousness, but its epidemiological dynamics may vary depending on the underlying immunity and behavior of distinct populations.

10.
MMWR Morb Mortal Wkly Rep ; 70(31): 1059-1062, 2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34351882

RESUMO

During July 2021, 469 cases of COVID-19 associated with multiple summer events and large public gatherings in a town in Barnstable County, Massachusetts, were identified among Massachusetts residents; vaccination coverage among eligible Massachusetts residents was 69%. Approximately three quarters (346; 74%) of cases occurred in fully vaccinated persons (those who had completed a 2-dose course of mRNA vaccine [Pfizer-BioNTech or Moderna] or had received a single dose of Janssen [Johnson & Johnson] vaccine ≥14 days before exposure). Genomic sequencing of specimens from 133 patients identified the B.1.617.2 (Delta) variant of SARS-CoV-2, the virus that causes COVID-19, in 119 (89%) and the Delta AY.3 sublineage in one (1%). Overall, 274 (79%) vaccinated patients with breakthrough infection were symptomatic. Among five COVID-19 patients who were hospitalized, four were fully vaccinated; no deaths were reported. Real-time reverse transcription-polymerase chain reaction (RT-PCR) cycle threshold (Ct) values in specimens from 127 vaccinated persons with breakthrough cases were similar to those from 84 persons who were unvaccinated, not fully vaccinated, or whose vaccination status was unknown (median = 22.77 and 21.54, respectively). The Delta variant of SARS-CoV-2 is highly transmissible (1); vaccination is the most important strategy to prevent severe illness and death. On July 27, CDC recommended that all persons, including those who are fully vaccinated, should wear masks in indoor public settings in areas where COVID-19 transmission is high or substantial.* Findings from this investigation suggest that even jurisdictions without substantial or high COVID-19 transmission might consider expanding prevention strategies, including masking in indoor public settings regardless of vaccination status, given the potential risk of infection during attendance at large public gatherings that include travelers from many areas with differing levels of transmission.


Assuntos
COVID-19/epidemiologia , COVID-19/transmissão , Aglomeração , Surtos de Doenças , Adolescente , Adulto , Idoso , Vacinas contra COVID-19/administração & dosagem , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Massachusetts/epidemiologia , Pessoa de Meia-Idade , Adulto Jovem
11.
Emerg Infect Dis ; 27(5): 1296-1300, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33900178

RESUMO

Zika virus diagnostic testing and laboratory research increased considerably when Zika virus began spreading through the Americas in 2015, increasing the risk for potential Zika virus exposure of laboratory workers and biomedical researchers. We report 4 cases of laboratory-associated Zika virus disease in the United States during 2016-2019. Of these, 2 were associated with needlestick injuries; for the other 2 cases, the route of transmission was undetermined. In laboratories in which work with Zika virus is performed, good laboratory biosafety practices must be implemented and practiced to reduce the risk for infection among laboratory personnel.


Assuntos
Infecção por Zika virus , Zika virus , América , Humanos , Laboratórios , Pesquisa , Estados Unidos
12.
Clin Infect Dis ; 73(9): 1693-1695, 2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-33704451

RESUMO

We describe 3 instances of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission despite medical masks and eye protection, including transmission despite the source person being masked, transmission despite the exposed person being masked, and transmission despite both parties being masked. Whole genome sequencing confirmed perfect homology between source and exposed persons' viruses in all cases.


Assuntos
COVID-19 , SARS-CoV-2 , Atenção à Saúde , Humanos , Máscaras
13.
Ann Intern Med ; 174(6): 794-802, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33556277

RESUMO

BACKGROUND: Little is known about clusters of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in acute care hospitals. OBJECTIVE: To describe the detection, mitigation, and analysis of a large cluster of SARS-CoV-2 infections in an acute care hospital with mature infection control policies. DESIGN: Descriptive study. SETTING: Brigham and Women's Hospital, Boston, Massachusetts. PARTICIPANTS: Patients and staff with cluster-related SARS-CoV-2 infections. INTERVENTION: Close contacts of infected patients and staff were identified and tested every 3 days, patients on affected units were preemptively isolated and repeatedly tested, affected units were cleaned, room ventilation was measured, and specimens were sent for whole-genome sequencing. A case-control study was done to compare clinical interactions, personal protective equipment use, and breakroom and workroom practices in SARS-CoV-2-positive versus negative staff. MEASUREMENTS: Description of the cluster, mitigation activities, and risk factor analysis. RESULTS: Fourteen patients and 38 staff members were included in the cluster per whole-genome sequencing and epidemiologic associations. The index case was a symptomatic patient in whom isolation was discontinued after 2 negative results on nasopharyngeal polymerase chain reaction testing. The patient subsequently infected multiple roommates and staff, who then infected others. Seven of 52 (13%) secondary infections were detected only on second or subsequent tests. Eight of 9 (89%) patients who shared rooms with potentially contagious patients became infected. Potential contributing factors included high viral loads, nebulization, and positive pressure in the index patient's room. Risk factors for transmission to staff included presence during nebulization, caring for patients with dyspnea or cough, lack of eye protection, at least 15 minutes of exposure to case patients, and interactions with SARS-CoV-2-positive staff in clinical areas. Whole-genome sequencing confirmed that 2 staff members were infected despite wearing surgical masks and eye protection. LIMITATION: Findings may not be generalizable. CONCLUSION: SARS-CoV-2 clusters can occur in hospitals despite robust infection control policies. Insights from this cluster may inform additional measures to protect patients and staff. PRIMARY FUNDING SOURCE: None.


Assuntos
COVID-19/epidemiologia , COVID-19/transmissão , Infecção Hospitalar/epidemiologia , Controle de Infecções/métodos , Transmissão de Doença Infecciosa do Paciente para o Profissional , Pneumonia Viral/epidemiologia , Pneumonia Viral/transmissão , Adulto , Boston/epidemiologia , Teste para COVID-19 , Estudos de Casos e Controles , Surtos de Doenças , Feminino , Humanos , Masculino , Equipamento de Proteção Individual , Pneumonia Viral/virologia , Fatores de Risco , SARS-CoV-2
14.
Science ; 371(6529)2021 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-33303686

RESUMO

Analysis of 772 complete severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genomes from early in the Boston-area epidemic revealed numerous introductions of the virus, a small number of which led to most cases. The data revealed two superspreading events. One, in a skilled nursing facility, led to rapid transmission and significant mortality in this vulnerable population but little broader spread, whereas other introductions into the facility had little effect. The second, at an international business conference, produced sustained community transmission and was exported, resulting in extensive regional, national, and international spread. The two events also differed substantially in the genetic variation they generated, suggesting varying transmission dynamics in superspreading events. Our results show how genomic epidemiology can help to understand the link between individual clusters and wider community spread.


Assuntos
COVID-19/epidemiologia , Genoma Viral , Filogenia , SARS-CoV-2/genética , Boston/epidemiologia , COVID-19/transmissão , Surtos de Doenças , Monitoramento Epidemiológico , Humanos
15.
medRxiv ; 2020 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-32869040

RESUMO

SARS-CoV-2 has caused a severe, ongoing outbreak of COVID-19 in Massachusetts with 111,070 confirmed cases and 8,433 deaths as of August 1, 2020. To investigate the introduction, spread, and epidemiology of COVID-19 in the Boston area, we sequenced and analyzed 772 complete SARS-CoV-2 genomes from the region, including nearly all confirmed cases within the first week of the epidemic and hundreds of cases from major outbreaks at a conference, a nursing facility, and among homeless shelter guests and staff. The data reveal over 80 introductions into the Boston area, predominantly from elsewhere in the United States and Europe. We studied two superspreading events covered by the data, events that led to very different outcomes because of the timing and populations involved. One produced rapid spread in a vulnerable population but little onward transmission, while the other was a major contributor to sustained community transmission, including outbreaks in homeless populations, and was exported to several other domestic and international sites. The same two events differed significantly in the number of new mutations seen, raising the possibility that SARS-CoV-2 superspreading might encompass disparate transmission dynamics. Our results highlight the failure of measures to prevent importation into MA early in the outbreak, underscore the role of superspreading in amplifying an outbreak in a major urban area, and lay a foundation for contact tracing informed by genetic data.

16.
J Endocr Soc ; 1(10): 1272-1286, 2017 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29264452

RESUMO

Enteroviral infections have been associated with the development of type 1 diabetes (T1D), a chronic inflammatory disease characterized by autoimmune destruction of insulin-producing pancreatic beta cells. Cultured human islets, including the insulin-producing beta cells, can be infected with coxsackievirus B4 (CVB4) and thus are useful for understanding cellular responses to infection. We performed quantitative mass spectrometry analysis on cultured primary human islets infected with CVB4 to identify molecules and pathways altered upon infection. Corresponding uninfected controls were included in the study for comparative protein expression analyses. Proteins were significantly and differentially regulated in human islets challenged with virus compared with their uninfected counterparts. Complementary analyses of gene transcripts in CVB4-infected primary islets over a time course validated the induction of RNA transcripts for many of the proteins that were increased in the proteomics studies. Notably, infection with CVB4 results in a considerable decrease in insulin. Genes/proteins modulated during CVB4 infection also include those involved in activation of immune responses, including type I interferon pathways linked to T1D pathogenesis and with antiviral, cell repair, and inflammatory properties. Our study applies proteomics analyses to cultured human islets challenged with virus and identifies target proteins that could be useful in T1D interventions.

17.
RNA ; 21(12): 2067-75, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26428694

RESUMO

Influenza A virus (IAV) lacks the enzyme for adding 5' caps to its RNAs and snatches the 5' ends of host capped RNAs to prime transcription. Neither the preference of the host RNA sequences snatched nor the effect of cap-snatching on host processes is completely defined. Previous studies of influenza cap-snatching used poly(A)-selected RNAs from infected cells or relied on annotated host genes to define the snatched host RNAs, and thus lack details on many noncoding host RNAs including snRNAs, snoRNAs, and promoter-associated capped small (cs)RNAs, which are made by "paused" Pol II during transcription initiation. In this study, we used a nonbiased technique, CapSeq, to identify host and viral-capped RNAs including nonpolyadenylated RNAs in the same samples, and investigated the substrate-product correlation between the host RNAs and the viral RNAs. We demonstrated that noncoding host RNAs, particularly U1 and U2, are the preferred cap-snatching source over mRNAs or pre-mRNAs. We also found that csRNAs are highly snatched by IAV. Because the functions of csRNAs remain mostly unknown, especially in somatic cells, our finding reveals that csRNAs at least play roles in the process of IAV infection. Our findings support a model where nascent RNAs including csRNAs are the preferred targets for cap-snatching by IAV and raise questions about how IAV might use snatching preferences to modulate host-mRNA splicing and transcription.


Assuntos
Vírus da Influenza A Subtipo H1N1/genética , Capuzes de RNA/metabolismo , Sequência de Bases , Linhagem Celular Tumoral , Regulação Viral da Expressão Gênica , Genes Virais , Humanos , Vírus da Influenza A Subtipo H1N1/metabolismo , Processamento Pós-Transcricional do RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Viral/genética , RNA Viral/metabolismo
18.
Mol Biol Evol ; 32(6): 1519-32, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25713211

RESUMO

Influenza A virus (IAV) has a segmented genome that allows for the exchange of genome segments between different strains. This reassortment accelerates evolution by breaking linkage, helping IAV cross species barriers to potentially create highly virulent strains. Challenges associated with monitoring the process of reassortment in molecular detail have limited our understanding of its evolutionary implications. We applied a novel deep sequencing approach with quantitative analysis to assess the in vitro temporal evolution of genomic reassortment in IAV. The combination of H1N1 and H3N2 strains reproducibly generated a new H1N2 strain with the hemagglutinin and nucleoprotein segments originating from H1N1 and the remaining six segments from H3N2. By deep sequencing the entire viral genome, we monitored the evolution of reassortment, quantifying the relative abundance of all IAV genome segments from the two parent strains over time and measuring the selection coefficients of the reassorting segments. Additionally, we observed several mutations coemerging with reassortment that were not found during passaging of pure parental IAV strains. Our results demonstrate how reassortment of the segmented genome can accelerate viral evolution in IAV, potentially enabled by the emergence of a small number of individual mutations.


Assuntos
Alphainfluenzavirus/genética , Genoma Viral , Vírus Reordenados/genética , Seleção Genética , Animais , Biologia Computacional , Cães , Evolução Molecular , Frequência do Gene , Genótipo , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Sequenciamento de Nucleotídeos em Larga Escala , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N2/genética , Vírus da Influenza A Subtipo H3N2/genética , Limite de Detecção , Células Madin Darby de Rim Canino , Nucleoproteínas/genética , Análise de Sequência de RNA
19.
Diabetes ; 64(4): 1358-69, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25392246

RESUMO

Type 1 diabetes (T1D) is characterized by the destruction of the insulin-producing ß-cells of pancreatic islets. Genetic and environmental factors both contribute to T1D development. Viral infection with enteroviruses is a suspected trigger for T1D, but a causal role remains unproven and controversial. Studies in animals are problematic because of species-specific differences in host cell susceptibility and immune responses to candidate viral pathogens such as coxsackievirus B (CVB). In order to resolve the controversial role of viruses in human T1D, we developed a viral infection model in immunodeficient mice bearing human islet grafts. Hyperglycemia was induced in mice by specific ablation of native ß-cells. Human islets, which are naturally susceptible to CVB infection, were transplanted to restore normoglycemia. Transplanted mice were infected with CVB4 and monitored for hyperglycemia. Forty-seven percent of CVB4-infected mice developed hyperglycemia. Human islet grafts from infected mice contained viral RNA, expressed viral protein, and had reduced insulin levels compared with grafts from uninfected mice. Human-specific gene expression profiles in grafts from infected mice revealed the induction of multiple interferon-stimulated genes. Thus, human islets can become severely dysfunctional with diminished insulin production after CVB infection of ß-cells, resulting in diabetes.


Assuntos
Infecções por Coxsackievirus/imunologia , Diabetes Mellitus Tipo 1/virologia , Hiperglicemia/virologia , Transplante das Ilhotas Pancreáticas , Ilhotas Pancreáticas/virologia , Animais , Diabetes Mellitus Tipo 1/imunologia , Enterovirus Humano B , Humanos , Hiperglicemia/imunologia , Ilhotas Pancreáticas/imunologia , Camundongos
20.
J Virol ; 88(1): 272-81, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24155392

RESUMO

Influenza A virus (IAV) is a major cause of morbidity and mortality throughout the world. Current antiviral therapies include oseltamivir, a neuraminidase inhibitor that prevents the release of nascent viral particles from infected cells. However, the IAV genome can evolve rapidly, and oseltamivir resistance mutations have been detected in numerous clinical samples. Using an in vitro evolution platform and whole-genome population sequencing, we investigated the population genomics of IAV during the development of oseltamivir resistance. Strain A/Brisbane/59/2007 (H1N1) was grown in Madin-Darby canine kidney cells with or without escalating concentrations of oseltamivir over serial passages. Following drug treatment, the H274Y resistance mutation fixed reproducibly within the population. The presence of the H274Y mutation in the viral population, at either a low or a high frequency, led to measurable changes in the neuraminidase inhibition assay. Surprisingly, fixation of the resistance mutation was not accompanied by alterations of viral population diversity or differentiation, and oseltamivir did not alter the selective environment. While the neighboring K248E mutation was also a target of positive selection prior to H274Y fixation, H274Y was the primary beneficial mutation in the population. In addition, once evolved, the H274Y mutation persisted after the withdrawal of the drug, even when not fixed in viral populations. We conclude that only selection of H274Y is required for oseltamivir resistance and that H274Y is not deleterious in the absence of the drug. These collective results could offer an explanation for the recent reproducible rise in oseltamivir resistance in seasonal H1N1 IAV strains in humans.


Assuntos
Antivirais/farmacologia , Farmacorresistência Viral/genética , Evolução Molecular , Genoma Viral , Vírus da Influenza A Subtipo H1N1/genética , Oseltamivir/farmacologia , Animais , Linhagem Celular , Cães , Ensaios de Triagem em Larga Escala , Técnicas In Vitro , Vírus da Influenza A Subtipo H1N1/crescimento & desenvolvimento , Concentração Inibidora 50 , Mutação , Ensaio de Placa Viral
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