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1.
PLoS Genet ; 19(5): e1010743, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37186602

RESUMO

Plasmids are diverse extrachromosomal elements significantly that contribute to interspecies dissemination of antimicrobial resistance (AMR) genes. However, within clinically important bacteria, plasmids can exhibit unexpected narrow host ranges, a phenomenon that has scarcely been examined. Here we show that pConj is largely restricted to the human-specific pathogen, Neisseria gonorrhoeae. pConj can confer tetracycline resistance and is central to the dissemination of other AMR plasmids. We tracked pConj evolution from the pre-antibiotic era 80 years ago to the modern day and demonstrate that, aside from limited gene acquisition and loss events, pConj is remarkably conserved. Notably, pConj has remained prevalent in gonococcal populations despite cessation of tetracycline use, thereby demonstrating pConj adaptation to its host. Equally, pConj imposes no measurable fitness costs and is stably inherited by the gonococcus. Its maintenance depends on the co-operative activity of plasmid-encoded Toxin:Antitoxin (TA) and partitioning systems rather than host factors. An orphan VapD toxin encoded on pConj forms a split TA with antitoxins expressed from an ancestral co-resident plasmid or a horizontally-acquired chromosomal island, potentially explaining pConj's limited distribution. Finally, ciprofloxacin can induce loss of this highly stable plasmid, reflecting epidemiological evidence of transient reduction in pConj prevalence when fluoroquinolones were introduced to treat gonorrhoea.


Assuntos
Gonorreia , Humanos , Gonorreia/tratamento farmacológico , Gonorreia/genética , Gonorreia/epidemiologia , Antibacterianos/farmacologia , Testes de Sensibilidade Microbiana , Plasmídeos/genética , Neisseria gonorrhoeae/genética , Farmacorresistência Bacteriana/genética
2.
J Antimicrob Chemother ; 79(7): 1529-1539, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38751093

RESUMO

OBJECTIVES: Comprehensive data on the genomic epidemiology of hospital-associated Klebsiella pneumoniae in Ghana are scarce. This study investigated the genomic diversity, antimicrobial resistance patterns, and clonal relationships of 103 clinical K. pneumoniae isolates from five tertiary hospitals in Southern Ghana-predominantly from paediatric patients aged under 5 years (67/103; 65%), with the majority collected from urine (32/103; 31%) and blood (25/103; 24%) cultures. METHODS: We generated hybrid Nanopore-Illumina assemblies and employed Pathogenwatch for genotyping via Kaptive [capsular (K) locus and lipopolysaccharide (O) antigens] and Kleborate (antimicrobial resistance and hypervirulence) and determined clonal relationships using core-genome MLST (cgMLST). RESULTS: Of 44 distinct STs detected, ST133 was the most common, comprising 23% of isolates (n = 23/103). KL116 (28/103; 27%) and O1 (66/103; 64%) were the most prevalent K-locus and O-antigen types. Single-linkage clustering highlighted the global spread of MDR clones such as ST15, ST307, ST17, ST11, ST101 and ST48, with minimal allele differences (1-5) from publicly available genomes worldwide. Conversely, 17 isolates constituted novel clonal groups and lacked close relatives among publicly available genomes, displaying unique genetic diversity within our study population. A significant proportion of isolates (88/103; 85%) carried resistance genes for ≥3 antibiotic classes, with the blaCTX-M-15 gene present in 78% (n = 80/103). Carbapenem resistance, predominantly due to blaOXA-181 and blaNDM-1 genes, was found in 10% (n = 10/103) of the isolates. CONCLUSIONS: Our findings reveal a complex genomic landscape of K. pneumoniae in Southern Ghana, underscoring the critical need for ongoing genomic surveillance to manage the substantial burden of antimicrobial resistance.


Assuntos
Antibacterianos , Variação Genética , Infecções por Klebsiella , Klebsiella pneumoniae , Tipagem de Sequências Multilocus , Centros de Atenção Terciária , Humanos , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/isolamento & purificação , Centros de Atenção Terciária/estatística & dados numéricos , Gana/epidemiologia , Infecções por Klebsiella/microbiologia , Infecções por Klebsiella/epidemiologia , Antibacterianos/farmacologia , Pré-Escolar , Lactente , Testes de Sensibilidade Microbiana , Genótipo , Feminino , Masculino , Criança , Farmacorresistência Bacteriana Múltipla/genética , Infecção Hospitalar/microbiologia , Infecção Hospitalar/epidemiologia , Genoma Bacteriano , Farmacorresistência Bacteriana/genética , Adulto , Epidemiologia Molecular
3.
Artigo em Inglês | MEDLINE | ID: mdl-37417270

RESUMO

Two novel bacterial isolates were cultured from faecal samples of patients attending the Breast Care clinic at the Norwich and Norfolk University Hospital. Strain LH1062T was isolated from a 58-year-old female diagnosed with invasive adenocarcinoma with ductal carcinoma in situ. Strain LH1063T was isolated from a healthy 51-year-old female. Isolate LH1062T was predicted to be a potential novel genus most closely related to Coprobacillus, whilst LH1063T was predicted to be a novel species belonging to Coprobacter. Both strains were characterized by polyphasic approaches including 16S rRNA gene analysis, core-genome analysis, average nucleotide identity (ANI) comparisons and phenotypic analysis. Initial screening of the 16S rRNA gene of LH1062T returned a nucleotide identity of 93.4 % to Longibaculum muris. For LH1063T, nucleotide identity was a 92.6 % to Coprobacter secundus. Further investigations showed that LH1062T had a genome size of 2.9 Mb and G+C content of 31.3 mol %. LH1063T had a genome size of 3.3Mb and G+C content of 39.2 mol %. Digital DNA-DNA hybridization (dDDH) and ANI values of LH1062T with its closest relative, Coprobacillus cateniformis JCM 10604T, were 20.9 and 79.54 %, respectively. For LH1063T, the dDDH and ANI values with its closest relative, Coprobacter secundus 177T, were 19.3 and 77.81 %, respectively. Phenotypic testing confirmed that LH1062T could not be matched to a known validly published isolate in any database; thereby indicating a novel genus for which the name Allocoprobacillus gen. nov. is now proposed with LH1062T (=DSM 114537T=NCTC 14686T) being the type strain of the proposed novel species Allocoprobacillus halotolerans sp. nov. Strain LH1063T (=DSM 114538T=NCTC 14698T) fits within the genus Coprobacter and, it being the third species within this genus, the name Coprobacter tertius sp. nov. is proposed.


Assuntos
Ácidos Graxos , Microbioma Gastrointestinal , Humanos , Pessoa de Meia-Idade , Ácidos Graxos/química , RNA Ribossômico 16S/genética , Composição de Bases , Filogenia , Análise de Sequência de DNA , DNA Bacteriano/genética , Técnicas de Tipagem Bacteriana , Clostridiaceae/genética , Hibridização de Ácido Nucleico
4.
Int J Syst Evol Microbiol ; 71(12)2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34919037

RESUMO

Four bacterial strains were isolated from two different colony sources of the wax moth Galleria mellonella. They were characterized by a polyphasic approach including 16S rRNA gene sequence analysis, core-genome analysis, average nucleotide identity (ANI) analysis, digital DNA-DNA hybridization (dDDH), determination of G+C content, screening of antibiotic resistance genes, and various phenotypic analyses. Initial analysis of 16S rRNA gene sequence identities indicated that strain GAL7T was potentially very closely related to Enterococcus casseliflavus and Enterococcus gallinarum, having 99.5-99.9 % sequence similarity. However, further analysis of whole genome sequences revealed a genome size of 3.69 Mb, DNA G+C content of 42.35 mol%, and low dDDH and ANI values between the genomes of strain GAL7T and closest phylogenetic relative E. casseliflavus NBRC 100478T of 59.0 and 94.5 %, respectively, indicating identification of a putative new Enterococcus species. In addition, all novel strains encoded the atypical vancomycin-resistance gene vanC-4. Results of phylogenomic, physiological and phenotypic characterization confirmed that strain GAL7T represented a novel species within the genus Enterococcus, for which the name Enterococcus innesii sp. nov. is proposed. The type strain is GAL7T (=DSM 112306T=NCTC 14608T).


Assuntos
Enterococcus/classificação , Mariposas , Filogenia , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Enterococcus/isolamento & purificação , Ácidos Graxos/química , Mariposas/microbiologia , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
5.
New Phytol ; 226(6): 1864-1872, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32083724

RESUMO

Introduced populations often experience lag times before invasion, but the mechanisms constraining rapid expansions of introduced populations are unclear. Solidago altissima is a North American native plant with highly invasive Japanese populations and introduced Australian populations that are not invasive despite the climatic and ecological suitability of the region. By contrasting Australian with Japanese populations, we tested the hypothesis that Australian population growth is limited by a lack of long-distance dispersal via seeds owing to a limited number of compatible mates. In the field, Australian populations rarely produced viable seeds. A cross-pollination experiment found that Australian plants are fertile, yet lack compatible mates within Australia. Genetic analysis revealed that Australian individuals descend from a small set of self-incompatible genetic clones, which explains the negligible seed set within Australia. Our results show that low genetic diversity, leading to mate incompatibility, inhibits invasiveness of Australian S.  altissima, and provides compelling evidence for genetic, rather than ecological, factors constraining invasion in Australia.


Assuntos
Plantas Daninhas , Solidago , Austrália , Variação Genética , Plantas Daninhas/genética , Polinização , Sementes/genética
6.
Diabetes Obes Metab ; 22(11): 1985-1994, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32519798

RESUMO

AIM: To test the hypothesis that glucokinase activators (GKAs) induce hepatic adaptations that alter intra-hepatocyte metabolite homeostasis. METHODS: C57BL/6 mice on a standard rodent diet were treated with a GKA (AZD1656) acutely or chronically. Hepatocytes were isolated from the mice after 4 or 8 weeks of treatment for analysis of cellular metabolites and gene expression in response to substrate challenge. RESULTS: Acute exposure of mice to AZD1656 or a liver-selective GKA (PF-04991532), before a glucose tolerance test, or challenge of mouse hepatocytes with GKAs ex vivo induced various Carbohydrate response element binding protein (ChREBP) target genes, including Carbohydrate response element binding protein beta isoform (ChREBP-ß), Gckr and G6pc. Both glucokinase activation and ChREBP target gene induction by PF-04991532 were dependent on the chirality of the molecule, confirming a mechanism linked to glucokinase activation. Hepatocytes from mice treated with AZD1656 for 4 or 8 weeks had lower basal glucose 6-phosphate levels and improved ATP homeostasis during high substrate challenge. They also had raised basal ChREBP-ß mRNA and AMPK-α mRNA (Prkaa1, Prkaa2) and progressively attenuated substrate induction of some ChREBP target genes and Prkaa1 and Prkaa2. CONCLUSIONS: Chronic GKA treatment of C57BL/6 mice for 8 weeks activates liver ChREBP and improves the resilience of hepatocytes to compromised ATP homeostasis during high-substrate challenge. These changes are associated with raised mRNA levels of ChREBP-ß and both catalytic subunits of AMP-activated protein kinase.


Assuntos
Glucoquinase , Fígado , Trifosfato de Adenosina , Animais , Proteínas de Transporte/genética , Glucoquinase/genética , Glucoquinase/metabolismo , Glucose , Glucose-6-Fosfato , Hepatócitos/metabolismo , Homeostase , Fígado/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Elementos de Resposta
7.
Conserv Biol ; 33(2): 319-328, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30047186

RESUMO

Human modification of the environment is driving declines in population size and distributional extent of much of the world's biota. These declines extend to many of the most abundant and widespread species, for which proportionally small declines can result in the loss of vast numbers of individuals, biomass, and interactions. These losses could have major localized effects on ecological and cultural processes and services without elevating a species' global extinction risk. Although most conservation effort is directed at species threatened with extinction in the very near term, the value of retaining abundance regardless of global extinction risk is justifiable based on many biodiversity or ecosystem service metrics, including cultural services, at scales from local to global. The challenges of identifying conservation priorities for widespread and abundant species include quantifying the effects of species' abundance on services and understanding how these effects are realized as populations decline. Negative effects of population declines may be disconnected from the threat processes driving declines because of species movements and environment flows (e.g., hydrology). Conservation prioritization for these species shares greater similarity with invasive species risk assessments than extinction risk assessments because of the importance of local context and per capita effects of abundance on other species. Because conservation priorities usually focus on preventing the extinction of threatened species, the rationale and objectives for incorporating declines of nonthreatened species must be clearly articulated, going beyond extinction risk to encompass the range of likely harmful effects (e.g., secondary extinctions, loss of ecosystem services) if declines persist or are not reversed. Research should focus on characterizing the effects of local declines in species that are not threatened globally across a range of ecosystem services and quantifying the spatial distribution of these effects through the distribution of abundance. The case for conserving abundance in nonthreatened species can be made most powerfully when the costs of losing this abundance are better understood.


Conservación de la Abundancia de Especies No Amenazadas Resumen La modificación del ambiente causada por los humanos está resultando en la declinación del tamaño poblacional y de la extensión de la distribución de la mayor parte de la biota mundial. Estas declinaciones llegan hasta muchas de las especies más abundantes y con mayor distribución, para las cuales una declinación proporcionalmente pequeña puede resultar en la pérdida de un número extenso de individuos, biomasa e interacciones. Estas pérdidas podrían tener mayores efectos localizados sobre los procesos y servicios ecológicos y culturales sin elevar el riesgo de extinción mundial de la especie. Aunque casi todos los esfuerzos de conservación están dirigidos hacia especies bajo amenaza de extinción a corto plazo, el valor de mantener la abundancia sin importar el riesgo de extinción mundial es justificable con base en muchas medidas de biodiversidad o de servicios ambientales, incluyendo los servicios culturales, a escalas desde lo local hasta lo global. El reto de identificar prioridades de conservación para especies abundantes y de distribución extensa incluye la cuantificación de los efectos que la abundancia de la especie tiene sobre los servicios y el entendimiento de cómo estos efectos ocurren conforme las poblaciones declinan. Los efectos negativos de la declinación poblacional pueden estar desconectados del proceso que ocasiona la declinación por causa del movimiento de las especies y los flujos ambientales (p. ej.: la hidrología). La priorización de la conservación de estas especies comparte muchas más similitudes con la evaluación de riesgo de las especies invasoras que las evaluaciones de extinción de riesgo debido a la importancia del contexto local y los efectos per cápita de la abundancia sobre otras especies. Ya que los esfuerzos de conservación generalmente se enfocan en la prevención de la extinción de las especies amenazadas, la lógica y los objetivos detrás de la incorporación de las declinaciones de las especies no amenazadas deben estar articulados claramente, llegando más allá del riesgo de extinción para englobar la gama de efectos dañinos probables (p. ej.: extinciones secundarias, pérdida de servicios ambientales) en el caso de que las declinaciones persistan o no sean revertidas. La investigación debería enfocarse en la caracterización de los efectos de las declinaciones locales de especies que no estén amenazadas mundialmente a lo largo de una gama de servicios ambientales y en la cuantificación de la distribución espacial de estos efectos por medio de la distribución de la abundancia. Se puede argumentar de manera más poderosa el caso para la conservación de la abundancia de especies no amenazadas cuando se entienden mejor los costos de la pérdida de esta abundancia.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Animais , Biodiversidade , Espécies em Perigo de Extinção , Extinção Biológica , Humanos
8.
Diabetologia ; 61(3): 711-721, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29119245

RESUMO

AIMS/HYPOTHESIS: Glucagon like peptide-1 (GLP-1) enhances glucose-dependent insulin secretion by binding to GLP-1 receptors (GLP1Rs) on pancreatic beta cells. GLP-1 mimetics are used in the clinic for the treatment of type 2 diabetes, but despite their therapeutic success, several clinical effects of GLP-1 remain unexplained at a mechanistic level, particularly in extrapancreatic tissues. The aim of this study was to generate and characterise a monoclonal antagonistic antibody for the GLP1R for use in vivo. METHODS: A naive phage display selection strategy was used to isolate single-chain variable fragments (ScFvs) that bound to GLP1R. The ScFv with the highest affinity, Glp1R0017, was converted into a human IgG1 and characterised further. In vitro antagonistic activity was assessed in a number of assays: a cAMP-based homogenous time-resolved fluorescence assay in GLP1R-overexpressing cell lines, a live cell cAMP imaging assay and an insulin secretion assay in INS-1 832/3 cells. Glp1R0017 was further tested in immunostaining of mouse pancreas, and the ability of Glp1R0017 to block GLP1R in vivo was assessed by both IPGTT and OGTT in C57/Bl6 mice. RESULTS: Antibodies to GLP1R were selected from naive antibody phage display libraries. The monoclonal antibody Glp1R0017 antagonised mouse, human, rat, cynomolgus monkey and dog GLP1R. This antagonistic activity was specific to GLP1R; no antagonistic activity was found in cells overexpressing the glucose-dependent insulinotropic peptide receptor (GIPR), glucagon like peptide-2 receptor or glucagon receptor. GLP-1-stimulated cAMP and insulin secretion was attenuated in INS-1 832/3 cells by Glp1R0017 incubation. Immunostaining of mouse pancreas tissue with Glp1R0017 showed specific staining in the islets of Langerhans, which was absent in Glp1r knockout tissue. In vivo, Glp1R0017 reversed the glucose-lowering effect of liraglutide during IPGTTs, and reduced glucose tolerance by blocking endogenous GLP-1 action in OGTTs. CONCLUSIONS/INTERPRETATION: Glp1R0017 is a monoclonal antagonistic antibody to the GLP1R that binds to GLP1R on pancreatic beta cells and blocks the actions of GLP-1 in vivo. This antibody holds the potential to be used in investigating the physiological importance of GLP1R signalling in extrapancreatic tissues where cellular targets and signalling pathways activated by GLP-1 are poorly understood.


Assuntos
Anticorpos/imunologia , Receptor do Peptídeo Semelhante ao Glucagon 1/antagonistas & inibidores , Receptor do Peptídeo Semelhante ao Glucagon 1/imunologia , Animais , Células CHO , Cálcio/metabolismo , Linhagem Celular , Cricetulus , AMP Cíclico/metabolismo , Células HEK293 , Humanos , Imunoglobulina G/metabolismo , Incretinas/metabolismo , Insulina/metabolismo , Camundongos , Biblioteca de Peptídeos
9.
J Biol Chem ; 292(52): 21253-21263, 2017 12 29.
Artigo em Inglês | MEDLINE | ID: mdl-29092909

RESUMO

K+/Cl- cotransporter 2 (KCC2) is selectively expressed in the adult nervous system and allows neurons to maintain low intracellular Cl- levels. Thus, KCC2 activity is an essential prerequisite for fast hyperpolarizing synaptic inhibition mediated by type A γ-aminobutyric acid (GABAA) receptors, which are Cl--permeable, ligand-gated ion channels. Consistent with this, deficits in the activity of KCC2 lead to epilepsy and are also implicated in neurodevelopmental disorders, neuropathic pain, and schizophrenia. Accordingly, there is significant interest in developing activators of KCC2 as therapeutic agents. To provide insights into the cellular processes that determine KCC2 activity, we have investigated the mechanism by which N-ethylmaleimide (NEM) enhances transporter activity using a combination of biochemical and electrophysiological approaches. Our results revealed that, within 15 min, NEM increased cell surface levels of KCC2 and modulated the phosphorylation of key regulatory residues within the large cytoplasmic domain of KCC2 in neurons. More specifically, NEM increased the phosphorylation of serine 940 (Ser-940), whereas it decreased phosphorylation of threonine 1007 (Thr-1007). NEM also reduced with no lysine (WNK) kinase phosphorylation of Ste20-related proline/alanine-rich kinase (SPAK), a kinase that directly phosphorylates KCC2 at residue Thr-1007. Mutational analysis revealed that Thr-1007 dephosphorylation mediated the effects of NEM on KCC2 activity. Collectively, our results suggest that compounds that either increase the surface stability of KCC2 or reduce Thr-1007 phosphorylation may be of use as enhancers of KCC2 activity.


Assuntos
Etilmaleimida/metabolismo , Simportadores/metabolismo , Animais , Membrana Celular/metabolismo , Embrião de Mamíferos , Humanos , Moduladores de Transporte de Membrana/metabolismo , Neurônios/metabolismo , Fosforilação/fisiologia , Ratos , Ratos Sprague-Dawley , Receptores de GABA/metabolismo , Simportadores/fisiologia , Cotransportadores de K e Cl-
10.
Biochem J ; 473(18): 2881-91, 2016 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-27422784

RESUMO

Dual-agonist molecules combining glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) activity represent an exciting therapeutic strategy for diabetes treatment. Although challenging due to shared downstream signalling pathways, determining the relative activity of dual agonists at each receptor is essential when developing potential novel therapeutics. The challenge is exacerbated in physiologically relevant cell systems expressing both receptors. To this end, either GIP receptors (GIPR) or GLP-1 receptors (GLP-1R) were ablated via RNA-guided clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 endonucleases in the INS-1 pancreatic ß-cell line. Multiple clonal cell lines harbouring gene disruptions for each receptor were isolated and assayed for receptor activity to identify functional knockouts (KOs). cAMP production in response to GIPR or GLP-1R activation was abolished and GIP- or GLP-1-induced potentiation of glucose-stimulated insulin secretion (GSIS) was attenuated in the cognate KO cell lines. The contributions of individual receptors derived from cAMP and GSIS assays were confirmed in vivo using GLP-1R KO mice in combination with a monoclonal antibody antagonist of GIPR. We have successfully applied CRISPR/Cas9-engineered cell lines to determining selectivity and relative potency contributions of dual-agonist molecules targeting receptors with overlapping native expression profiles and downstream signalling pathways. Specifically, we have characterised molecules as biased towards GIPR or GLP-1R, or with relatively balanced potency in a physiologically relevant ß-cell system. This demonstrates the broad utility of CRISPR/Cas9 when applied to native expression systems for the development of drugs that target multiple receptors, particularly where the balance of receptor activity is critical.


Assuntos
Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Peptídeo 1 Semelhante ao Glucagon/agonistas , Ilhotas Pancreáticas/citologia , Receptores dos Hormônios Gastrointestinais/agonistas , Animais , Linhagem Celular , Glucose/farmacologia , Teste de Tolerância a Glucose , Humanos , Insulina/metabolismo , Secreção de Insulina , Cariotipagem , Camundongos , Camundongos Knockout , Receptores dos Hormônios Gastrointestinais/genética
11.
Glob Chang Biol ; 22(7): 2392-404, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26950769

RESUMO

Climate data created from historic climate observations are integral to most assessments of potential climate change impacts, and frequently comprise the baseline period used to infer species-climate relationships. They are often also central to downscaling coarse resolution climate simulations from General Circulation Models (GCMs) to project future climate scenarios at ecologically relevant spatial scales. Uncertainty in these baseline data can be large, particularly where weather observations are sparse and climate dynamics are complex (e.g. over mountainous or coastal regions). Yet, importantly, this uncertainty is almost universally overlooked when assessing potential responses of species to climate change. Here, we assessed the importance of historic baseline climate uncertainty for projections of species' responses to future climate change. We built species distribution models (SDMs) for 895 African bird species of conservation concern, using six different climate baselines. We projected these models to two future periods (2040-2069, 2070-2099), using downscaled climate projections, and calculated species turnover and changes in species-specific climate suitability. We found that the choice of baseline climate data constituted an important source of uncertainty in projections of both species turnover and species-specific climate suitability, often comparable with, or more important than, uncertainty arising from the choice of GCM. Importantly, the relative contribution of these factors to projection uncertainty varied spatially. Moreover, when projecting SDMs to sites of biodiversity importance (Important Bird and Biodiversity Areas), these uncertainties altered site-level impacts, which could affect conservation prioritization. Our results highlight that projections of species' responses to climate change are sensitive to uncertainty in the baseline climatology. We recommend that this should be considered routinely in such analyses.


Assuntos
Biodiversidade , Mudança Climática , Animais , Clima , Previsões , Modelos Teóricos , Incerteza
12.
Proc Biol Sci ; 282(1818): 20151561, 2015 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-26511054

RESUMO

Despite increasing concerns about the vulnerability of species' populations to climate change, there has been little overall synthesis of how individual population responses to variation in climate differ between taxa, with trophic level or geographically. To address this, we extracted data from 132 long-term (greater than or equal to 20 years) studies of population responses to temperature and precipitation covering 236 animal and plant species across terrestrial and freshwater habitats. Our results identify likely geographical differences in the effects of climate change on populations and communities in line with macroecological theory. Temperature tended to have a greater overall impact on populations than precipitation, although the effects of increased precipitation varied strongly with latitude, being most positive at low latitudes. Population responses to increased temperature were generally positive, but did not vary significantly with latitude. Studies reporting significant climatic trends through time tended to show more negative effects of temperature and more positive effects of precipitation upon populations than other studies, indicating climate change has already impacted many populations. Most studies of climate change impacts on biodiversity have focused on temperature and are from middle to high northern latitudes. Our results suggest their findings may be less applicable to low latitudes.


Assuntos
Biodiversidade , Mudança Climática , Chuva , Temperatura , Animais , Ecossistema , Geografia , Plantas , Dinâmica Populacional
13.
Glob Chang Biol ; 20(7): 2221-9, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24677405

RESUMO

Shifts in species' distribution and abundance in response to climate change have been well documented, but the underpinning processes are still poorly understood. We present the results of a systematic literature review and meta-analysis investigating the frequency and importance of different mechanisms by which climate has impacted natural populations. Most studies were from temperate latitudes of North America and Europe; almost half investigated bird populations. We found significantly greater support for indirect, biotic mechanisms than direct, abiotic mechanisms as mediators of the impact of climate on populations. In addition, biotic effects tended to have greater support than abiotic factors in studies of species from higher trophic levels. For primary consumers, the impact of climate was equally mediated by biotic and abiotic mechanisms, whereas for higher level consumers the mechanisms were most frequently biotic, such as predation or food availability. Biotic mechanisms were more frequently supported in studies that reported a directional trend in climate than in studies with no such climatic change, although sample sizes for this comparison were small. We call for more mechanistic studies of climate change impacts on populations, particularly in tropical systems.


Assuntos
Biota , Mudança Climática , Animais , Aves/fisiologia , Europa (Continente) , Peixes/fisiologia , Invertebrados/fisiologia , Mamíferos/fisiologia , América do Norte , Fenômenos Fisiológicos Vegetais , Dinâmica Populacional
14.
Curr Biol ; 34(6): R233-R234, 2024 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-38531312

RESUMO

Rapid advances over the last decade in DNA sequencing and statistical genetics enable us to investigate the genomic makeup of individuals throughout history. In a recent notable study, Begg et al.1 used Ludwig van Beethoven's hair strands for genome sequencing and explored genetic predispositions for some of his documented medical issues. Given that it was arguably Beethoven's skills as a musician and composer that made him an iconic figure in Western culture, we here extend the approach and apply it to musicality. We use this as an example to illustrate the broader challenges of individual-level genetic predictions.


Assuntos
Surdez , Pessoas Famosas , Música , Humanos , Masculino , Genômica , Cabelo , Predisposição Genética para Doença , Alemanha
15.
Microb Genom ; 9(7)2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37463032

RESUMO

Bacteriophages (phages) within the genus Przondovirus are T7-like podoviruses belonging to the subfamily Studiervirinae, within the family Autographiviridae, and have a highly conserved genome organisation. The genomes of these phages range from 37 to 42 kb in size, encode 50-60 genes and are characterised by the presence of direct terminal repeats (DTRs) flanking the linear chromosome. These DTRs are often deleted during short-read-only and hybrid assemblies. Moreover, long-read-only assemblies are often littered with sequencing and/or assembly errors and require additional curation. Here, we present the isolation and characterisation of ten novel przondoviruses targeting Klebsiella spp. We describe HYPPA, a HYbrid and Poly-polish Phage Assembly workflow, which utilises long-read assemblies in combination with short-read sequencing to resolve phage DTRs and correcting errors, negating the need for laborious primer walking and Sanger sequencing validation. Our assembly workflow utilised Oxford Nanopore Technologies for long-read sequencing for its accessibility, making it the more relevant long-read sequencing technology at this time, and Illumina DNA Prep for short-read sequencing, representing the most commonly used technologies globally. Our data demonstrate the importance of careful curation of phage assemblies before publication, and prior to using them for comparative genomics.


Assuntos
Bacteriófagos , Bacteriófagos/genética , Sequenciamento de Nucleotídeos em Larga Escala , Análise de Sequência de DNA , Fluxo de Trabalho
16.
Prehosp Disaster Med ; 27(4): 385-91, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22800859

RESUMO

The immediate patterns of injury from explosions are well documented, from both military and civil experience. However, few studies have focused on less immediately apparent health consequences and latent effects of explosions in survivors, emergency responders and the surrounding community. This review aimed to analyze the risks to health following an explosion in a civil setting. A comprehensive review of the open literature was conducted, and data on 10 relevant military, civilian and industrial events were collected. Events were selected according to availability of published studies and involvement of large numbers of people injured. In addition, structured interviews with experts in the field were conducted, and existing national guidelines reviewed. The review revealed significant and potentially long-term health implications affecting various body systems and psychological well-being following exposure to an explosion. An awareness of the short- and long-term health effects of explosions is essential in screening for blast injuries, and identifying latent pathologies that could otherwise be overlooked in stressful situations with other visually distracting injuries and, often, mass casualties. Such knowledge would guide responsible medical staff in implementing early appropriate interventions to reduce the burden of long-term sequelae. Effective planning and response strategies would ensure accessibility of appropriate health care resources and evidence-based information in the aftermath of an explosion.


Assuntos
Traumatismos por Explosões/complicações , Explosões , Traumatismos por Explosões/psicologia , Guias como Assunto , Humanos
17.
Sci Total Environ ; 831: 154893, 2022 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-35364173

RESUMO

Artificial light at night (ALAN) has become a profound form of global anthropogenic environmental change differing in from natural light regimes in intensity, duration, distribution and spectra. It is clear that ALAN impacts individual organisms, however, population level effects, particularly of spectral changes, remain poorly understood. Here we exposed experimental multigenerational aphid-parasitoid communities in the field to seven different light spectra at night ranging from 385 to 630 nm and compared responses to a natural day-night light regime. We found that while aphid population growth was initially unaffected by ALAN, parasitoid efficiency declined under most ALAN spectra, leading to reduced top-down control and higher aphid densities. These results differ from those previously found for white light, showing a strong impact on species' daytime performance. This highlights the importance of ALAN spectra when considering their environmental impact. ALAN can have large impacts on the wider ecological community by influencing diurnal species.


Assuntos
Afídeos , Cadeia Alimentar , Animais , Afídeos/fisiologia , Ecossistema , Insetos , Luz , Poluição Luminosa
18.
Mol Metab ; 43: 101118, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33221554

RESUMO

OBJECTIVES: Combinatorial therapies are under intense investigation to develop more efficient anti-obesity drugs; however, little is known about how they act in the brain to produce enhanced anorexia and weight loss. The goal of this study was to identify the brain sites and neuronal populations engaged during the co-administration of GLP-1R and CCK1R agonists, an efficient combination therapy in obese rodents. METHODS: We measured acute and long-term feeding and body weight responses and neuronal activation patterns throughout the neuraxis and in specific neuronal subsets in response to GLP-1R and CCK1R agonists administered alone or in combination in lean and high-fat diet fed mice. We used PhosphoTRAP to obtain unbiased molecular markers for neuronal populations selectively activated by the combination of the two agonists. RESULTS: The initial anorectic response to GLP-1R and CCK1R co-agonism was mediated by a reduction in meal size, but over a few hours, a reduction in meal number accounted for the sustained feeding suppressive effects. The nucleus of the solitary tract (NTS) is one of the few brain sites where GLP-1R and CCK1R signalling interact to produce enhanced neuronal activation. None of the previously categorised NTS neuronal subpopulations relevant to feeding behaviour were implicated in this increased activation. However, we identified NTS/AP Calcrl+ neurons as treatment targets. CONCLUSIONS: Collectively, these studies indicated that circuit-level integration of GLP-1R and CCK1R co-agonism in discrete brain nuclei including the NTS produces enhanced rapid and sustained appetite suppression and weight loss.


Assuntos
Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Obesidade/tratamento farmacológico , Receptores da Colecistocinina/metabolismo , Animais , Fármacos Antiobesidade/farmacologia , Regulação do Apetite , Encéfalo/metabolismo , Dieta Hiperlipídica , Ingestão de Alimentos/efeitos dos fármacos , Comportamento Alimentar/efeitos dos fármacos , Peptídeo 1 Semelhante ao Glucagon/farmacologia , Receptor do Peptídeo Semelhante ao Glucagon 1/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Obesidade/metabolismo , Núcleo Solitário/metabolismo , Redução de Peso/efeitos dos fármacos
19.
Microb Genom ; 7(11)2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34846280

RESUMO

The SARS-CoV-2 pandemic continues to expand globally, with case numbers rising in many areas of the world, including the Indian sub-continent. Pakistan has one of the world's largest populations, of over 200 million people and is experiencing a severe third wave of infections caused by SARS-CoV-2 that began in March 2021. In Pakistan, during the third wave until now only 12 SARS-CoV-2 genomes have been collected and among these nine are from Islamabad. This highlights the need for more genome sequencing to allow surveillance of variants in circulation. In fact, more genomes are available among travellers with a travel history from Pakistan, than from within the country itself. We thus aimed to provide a snapshot assessment of circulating lineages in Lahore and surrounding areas with a combined population of 11.1 million. Within a week of April 2021, 102 samples were sequenced. The samples were randomly collected from two hospitals with a diagnostic PCR cutoff value of less than 25 cycles. Analysis of the lineages shows that the Alpha variant of concern (first identified in the UK) dominates, accounting for 97.9 % (97/99) of cases, with the Beta variant of concern (first identified in South Africa) accounting for 2.0 % (2/99) of cases. No other lineages were observed. In depth analysis of the Alpha lineages indicated multiple separate introductions and subsequent establishment within the region. Eight samples were identical to genomes observed in Europe (seven UK, one Switzerland), indicating recent transmission. Genomes of other samples show evidence that these have evolved, indicating sustained transmission over a period of time either within Pakistan or other countries with low-density genome sequencing. Vaccines remain effective against Alpha, however, the low level of Beta against which some vaccines are less effective demonstrates the requirement for continued prospective genomic surveillance.


Assuntos
COVID-19/virologia , SARS-CoV-2/isolamento & purificação , Adulto , Idoso , Idoso de 80 Anos ou mais , COVID-19/epidemiologia , COVID-19/prevenção & controle , Vacinas contra COVID-19/administração & dosagem , Feminino , Genoma Viral , Humanos , Masculino , Pessoa de Meia-Idade , Paquistão/epidemiologia , Pandemias , Filogenia , SARS-CoV-2/classificação , SARS-CoV-2/genética , SARS-CoV-2/fisiologia , Adulto Jovem
20.
Microb Genom ; 7(6)2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34184982

RESUMO

The COVID-19 pandemic has spread rapidly throughout the world. In the UK, the initial peak was in April 2020; in the county of Norfolk (UK) and surrounding areas, which has a stable, low-density population, over 3200 cases were reported between March and August 2020. As part of the activities of the national COVID-19 Genomics Consortium (COG-UK) we undertook whole genome sequencing of the SARS-CoV-2 genomes present in positive clinical samples from the Norfolk region. These samples were collected by four major hospitals, multiple minor hospitals, care facilities and community organizations within Norfolk and surrounding areas. We combined clinical metadata with the sequencing data from regional SARS-CoV-2 genomes to understand the origins, genetic variation, transmission and expansion (spread) of the virus within the region and provide context nationally. Data were fed back into the national effort for pandemic management, whilst simultaneously being used to assist local outbreak analyses. Overall, 1565 positive samples (172 per 100 000 population) from 1376 cases were evaluated; for 140 cases between two and six samples were available providing longitudinal data. This represented 42.6 % of all positive samples identified by hospital testing in the region and encompassed those with clinical need, and health and care workers and their families. In total, 1035 cases had genome sequences of sufficient quality to provide phylogenetic lineages. These genomes belonged to 26 distinct global lineages, indicating that there were multiple separate introductions into the region. Furthermore, 100 genetically distinct UK lineages were detected demonstrating local evolution, at a rate of ~2 SNPs per month, and multiple co-occurring lineages as the pandemic progressed. Our analysis: identified a discrete sublineage associated with six care facilities; found no evidence of reinfection in longitudinal samples; ruled out a nosocomial outbreak; identified 16 lineages in key workers which were not in patients, indicating infection control measures were effective; and found the D614G spike protein mutation which is linked to increased transmissibility dominates the samples and rapidly confirmed relatedness of cases in an outbreak at a food processing facility. The large-scale genome sequencing of SARS-CoV-2-positive samples has provided valuable additional data for public health epidemiology in the Norfolk region, and will continue to help identify and untangle hidden transmission chains as the pandemic evolves.


Assuntos
COVID-19/patologia , Genoma Viral , SARS-CoV-2/genética , COVID-19/epidemiologia , COVID-19/virologia , Análise por Conglomerados , Surtos de Doenças , Ligação Genética , Humanos , Estudos Longitudinais , Pandemias , Filogenia , Polimorfismo de Nucleotídeo Único , SARS-CoV-2/classificação , SARS-CoV-2/isolamento & purificação , Glicoproteína da Espícula de Coronavírus/genética , Reino Unido/epidemiologia , Sequenciamento Completo do Genoma
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