Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 36
Filtrar
1.
BMC Pediatr ; 24(1): 408, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38918745

RESUMO

Hypereosinophilia is a rare presentation in all age groups, particularly when it is severe, persistent, and progressive. We describe the clinical characteristics and course of severe hypereosinophilia in a full-term Saudi female neonate. A febrile respiratory illness evolved with a progressive increase in peripheral blood leukocyte and eosinophil counts, reaching 44.9% of leukocytes and an absolute value of 57,000 cells/µl. Different etiological examinations (for viral, bacterial, immunodeficiency, hyper IgE syndrome, gene mutations) revealed extremely high CMV antigenemia and a homozygous mutation in the STAT1 gene. Anhelation was relieved by oxygen and anti-viral treatment. Steroids brought a dramatic response in peripheral blood counts within 24 h. After a 6-week course of antiviral and steroid treatment at home, she had an excellent general condition. Conclusion: Although a rare pathology, it is important to consider genetic disorders when there is an atypical immune response to viral infections.


Assuntos
Infecções por Citomegalovirus , Mutação , Fator de Transcrição STAT1 , Humanos , Feminino , Fator de Transcrição STAT1/genética , Recém-Nascido , Infecções por Citomegalovirus/complicações , Eosinofilia/genética
2.
Sci Rep ; 14(1): 8976, 2024 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-38637584

RESUMO

Autologous administration of attenuated Theileria parva-infected cells induces immunity to T. parva in cattle. The mechanism of attenuation, however, is largely unknown. Here, we used RNA sequencing of pathogenic and attenuated T. parva-infected T-cells to elucidate the transcriptional changes underpinning attenuation. We observed differential expression of several host genes, including TRAIL, PD-1, TGF-ß and granzymes that are known to regulate inflammation and proliferation of infected cells. Importantly, many genes linked with the attenuation of the related T. annulata-infected cells were not dysregulated in this study. Furthermore, known T. parva antigens were not dysregulated in attenuated relative to pathogenic cells, indicating that attenuation is not due to enhanced immunogenicity. Overall this study suggests that attenuation is driven by a decrease in proliferation and restoration of the inflammatory profile of T. parva-infected cells. Additionally, it provides a foundation for future mechanistic studies of the attenuation phenotype in Theileria-infected cells.


Assuntos
Theileria parva , Theileria , Theileriose , Animais , Bovinos , Theileria parva/genética , Theileriose/genética , Theileria/genética , Linfócitos T , Antígenos
3.
BMC Genomics ; 24(1): 161, 2023 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-36991327

RESUMO

BACKGROUND: Infectious Salmon Anaemia Virus (ISAV) is an Orthomixovirus that represents a large problem for salmonid aquaculture worldwide. Current prevention and treatment methods are only partially effective. Genetic selection and genome engineering have the potential to develop ISAV resistant salmon stocks. Both strategies can benefit from an improved understanding of the genomic regulation of ISAV pathogenesis. Here, we used single-cell RNA sequencing of an Atlantic salmon cell line to provide the first high dimensional insight into the transcriptional landscape that underpins host-virus interaction during early ISAV infection. RESULTS: Salmon head kidney (SHK-1) cells were single-cell RNA sequenced at 24, 48 and 96 h post-ISAV challenge. At 24 h post infection, cells showed expression signatures consistent with viral entry, with genes such as PI3K, FAK or JNK being upregulated relative to uninfected cells. At 48 and 96 h, infected cells showed a clear anti-viral response, characterised by the expression of IFNA2 or IRF2. Uninfected bystander cells at 48 and 96 h also showed clear transcriptional differences, potentially suggesting paracrine signalling from infected cells. These bystander cells expressed pathways such as mRNA sensing, RNA degradation, ubiquitination or proteasome; and up-regulation of mitochondrial ribosome genes also seemed to play a role in the host response to the infection. Correlation between viral and host genes revealed novel genes potentially key for this fish-virus interaction. CONCLUSIONS: This study has increased our understanding of the cellular response of Atlantic salmon during ISAV infection and revealed host-virus interactions at the cellular level. Our results highlight various potential key genes in this host-virus interaction, which can be manipulated in future functional studies to increase the resistance of Atlantic salmon to ISAV.


Assuntos
Doenças dos Peixes , Isavirus , Infecções por Orthomyxoviridae , Salmo salar , Animais , Salmo salar/genética , Isavirus/genética , Regulação para Cima , Linhagem Celular , Análise de Sequência de RNA , Doenças dos Peixes/genética , Infecções por Orthomyxoviridae/genética , Infecções por Orthomyxoviridae/veterinária
4.
Commun Biol ; 5(1): 1003, 2022 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-36131008

RESUMO

Despite the clear potential of livestock models of human functional variants to provide important insights into the biological mechanisms driving human diseases and traits, their use to date has been limited. Generating such models via genome editing is costly and time consuming, and it is unclear which variants will have conserved effects across species. In this study we address these issues by studying naturally occurring livestock models of human functional variants. We show that orthologues of over 1.6 million human variants are already segregating in domesticated mammalian species, including several hundred previously directly linked to human traits and diseases. Models of variants linked to particular phenotypes, including metabolomic disorders and height, are preferentially shared across species, meaning studying the genetic basis of these phenotypes is particularly tractable in livestock. Using machine learning we demonstrate it is possible to identify human variants that are more likely to have an existing livestock orthologue, and, importantly, we show that the effects of functional variants are often conserved in livestock, acting on orthologous genes with the same direction of effect. Consequently, this work demonstrates the substantial potential of naturally occurring livestock carriers of orthologues of human functional variants to disentangle their functional impacts.


Assuntos
Edição de Genes , Gado , Animais , Humanos , Gado/genética , Mamíferos/genética , Fenótipo
5.
PLoS Genet ; 18(4): e1010099, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35446841

RESUMO

East Coast fever, a tick-borne cattle disease caused by the Theileria parva parasite, is among the biggest natural killers of cattle in East Africa, leading to over 1 million deaths annually. Here we report on the genetic analysis of a cohort of Bos indicus (Boran) cattle demonstrating heritable tolerance to infection with T. parva (h2 = 0.65, s.e. 0.57). Through a linkage analysis we identify a 6 Mb genomic region on bovine chromosome 15 that is significantly associated with survival outcome following T. parva exposure. Testing this locus in an independent cohort of animals replicates this association with survival following T. parva infection. A stop gained variant in a paralogue of the FAF1 gene in this region was found to be highly associated with survival across both related and unrelated animals, with only one of the 20 homozygote carriers (T/T) of this change succumbing to the disease in contrast to 44 out of 97 animals homozygote for the reference allele (C/C). Consequently, we present a genetic locus linked to tolerance of one of Africa's most important cattle diseases, raising the promise of marker-assisted selection for cattle that are less susceptible to infection by T. parva.


Assuntos
Doenças dos Bovinos , Theileria parva , Theileria , Theileriose , Proteínas Adaptadoras de Transdução de Sinal/genética , Alelos , Animais , Proteínas Reguladoras de Apoptose/genética , Bovinos , Doenças dos Bovinos/genética , Humanos , Theileria/genética , Theileria parva/genética , Theileriose/genética , Theileriose/parasitologia
6.
BMC Bioinformatics ; 23(1): 45, 2022 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-35042461

RESUMO

BACKGROUND: Differential isoform usage is an important driver of inter-individual phenotypic diversity and is linked to various diseases and traits. However, accurately detecting the differential usage of different gene transcripts between groups can be difficult, in particular in less well annotated genomes where the spectrum of transcript isoforms is largely unknown. RESULTS: We investigated whether machine learning approaches can detect differential isoform usage based purely on the distribution of reads across a gene region. We illustrate that gradient boosting and elastic net approaches can successfully identify large numbers of genes showing potential differential isoform usage between Europeans and Africans, that are enriched among relevant biological pathways and significantly overlap those identified by previous approaches. We demonstrate that diversity at the 3' and 5' ends of genes are primary drivers of these differences between populations. CONCLUSION: Machine learning methods can effectively detect differential isoform usage from read fraction data, and can provide novel insights into the biological differences between groups.


Assuntos
Perfilação da Expressão Gênica , Aprendizado de Máquina , Processamento Alternativo , Éxons , Isoformas de Proteínas/genética , Análise de Sequência de RNA
7.
BMC Biol ; 20(1): 14, 2022 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-35027054

RESUMO

BACKGROUND: Infectious diseases of farmed and wild animals pose a recurrent threat to food security and human health. The macrophage, a key component of the innate immune system, is the first line of defence against many infectious agents and plays a major role in shaping the adaptive immune response. However, this phagocyte is a target and host for many pathogens. Understanding the molecular basis of interactions between macrophages and pathogens is therefore crucial for the development of effective strategies to combat important infectious diseases. RESULTS: We explored how porcine pluripotent stem cells (PSCs) can provide a limitless in vitro supply of genetically and experimentally tractable macrophages. Porcine PSC-derived macrophages (PSCdMs) exhibited molecular and functional characteristics of ex vivo primary macrophages and were productively infected by pig pathogens, including porcine reproductive and respiratory syndrome virus (PRRSV) and African swine fever virus (ASFV), two of the most economically important and devastating viruses in pig farming. Moreover, porcine PSCdMs were readily amenable to genetic modification by CRISPR/Cas9 gene editing applied either in parental stem cells or directly in the macrophages by lentiviral vector transduction. CONCLUSIONS: We show that porcine PSCdMs exhibit key macrophage characteristics, including infection by a range of commercially relevant pig pathogens. In addition, genetic engineering of PSCs and PSCdMs affords new opportunities for functional analysis of macrophage biology in an important livestock species. PSCs and differentiated derivatives should therefore represent a useful and ethical experimental platform to investigate the genetic and molecular basis of host-pathogen interactions in pigs, and also have wider applications in livestock.


Assuntos
Vírus da Febre Suína Africana , Doenças Transmissíveis , Vírus da Febre Suína Africana/genética , Animais , Interações Hospedeiro-Patógeno/genética , Macrófagos , Células-Tronco , Suínos
8.
Int Health ; 14(1): 18-52, 2022 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-33620427

RESUMO

As the coronavirus disease 2019 (COVID-19) pandemic continues to rise and second waves are reported in some countries, serological test kits and strips are being considered to scale up an adequate laboratory response. This study provides an update on the kinetics of humoral immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and performance characteristics of serological protocols (lateral flow assay [LFA], chemiluminescence immunoassay [CLIA] and ELISA) used for evaluations of recent and past SARS-CoV-2 infection. A thorough and comprehensive review of suitable and eligible full-text articles was performed on PubMed, Scopus, Web of Science, Wordometer and medRxiv from 10 January to 16 July 2020. These articles were searched using the Medical Subject Headings terms 'COVID-19', 'Serological assay', 'Laboratory Diagnosis', 'Performance characteristics', 'POCT', 'LFA', 'CLIA', 'ELISA' and 'SARS-CoV-2'. Data from original research articles on SARS-CoV-2 antibody detection ≥second day postinfection were included in this study. In total, there were 7938 published articles on humoral immune response and laboratory diagnosis of COVID-19. Of these, 74 were included in this study. The detection, peak and decline period of blood anti-SARS-CoV-2 IgM, IgG and total antibodies for point-of-care testing (POCT), ELISA and CLIA vary widely. The most promising of these assays for POCT detected anti-SARS-CoV-2 at day 3 postinfection and peaked on the 15th day; ELISA products detected anti-SARS-CoV-2 IgM and IgG at days 2 and 6 then peaked on the eighth day; and the most promising CLIA product detected anti-SARS-CoV-2 at day 1 and peaked on the 30th day. The most promising LFA, ELISA and CLIA that had the best performance characteristics were those targeting total SARS-CoV-2 antibodies followed by those targeting anti-SARS-CoV-2 IgG then IgM. Essentially, the CLIA-based SARS-CoV-2 tests had the best performance characteristics, followed by ELISA then POCT. Given the varied performance characteristics of all the serological assays, there is a need to continuously improve their detection thresholds, as well as to monitor and re-evaluate their performances to assure their significance and applicability for COVID-19 clinical and epidemiological purposes.


Assuntos
COVID-19 , Humanos , Cinética , Pandemias , SARS-CoV-2 , Sensibilidade e Especificidade
9.
G3 (Bethesda) ; 12(2)2022 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-34897420

RESUMO

There is very little information about how the genome is regulated in domestic pigs (Sus scrofa). This lack of knowledge hinders efforts to define and predict the effects of genetic variants in pig breeding programs. To address this knowledge gap, we need to identify regulatory sequences in the pig genome starting with regions of open chromatin. We used the "Improved Protocol for the Assay for Transposase-Accessible Chromatin (Omni-ATAC-Seq)" to identify putative regulatory regions in flash-frozen semitendinosus muscle from 24 male piglets. We collected samples from the smallest-, average-, and largest-sized male piglets from each litter through five developmental time points. Of the 4661 ATAC-Seq peaks identified that represent regions of open chromatin, >50% were within 1 kb of known transcription start sites. Differential read count analysis revealed 377 ATAC-Seq defined genomic regions where chromatin accessibility differed significantly across developmental time points. We found regions of open chromatin associated with downregulation of genes involved in muscle development that were present in small-sized fetal piglets but absent in large-sized fetal piglets at day 90 of gestation. The dataset that we have generated provides a resource for studies of genome regulation in pigs and contributes valuable functional annotation information to filter genetic variants for use in genomic selection in pig breeding programs.


Assuntos
Cromatina , Sequências Reguladoras de Ácido Nucleico , Animais , Cromatina/genética , Sequenciamento de Cromatina por Imunoprecipitação , Feminino , Masculino , Músculos , Gravidez , Sus scrofa/genética , Suínos/genética
10.
Sci Rep ; 10(1): 21047, 2020 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-33273621

RESUMO

Monocytes are among the major myeloid cells that respond to Toxoplasma, a ubiquitous foodborne that infects ≥ 1 billion people worldwide, in human peripheral blood. As such, a molecular understanding of human monocyte-Toxoplasma interactions can expedite the development of novel human toxoplasmosis control strategies. Current molecular studies on monocyte-Toxoplasma interactions are based on average cell or parasite responses across bulk cell populations. Although informative, population-level averages of monocyte responses to Toxoplasma have sometimes produced contradictory results, such as whether CCL2 or IL12 define effective monocyte responses to the parasite. Here, we used single-cell dual RNA sequencing (scDual-Seq) to comprehensively define, for the first time, the monocyte and parasite transcriptional responses that underpin human monocyte-Toxoplasma encounters at the single cell level. We report extreme transcriptional variability between individual monocytes. Furthermore, we report that Toxoplasma-exposed and unexposed monocytes are transcriptionally distinguished by a reactive subset of CD14+CD16- monocytes. Functional cytokine assays on sorted monocyte populations show that the infection-distinguishing monocytes secrete high levels of chemokines, such as CCL2 and CXCL5. These findings uncover the Toxoplasma-induced monocyte transcriptional heterogeneity and shed new light on the cell populations that largely define cytokine and chemokine secretion in human monocytes exposed to Toxoplasma.


Assuntos
Monócitos/metabolismo , Toxoplasmose/metabolismo , Transcriptoma , Células Cultivadas , Humanos , RNA-Seq , Receptores de IgG/genética , Receptores de IgG/metabolismo , Análise de Célula Única , Toxoplasmose/genética
11.
Artigo em Inglês | MEDLINE | ID: mdl-33014886

RESUMO

The obligate intracellular parasite, Toxoplasma gondii, is highly prevalent among livestock species. Although cattle are generally resistant to Toxoplasma strains circulating in Europe and North America, the underlying mechanisms are largely unknown. Here, we report that bovine bone marrow-derived macrophage (BMDM) pre-stimulated with interferon gamma (IFNγ) restricts intracellular Toxoplasma growth independently of nitric oxide. While Toxoplasma promoted the expression of genes associated with alternative macrophage activation and lipid metabolism, IFNγ abrogated parasite-induced transcriptional responses and promoted the expression of genes linked to the classical macrophage activation phenotype. Additionally, several chemokines, including CCL22, that are linked to parasite-induced activation of the Wnt/ß-catenin signaling were highly expressed in Toxoplasma-exposed naïve BMDMs. A chemical Wnt/ß-catenin signaling pathway antagonist (IWR-1-endo) significantly reduced intracellular parasite burden in naïve BMDMs, suggesting that Toxoplasma activates this pathway to evade bovine macrophage anti-parasitic responses. Congruently, intracellular burden of a mutant Toxoplasma strain (RHΔASP5) that does not secrete dense granule proteins into the host cell, which is an essential requirement for parasite-induced activation of the Wnt/ß-catenin pathway, was significantly reduced in naïve BMDMs. However, both the Wnt/ß-catenin antagonist and RHASPΔ5 did not abolish parasite burden differences in naïve and IFNγ-stimulated BMDMs. Finally, we observed that parasites infecting IFNγ-stimulated BMDMs largely express genes associated with the slow dividing bradyzoite stage. Overall, this study provides novel insights into bovine macrophage transcriptional response to Toxoplasma. It establishes a foundation for a mechanistic analysis IFNγ-induced bovine anti-Toxoplasma responses and the counteracting Toxoplasma survival strategies.


Assuntos
Toxoplasma , Animais , Bovinos , Europa (Continente) , Ativação de Macrófagos , Macrófagos , América do Norte
12.
Nat Commun ; 11(1): 5258, 2020 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-33067458

RESUMO

Macrophages play an essential role in the early immune response against Toxoplasma and are the cell type preferentially infected by the parasite in vivo. Interferon gamma (IFNγ) elicits a variety of anti-Toxoplasma activities in macrophages. Using a genome-wide CRISPR screen we identify 353 Toxoplasma genes that determine parasite fitness in naїve or IFNγ-activated murine macrophages, seven of which are further confirmed. We show that one of these genes encodes dense granule protein GRA45, which has a chaperone-like domain, is critical for correct localization of GRAs into the PVM and secretion of GRA effectors into the host cytoplasm. Parasites lacking GRA45 are more susceptible to IFNγ-mediated growth inhibition and have reduced virulence in mice. Together, we identify and characterize an important chaperone-like GRA in Toxoplasma and provide a resource for the community to further explore the function of Toxoplasma genes that determine fitness in IFNγ-activated macrophages.


Assuntos
Interferon gama/imunologia , Macrófagos/imunologia , Toxoplasma/genética , Toxoplasmose/imunologia , Animais , Feminino , Genoma de Protozoário , Interações Hospedeiro-Parasita , Humanos , Interferon gama/genética , Macrófagos/parasitologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Toxoplasma/crescimento & desenvolvimento , Toxoplasma/metabolismo , Toxoplasma/patogenicidade , Toxoplasmose/genética , Toxoplasmose/parasitologia , Virulência
13.
J Equine Sci ; 31(1): 5-10, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32206033

RESUMO

A cross-sectional survey was conducted to determine the seroprevalence and risk factors influencing the presence of Brucella spp. antibodies in donkeys in Yobe south senatorial zone, Nigeria. The study was aimed at determining the importance of Brucella spp. infection in donkeys (Equus asinus). A total of 200 sera samples from of 105 males and 95 female donkeys were collected and screened for brucellosis using the rose bengal plate test (RBPT) and the indirect enzyme-linked immunosorbent assay (iELISA). Data obtained were analyzed to determine associations and risk factors. The analysis revealed that 21.5% and 18.5% were seropositive by RBPT and iELISA respectively, with 22.0% and 20.0% of the male and female donkeys being seropositive by RBPT, and 19.0% and 17.9% of the male and female donkeys being seropositive by iELISA, respectively. There was a statistically significant association between donkey age and positive rate of iELISA for detecting Brucella infection. Though the positive rate was higher for males than females, there was no statistically significant association between sex and location of donkeys and the sensitivities of RBPT and iELISA for detecting Brucella infection. In conclusion, this study indicates that brucellosis exists with high seroprevalence particularly among male and adult donkeys and is of public health significance and economic importance because it can lead to infertility and abortion in the stock.

14.
J Infect Public Health ; 13(4): 514-520, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31831393

RESUMO

BACKGROUND AND OBJECTIVES: This study provides a longitudinal scientometric analysis of global trypanosomiasis research between 1988 and 2017 as indexed in Clarivate Analytics' Web of Science (WoS). Contributions by researchers from different countries and continents are outlined based on publication productivity, international collaborations, citation analysis, and keyword analysis. METHODS: Bibliographic records of research publications indexed by WoS were downloaded based on a broad search of related terms. The authors compared the growth of literature by continent using 5-year increments, conducted a citation and co-authorship analysis by country, and a keyword analysis by publication using the scientometric visualization software VOSviewer. RESULTS: The trypanosomiasis research literature has seen more than a fourfold annual increase in production over the study period. Contributions by authors affiliated with European and South American countries proportionately account for the most research literature. The United States and Brazil, however, occupy central roles for citations and as national contributors to the literature. The terms 'trypanosomiasis cruzi' and 'chagas disease' have become more prominent, reflecting the regional growth of research from South America. INTERPRETATION AND CONCLUSION: Relative contributions from regions where the disease is prevalent show mixed developments. Contributions by African authors have declined proportionately to other areas of the world. However, South American contributions have increased during the study period. The contributing countries to the literature do not necessarily represent regions in which the diseases are prevalent. The same is true of the citation relationships, where European and North American contributions are more frequently cited.


Assuntos
Bibliometria , Pesquisa Biomédica/estatística & dados numéricos , Tripanossomíase , Animais , Europa (Continente) , Humanos , Cooperação Internacional , América do Sul , Trypanosoma , Estados Unidos
15.
Front Plant Sci ; 10: 1160, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31632417

RESUMO

Alternative splicing (AS) of pre-mRNAs contributes to transcriptome diversity and enables plants to generate different protein isoforms from a single gene and/or fine-tune gene expression during different development stages and environmental changes. Although AS is pervasive, the genetic basis for differential isoform usage in plants is still emerging. In this study, we performed genome-wide analysis in 666 geographically distributed diverse ecotypes of Arabidopsis thaliana to identify genomic regions [splicing quantitative trait loci (sQTLs)] that may regulate differential AS. These ecotypes belong to different microclimatic conditions and are part of the relict and non-relict populations. Although sQTLs were spread across the genome, we observed enrichment for trans-sQTL (trans-sQTLs hotspots) on chromosome one. Furthermore, we identified several sQTL (911) that co-localized with trait-linked single nucleotide polymorphisms (SNP) identified in the Arabidopsis genome-wide association studies (AraGWAS). Many sQTLs were enriched among circadian clock, flowering, and stress-responsive genes, suggesting a role for differential isoform usage in regulating these important processes in diverse ecotypes of Arabidopsis. In conclusion, the current study provides a deep insight into SNPs affecting isoform ratios/genes and facilitates a better mechanistic understanding of trait-associated SNPs in GWAS studies. To the best of our knowledge, this is the first report of sQTL analysis in a large set of Arabidopsis ecotypes and can be used as a reference to perform sQTL analysis in the Brassicaceae family. Since whole genome and transcriptome datasets are available for these diverse ecotypes, it could serve as a powerful resource for the biological interpretation of trait-associated loci, splice isoform ratios, and their phenotypic consequences to help produce more resilient and high yield crop varieties.

16.
mBio ; 10(1)2019 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-30622189

RESUMO

Upon invasion of Lewis rat macrophages, Toxoplasma rapidly induces programmed cell death (pyroptosis), which prevents Toxoplasma replication, possibly explaining the resistance of the Lewis rat to Toxoplasma Using a chemical mutagenesis screen, we identified Toxoplasma mutants that no longer induced pyroptosis. Whole-genome sequencing led to the identification of three Toxoplasma parasitophorous vacuole-localized dense granule proteins, GRA35, GRA42, and GRA43, that are individually required for induction of Lewis rat macrophage pyroptosis. Macrophage infection with Δgra35, Δgra42, and Δgra43 parasites led to greatly reduced cell death rates and enhanced parasite replication. Lewis rat macrophages infected with parasites containing a single, double, or triple deletion of these GRAs showed similar levels of cell viability, suggesting that the three GRAs function in the same pathway. Deletion of GRA42 or GRA43 resulted in GRA35 (and other GRAs) being retained inside the parasitophorous vacuole instead of being localized to the parasitophorous vacuole membrane. Despite having greatly enhanced replication in Lewis rat macrophages in vitro, Δgra35, Δgra42, and Δgra43 parasites did not establish a chronic infection in Lewis rats. Toxoplasma did not induce F344 rat macrophage pyroptosis, but F344 rats infected with Δgra35, Δgra42, and Δgra43 parasites had reduced cyst numbers. Thus, these GRAs determined parasite in vivo fitness in F344 rats. Overall, our data suggest that these three Toxoplasma dense granule proteins play a critical role in establishing a chronic infection in vivo, independently of their role in mediating macrophage pyroptosis, likely due to their importance in regulating protein localization to the parasitophorous vacuole membrane.IMPORTANCE Inflammasomes are major components of the innate immune system and are responsible for detecting various microbial and environmental danger signals. Upon invasion of Lewis rat macrophages, the parasite rapidly activates the NLRP1 inflammasome, resulting in pyroptosis and elimination of the parasite's replication niche. The work reported here revealed that Toxoplasma GRA35, GRA42, and GRA43 are required for induction of Lewis rat macrophage pyroptosis. GRA42 and GRA43 mediate the correct localization of other GRAs, including GRA35, to the parasitophorous vacuole membrane. These three GRAs were also found to be important for parasite in vivo fitness in a Toxoplasma-susceptible rat strain, independently of their role in NLRP1 inflammasome activation, suggesting that they perform other important functions. Thus, this study identified three GRAs that mediate the induction of Lewis rat macrophage pyroptosis and are required for pathogenesis of the parasite.


Assuntos
Interações Hospedeiro-Patógeno , Macrófagos/imunologia , Macrófagos/parasitologia , Proteínas de Protozoários/metabolismo , Piroptose , Toxoplasma/imunologia , Animais , Sobrevivência Celular , Células Cultivadas , Análise Mutacional de DNA , Deleção de Genes , Mutagênese , Proteínas de Protozoários/genética , Ratos Endogâmicos F344 , Ratos Endogâmicos Lew , Toxoplasma/genética , Sequenciamento Completo do Genoma
17.
Int J Parasitol ; 49(1): 63-70, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30471286

RESUMO

The severe virulence of Toxoplasma gondii in classical laboratory inbred mouse strains contradicts the hypothesis that house mice (Mus musculus) are the most important intermediate hosts for its transmission and evolution because death of the mouse before parasite transmission equals death of the parasite. However, the classical laboratory inbred mouse strains (Mus musculus domesticus), commonly used to test Toxoplasma strain differences in virulence, do not capture the genetic diversity within Mus musculus. Thus, it is possible that Toxoplasma strains that are severely virulent in laboratory inbred mice are avirulent in some other mouse sub-species. Here, we present insight into the responses of individual mouse strains, representing strains of the genetically divergent Mus musculus musculus, Mus musculus castaneus and Mus musculus domesticus, to infection with individual clonal and atypical Toxoplasma strains. We observed that, unlike M. m. domesticus, M. m. musculus and M. m. castaneus are resistant to the clonal Toxoplasma strains. For M. m. musculus, we show that this is due to a locus on chromosome 11 that includes the genes that encode the interferon gamma (IFNG)-inducible immunity-related GTPases (Irgs) that can kill the parasite by localising and subsequently vesiculating the parasitophorous vacuole membrane. However, despite the localization of known effector Irgs to the Toxoplasma parasitophorous vacuole membrane, we observed that some atypical Toxoplasma strains are virulent in all the mouse strains tested. The virulence of these atypical strains in M. m. musculus could not be attributed to individual rhoptry protein 5 (ROP5) alleles, a secreted parasite pseudokinase that antagonises the canonical effector Irgs and is indispensable for parasite virulence in laboratory inbred mice (M. m. domesticus). We conclude that murine resistance to Toxoplasma is modulated by complex interactions between host and parasite genotypes and may be independent of known effector Irgs on murine chromosome 11.


Assuntos
Resistência à Doença , Interações Hospedeiro-Patógeno , Camundongos/parasitologia , Toxoplasma/crescimento & desenvolvimento , Toxoplasma/imunologia , Toxoplasmose Animal/patologia , Toxoplasmose Animal/parasitologia , Animais , Camundongos/imunologia , Virulência
18.
J Wound Care ; 27(12): 885-890, 2018 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-30557106

RESUMO

OBJECTIVE: To assess the extra health-care costs and length of stay resulting from surgical site infection (SSI), as well as to identify the most frequent aetiological microorganisms of SSIs among Jordanian craniotomy surgery patients. METHOD: A retrospective, descriptive, correlational and nested 1:1 matched case-control design was used. A computerised list of patients, who underwent surgery between May 2009 and March 2015, was generated in the targeted hospital. A final bill for every selected patient was also determined. Patients were divided equally into two groups: patients with an SSI and patients without an SSI. RESULTS: A total of 64 patients were recruited. The SSI-group had a significant higher mean health-care cost of $7,899.08 (p=0.001) and a longer stay in hospital (mean additional days: 23.17) than the non-SSI group. Furthermore, Acinetobacter baumannii and Staphylococcus aureus were determined as the most predominant causative agents of SSI, at 39.1% and 26.1% of SSI patients, respectively. CONCLUSION: The results of this study can be considered as a baseline for national benchmarking to evaluate the quality of care provided to targeted patients. This study should encourage nurse administrators to adopt protocols and strategies that promote infection control measures, as well as to develop new methods of surveillance on universal precautions adherence. This may limit pathogen contamination in the surgical wound, shorten length of stay and decrease health-care costs.


Assuntos
Craniotomia/efeitos adversos , Custos de Cuidados de Saúde/estatística & dados numéricos , Tempo de Internação/economia , Infecção da Ferida Cirúrgica/etiologia , Infecção da Ferida Cirúrgica/terapia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Humanos , Jordânia , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
19.
BMC Genomics ; 18(1): 961, 2017 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-29228904

RESUMO

BACKGROUND: The lytic cycle of the protozoan parasite Toxoplasma gondii, which involves a brief sojourn in the extracellular space, is characterized by defined transcriptional profiles. For an obligate intracellular parasite that is shielded from the cytosolic host immune factors by a parasitophorous vacuole, the brief entry into the extracellular space is likely to exert enormous stress. Due to its role in cellular stress response, we hypothesize that translational control plays an important role in regulating gene expression in Toxoplasma during the lytic cycle. Unlike transcriptional profiles, insights into genome-wide translational profiles of Toxoplasma gondii are lacking. METHODS: We have performed genome-wide ribosome profiling, coupled with high throughput RNA sequencing, in intracellular and extracellular Toxoplasma gondii parasites to investigate translational control during the lytic cycle. RESULTS: Although differences in transcript abundance were mostly mirrored at the translational level, we observed significant differences in the abundance of ribosome footprints between the two parasite stages. Furthermore, our data suggest that mRNA translation in the parasite is potentially regulated by mRNA secondary structure and upstream open reading frames. CONCLUSION: We show that most of the Toxoplasma genes that are dysregulated during the lytic cycle are translationally regulated.


Assuntos
Biossíntese de Proteínas , Toxoplasma/genética , Regiões 5' não Traduzidas , Perfilação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Fases de Leitura Aberta , Ribossomos/metabolismo , Análise de Sequência de RNA
20.
Dimens Crit Care Nurs ; 36(4): 226-233, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28570376

RESUMO

BACKGROUND: There is a distinct gap between theory and practice with respect to research use in clinical practice, particularly in critical care units, that could be related to the presence of a number of barriers that hinder the use of research findings. AIMS: The aims of the study were to identify barriers and facilitators to research use as perceived by Jordanian nurses in critical care units and to examine the predictors of research use among those nurses. METHODS: The study used a cross-sectional, correlational design. The self-administered "Barriers Scale" was introduced to 200 registered critical care nurses, using the drop-and-collect technique, between October and November 2015. RESULTS: The results revealed that "nurse does not have time to read research at work" was the top ranked barrier that hinders research use (mean [SD], 3.45 [0.79]). The first 7 ranked barriers were related to the organizational subscale. Managerial support was the top perceived facilitator for research use. Only "attending special training courses in nursing research" was the significant predictor of research use and explained 59.1% of the variance in research use, t(190) = -3.93, P = .003. The most identified barriers toward research use revealed by the qualitative data include dominant routine nursing tasks, existence of gap between theory and practice, shortage of nursing staff, and public negative image about nursing profession. Participants suggested the importance of increasing organizational support and creating an organizational research culture to further promote research use in clinical nursing practice. CONCLUSIONS: Research use has not been widely implemented yet in Jordan because of various barriers. The organization-related barriers were the most influential. Factors hindering research use are multidimensional, and optimizing them should be a shared responsibility of nurse managers, researchers, clinicians, and academicians. Further initiatives are required to raise awareness of the importance of using evidence-based practice.


Assuntos
Enfermagem de Cuidados Críticos , Prática Clínica Baseada em Evidências , Pesquisa em Enfermagem , Recursos Humanos de Enfermagem Hospitalar , Adulto , Atitude do Pessoal de Saúde , Estudos Transversais , Feminino , Humanos , Jordânia , Masculino
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...