RESUMEN
Humans are considered as the main host for Mycobacterium leprae1, the aetiological agent of leprosy, but spillover has occurred to other mammals that are now maintenance hosts, such as nine-banded armadillos and red squirrels2,3. Although naturally acquired leprosy has also been described in captive nonhuman primates4-7, the exact origins of infection remain unclear. Here we describe leprosy-like lesions in two wild populations of western chimpanzees (Pan troglodytes verus) in Cantanhez National Park, Guinea-Bissau and Taï National Park, Côte d'Ivoire, West Africa. Longitudinal monitoring of both populations revealed the progression of disease symptoms compatible with advanced leprosy. Screening of faecal and necropsy samples confirmed the presence of M. leprae as the causative agent at each site and phylogenomic comparisons with other strains from humans and other animals show that the chimpanzee strains belong to different and rare genotypes (4N/O and 2F). These findings suggest that M. leprae may be circulating in more wild animals than suspected, either as a result of exposure to humans or other unknown environmental sources.
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Lepra/veterinaria , Pan troglodytes/microbiología , Animales , Autopsia/veterinaria , Côte d'Ivoire , Heces/microbiología , Genotipo , Guinea Bissau , Humanos , Lepra/microbiología , Mycobacterium leprae/genética , Mycobacterium leprae/aislamiento & purificación , FilogeniaRESUMEN
Distribution of Earth's biomes is structured by the match between climate and plant traits, which in turn shape associated communities and ecosystem processes and services. However, that climate-trait match can be disrupted by historical events, with lasting ecosystem impacts. As Earth's environment changes faster than at any time in human history, critical questions are whether and how organismal traits and ecosystems can adjust to altered conditions. We quantified the relative importance of current environmental forcing versus evolutionary history in shaping the growth form (stature and biomass) and associated community of eelgrass (Zostera marina), a widespread foundation plant of marine ecosystems along Northern Hemisphere coastlines, which experienced major shifts in distribution and genetic composition during the Pleistocene. We found that eelgrass stature and biomass retain a legacy of the Pleistocene colonization of the Atlantic from the ancestral Pacific range and of more recent within-basin bottlenecks and genetic differentiation. This evolutionary legacy in turn influences the biomass of associated algae and invertebrates that fuel coastal food webs, with effects comparable to or stronger than effects of current environmental forcing. Such historical lags in phenotypic acclimatization may constrain ecosystem adjustments to rapid anthropogenic climate change, thus altering predictions about the future functioning of ecosystems.
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Ecosistema , Zosteraceae , Aclimatación , Animales , Evolución Biológica , Biomasa , Cadena Alimentaria , Invertebrados , Zosteraceae/genéticaRESUMEN
BACKGROUND: Actigraphy is often used to measure sleep in pediatric populations, despite little confirmatory evidence of the accuracy of existing sleep/wake algorithms. The aim of this study was to determine the performance of 11 sleep algorithms in relation to overnight polysomnography in children and adolescents. METHODS: One hundred thirty-seven participants aged 8-16 years wore two Actigraph wGT3X-BT (wrist, waist) and three Axivity AX3 (wrist, back, thigh) accelerometers over 24-h. Gold standard measures of sleep were obtained using polysomnography (PSG; Embletta MPRPG, ST + Proxy and TX Proxy) in the home environment, overnight. Epoch by epoch comparisons of the Sadeh (two algorithms), Cole-Kripke (three algorithms), Tudor-Locke (four algorithms), Count-Scaled (CS), and HDCZA algorithms were undertaken. Mean differences from PSG values were calculated for various sleep outcomes. RESULTS: Overall, sensitivities were high (mean ± SD: 91.8%, ± 5.6%) and specificities moderate (63.8% ± 13.8%), with the HDCZA algorithm performing the best overall in terms of specificity (87.5% ± 1.3%) and accuracy (86.4% ± 0.9%). Sleep outcome measures were more accurately measured by devices worn at the wrist than the hip, thigh or lower back, with the exception of sleep efficiency where the reverse was true. The CS algorithm provided consistently accurate measures of sleep onset: the mean (95%CI) difference at the wrist with Axivity was 2 min (-6; -14,) and the offset was 10 min (5, -19). Several algorithms provided accurate measures of sleep quantity at the wrist, showing differences with PSG of just 1-18 min a night for sleep period time and 5-22 min for total sleep time. Accuracy was generally higher for sleep efficiency than for frequency of night wakings or wake after sleep onset. The CS algorithm was more accurate at assessing sleep period time, with narrower 95% limits of agreement compared to the HDCZA (CS:-165 to 172 min; HDCZA: -212 to 250 min). CONCLUSION: Although the performance of existing count-based sleep algorithms varies markedly, wrist-worn devices provide more accurate measures of most sleep measures compared to other sites. Overall, the HDZCA algorithm showed the greatest accuracy, although the most appropriate algorithm depends on the sleep measure of focus.
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Actigrafía , Sueño , Niño , Adolescente , Humanos , Reproducibilidad de los Resultados , Polisomnografía , AlgoritmosRESUMEN
Differences in workload exist between netball playing positions and competition levels, but no research has compared workloads experienced by the same elite players during national and international competitions. This study collected internal (heart rate) and external (PlayerLoad·min-1) workload data per match quarter from 44 players during a national competition and 12 players during an international competition. Nine players played in both competitions. Linear mixed models compared percentage of match quarter in each heart rate zone and PlayerLoad·min-1 between competitions for each playing position. Workloads against low- and high-ranked international opponents were also compared. Internal workloads were greater in national compared to international competition for GD and WD positions. PlayerLoad·min-1 was significantly higher by 8-13% in the national competition for positions WD and C, and by 5-8% in the international competition for GD and GA. Positional differences may indicate a role of the team's tactical style of play. Workloads were generally greater against higher- rather than lower-ranked international opponents. These results indicate that tactical factors in combination with playing position and opposition characteristics should be considered when preparing physically for matches.
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Rendimiento Atlético , Baloncesto , Humanos , Baloncesto/fisiología , Carga de Trabajo , Rendimiento Atlético/fisiología , Frecuencia Cardíaca/fisiología , Modelos LinealesRESUMEN
The Mycobacterium tuberculosis type-7 protein secretion system ESX-1 is a major driver of its virulence. While the functions of most ESX-1 components are characterized, many others remain poorly defined. In this study, we examined the role of EspK, an ESX-1-associated protein that is thought to be dispensable for ESX-1 activity in members of the Mycobacterium tuberculosis complex. We show that EspK is needed for the timely and optimal secretion of EsxA and absolutely essential for EspB secretion in M. tuberculosis Erdman. We demonstrate that only the EsxA secretion defect can be alleviated in EspK-deficient M. tuberculosis by culturing it in media containing detergents like Tween 80 or tyloxapol. Subcellular fractionation experiments reveal EspK is exported by M. tuberculosis in an ESX-1-independent manner and localized to its cell wall. We also show a conserved W-X-G motif in EspK is important for its interaction with EspB and enabling its secretion. The same motif, however, is not important for EspK localization in the cell wall. Finally, we show EspB in EspK-deficient M. tuberculosis tends to adopt higher-order oligomeric conformations, more so than EspB in wild-type M. tuberculosis. These results suggest EspK interacts with EspB and prevents it from assembling prematurely into macromolecular complexes that are presumably too large to pass through the membrane-spanning ESX-1 translocon assembly. Collectively, our findings indicate M. tuberculosis EspK has a far more active role in ESX-1-mediated secretion than was previously appreciated and underscores the complex nature of this secretion apparatus. IMPORTANCE Mycobacterium tuberculosis uses its ESX-1 system to secrete EsxA and EspB into a host to cause disease. We show that EspK, a protein whose role in the ESX-1 machinery was thought to be nonessential, is needed by M. tuberculosis for optimal EsxA and EspB secretion. Culturing EspK-deficient M. tuberculosis with detergents alleviates EsxA but not EspB secretion defects. We also show that EspK, which is exported by M. tuberculosis in an ESX-1-independent manner to the cell wall, interacts with and prevents EspB from assembling into large structures inside the M. tuberculosis cell that are nonsecretable. Collectively, our observations demonstrate EspK is an active component of the ESX-1 secretion machinery of the tubercle bacillus.
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Mycobacterium tuberculosis , Tuberculosis , Sistemas de Secreción Tipo VII , Proteínas Bacterianas/metabolismo , Detergentes/metabolismo , Humanos , Mycobacterium tuberculosis/metabolismo , Tuberculosis/microbiología , Sistemas de Secreción Tipo VII/metabolismoRESUMEN
The emergence of multi-drug (MDR-TB) and extensively-drug resistant tuberculosis (XDR-TB) is a major threat to the global management of tuberculosis (TB) worldwide. New chemical entities are of need to treat drug-resistant TB. In this study, the mode of action of new, potent quinazoline derivatives was investigated against Mycobacterium tuberculosis (M. tb). Four derivatives 11626141, 11626142, 11626252 and 11726148 showed good activity (MIC ranging from 0.02-0.09 µg/mL) and low toxicity (TD50 ≥ 5µg/mL) in vitro against M. tb strain H37Rv and HepG2 cells, respectively. 11626252 was the most selective compound from this series. Quinazoline derivatives were found to target cytochrome bc1 by whole-genome sequencing of mutants selected with 11626142. Two resistant mutants harboured the transversion T943G (Trp312Gly) and the transition G523A (Gly175Ser) in the cytochrome bc1 complex cytochrome b subunit (QcrB). Interestingly, a third mutant QuinR-M1 contained a mutation in the Rieske iron-sulphur protein (QcrA) leading to resistance to quinazoline and other QcrB inhibitors, the first report of cross-resistance involving QcrA. Modelling of both QcrA and QcrB revealed that all three resistance mutations are located in the stigmatellin pocket, as previously observed for other QcrB inhibitors such as Q203, AX-35, and lansoprazole sulfide (LPZs). Further analysis of the mode of action in vitro revealed that 11626252 exposure leads to ATP depletion, a decrease in the oxygen consumption rate and also overexpression of the cytochrome bd oxidase in M. tb. Our findings suggest that quinazoline-derived compounds are a new and attractive chemical entity for M. tb drug development targeting two separate subunits of the cytochrome bc1 complex.
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Antituberculosos/farmacología , Proteínas Bacterianas/antagonistas & inhibidores , Complejo III de Transporte de Electrones/antagonistas & inhibidores , Mycobacterium tuberculosis/efectos de los fármacos , Quinazolinas/farmacología , Tuberculosis Resistente a Múltiples Medicamentos/microbiología , Antituberculosos/química , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Farmacorresistencia Bacteriana , Complejo III de Transporte de Electrones/genética , Complejo III de Transporte de Electrones/metabolismo , Humanos , Pruebas de Sensibilidad Microbiana , Mutación , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/metabolismo , Quinazolinas/química , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológicoRESUMEN
The COVID-19 pandemic has created an urgent need for models that can project epidemic trends, explore intervention scenarios, and estimate resource needs. Here we describe the methodology of Covasim (COVID-19 Agent-based Simulator), an open-source model developed to help address these questions. Covasim includes country-specific demographic information on age structure and population size; realistic transmission networks in different social layers, including households, schools, workplaces, long-term care facilities, and communities; age-specific disease outcomes; and intrahost viral dynamics, including viral-load-based transmissibility. Covasim also supports an extensive set of interventions, including non-pharmaceutical interventions, such as physical distancing and protective equipment; pharmaceutical interventions, including vaccination; and testing interventions, such as symptomatic and asymptomatic testing, isolation, contact tracing, and quarantine. These interventions can incorporate the effects of delays, loss-to-follow-up, micro-targeting, and other factors. Implemented in pure Python, Covasim has been designed with equal emphasis on performance, ease of use, and flexibility: realistic and highly customized scenarios can be run on a standard laptop in under a minute. In collaboration with local health agencies and policymakers, Covasim has already been applied to examine epidemic dynamics and inform policy decisions in more than a dozen countries in Africa, Asia-Pacific, Europe, and North America.
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COVID-19 , Modelos Biológicos , SARS-CoV-2 , Análisis de Sistemas , Número Básico de Reproducción , COVID-19/etiología , COVID-19/prevención & control , COVID-19/transmisión , Prueba de COVID-19 , Vacunas contra la COVID-19 , Biología Computacional , Simulación por Computador , Trazado de Contacto , Progresión de la Enfermedad , Desinfección de las Manos , Interacciones Microbiota-Huesped , Humanos , Máscaras , Conceptos Matemáticos , Pandemias , Distanciamiento Físico , Cuarentena , Programas InformáticosRESUMEN
BACKGROUND: Hansen's disease (leprosy), widespread in medieval Europe, is today mainly prevalent in tropical and subtropical regions with around 200,000 new cases reported annually. Despite its long history and appearance in historical records, its origins and past dissemination patterns are still widely unknown. Applying ancient DNA approaches to its major causative agent, Mycobacterium leprae, can significantly improve our understanding of the disease's complex history. Previous studies have identified a high genetic continuity of the pathogen over the last 1500 years and the existence of at least four M. leprae lineages in some parts of Europe since the Early Medieval period. RESULTS: Here, we reconstructed 19 ancient M. leprae genomes to further investigate M. leprae's genetic variation in Europe, with a dedicated focus on bacterial genomes from previously unstudied regions (Belarus, Iberia, Russia, Scotland), from multiple sites in a single region (Cambridgeshire, England), and from two Iberian leprosaria. Overall, our data confirm the existence of similar phylogeographic patterns across Europe, including high diversity in leprosaria. Further, we identified a new genotype in Belarus. By doubling the number of complete ancient M. leprae genomes, our results improve our knowledge of the past phylogeography of M. leprae and reveal a particularly high M. leprae diversity in European medieval leprosaria. CONCLUSIONS: Our findings allow us to detect similar patterns of strain diversity across Europe with branch 3 as the most common branch and the leprosaria as centers for high diversity. The higher resolution of our phylogeny tree also refined our understanding of the interspecies transfer between red squirrels and humans pointing to a late antique/early medieval transmission. Furthermore, with our new estimates on the past population diversity of M. leprae, we gained first insights into the disease's global history in relation to major historic events such as the Roman expansion or the beginning of the regular transatlantic long distance trade. In summary, our findings highlight how studying ancient M. leprae genomes worldwide improves our understanding of leprosy's global history and can contribute to current models of M. leprae's worldwide dissemination, including interspecies transmissions.
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Mycobacterium leprae , Europa (Continente) , Genoma Bacteriano/genética , Humanos , Lepra/genética , Mycobacterium leprae/genética , Dinámica PoblacionalRESUMEN
The increasing resistance to anthelmintics has necessitated the exploration of alternative control strategies of gastrointestinal nematode (GIN) infections. A sustainable option is genetic selection based on differences in susceptibility to GIN infection between and within breeds of sheep. Here, three-month-old Canaria Hair breed (GIN-resistant) and Canaria Sheep breed (GIN-susceptible) showed no significant between-breed differences after trickle infection with Teladorsagia circumcincta, whereas considerable individual variability was found in both breeds. Next, data from lambs of both breeds were used to explore the relationships between parasitological variables and T. circumcincta-specific IgA levels, local immune cell populations, and abomasal lymph node gene expression to understand the possible mechanisms underlying resistance. Mucosal IgA levels as well as numbers of globular leukocytes and MHC-II+ cells were associated with protection. Analysis of lymph node gene expression revealed the associations between lower parasite numbers and cumulative fecal egg counts and several immune pathways, such as leukocyte cell adhesion, activation and differentiation of T cells, in particular CD4+ and IL-4 production. The data obtained here may inform on the relationship between phenotypic resistance variability and protective responses at the humoral, cellular, and transcriptomic levels, thus contributing to identifying immune responses in young lambs that could be used as markers for selection.
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Enfermedades Gastrointestinales , Enfermedades de las Ovejas , Tricostrongiloidiasis , Animales , Heces , Inmunoglobulina A/genética , Ovinos/genética , Enfermedades de las Ovejas/genética , Transcriptoma , Trichostrongyloidea , Tricostrongiloidiasis/inmunología , Tricostrongiloidiasis/veterinariaRESUMEN
BACKGROUND: The blood feeding poultry red mite (PRM), Dermanyssus gallinae, causes substantial economic damage to the egg laying industry worldwide, and is a serious welfare concern for laying hens and poultry house workers. In this study we have investigated the temporal gene expression across the 6 stages/sexes (egg, larvae, protonymph and deutonymph, adult male and adult female) of this neglected parasite in order to understand the temporal expression associated with development, parasitic lifestyle, reproduction and allergen expression. RESULTS: RNA-seq transcript data for the 6 stages were mapped to the PRM genome creating a publicly available gene expression atlas (on the OrcAE platform in conjunction with the PRM genome). Network analysis and clustering of stage-enriched gene expression in PRM resulted in 17 superclusters with stage-specific or multi-stage expression profiles. The 6 stage specific superclusters were clearly demarked from each other and the adult female supercluster contained the most stage specific transcripts (2725), whilst the protonymph supercluster the fewest (165). Fifteen pairwise comparisons performed between the different stages resulted in a total of 6025 Differentially Expressed Genes (DEGs) (P > 0.99). These data were evaluated alongside a Venn/Euler analysis of the top 100 most abundant genes in each stage. An expanded set of cuticle proteins and enzymes (chitinase and metallocarboxypeptidases) were identified in larvae and underpin cuticle formation and ecdysis to the protonymph stage. Two mucin/peritrophic-A salivary proteins (DEGAL6771g00070, DEGAL6824g00220) were highly expressed in the blood-feeding stages, indicating peritrophic membrane formation during feeding. Reproduction-associated vitellogenins were the most abundant transcripts in adult females whilst, in adult males, an expanded set of serine and cysteine proteinases and an epididymal protein (DEGAL6668g00010) were highly abundant. Assessment of the expression patterns of putative homologues of 32 allergen groups from house dust mites indicated a bias in their expression towards the non-feeding larval stage of PRM. CONCLUSIONS: This study is the first evaluation of temporal gene expression across all stages of PRM and has provided insight into developmental, feeding, reproduction and survival strategies employed by this mite. The publicly available PRM resource on OrcAE offers a valuable tool for researchers investigating the biology and novel interventions of this parasite.
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Infestaciones por Ácaros , Ácaros , Enfermedades de las Aves de Corral , Animales , Pollos , Femenino , Humanos , Masculino , Ácaros/genética , Aves de Corral , TranscriptomaRESUMEN
Much of our current understanding about novel coronavirus disease 2019 (COVID-19) comes from hospitalised patients. However, the spectrum of mild and subclinical disease has implications for population-level screening and control. Forty-nine participants were recruited from a group of 99 adults repatriated from a cruise ship with a high incidence of COVID-19. Respiratory and rectal swabs were tested by polymerase chain reaction (PCR) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Sera were tested for anti-SARS-CoV-2 antibodies by enzyme-linked immunosorbent assay (ELISA) and microneutralisation assay. Symptoms, viral shedding and antibody response were examined. Forty-five participants (92%) were considered cases based on either positive PCR or positive ELISA for immunoglobulin G. Forty-two percent of cases were asymptomatic. Only 15% of symptomatic cases reported fever. Serial respiratory and rectal swabs were positive for 10% and 5% of participants respectively about 3 weeks after median symptom onset. Cycle threshold values were high (range 31-45). Attempts to isolate live virus were unsuccessful. The presence of symptoms was not associated with demographics, comorbidities or antibody response. In closed settings, incidence of COVID-19 could be almost double that suggested by symptom-based screening. Serology may be useful in diagnosis of mild disease and in aiding public health investigations.
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Anticuerpos Antivirales/sangre , COVID-19/epidemiología , COVID-19/virología , Navíos , Evaluación de Síntomas , Esparcimiento de Virus , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Pruebas de Neutralización , SARS-CoV-2/fisiología , Turismo , Uruguay , Victoria/epidemiologíaRESUMEN
Mycobacterium tuberculosis is a slow-growing intracellular bacterium with the ability to induce host cell death and persist indefinitely in the human body. This pathogen uses the specialized ESX-1 secretion system to secrete virulence factors and potent immunogenic effectors required for disease progression. ESX-1 is a multisubunit apparatus with a membrane complex that is predicted to form a channel in the cytoplasmic membrane. In M. tuberculosis this complex is composed of five membrane proteins: EccB1, EccCa1, EccCb1, EccD1, and EccE1 In this study, we have characterized the membrane component EccE1 and found that deletion of eccE1 lowers the levels of EccB1, EccCa1, and EccD1, thereby abolishing ESX-1 secretion and attenuating M. tuberculosisex vivo Surprisingly, secretion of EspB was not affected by loss of EccE1 Furthermore, EccE1 was found to be a membrane- and cell wall-associated protein that needs the presence of other ESX-1 components to assemble into a stable complex at the poles of M. tuberculosis Overall, this investigation provides new insights into the role of EccE1 and its localization in M. tuberculosisIMPORTANCE Tuberculosis (TB), the world's leading cause of death of humans from an infectious disease, is caused by the intracellular bacterium Mycobacterium tuberculosis The development of successful strategies to control TB requires better understanding of the complex interactions between the pathogen and the human host. We investigated the contribution of EccE1, a membrane protein, to the function of the ESX-1 secretion system, the major virulence determinant of M. tuberculosis By combining genetic analysis of selected mutants with eukaryotic cell biology and proteomics, we demonstrate that EccE1 is critical for ESX-1 function, secretion of effector proteins, and pathogenesis. Our research improves knowledge of the molecular basis of M. tuberculosis virulence and enhances our understanding of pathogenesis.
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Antígenos Bacterianos/genética , Antígenos Bacterianos/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Regulación Bacteriana de la Expresión Génica , Mycobacterium tuberculosis/fisiología , Tuberculosis/microbiología , Interacción Gen-Ambiente , Genoma Bacteriano , Interacciones Huésped-Patógeno , Humanos , Proteínas de la Membrana , Metales/metabolismo , Mutación , Estabilidad Proteica , Transporte de Proteínas , Proteómica , Estrés Fisiológico , VirulenciaRESUMEN
In bacteria, nucleoid associated proteins (NAPs) take part in active chromosome organization by supercoil management, three-dimensional DNA looping and direct transcriptional control. Mycobacterial integration host factor (mIHF, rv1388) is a NAP restricted to Actinobacteria and essential for survival of the human pathogen Mycobacterium tuberculosis. We show in vitro that DNA binding by mIHF strongly stabilizes the protein and increases its melting temperature. The structure obtained by Nuclear Magnetic Resonance (NMR) spectroscopy characterizes mIHF as a globular protein with a protruding alpha helix and a disordered N-terminus, similar to Streptomyces coelicolor IHF (sIHF). NMR revealed no residues of high flexibility, suggesting that mIHF is a rigid protein overall that does not undergo structural rearrangements. We show that mIHF only binds to double stranded DNA in solution, through two DNA binding sites (DBSs) similar to those identified in the X-ray structure of sIHF. According to Atomic Force Microscopy, mIHF is able to introduce left-handed loops of ca. 100 nm size (~300 bp) in supercoiled cosmids, thereby unwinding and relaxing the DNA.
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Proteínas de Unión al ADN/ultraestructura , Factores de Integración del Huésped/ultraestructura , Mycobacterium tuberculosis/genética , Tuberculosis/microbiología , Sitios de Unión/genética , ADN Bacteriano/genética , Proteínas de Unión al ADN/genética , Interacciones Huésped-Patógeno/genética , Humanos , Factores de Integración del Huésped/genética , Espectroscopía de Resonancia Magnética , Microscopía de Fuerza Atómica , Mycobacterium tuberculosis/patogenicidad , Conformación Proteica en Hélice alfa/genética , Streptomyces coelicolor/genética , Tuberculosis/genéticaRESUMEN
The ESX-1, type VII, secretion system represents the major virulence determinant of Mycobacterium tuberculosis, one of the most successful intracellular pathogens. Here, by combining genetic and high-throughput approaches, we show that EspL, a protein of 115 amino acids, is essential for mediating ESX-1-dependent virulence and for stabilization of EspE, EspF and EspH protein levels. Indeed, an espL knock-out mutant was unable to replicate intracellularly, secrete ESX-1 substrates or stimulate innate cytokine production. Moreover, proteomic studies detected greatly reduced amounts of EspE, EspF and EspH in the espL mutant as compared to the wild type strain, suggesting a role for EspL as a chaperone. The latter conclusion was further supported by discovering that EspL interacts with EspD, which was previously demonstrated to stabilize the ESX-1 substrates and effector proteins, EspA and EspC. Loss of EspL also leads to downregulation in M. tuberculosis of WhiB6, a redox-sensitive transcriptional activator of ESX-1 genes. Overall, our data highlight the importance of a so-far overlooked, though conserved, component of the ESX-1 secretion system and begin to delineate the role played by EspE, EspF and EspH in virulence and host-pathogen interaction.
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Antígenos Bacterianos/metabolismo , Proteínas Bacterianas/metabolismo , Mycobacterium tuberculosis/patogenicidad , Factores de Virulencia/metabolismo , Virulencia/fisiología , Humanos , Mycobacterium tuberculosis/metabolismo , Células THP-1 , Tuberculosis/microbiologíaRESUMEN
Studying ancient DNA allows us to retrace the evolutionary history of human pathogens, such as Mycobacterium leprae, the main causative agent of leprosy. Leprosy is one of the oldest recorded and most stigmatizing diseases in human history. The disease was prevalent in Europe until the 16th century and is still endemic in many countries with over 200,000 new cases reported annually. Previous worldwide studies on modern and European medieval M. leprae genomes revealed that they cluster into several distinct branches of which two were present in medieval Northwestern Europe. In this study, we analyzed 10 new medieval M. leprae genomes including the so far oldest M. leprae genome from one of the earliest known cases of leprosy in the United Kingdom-a skeleton from the Great Chesterford cemetery with a calibrated age of 415-545 C.E. This dataset provides a genetic time transect of M. leprae diversity in Europe over the past 1500 years. We find M. leprae strains from four distinct branches to be present in the Early Medieval Period, and strains from three different branches were detected within a single cemetery from the High Medieval Period. Altogether these findings suggest a higher genetic diversity of M. leprae strains in medieval Europe at various time points than previously assumed. The resulting more complex picture of the past phylogeography of leprosy in Europe impacts current phylogeographical models of M. leprae dissemination. It suggests alternative models for the past spread of leprosy such as a wide spread prevalence of strains from different branches in Eurasia already in Antiquity or maybe even an origin in Western Eurasia. Furthermore, these results highlight how studying ancient M. leprae strains improves understanding the history of leprosy worldwide.
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Lepra/historia , Mycobacterium leprae/genética , ADN Bacteriano/genética , ADN Bacteriano/historia , Europa (Continente)/epidemiología , Evolución Molecular , Variación Genética , Genoma Bacteriano , Historia Medieval , Interacciones Huésped-Patógeno/genética , Humanos , Lepra/epidemiología , Lepra/microbiología , Mycobacterium leprae/clasificación , Mycobacterium leprae/patogenicidad , Filogenia , Filogeografía , Polimorfismo de Nucleótido SimpleRESUMEN
BACKGROUND: Incisional hernia repair with mesh improves long-term outcomes, but the ideal mesh position remains unclear. This study compared intraperitoneal versus retromuscular or preperitoneal sublay (RPS) mesh positions for open incisional hernia repairs. METHODS: All patients who had elective open incisional hernia repairs were identified retrospectively in the Americas Hernia Society Quality Collaborative database. The primary outcome was the rate of 30-day surgical-site infection (SSI). Other outcomes of interest included 30-day surgical-site occurrences requiring procedural intervention (SSOPI), hernia-related quality-of-life survey (HerQLes) scores and long-term recurrence. A logistic model was used to generate propensity scores for mesh position using several clinically relevant co-variables. Regression models adjusting for propensity score and baseline characteristics were developed to assess the effect of mesh placement. RESULTS: A total of 4211 patients were included in the study population: 587 had intraperitoneal mesh and 3624 had RPS mesh. Analysis with propensity score adjustment provided no evidence for differences in SSOPI (odds ratio (OR) 0·79, 95 per cent c.i. 0·49 to 1·26) and SSI (OR 0·91, 0·50 to 1·67) rates or HerQLes scores at 30 days (OR 1·20, 0·79 to 1·82), or recurrence rates (hazard ratio 1·28, 0·90 to 1·82). CONCLUSION: Mesh position had no effect on short- or long-term outcomes, including SSOPI and SSI rates, HerQLes scores and long-term recurrence rates.
ANTECEDENTES: La reparación de una eventración con malla mejora los resultados a largo plazo, pero sigue sin estar definida cuál es la posición ideal de colocación de la malla. Este estudio comparó los resultados de la reparación abierta de una eventración con malla en posición intraperitoneal versus retromuscular o preperitoneal (retromuscular or preperitoneal sublay, RPS). MÉTODOS: Se identificaron de forma retrospectiva todos los pacientes a los que se reparó una eventración por via abierta en el Americas Hernia Society Quality Collaborative. La variable principal fue la tasa de infección de la herida quirúrgica (surgical site infections, SSI) a los 30 días. Se analizaron también las incidencias acaecidas en la herida que hubieran precisado algún tratamiento (surgical site occurrences requiring procedural intervention, SSOPI) dentro de los 30 días postintervención, los resultados de una encuesta de calidad de vida relacionada con la hernia (HerQles) y la recidiva a largo plazo. Se utilizó un modelo logístico con diferentes covariables clínicas relevantes para generar puntajes de propensión con respecto a la posición de malla. Para analizar el efecto de la posición de la malla, se desarrollaron diferentes modelos de regresión ajustados por las características basales y el puntaje de propensión. RESULTADOS: Se incluyeron en el estudio 4.211 pacientes, 587 con malla intraperitoneal y 3.624 con malla RPS. El análisis con ajuste por puntaje de propensión no mostró diferencias en SSOPI (razón de oportunidades, odds ratio, OR 0,624, i.c. del 95% 0,364-1,07), SSI (OR 0,927, i.c. del 95% 0,475-1,81), puntuación HerQles a 30 días (OR 1,19, i.c. del 95% 0,79-1,8) o en el índice de recidivas (OR 1,28, i.c. del 95% 0,897-1,82). CONCLUSIÓN: La posición de la colocación de la malla no tuvo efecto en los resultados a corto o largo plazo, incluidas las tasas de SSOPI y SSI, las puntuaciones de HerQles y la tasa de recidiva a largo plazo.
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Hernia Incisional/cirugía , Mallas Quirúrgicas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Puntaje de Propensión , Reoperación/estadística & datos numéricos , Estudios Retrospectivos , Infección de la Herida Quirúrgica/epidemiología , Resultado del TratamientoRESUMEN
AIMS: Serodiagnosis of sheep scab is an established diagnostic method and has become popular in recent years. However, the current diagnostic antigen, Pso o 2, has shown promise as a component of a recombinant vaccine for scab, making it incompatible with discriminating between infected and vaccinated animals (DIVA). Here, we describe the discovery and characterization of a novel Psoroptes ovis immunodiagnostic antigen, P. ovis-Early Immunoreactive Protein-1 (Pso-EIP-1). METHODS AND RESULTS: Pso-EIP-1 is a highly abundant member of a six-gene family with no known homologs, indicating its potential uniqueness to P. ovis. Expression of recombinant Pso-EIP-1 (rPso-EIP-1) required a C-terminal fusion protein for stability and specific IgG immunoreactivity against rPso-EIP-1 was observed in sheep serum from 1 to 2 weeks post-infestation, indicating its highly immunogenic nature. Two of the three in silico-predicted B-cell epitopes of Pso-EIP-1 were confirmed by in vitro epitope mapping and, in a direct comparison by ELISA, Pso-EIP-1 performed to the same levels as Pso o 2 in terms of sensitivity, specificity and ability to diagnose P. ovis on sheep within 2 weeks of infestation. CONCLUSION: Pso-EIP-1 represents a novel diagnostic antigen for sheep scab with comparable levels of sensitivity and specificity to the existing Pso o 2 antigen.
Asunto(s)
Proteínas de Artrópodos/inmunología , Infestaciones por Ácaros/veterinaria , Psoroptidae/inmunología , Pruebas Serológicas/veterinaria , Enfermedades de las Ovejas/diagnóstico , Animales , Inmunoglobulina G/sangre , Infestaciones por Ácaros/diagnóstico , Proteínas Recombinantes de Fusión/inmunología , Sensibilidad y Especificidad , Pruebas Serológicas/métodos , OvinosRESUMEN
Movement of the transcription machinery along a template alters DNA topology resulting in the accumulation of supercoils in DNA. The positive supercoils generated ahead of transcribing RNA polymerase (RNAP) and the negative supercoils accumulating behind impose severe topological constraints impeding transcription process. Previous studies have implied the role of topoisomerases in the removal of torsional stress and the maintenance of template topology but the in vivo interaction of functionally distinct topoisomerases with heterogeneous chromosomal territories is not deciphered. Moreover, how the transcription-induced supercoils influence the genome-wide recruitment of DNA topoisomerases remains to be explored in bacteria. Using ChIP-Seq, we show the genome-wide occupancy profile of both topoisomerase I and DNA gyrase in conjunction with RNAP in Mycobacterium tuberculosis taking advantage of minimal topoisomerase representation in the organism. The study unveils the first in vivo genome-wide interaction of both the topoisomerases with the genomic regions and establishes that transcription-induced supercoils govern their recruitment at genomic sites. Distribution profiles revealed co-localization of RNAP and the two topoisomerases on the active transcriptional units (TUs). At a given locus, topoisomerase I and DNA gyrase were localized behind and ahead of RNAP, respectively, correlating with the twin-supercoiled domains generated. The recruitment of topoisomerases was higher at the genomic loci with higher transcriptional activity and/or at regions under high torsional stress compared to silent genomic loci. Importantly, the occupancy of DNA gyrase, sole type II topoisomerase in Mtb, near the Ter domain of the Mtb chromosome validates its function as a decatenase.
Asunto(s)
Girasa de ADN/genética , ADN-Topoisomerasas de Tipo I/genética , ADN/genética , Mycobacterium tuberculosis/genética , Transcripción Genética , ADN Superhelicoidal/genética , ARN Polimerasas Dirigidas por ADN/genética , Regulación Bacteriana de la Expresión Génica , Genoma Bacteriano , Genómica , Humanos , Motivos de Nucleótidos/genética , Transducción de Señal/genéticaRESUMEN
Emotional contagion has been recognized as a variable influencing individual behaviour and team functioning. In particular, leaders within the team have been suggested to have a significant impact on their teammates through the expression of their emotions. As a result, the aim of this study was to provide greater insight into how different athlete leaders impact the emotional state of their team members, and whether gender differences existed in these relationships. Participants were 295 university student-athletes (200 male and 95 female) recruited from four universities in the UK. Data were collected in a two-step process. First, a voting/rating procedure was conducted within team to identify dominant task, motivational, social and external leaders. Then, participants completed the emotional contagion subscale of the Measure of Empathetic Tendency to rate the impact different athlete leaders had upon their emotional state. A MANOVA was conducted to explore gender differences in reported emotional susceptibility by leadership role. Subsequent ANOVAs highlighted significant differences between leadership role scores for female participants only. The results suggest that female athletes are more susceptible to emotional influence than male athletes. Furthermore, female athletes experienced a greater variation in the perceived emotional influence of different leadership roles in the team.
Asunto(s)
Atletas/psicología , Conducta Competitiva , Emociones , Liderazgo , Motivación , Rendimiento Atlético/psicología , Inglaterra , Femenino , Humanos , Masculino , Factores Sexuales , Adulto JovenRESUMEN
BACKGROUND: Psoroptic mange, caused by infestation with the ectoparasitic mite, Psoroptes ovis, is highly contagious, resulting in intense pruritus and represents a major welfare and economic concern for the livestock industry Worldwide. Control relies on injectable endectocides and organophosphate dips, but concerns over residues, environmental contamination, and the development of resistance threaten the sustainability of this approach, highlighting interest in alternative control methods. However, development of vaccines and identification of chemotherapeutic targets is hampered by the lack of P. ovis transcriptomic and genomic resources. RESULTS: Building on the recent publication of the P. ovis draft genome, here we present a genomic analysis and transcriptomic atlas of gene expression in P. ovis revealing feeding- and stage-specific patterns of gene expression, including novel multigene families and allergens. Network-based clustering revealed 14 gene clusters demonstrating either single- or multi-stage specific gene expression patterns, with 3075 female-specific, 890 male-specific and 112, 217 and 526 transcripts showing larval, protonymph and tritonymph specific-expression, respectively. Detailed analysis of P. ovis allergens revealed stage-specific patterns of allergen gene expression, many of which were also enriched in "fed" mites and tritonymphs, highlighting an important feeding-related allergenicity in this developmental stage. Pair-wise analysis of differential expression between life-cycle stages identified patterns of sex-biased gene expression and also identified novel P. ovis multigene families including known allergens and novel genes with high levels of stage-specific expression. CONCLUSIONS: The genomic and transcriptomic atlas described here represents a unique resource for the acarid-research community, whilst the OrcAE platform makes this freely available, facilitating further community-led curation of the draft P. ovis genome.