Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 86
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Mol Psychiatry ; 2020 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-31988436

RESUMO

Single nucleotide exact amplicon sequence variants (ASV) of the human gut microbiome were used to evaluate if individuals with a depression phenotype (DEPR) could be identified from healthy reference subjects (NODEP). Microbial DNA in stool samples obtained from 40 subjects were characterized using high throughput microbiome sequence data processed via DADA2 error correction combined with PIME machine-learning de-noising and taxa binning/parsing of prevalent ASVs at the single nucleotide level of resolution. Application of ALDEx2 differential abundance analysis with assessed effect sizes and stringent PICRUSt2 predicted metabolic pathways. This multivariate machine-learning approach significantly differentiated DEPR (n = 20) vs. NODEP (n = 20) (PERMANOVA P < 0.001) based on microbiome taxa clustering and neurocircuit-relevant metabolic pathway network analysis for GABA, butyrate, glutamate, monoamines, monosaturated fatty acids, and inflammasome components. Gut microbiome dysbiosis using ASV prevalence data may offer the diagnostic potential of using human metaorganism biomarkers to identify individuals with a depression phenotype.

2.
Mol Ecol Resour ; 20(2): 415-428, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31698527

RESUMO

The data used for profiling microbial communities is usually sparse with some microbes having high abundance in a few samples and being nearly absent in others. However, current bioinformatics tools able to deal with this sparsity are lacking. pime (Prevalence Interval for Microbiome Evaluation) was designed to remove those taxa that may be high in relative abundance in just a few samples but have a low prevalence overall. The reliability and robustness of pime were compared against existing methods and tested using 16S rRNA independent data sets. pime filters microbial taxa not shared in a per treatment prevalence interval started at 5% prevalence with increasing increments of 5% at each filtering step. For each prevalence interval, hundreds of decision trees were calculated to predict the likelihood of detecting differences in treatments. The best prevalence-filtered data set was user-selected by choosing the prevalence interval that kept a large portion of the 16S rRNA sequences in the data set while also showing the lowest error rate. To obtain the likelihood of introducing type I error while building prevalence-filtered data sets, an error detection step based was also included. A pime reanalysis of published data sets uncovered other expected microbial associations than previously reported, which may be masked when only relative abundance was considered.

3.
PLoS One ; 14(11): e0224288, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31738797

RESUMO

Bioinformatics, a discipline that combines aspects of biology, statistics, mathematics, and computer science, is becoming increasingly important for biological research. However, bioinformatics instruction is not yet generally integrated into undergraduate life sciences curricula. To understand why we studied how bioinformatics is being included in biology education in the US by conducting a nationwide survey of faculty at two- and four-year institutions. The survey asked several open-ended questions that probed barriers to integration, the answers to which were analyzed using a mixed-methods approach. The barrier most frequently reported by the 1,260 respondents was lack of faculty expertise/training, but other deterrents-lack of student interest, overly-full curricula, and lack of student preparation-were also common. Interestingly, the barriers faculty face depended strongly on whether they are members of an underrepresented group and on the Carnegie Classification of their home institution. We were surprised to discover that the cohort of faculty who were awarded their terminal degree most recently reported the most preparation in bioinformatics but teach it at the lowest rate.

4.
Artigo em Inglês | MEDLINE | ID: mdl-31768212

RESUMO

The Microbiology and Cell Science program at the University of Florida compressed two standard 16-week lab courses into five-day versions of the course, which are referred to as bootcamp labs. The bootcamp labs have the same objectives, activities, and assessments as their traditional counterparts. Development of the bootcamp labs was part of a larger effort to increase access to the major, and more broadly STEM, by offering a 2+2 hybrid online transfer program. The results of this mixed-methods study include a direct comparison between bootcamp and traditional lab format as an approach for delivery of a face-to-face lab course. The bootcamp lab cohort has a greater diversity of students, with more women and underrepresented minorities in STEM than the traditional semester-long cohorts. Students in the bootcamp labs have comparable grade outcomes and learning gains to students in traditional lab format. Regression analysis identified GPA, but not lab format, as the most significant predictor of success for students enrolled in lab courses. Qualitative results suggest that the bootcamp format may be a better way than traditional formats to teach microbiology lab. In summary, the results demonstrate that a bootcamp version of a face-to-face microbiology course is just as effective as the traditional semester-long version. This work has broader implications as it supports the bootcamp lab approach as a model in STEM education for increasing access and for overcoming a major barrier to online STEM programs: face-to-face delivery of key lab courses.

5.
BMC Microbiol ; 19(1): 222, 2019 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-31606047

RESUMO

BACKGROUND: Liberibacter crescens is the closest cultured relative of four important uncultured crop pathogens. Candidatus. L. asiaticus, L. americanus, L. africanus cause citrus greening disease, while Ca. L. solanacearum causes potato Zebra chip disease. None of the pathogens grows in axenic culture. L. crescens grows in three media: a BM-7, a serum-free Hi® Grace's Insect Medium (Hi-GI), and a chemically-defined medium called M15. To date, no optimal growth parameters of the model species L. crescens have been reported. Studying the main growth parameters of L. crescens in axenic culture will give us insights into the lifestyle of the Ca. Liberibacter pathogens. RESULTS: The evaluation of the growth parameters-pH, aeration, temperature, and buffering capacity-reflects the optimal living conditions of L. crescens. These variables revealed that L. crescens is an aerobic, neutrophilic bacterium, that grows optimally in broth in a pH range of 5.8 to 6.8, in a fully oxygenated environment (250 rpm), at 28 °C, and with monosodium phosphate (10 mM or 11.69 mM) as the preferred buffer for growth. The increase of pH in the external media likely results from the deamination activity within the cell, with the concomitant over-production of ammonium in the external medium. CONCLUSION: L. crescens and the Ca. Liberibacter pathogens are metabolically similar and grow in similar environments-the phloem and the gut of their insect vectors. The evaluation of the growth parameters of L. crescens reveals the lifestyle of Liberibacter, elucidating ammonium and phosphate as essential molecules for colonization within the hosts. Ammonium is the main driver of pH modulation by active deamination of amino acids in the L. crescens amino acid rich media. In plants, excess ammonium induces ionic imbalances, oxidative stress, and pH disturbances across cell membranes, causing stunted root and shoot growth and chlorosis-the common symptoms of HLB-disease. Phosphate, which is also present in Ca. L. asiaticus hosts, is the preferred buffer for the growth of L. crescens. The interplay between ammonium, sucrose, potassium (K+), phosphate, nitrate (NO3-), light and other photosynthates might lead to develop better strategies for disease management.

6.
Nat Commun ; 10(1): 3621, 2019 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-31399563

RESUMO

Susceptibility to many human autoimmune diseases is under strong genetic control by class II human leukocyte antigen (HLA) allele combinations. These genes remain by far the greatest risk factors in the development of type 1 diabetes and celiac disease. Despite this, little is known about HLA influences on the composition of the human gut microbiome, a potential source of environmental influence on disease. Here, using a general population cohort from the All Babies in Southeast Sweden study, we report that genetic risk for developing type 1 diabetes autoimmunity is associated with distinct changes in the gut microbiome. Both the core microbiome and beta diversity differ with HLA risk group and genotype. In addition, protective HLA haplotypes are associated with bacterial genera Intestinibacter and Romboutsia. Thus, general population cohorts are valuable in identifying potential environmental triggers or protective factors for autoimmune diseases that may otherwise be masked by strong genetic control.


Assuntos
Doenças Autoimunes/genética , Autoimunidade/genética , Diabetes Mellitus Tipo 1/imunologia , Microbioma Gastrointestinal/imunologia , Antígenos de Histocompatibilidade Classe II/genética , Alelos , Bactérias/classificação , Bactérias/genética , Biodiversidade , Doença Celíaca/genética , Criança , Pré-Escolar , Fezes/microbiologia , Predisposição Genética para Doença/genética , Genótipo , Haplótipos , Humanos , Lactente , RNA Ribossômico 16S/genética , Fatores de Risco , Suécia
7.
Appl Environ Microbiol ; 85(19)2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31350318

RESUMO

Differentiating between contamination and the genuine presence of 16S rRNA genes in gestational tissue samples is the gold standard for supporting the in utero colonization hypothesis. During gestation, the fetus undergoes significant physiological changes that may be directly affected by maternal colonization of key bacterial genera. In this study, lab benches, necropsy tables, and air ducts were swabbed at the same time as clinical sampling. The relative and absolute abundance of bacteria present in sheep samples was determined by culture-independent and culture-dependent means. Of 14 healthy pregnant ewes, there was no evidence of any bacteria in the fetal liver, spleen, or brain cortex using culture-independent techniques despite evidence of the presence of bacteria in various locations of the necropsy room used for 11 of these 14 sheep. Of the 336 bacterial genera found in the room swabs, only 12 (5%) were also found in the saliva and vaginal swabs among the three ewes for which bacteria were detected. These 12 taxa represent 1.32% of the relative abundance and approximately 393 16S rRNA copies/swab in these three ewes. Using careful necropsy protocols, bacterial contamination of sheep tissues was avoided. Contamination of saliva and vaginal samples was limited to less than 2% of the bacterial population.IMPORTANCE Recent evidence for a gestational microbiome suggests that active transfer between mother and fetus in utero is possible, and, therefore, actions must be taken to clarify the presence versus absence of these organisms in their respected sources. The value of this study is the differentiation between bacterial DNA identified in the necropsy rooms of animals and bacterial DNA whose origin is purely clinical in nature. We do not know the extent to which microorganisms traverse maternal tissues and infiltrate fetal circulation, so measures taken to control for contamination during sample processing are vital for addressing these concerns.

8.
PLoS One ; 14(6): e0217211, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31170184

RESUMO

Fetal development is thought to proceed in a sterile environment. Recent reports of the presence of bacterial DNA in human placenta, the transfer of live bacteria from mother to fetus after hypoxia in the pregnant sheep, and the presence of bacteria in the meconium of newborn infants have suggested that the fetus might be exposed to bacteria in utero. The present experiments were designed to test the hypothesis that small numbers of bacteria introduced into the maternal bloodstream (too few to induce fever or changes in maternal food consumption), can be found in the fetus days later. We injected 100 colony forming units of green-, red- and far red- fluorescent protein (GFP, RFP, FRFP) expressing S. aureus into late-gestation pregnant sheep intravenously. Five to 7 days later, the animals were euthanized and tissues collected for analysis of GFP. The inoculations did not cause any fever or other measurable behavioral response in the ewes, but did result in the appearance of GFP DNA, and protein in various tissues within the fetuses. Immunohistochemical analysis reveals GFP protein-containing bacteria that appear to be mostly contained within other cells. We were unable to recover any live GFP-expressing bacteria from the fetal tissues. We conclude that S. aureus, and perhaps other bacteria, gain access to the fetus, although it is not clear from these experiments that they survive in the fetus. It is possible that these low inocula and their progeny were effectively cleared by the fetal immune system.


Assuntos
Feto/microbiologia , Transmissão Vertical de Doença Infecciosa , Mães , Ovinos , Animais , Feminino , Viabilidade Microbiana , Gravidez , Staphylococcus aureus/fisiologia
10.
PLoS One ; 14(4): e0214582, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30939160

RESUMO

INTRODUCTION: The gut microbiome has been related to several features present in Glycogen Storage Diseases (GSD) patients including obesity, inflammatory bowel disease (IBD) and liver disease. OBJECTIVES: The primary objective of this study was to investigate associations between GSD and the gut microbiota. METHODS: Twenty-four GSD patients on treatment with uncooked cornstarch (UCCS), and 16 healthy controls had their faecal microbiota evaluated through 16S rRNA gene sequencing. Patients and controls were ≥3 years of age and not on antibiotics. Faecal pH, calprotectin, mean daily nutrient intake and current medications were recorded and correlated with gut microbiome. RESULTS: Patients' group presented higher intake of UCCS, higher prevalence of IBD (n = 04/24) and obesity/overweight (n = 18/24) compared to controls (n = 0 and 06/16, respectively). Both groups differed regarding diet (in patients, the calories' source was mainly the UCSS, and the intake of fat, calcium, sodium, and vitamins was lower than in controls), use of angiotensin-converting enzyme inhibitors (patients = 11, controls = 0; p-value = 0.001) multivitamins (patients = 22, controls = 01; p-value = 0.001), and mean faecal pH (patients = 6.23; controls = 7.41; p = 0.001). The GSD microbiome was characterized by low diversity and distinct microbial structure. The operational taxonomic unit (OTU) abundance was significantly influenced by faecal pH (r = 0.77; p = 6.8e-09), total carbohydrate (r = -0.6; p = 4.8e-05) and sugar (r = 0.057; p = 0.00013) intakes. CONCLUSIONS: GSD patients presented intestinal dysbiosis, showing low faecal microbial diversity in comparison with healthy controls. Those findings might be due to the disease per se, and/or to the different diets, use of UCSS and of medicines, and obesity rate found in patients. Although the main driver of these differences is unknown, this study might help to understand how the nutritional management affects GSD patients.


Assuntos
Disbiose , Doença de Depósito de Glicogênio/microbiologia , Doenças Inflamatórias Intestinais/microbiologia , Fígado/metabolismo , Adolescente , Inibidores da Enzima Conversora de Angiotensina , Estudos de Casos e Controles , Criança , Estudos Transversais , Ingestão de Energia , Fezes , Feminino , Microbioma Gastrointestinal , Doença de Depósito de Glicogênio/fisiopatologia , Humanos , Concentração de Íons de Hidrogênio , Inflamação , Doenças Inflamatórias Intestinais/fisiopatologia , Complexo Antígeno L1 Leucocitário , Masculino , Obesidade/complicações , Sobrepeso/complicações , Fenótipo , Análise de Componente Principal , RNA Ribossômico 16S/genética , Amido , Adulto Jovem
11.
PLoS One ; 13(6): e0196878, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29870542

RESUMO

Although bioinformatics is becoming increasingly central to research in the life sciences, bioinformatics skills and knowledge are not well integrated into undergraduate biology education. This curricular gap prevents biology students from harnessing the full potential of their education, limiting their career opportunities and slowing research innovation. To advance the integration of bioinformatics into life sciences education, a framework of core bioinformatics competencies is needed. To that end, we here report the results of a survey of biology faculty in the United States about teaching bioinformatics to undergraduate life scientists. Responses were received from 1,260 faculty representing institutions in all fifty states with a combined capacity to educate hundreds of thousands of students every year. Results indicate strong, widespread agreement that bioinformatics knowledge and skills are critical for undergraduate life scientists as well as considerable agreement about which skills are necessary. Perceptions of the importance of some skills varied with the respondent's degree of training, time since degree earned, and/or the Carnegie Classification of the respondent's institution. To assess which skills are currently being taught, we analyzed syllabi of courses with bioinformatics content submitted by survey respondents. Finally, we used the survey results, the analysis of the syllabi, and our collective research and teaching expertise to develop a set of bioinformatics core competencies for undergraduate biology students. These core competencies are intended to serve as a guide for institutions as they work to integrate bioinformatics into their life sciences curricula.


Assuntos
Biologia Computacional/educação , Competência Mental , Aprendizagem Baseada em Problemas , Adolescente , Adulto , Feminino , Humanos , Masculino , Estados Unidos
12.
PeerJ ; 6: e4991, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29915701

RESUMO

Soil microbial communities' assembly is strongly tied to changes in temperature and moisture. Although microbial functional redundancy seems to overcome taxonomical composition changes, the sensitivity and resilience of soil microbial communities from subtropical regions in response to seasonal variations are still poorly understood. Thus, the development of new strategies for biodiversity conservation and sustainable management require a complete understanding of the soil abiotic process involved in the selection of microbial taxa and functions. In this work, we used state of the art molecular methodologies (Next Generation Sequencing) to compare the taxonomic (metataxonomics) and functional (metatranscriptomics) profiles among soil samples from two subtropical natural grasslands located in the Pampa biome, Brazil, in response to short-term seasonal variations. Our data suggest that grasslands maintained a stable microbial community membership along the year with oscillation in abundance. Apparently soil microbial taxa are more susceptible to natural climatic disturbances while functions are more stable and change with less intensity along the year. Finally, our data allow us to conclude that the most abundant microbial groups and functions were shared between seasons and locations reflecting the existence of a stable taxonomical and functional core microbiota.

13.
Front Microbiol ; 9: 668, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29675013

RESUMO

Liberibacter crescens is the closest cultured relative of four important uncultured crop pathogens. Candidatus L. asiaticus, L. americanus, and L. africanus are causal agents of citrus greening disease, otherwise known as huanglongling (HLB). Candidatus L. solanacearum is responsible for potato Zebra chip disease. Cultures of L. crescens grow slowly on BM-7 complex medium, while attempts to culture the Ca. Liberibacter pathogens in BM-7 have failed. Developing a defined medium for the growth of L. crescens will be useful in the study of Liberibacter metabolism and will improve the prospects for culturing the Ca. Liberibacter pathogens. Here, M15 medium is presented and described as the first chemically defined medium for the growth of L. crescens cultures that approaches the growth rates obtained with BM-7. The development of M15 was a four step process including: (1) the identification of Hi-Graces Insect medium (Hi-GI) as an essential, yet undefined component in BM-7, for the growth of L. crescens, (2) metabolomic reconstruction of Hi-GI to create a defined medium for the growth of L. crescens cultures, and (3) the discovery of citrate as the preferred carbon and energy source for L. crescens growth. The composition of M15 medium includes inorganic salts as in the Hi-GI formula, amino acids derived from the metabolomic analyses of Hi-GI, and a 10-fold increase in vitamins compared to the Hi-GI formula, with exception choline chloride, which was increased 5000-fold in M15. Since genome comparisons of L. crescens and the Ca. Liberibacter pathogens show that they are very similar metabolically. Thus, these results imply citrate and other TCA cycle intermediates are main energy sources for these pathogens in their insect and plant hosts. Thus, strategies to reduce citrate levels in the habitats of these pathogens may be effective in reducing Ca. Liberibacter pathogen populations thereby reducing symptoms in the plant host.

15.
Nat Biotechnol ; 36(1): 61-69, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29227468

RESUMO

Shotgun metagenomics methods enable characterization of microbial communities in human microbiome and environmental samples. Assembly of metagenome sequences does not output whole genomes, so computational binning methods have been developed to cluster sequences into genome 'bins'. These methods exploit sequence composition, species abundance, or chromosome organization but cannot fully distinguish closely related species and strains. We present a binning method that incorporates bacterial DNA methylation signatures, which are detected using single-molecule real-time sequencing. Our method takes advantage of these endogenous epigenetic barcodes to resolve individual reads and assembled contigs into species- and strain-level bins. We validate our method using synthetic and real microbiome sequences. In addition to genome binning, we show that our method links plasmids and other mobile genetic elements to their host species in a real microbiome sample. Incorporation of DNA methylation information into shotgun metagenomics analyses will complement existing methods to enable more accurate sequence binning.


Assuntos
Metilação de DNA/genética , Metagenoma/genética , Metagenômica , Microbiota/genética , Algoritmos , Bactérias/genética , Análise por Conglomerados , Microbiologia Ambiental , Genoma Bacteriano/genética , Humanos , Plasmídeos/genética , Análise de Sequência de DNA
16.
JAMA Pediatr ; 171(12): 1217-1225, 2017 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-29052687

RESUMO

Importance: Evidence is lacking regarding the consequences of antibiotic use in early life and the risk of certain autoimmune diseases. Objective: To test the association between early-life antibiotic use and islet or celiac disease (CD) autoimmunity in genetically at-risk children prospectively followed up for type 1 diabetes (T1D) or CD. Design, Setting, and Participants: HLA-genotyped newborns from Finland, Germany, Sweden, and the United States were enrolled in the prospective birth cohort of The Environmental Determinants of Diabetes in the Young (TEDDY) study between November 20, 2004, and July 8, 2010. The dates of analysis were November 20, 2004, to August 31, 2014. Individuals from the general population and those having a first-degree relative with T1D were enrolled if they had 1 of 9 HLA genotypes associated with a risk for T1D. Exposures: Parental reports of the most common antibiotics (cephalosporins, penicillins, and macrolides) used between age 3 months and age 4 years were recorded prospectively. Main Outcomes and Measures: Islet autoimmunity and CD autoimmunity were defined as being positive for islet or tissue transglutaminase autoantibodies at 2 consecutive clinic visits at least 3 months apart. Hazard ratios and 95% CIs calculated from Cox proportional hazards regression models were used to assess the relationship between antibiotic use in early life before seroconversion and the development of autoimmunity. Results: Participants were 8495 children (49.0% female) and 6558 children (48.7% female) enrolled in the TEDDY study who were tested for islet and tissue transglutaminase autoantibodies, respectively. Exposure to and frequency of use of any antibiotic assessed in this study in early life or before seroconversion did not influence the risk of developing islet autoimmunity or CD autoimmunity. Cumulative use of any antibiotic during the first 4 years of life was not associated with the appearance of any autoantibody (hazard ratio [HR], 0.98; 95% CI, 0.95-1.01), multiple islet autoantibodies (HR, 0.99; 95% CI, 0.95-1.03), or the transglutaminase autoantibody (HR, 1.00; 95% CI, 0.98-1.02). Conclusions and Relevance: The use of the most prescribed antibiotics during the first 4 years of life, regardless of geographic region, was not associated with the development of autoimmunity for T1D or CD. These results suggest that a risk of islet or tissue transglutaminase autoimmunity need not influence the recommendations for clinical use of antibiotics in young children at risk for T1D or CD.


Assuntos
Antibacterianos/efeitos adversos , Doenças Autoimunes/induzido quimicamente , Doença Celíaca/induzido quimicamente , Diabetes Mellitus Tipo 1/induzido quimicamente , Fatores Etários , Antibacterianos/administração & dosagem , Autoanticorpos/sangue , Doenças Autoimunes/epidemiologia , Doenças Autoimunes/genética , Doença Celíaca/epidemiologia , Doença Celíaca/genética , Pré-Escolar , Diabetes Mellitus Tipo 1/epidemiologia , Diabetes Mellitus Tipo 1/genética , Relação Dose-Resposta a Droga , Esquema de Medicação , Uso de Medicamentos/estatística & dados numéricos , Europa (Continente)/epidemiologia , Feminino , Seguimentos , Predisposição Genética para Doença , Antígenos HLA-DR/genética , Teste de Histocompatibilidade , Humanos , Lactente , Ilhotas Pancreáticas/imunologia , Masculino , Estudos Prospectivos , Medição de Risco/métodos , Sensibilidade e Especificidade , Estados Unidos/epidemiologia
17.
Sci Rep ; 7(1): 6458, 2017 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-28743956

RESUMO

Herein we describe an association between activation of inflammatory pathways following transient hypoxia and the appearance of the multidrug resistant bacteria Staphylococcus simulans in the fetal brain. Reduction of maternal arterial oxygen tension by 50% over 30 min resulted in a subseiuent significant over-expression of genes associated with immune responses 24 h later in the fetal brain. The activated genes were consistent with stimulation by bacterial lipopolysaccharide; an influx of macrophages and appearance of live bacteria were found in these fetal brains. S. simulans was the predominant bacterial species in fetal brain after hypoxia, but was found in placenta of all animals. Strains of S. simulans from the placenta and fetal brain were equally highly resistant to multiple antibiotics including methicillin and had identical genome sequences. These results suggest that bacteria from the placenta invade the fetal brain after maternal hypoxia.


Assuntos
Encéfalo/microbiologia , Farmacorresistência Bacteriana Múltipla , Hipóxia Fetal/complicações , Placenta/microbiologia , Staphylococcus/patogenicidade , Animais , Encéfalo/embriologia , Encéfalo/patologia , Feminino , Hipóxia Fetal/patologia , Hipóxia Fetal/fisiopatologia , Regulação da Expressão Gênica no Desenvolvimento , Macrófagos/patologia , Microglia/patologia , Gravidez , Ovinos , Staphylococcus/efeitos dos fármacos , Staphylococcus/genética
18.
Eur J Protistol ; 61(Pt B): 359-365, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28595932

RESUMO

Bromeliads are a diverse group of plants that includes many species whose individuals are capable of retaining water, forming habitats called phytotelmata. These habitats harbor a diversity of organisms including prokaryotes, unicellular eukaryotes, metazoans, and fungi. Among single-celled eukaryotic organisms, ciliates are generally the most abundant. In the present study, we used Illumina DNA sequencing to survey the eukaryotic communities, especially ciliates, inhabiting the tanks of the bromeliads Aechmea gamosepala and Vriesea platynema in the Atlantic Forest of southern Brazil. Filtered sequences were clustered into distinct OTUs using a 99% identity threshold, and then assigned to phylum and genus using a BLAST-based approach (implemented in QIIME) and the SILVA reference database. Both bromeliad species harbored very diverse eukaryotic communities, with Arthropoda and Ciliophora showing the highest abundance (as estimated by the number of sequence reads). The ciliate genus Tetrahymena was the most abundant among single-celled organisms, followed by apicomplexan gregarines and the ciliate genus Glaucoma. Another interesting finding was the presence and high abundance of Trypanosoma in these bromeliad tanks, demonstrating their occurrence in this type of environment. The results presented here demonstrate a hidden diversity of eukaryotes in bromeliad tank waters, opening up new avenues for their in-depth characterization.


Assuntos
Biodiversidade , Bromeliaceae , Cilióforos/fisiologia , Brasil , Cilióforos/classificação , Cilióforos/genética , DNA de Protozoário/genética , Florestas , Água/parasitologia
19.
Clin Gastroenterol Hepatol ; 15(5): 694-702.e5, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27840181

RESUMO

BACKGROUND & AIMS: Little is known about the pathogenic mechanisms of gluten immunogenicity in patients with celiac disease. We studied temporal associations between infections and the development of celiac disease autoimmunity, and examined effects of HLA alleles, rotavirus vaccination status, and infant feeding. METHODS: We monitored 6327 children in the United States and Europe carrying HLA risk genotypes for celiac disease from 1 to 4 years of age for presence of tissue transglutaminase autoantibodies (the definition of celiac disease autoimmunity), until March 31, 2015. Parental reports of gastrointestinal and respiratory infections were collected every third month from birth. We analyzed time-varying relationships among reported infections, rotavirus vaccination status, time to first introduction of gluten, breastfeeding, and risk of celiac disease autoimmunity using proportional hazard models. RESULTS: We identified 13,881 gastrointestinal infectious episodes (GIE) and 79,816 respiratory infectious episodes. During the follow-up period, 732 of 6327 (11.6%) children developed celiac disease autoimmunity. A GIE increased the risk of celiac disease autoimmunity within the following 3 months by 33% (hazard ratio [HR], 1.33; 95% confidence interval [CI], 1.11-1.59). This risk increased 2-fold among children born in winter and introduced to gluten before age 6 months (HR, 2.08; 95% CI, 1.46-2.98), and increased 10-fold among children without HLA-DQ2 alleles and breastfed for fewer than 4 months (HR, 9.76; 95% CI, 3.87-24.8). Risk of celiac disease autoimmunity was reduced in children vaccinated against rotavirus and introduced to gluten before age 6 months (HR, 0.57; 95% CI, 0.36-0.88). CONCLUSIONS: Gastrointestinal infections increase the risk of celiac disease autoimmunity in children with genetic susceptibility to this autoimmune disorder. The risk is modified by HLA genotype, infant gluten consumption, breastfeeding, and rotavirus vaccination, indicating complex interactions among infections, genetic factors, and diet in the etiology of celiac disease in early childhood.


Assuntos
Doença Celíaca/epidemiologia , Doença Celíaca/etiologia , Gastroenterite/complicações , Adulto , Pré-Escolar , Dieta/métodos , Suscetibilidade a Doenças , Europa (Continente)/epidemiologia , Feminino , Genótipo , Antígenos HLA/genética , Humanos , Lactente , Recém-Nascido , Masculino , Estudos Prospectivos , Infecções Respiratórias/complicações , Medição de Risco , Rotavirus/imunologia , Vacinas contra Rotavirus/administração & dosagem , Estados Unidos/epidemiologia
20.
Front Microbiol ; 8: 2491, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29312199

RESUMO

Here, the genes encoding three different fluorescent proteins were cloned into the stably maintained Staphylococcus aureus shuttle vector pKK30. The resulting plasmids were transformed into two S. aureus strains; SH1000 and RN4220. Stability assays illustrated that the three recombinant plasmids retained near 100% maintenance in vitro for 160 generations. S. aureus strain SH1000 expressing green fluorescent protein was then inoculated in an ovine model and in vivo stability for 6 days was demonstrated. In essence, these reporter plasmids represent a useful set of tools for dynamic imaging studies in S. aureus. These three reporter plasmids are available through BEI Resources.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA