Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 59
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Artigo em Inglês | MEDLINE | ID: mdl-31714477

RESUMO

OBJECTIVES: Microbial communities influencing health and disease are being increasingly studied in preterm neonates. However, there exists little data detailing longitudinal microbial acquisition, especially in the most extremely preterm (<26 weeks gestation). This study aims to characterise the development of the microbiota in this previously under-represented cohort. METHODS: Seven extremely preterm infant-mother dyads (mean gestation 23.6 weeks) were recruited from a single neonatal intensive care unit. Oral and endotracheal secretions, stool and breast milk (n = 157 total), were collected over the first 60 days of life. Targeted 16S rRNA gene sequencing identified bacterial communities present. RESULTS: Microbiota of all body sites were most similar immediately following birth and diverged longitudinally. Throughout the sampling period Escherichia, Enterococcus, Staphylococcus and an Enterobacteriaceae were dominant and well dispersed across all sites. Temporal divergence of the stool from other microbiota was driven by decreasing diversity and significantly greater proportional abundance of Bifidobacteriaceae compared to other sites. CONCLUSIONS: Four taxa dominated all anatomical sampling sites. Rare taxa promoted dissimilarity. Cross- seeding between upstream communities and the stool was demonstrated, possibly relating to buccal colostrum / breast milk exposure and indwelling tubes. Given the importance of dysbiosis in health and disease of extremely preterm infants better understanding of microbial acquisition within this context may be of clinical benefit.

2.
Lancet Infect Dis ; 2019 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-31630990

RESUMO

BACKGROUND: Influenza viruses cause substantial annual morbidity and mortality globally. Current vaccines protect against influenza only when well matched to the circulating strains. However, antigenic drift can cause considerable mismatches between vaccine and circulating strains, substantially reducing vaccine effectiveness. Moreover, current seasonal vaccines are ineffective against pandemic influenza, and production of a vaccine matched to a newly emerging virus strain takes months. Therefore, there is an unmet medical need for a broadly protective influenza virus vaccine. We aimed to test the ability of chimeric H1 haemagglutinin-based universal influenza virus vaccine candidates to induce broadly cross-reactive antibodies targeting the stalk domain of group 1 haemagglutinin-expressing influenza viruses. METHODS: We did a randomised, observer-blinded, phase 1 study in healthy adults in two centres in the USA. Participants were randomly assigned to one of three prime-boost, chimeric haemagglutinin-based vaccine regimens or one of two placebo groups. The vaccine regimens included a chimeric H8/1, intranasal, live-attenuated vaccine on day 1 followed by a non-adjuvanted, chimeric H5/1, intramuscular, inactivated vaccine on day 85; the same regimen but with the inactivated vaccine being adjuvanted with AS03; and an AS03-adjuvanted, chimeric H8/1, intramuscular, inactivated vaccine followed by an AS03-adjuvanted, chimeric H5/1, intramuscular, inactivated vaccine. In this planned interim analysis, the primary endpoints of reactogenicity and safety were assessed by blinded study group. We also assessed anti-H1 haemagglutinin stalk, anti-H2, anti-H9, and anti-H18 IgG antibody titres and plasmablast and memory B-cell responses in peripheral blood. This trial is registered with ClinicalTrials.gov, number NCT03300050. FINDINGS: Between Oct 10, 2017, and Nov 27, 2017, 65 participants were enrolled and randomly assigned. The adjuvanted inactivated vaccine, but not the live-attenuated vaccine, induced a substantial serum IgG antibody response after the prime immunisation, with a seven times increase in anti-H1 stalk antibody titres on day 29. After boost immunisation, all vaccine regimens induced detectable anti-H1 stalk antibody (2·2-5·6 times induction over baseline), cross-reactive serum IgG antibody, and peripheral blood plasmablast responses. An unsolicited adverse event was reported for 29 (48%) of 61 participants. Solicited local adverse events were reported in 12 (48%) of 25 participants following prime vaccination with intramuscular study product or placebo, in 12 (33%) of 36 after prime immunisation with intranasal study product or placebo, and in 18 (32%) of 56 following booster doses of study product or placebo. Solicited systemic adverse events were reported in 14 (56%) of 25 after prime immunisation with intramuscular study product or placebo, in 22 (61%) of 36 after immunisation with intranasal study product or placebo, and in 21 (38%) of 56 after booster doses of study product or placebo. Disaggregated safety data were not available at the time of this interim analysis. INTERPRETATION: The tested chimeric haemagglutinin-based, universal influenza virus vaccine regimens elicited cross-reactive serum IgG antibodies that targeted the conserved haemagglutinin stalk domain. This is the first proof-of-principle study to show that high anti-stalk titres can be induced by a rationally designed vaccine in humans and opens up avenues for further development of universal influenza virus vaccines. On the basis of the blinded study group, the vaccine regimens were tolerable and no safety concerns were observed. FUNDING: Bill & Melinda Gates Foundation.

3.
Lancet ; 394(10193): 148-158, 2019 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-31174831

RESUMO

BACKGROUND: Use of oral live-attenuated polio vaccines (OPV), and injected inactivated polio vaccines (IPV) has almost achieved global eradication of wild polio viruses. To address the goals of achieving and maintaining global eradication and minimising the risk of outbreaks of vaccine-derived polioviruses, we tested novel monovalent oral type-2 poliovirus (OPV2) vaccine candidates that are genetically more stable than existing OPVs, with a lower risk of reversion to neurovirulence. Our study represents the first in-human testing of these two novel OPV2 candidates. We aimed to evaluate the safety and immunogenicity of these vaccines, the presence and extent of faecal shedding, and the neurovirulence of shed virus. METHODS: In this double-blind, single-centre phase 1 trial, we isolated participants in a purpose-built containment facility at the University of Antwerp Hospital (Antwerp, Belgium), to minimise the risk of environmental release of the novel OPV2 candidates. Participants, who were recruited by local advertising, were adults (aged 18-50 years) in good health who had previously been vaccinated with IPV, and who would not have any contact with immunosuppressed or unvaccinated people for the duration of faecal shedding at the end of the study. The first participant randomly chose an envelope containing the name of a vaccine candidate, and this determined their allocation; the next 14 participants to be enrolled in the study were sequentially allocated to this group and received the same vaccine. The subsequent 15 participants enrolled after this group were allocated to receive the other vaccine. Participants and the study staff were masked to vaccine groups until the end of the study period. Participants each received a single dose of one vaccine candidate (candidate 1, S2/cre5/S15domV/rec1/hifi3; or candidate 2, S2/S15domV/CpG40), and they were monitored for adverse events, immune responses, and faecal shedding of the vaccine virus for 28 days. Shed virus isolates were tested for the genetic stability of attenuation. The primary outcomes were the incidence and type of serious and severe adverse events, the proportion of participants showing viral shedding in their stools, the time to cessation of viral shedding, the cell culture infective dose of shed virus in virus-positive stools, and a combined index of the prevalence, duration, and quantity of viral shedding in all participants. This study is registered with EudraCT, number 2017-000908-21 and ClinicalTrials.gov, number NCT03430349. FINDINGS: Between May 22 and Aug 22, 2017, 48 volunteers were screened, of whom 15 (31%) volunteers were excluded for reasons relating to the inclusion or exclusion criteria, three (6%) volunteers were not treated because of restrictions to the number of participants in each group, and 30 (63%) volunteers were sequentially allocated to groups (15 participants per group). Both novel OPV2 candidates were immunogenic and increased the median blood titre of serum neutralising antibodies; all participants were seroprotected after vaccination. Both candidates had acceptable tolerability, and no serious adverse events occurred during the study. However, severe events were reported in six (40%) participants receiving candidate 1 (eight events) and nine (60%) participants receiving candidate 2 (12 events); most of these events were increased blood creatinine phosphokinase but were not accompanied by clinical signs or symptoms. Vaccine virus was detected in the stools of 15 (100%) participants receiving vaccine candidate 1 and 13 (87%) participants receiving vaccine candidate 2. Vaccine poliovirus shedding stopped at a median of 23 days (IQR 15-36) after candidate 1 administration and 12 days (1-23) after candidate 2 administration. Total shedding, described by the estimated median shedding index (50% cell culture infective dose/g), was observed to be greater with candidate 1 than candidate 2 across all participants (2·8 [95% CI 1·8-3·5] vs 1·0 [0·7-1·6]). Reversion to neurovirulence, assessed as paralysis of transgenic mice, was low in isolates from those vaccinated with both candidates, and sequencing of shed virus indicated that there was no loss of attenuation in domain V of the 5'-untranslated region, the primary site of reversion in Sabin OPV. INTERPRETATION: We found that the novel OPV2 candidates were safe and immunogenic in IPV-immunised adults, and our data support the further development of these vaccines to potentially be used for maintaining global eradication of neurovirulent type-2 polioviruses. FUNDING: Bill & Melinda Gates Foundation.


Assuntos
Imunogenicidade da Vacina , Vacina Antipólio Oral/efeitos adversos , Vacina Antipólio Oral/imunologia , Poliovirus/imunologia , Adulto , Anticorpos Antivirais/sangue , Método Duplo-Cego , Fezes/virologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Poliomielite/prevenção & controle , Vacina Antipólio Oral/administração & dosagem , RNA Viral/análise , Método Simples-Cego , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/efeitos adversos , Vacinas Atenuadas/imunologia , Virulência/imunologia , Eliminação de Partículas Virais/imunologia , Adulto Jovem
5.
Artigo em Inglês | MEDLINE | ID: mdl-30224525

RESUMO

We evaluated the effects of rifampin coadministration and MDR1 single nucleotide polymorphisms on the disposition of daptomycin in twelve healthy adults. There were no significant changes from baseline in the clearance (0.53 versus 0.55 liters/h, P = 1.00), volume of distribution (7.0 versus 7.2 liter, P = 0.62), or half-life (9.7 versus 9.6 h, P = 0.89) of daptomycin after exposure to rifampin. The tested MDR1 polymorphisms were not associated with significant differences in daptomycin disposition.

6.
Front Microbiol ; 9: 168, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29503632

RESUMO

Microbial communities closely associated with the rhizosphere can have strong positive and negative impacts on plant health and growth. We used a group-specific amplicon approach to investigate local scale drivers in the diversity and distribution of plasmodiophorids in rhizosphere/root and bulk soil samples from oilseed rape (OSR) and wheat agri-systems. Plasmodiophorids are plant- and stramenopile-associated protists including well known plant pathogens as well as symptomless endobiotic species. We detected 28 plasmodiophorid lineages (OTUs), many of them novel, and showed that plasmodiophorid communities were highly dissimilar and significantly divergent between wheat and OSR rhizospheres and between rhizosphere and bulk soil samples. Bulk soil communities were not significantly different between OSR and wheat systems. Wheat and OSR rhizospheres selected for different plasmodiophorid lineages. An OTU corresponding to Spongospora nasturtii was positively selected in the OSR rhizosphere, as were two genetically distinct OTUs. Two novel lineages related to Sorosphaerula veronicae were significantly associated with wheat rhizosphere samples, indicating unknown plant-protist relationships. We show that group-targeted eDNA approaches to microbial symbiont-host ecology reveal significant novel diversity and enable inference of differential activity and potential interactions between sequence types, as well as their presence.

7.
New Phytol ; 220(4): 1172-1184, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29350759

RESUMO

Global warming is resulting in increased frequency of weather extremes. Root-associated fungi play important roles in terrestrial biogeochemical cycling processes, but the way in which they are affected by extreme weather is unclear. Here, we performed long-term field monitoring of the root-associated fungus community of a short rotation coppice willow plantation, and compared community dynamics before and after a once in 100 yr rainfall event that occurred in the UK in 2012. Monitoring of the root-associated fungi was performed over a 3-yr period by metabarcoding the fungal internal transcribed spacer (ITS) region. Repeated soil testing and continuous climatic monitoring supplemented community data, and the relative effects of environmental and temporal variation were determined on the root-associated fungal community. Soil saturation and surface water were recorded throughout the early growing season of 2012, following extreme rainfall. This was associated with a crash in the richness and relative abundance of ectomycorrhizal fungi, with each declining by over 50%. Richness and relative abundance of saprophytes and pathogens increased. We conclude that extreme rainfall events may be important yet overlooked determinants of root-associated fungal community assembly. Given the integral role of ectomycorrhizal fungi in biogeochemical cycles, these events may have considerable impacts upon the functioning of terrestrial ecosystems.

8.
Sci Rep ; 7(1): 10493, 2017 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-28874831

RESUMO

Sequestration of atmospheric CO2 as organic carbon by agricultural soils (SOC) is promoted as a climate change mitigation option. IPCC provides guidelines for determining carbon stocks and sequestration potential, incentivising policy changes towards management of farmland for carbon sequestration. However, the basis of the assumption that agricultural soils can sequester significant atmospheric CO2 has been questioned. We sought to determine the potential for conversion of arable cropland to grassland to sequester carbon in the short to medium term and potential limiting factors. There were no differences in SOC stocks in the top 30 cm between grassland up to 17 years old and arable cropland at 14 sites across the UK. However, SOC showed different distribution patterns, being concentrated in the top 10 cm under grassland. Soil microbial communities were significantly different between arable and grassland, with higher biomass and lesser dominance by bacteria in grassland soils. A land use conversion experiment showed these changes occurred within one year of land use change. Failure of grassland soils to accumulate SOC was attributed to reduced available soil nitrogen, resulting in low productivity. The implications of these results for carbon sequestration in soils as a climate change mitigation strategy are discussed.

9.
Artigo em Inglês | MEDLINE | ID: mdl-28634574

RESUMO

Necrotising enterocolitis (NEC) and sepsis are serious diseases of preterm infants that can result in feeding intolerance, the need for bowel resection, impaired physiological and neurological development, and high mortality rates. Neonatal healthcare improvements have allowed greater survival rates in preterm infants leading to increased numbers at risk of developing NEC and sepsis. Gut bacteria play a role in protection from or propensity to these conditions and have therefore, been studied extensively using targeted 16S rRNA gene sequencing methods. However, exact epidemiology of these conditions remain unknown and the role of the gut microbiota in NEC remains enigmatic. Many studies have confounding variables such as differing clinical intervention strategies or major methodological issues such as the inability of 16S rRNA gene sequencing methods to determine viable from non-viable taxa. Identification of viable community members is important to identify links between the microbiota and disease in the highly unstable preterm infant gut. This is especially important as remnant DNA is robust and persists in the sampling environment following cell death. Chelation of such DNA prevents downstream amplification and inclusion in microbiota characterisation. This study validates use of propidium monoazide (PMA), a DNA chelating agent that is excluded by an undamaged bacterial membrane, to reduce bias associated with 16S rRNA gene analysis of clinical stool samples. We aim to improve identification of the viable microbiota in order to increase the accuracy of clinical inferences made regarding the impact of the preterm gut microbiota on health and disease. Gut microbiota analysis was completed on stools from matched twins (n = 16) that received probiotics. Samples were treated with PMA, prior to bacterial DNA extraction. Meta-analysis highlighted a significant reduction in bacterial diversity in 68.8% of PMA treated samples as well as significantly reduced overall rare taxa abundance. Importantly, overall abundances of genera associated with protection from and propensity to NEC and sepsis such as: Bifidobacterium; Clostridium, and Staphylococcus sp. were significantly different following PMA-treatment. These results suggest non-viable cell exclusion by PMA-treatment reduces bias in gut microbiota analysis from which clinical inferences regarding patient susceptibility to NEC and sepsis are made.


Assuntos
Bactérias/classificação , Enterocolite Necrosante/microbiologia , Microbioma Gastrointestinal , Trato Gastrointestinal/microbiologia , Azidas , Bactérias/genética , Bactérias/isolamento & purificação , Viés , Biodiversidade , DNA Bacteriano/genética , Enterocolite Necrosante/epidemiologia , Enterocolite Necrosante/mortalidade , Fezes/microbiologia , Humanos , Lactente , Recém-Nascido Prematuro , Reação em Cadeia da Polimerase , Probióticos/uso terapêutico , Propídio/análogos & derivados , RNA Ribossômico 16S/genética , Taxa de Sobrevida
10.
Gut Microbes ; 8(4): 359-365, 2017 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-28112583

RESUMO

Siblings of patients with Crohn's disease (CD) have elevated risk of developing CD and display aspects of disease phenotype, including faecal dysbiosis. In our recent article we have used 16S rRNA gene targeted high-throughput sequencing to comprehensively characterize the mucosal microbiota in healthy siblings of CD patients, and determine the influence of genotypic and phenotypic factors on the gut microbiota (dysbiosis). We have demonstrated that the core microbiota of both patients with CD and healthy siblings is significantly less diverse than controls. Faecalibacterium prausnitzii contributed most to core metacommunity dissimilarity between both patients and controls and between siblings and controls. Phenotype/genotype markers of CD risk significantly influenced microbiota variation between and within groups, of which genotype had the largest effect. Individuals with elevated CD-risk display mucosal dysbiosis characterized by reduced diversity of core microbiota and lower abundance of F. prausnitzii. The presence of this dysbiosis in healthy people at-risk of CD implicates microbiological processes in CD pathogenesis.


Assuntos
Bactérias/isolamento & purificação , Microbioma Gastrointestinal , Doenças Inflamatórias Intestinais/microbiologia , Irmãos , Bactérias/classificação , Bactérias/genética , Disbiose/microbiologia , Feminino , Genótipo , Humanos , Masculino , Fenótipo
11.
ISME J ; 11(3): 663-675, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27983724

RESUMO

Infection by gastrointestinal helminths of humans, livestock and wild animals is common, but the impact of such endoparasites on wild hosts and their gut microbiota represents an important overlooked component of population dynamics. Wild host gut microbiota and endoparasites occupy the same physical niche spaces with both affecting host nutrition and health. However, associations between the two are poorly understood. Here we used the commonly parasitized European shag (Phalacrocorax aristotelis) as a model wild host. Forty live adults from the same colony were sampled. Endoscopy was employed to quantify helminth infection in situ. Microbiota from the significantly distinct proventriculus (site of infection), cloacal and faecal gastrointestinal tract microbiomes were characterised using 16S rRNA gene-targeted high-throughput sequencing. We found increasingly strong associations between helminth infection and microbiota composition progressing away from the site of infection, observing a pronounced dysbiosis in microbiota when samples were partitioned into high- and low-burden groups. We posit this dysbiosis is predominately explained by helminths inducing an anti-inflammatory environment in the proventriculus, diverting host immune responses away from themselves. This study, within live wild animals, provides a vital foundation to better understand the mechanisms that underpin the three-way relationship between helminths, microbiota and hosts.


Assuntos
Infecções por Ascaridida/veterinária , Ascaridoidea/classificação , Ascaridoidea/isolamento & purificação , Doenças das Aves/parasitologia , Aves , Trato Gastrointestinal/parasitologia , Animais , Infecções por Ascaridida/parasitologia , Ascaridoidea/genética , Aves/classificação , Feminino , Masculino
12.
Chemosphere ; 164: 355-362, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27596822

RESUMO

In order to predict the fate of chemicals in the environment, a range of regulatory tests are performed with microbial inocula collected from environmental compartments to investigate the potential for biodegradation. The abundance and distribution of microbes in the environment is affected by a range of variables, hence diversity and biomass of inocula used in biodegradation tests can be highly variable in space and time. The use of artificial or natural biofilms in regulatory tests could enable more consistent microbial communities be used as inocula, in order to increase test consistency. We investigated spatial and temporal variation in composition, biomass and chemical biodegradation potential of bacterial biofilms formed in river water. Sampling time and sampling location impacted the capacity of biofilms to degrade p-nitrophenol (PNP). Biofilm bacterial community structure varied across sampling times, but was not affected by sampling location. Degradation of PNP was associated with increased relative abundance of Pseudomonas syringae. Partitioning of the bacterial metacommunity into core and satellite taxa revealed that the P. syringae could be either a satellite or core member of the community across sampling times, but this had no impact on PNP degradation. Quantitative PCR analysis of the pnpA gene showed that it was present in all samples irrespective of their ability to degrade PNP. River biofilms showed seasonal variation in biomass, microbial community composition and PNP biodegradation potential, which resulted in inconsistent biodegradation test results. We discuss the results in the context of the mechanisms underlying variation in regulatory chemical degradation tests.


Assuntos
Biofilmes/crescimento & desenvolvimento , Água Doce/análise , Nitrofenóis/metabolismo , Pseudomonas syringae/metabolismo , Poluentes Químicos da Água/metabolismo , Biodegradação Ambiental , Biomassa , Nitrofenóis/análise , Pseudomonas syringae/isolamento & purificação , Rios , Estações do Ano , Poluentes Químicos da Água/análise
13.
Front Microbiol ; 7: 1278, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27597844

RESUMO

Arbuscular mycorrhizal fungi (AMF) are a group of obligate plant symbionts which can promote plant nutrition. AMF communities are diverse, but the factors which control their assembly in space and time remain unclear. In this study, the contributions of geographical distance, environmental heterogeneity and time in shaping AMF communities associated with Miscanthus giganteus (a perennial grass originating from south-east Asia) were determined over a 13 months period. In particular, the community was partitioned into core (abundant and persistent taxa) and satellite (taxa with low abundance and persistence) constituents and the drivers of community assembly for each determined. ß-diversity was exceptionally low across the 140 m line transects, and there was limited evidence of geographical scaling effects on the composition of the core, satellite or combined communities. However, AMF richness and community composition changed over time associated with fluctuation within both the core and satellite communities. The degree to which AMF community variation was explained by soil properties was consistently higher in the core community than the combined and satellite communities, suggesting that the satellite community had considerable stochasticity associated with it. We suggest that the partitioning of communities into their core and satellite constituents could be employed to enhance the variation explained within microbial community analyses.

14.
Pharmacotherapy ; 36(9): 994-1002, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27485941

RESUMO

PRIMARY OBJECTIVE: To retrospectively review nafcillin plasma concentrations (CNAF ) and determine nafcillin clearance (CLNAF ) in a diverse sample of patients treated with nafcillin administered as a continuous infusion. SECONDARY OBJECTIVE: To identify clinical variables associated with CLNAF and nafcillin-related adverse drug reactions (ADRs). METHODS: Retrospective chart review of patients receiving nafcillin via continuous infusion at University of Utah Health Care from 2006 to 2013 who had at least one steady-state CNAF measured. CLNAF was determined by dividing the nafcillin rate of infusion by CNAF . Adverse drug reactions (ADRs) were defined using the National Institutes of Health, Division of Microbiology and Infectious Diseases criteria and scored for probability of association with nafcillin by using Naranjo criteria. Multivariate models were constructed to identify independent variables associated with CLNAF and ADRs. MAIN RESULTS: Seventy-six CNAF from 54 patients were included. Median CLNAF was 13.9 L/hour (range ≤ 4.2 to 36.9 L/hr). Congestive heart failure (p=0.007), hyperbilirubinemia (p<0.0001), and serum creatinine (p<0.0001) were associated with reduced CLNAF , and Hispanic race (p=0.002) was associated with increased CLNAF by multivariate analysis. Twenty patients (37.0%) experienced an ADR. CNAF were significantly higher between patients that experienced an ADR and those that did not (66.0 vs 25.5 mg/L, p<0.001). Individual ADRs associated with CNAF included hepatotoxicity (62.8 vs 27.0 mg/L, p=0.001), nausea/vomiting (80.0 vs 28.5 mg/L, p=0.01), and diarrhea (66.5 vs 26.5 mg/L, p<0.001). Multivariate analysis identified CNAF as being independently associated with ADRs. A putative toxicity relationship between CNAF and predicted probability of ADR was established. CONCLUSIONS: Several patient variables were associated with impaired CLNAF , and elevated CNAF were associated with ADRs. Additional studies assessing the utility of nafcillin therapeutic drug monitoring to minimize toxicity are warranted.


Assuntos
Nafcilina/efeitos adversos , Nafcilina/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Monitoramento de Medicamentos , Feminino , Humanos , Masculino , Taxa de Depuração Metabólica , Pessoa de Meia-Idade , Estudos Retrospectivos
15.
J Microbiol Biol Educ ; 17(1): 172-82, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27047615

RESUMO

In a laboratory exercise for undergraduate biology majors, students plated bacteria from swabs of their facial skin under conditions that selected for coagulase-negative Staphylococcus; added disks containing the antibiotics penicillin, oxacillin, tetracycline, and erythromycin; and measured zones of inhibition. Students also recorded demographic and lifestyle variables and merged this information with similar data collected from 9,000 other students who had contributed to the database from 2003 to 2011. Minimum inhibitory concentration (MIC) testing performed at the Harborview Medical Center Microbiology Laboratory (Seattle, WA) indicated a high degree of accuracy for student-generated data; species identification with a matrix-assisted laser desorption ionization (MALDI) Biotyper revealed that over 88% of the cells analyzed by students were S. epidermidis or S. capitus. The overall frequency of resistant cells was high, ranging from 13.2% of sampled bacteria resistant to oxacillin to 61.7% resistant to penicillin. Stepwise logistic regressions suggested that recent antibiotic use was strongly associated with resistance to three of the four antibiotics tested (p = 0.0003 for penicillin, p << 0.0001 for erythromycin and tetracycline), and that age, gender, use of acne medication, use of antibacterial soaps, or makeup use were associated with resistance to at least one of the four antibiotics. Furthermore, drug resistance to one antibiotic was closely linked to resistance to the other three antibiotics in every case (all p values << 0.0001), suggesting the involvement of multidrug-resistant strains. The data reported here suggest that citizen science could not only provide an important educational experience for undergraduates, but potentially play a role in efforts to expand antibiotic resistance (ABR) surveillance.

17.
Front Microbiol ; 7: 195, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26941720

RESUMO

Root-associated fungi are key contributors to ecosystem functioning, however, the factors which determine community assembly are still relatively poorly understood. This study simultaneously quantified the roles of geographical distance, environmental heterogeneity and time in determining root-associated fungal community composition at the local scale within a short rotation coppice (SRC) willow plantation. Culture independent molecular analyses of the root-associated fungal community suggested a strong but temporally variable effect of geographical distance among fungal communities in terms of composition at the local geographical level. Whilst these distance effects were most prevalent on October communities, soil pH had an effect on structuring of the communities throughout the sampling period. Given the temporal variation in the effects of geographical distance and the environment for shaping root-associated fungal communities, there is clearly need for a temporal component to sampling strategies in future investigations of fungal ecology.

18.
Gut ; 65(6): 944-53, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-25856344

RESUMO

OBJECTIVE: To determine the existence of mucosal dysbiosis in siblings of patients with Crohn's disease (CD) using 454 pyrosequencing and to comprehensively characterise and determine the influence of genotypical and phenotypical factors, on that dysbiosis. Siblings of patients with CD have elevated risk of developing CD and display aspects of disease phenotype, including faecal dysbiosis. Whether the mucosal microbiota is disrupted in these at-risk individuals is unknown. DESIGN: Rectal biopsy DNA was extracted from 21 patients with quiescent CD, 17 of their healthy siblings and 19 unrelated healthy controls. Mucosal microbiota was analysed by 16S rRNA gene pyrosequencing and were classified into core and rare species. Genotypical risk was determined using Illumina Immuno BeadChip, faecal calprotectin by ELISA and blood T-cell phenotype by flow cytometry. RESULTS: Core microbiota of both patients with CD and healthy siblings was significantly less diverse than controls. Metacommunity profiling (Bray-Curtis (SBC) index) showed the sibling core microbial composition to be more similar to CD (SBC=0.70) than to healthy controls, whereas the sibling rare microbiota was more similar to healthy controls (SBC=0.42). Faecalibacterium prausnitzii contributed most to core metacommunity dissimilarity both between siblings and controls, and between patients and controls. Phenotype/genotype markers of CD risk significantly influenced microbiota variation between and within groups, of which genotype had the largest effect. CONCLUSIONS: Individuals with elevated CD-risk display mucosal dysbiosis characterised by reduced diversity of core microbiota and lower abundance of F. prausnitzii. This dysbiosis in healthy people at risk of CD implicates microbiological processes in CD pathogenesis.


Assuntos
Doença de Crohn/microbiologia , Doença de Crohn/patologia , Disbiose/microbiologia , Microbiota , Irmãos , Adolescente , Adulto , Biópsia , Estudos de Casos e Controles , Doença de Crohn/genética , Faecalibacterium prausnitzii/isolamento & purificação , Fezes/microbiologia , Feminino , Genótipo , Humanos , Mucosa Intestinal/microbiologia , Mucosa Intestinal/patologia , Intestinos/microbiologia , Masculino , Fenótipo
19.
ISME J ; 10(5): 1081-91, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26555248

RESUMO

Pulmonary symptoms in cystic fibrosis (CF) begin in early life with chronic lung infections and concomitant airway inflammation leading to progressive loss of lung function. Gradual pulmonary function decline is interspersed with periods of acute worsening of respiratory symptoms known as CF pulmonary exacerbations (CFPEs). Cumulatively, CFPEs are associated with more rapid disease progression. In this study multiple sputum samples were collected from adult CF patients over the course of CFPEs to better understand how changes in microbiota are associated with CFPE onset and management. Data were divided into five clinical periods: pre-CFPE baseline, CFPE, antibiotic treatment, recovery, and post-CFPE baseline. Samples were treated with propidium monoazide prior to DNA extraction, to remove the impact of bacterial cell death artefacts following antibiotic treatment, and then characterised by 16S rRNA gene-targeted high-throughput sequencing. Partitioning CF microbiota into core and rare groups revealed compositional resistance to CFPE and resilience to antibiotics interventions. Mixed effects modelling of core microbiota members revealed no significant negative impact on the relative abundance of Pseudomonas aeruginosa across the exacerbation cycle. Our findings have implications for current CFPE management strategies, supporting reassessment of existing antimicrobial treatment regimens, as antimicrobial resistance by pathogens and other members of the microbiota may be significant contributing factors.


Assuntos
Fibrose Cística/microbiologia , Fibrose Cística/fisiopatologia , Microbiota , Infecções Respiratórias/microbiologia , Escarro/microbiologia , Adolescente , Adulto , Antibacterianos/uso terapêutico , Doença Crônica , Fibrose Cística/complicações , Fibrose Cística/tratamento farmacológico , DNA Bacteriano/genética , Feminino , Humanos , Pulmão/microbiologia , Pulmão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/isolamento & purificação , RNA Ribossômico 16S/genética , Infecções Respiratórias/complicações , Adulto Jovem
20.
Environ Microbiol Rep ; 7(4): 634-41, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25994560

RESUMO

Bumblebees are ecologically and economically important as pollinators of crop and wild plants, especially in temperate systems. Species, such as the buff-tailed bumblebee (Bombus terrestris), are reared commercially to pollinate high-value crops. Their highly specific gut microbiota, characterized by low diversity, may affect nutrition and immunity and are likely to be important for fitness and colony health. However, little is known about how environmental factors affect bacterial community structure. We analysed the gut microbiota from three groups of worker bumblebees (B. terrestris) from distinct colonies that varied in rearing and foraging characteristics: commercially reared with restricted foraging (RR); commercially reared with outside foraging (RF); and wild-caught workers (W). Contrary to previous studies, which indicate that bacterial communities are highly conserved across workers, we found that RF individuals had an intermediate community structure compared with RR and W types. Further, this was shaped by differences in the abundances of common operational taxonomic units (OTUs) and the diversity of rare OTUs present, which we propose results from an increase in the variety of carbohydrates obtained through foraging.


Assuntos
Abelhas/crescimento & desenvolvimento , Abelhas/microbiologia , Biota , Comportamento Alimentar , Microbioma Gastrointestinal , Animais , Abelhas/fisiologia , Análise por Conglomerados , Dados de Sequência Molecular , Análise de Sequência de DNA
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA