34 research outputs found
Identificación de la flora bacteriana en la tortuga lora (Lepidochelys kempii ) en el ejido Barra Galindo, Tuxpan, Veracruz, México
Kemps Ridley turtle (Lepidochelys kempii) is considered as critically endangered by Mexican laws and by several international organizations. One of the main dangers is the indiscriminate capture and destruction of nests by humans, and a second source of mortality are viral, as well as bacterial or fungal infections. This study took place in the conservation area Campamento tortuguero Ejido Barra Galindo, Tuxpan, Veracruz. Samples were obtained from nesting females, hatchlings, and nests. In total 14 bacterial species were identified, 10Gram negative and four Gram positive. The species identified were: Aeromonas hydrophila, Bacillus sp., Citrobacter sp., Edwardsiella sp., Enterobacter sp., Escherichia coli, Flavobacterium sp., Mycobacterium sp., Proteussp., Pseudomonas sp., Salmonella sp., Staphylococcus sp., Streptococcus aureus and Vibrio alginolyticus. The four more frequent were: Edwardsiella sp., Escherichia coli, Salmonella sp. and Vibrio alginolyticus. This type of studies may allow an understanding of the role played by microorganisms in infectious diseases of marine turtles and how they may affect the survival of natural populations of these animals under natural conditions.La tortuga lora (Lepidochelys kempii) es una especie considerada en peligro de extinción por las leyes mexicanas y por varios organismos internacionales. Una de las principales amenazas a la existencia de este quelonio, es su captura indiscriminada y la destrucción de sus nidos por parte de los seres humanos. Un peligro adicional son los agentes etiológicos virales, bacterianos o micóticos. El presente estudio se llevó a cabo en el área de conservación Campamento tortuguero Ejido Barra Galindo, Tuxpan, Veracruz. Se tomaron muestras de hembras anidadoras, de crías y de los nidos. En total se obtuvieron 14 especies de bacterias, de las cuales 10 fueron Gram negativas y cuatro Gram positivas. Las especies identificadas fueron: Aeromonas hydrophila, Bacillus sp., Citrobacter sp., Edwardsiella sp., Enterobacter sp., Escherichia coli, Flavobacterium sp., Mycobacterium sp., Proteus sp., Pseudomonas sp., Salmonella sp., Staphylococcus sp., Streptococcus aureus y Vibrio alginolyticus. Las cuatro bacterias más frecuentes fueron: Edwardsiella sp., Escherichia coli., Salmonella sp. y Vibrio alginolyticus. Este tipo de estudios permitirá conocer el papel que juegan las bacterias patógenas en las enfermedades infecciosas de las tortugas marinas y cómo estas afectan la sobrevivencia de sus poblaciones en condiciones naturales
Extreme wave height events in NW Spain: a combined multi-sensor and model approach
The Galician coast (NW Spain) is a region that is strongly influenced by the presence of
low pressure systems in the mid-Atlantic Ocean and the periodic passage of storms that give rise
to severe sea states. Since its wave climate is one of the most energetic in Europe, the objectives of
this paper were twofold. The first objective was to characterize the most extreme wave height events
in Galicia over the wintertime of a two-year period (2015–2016) by using reliable high-frequency
radar wave parameters in concert with predictions from a regional wave (WAV) forecasting system
running operationally in the Iberia-Biscay-Ireland (IBI) area, denominated IBI-WAV. The second
objective was to showcase the application of satellite wave altimetry (in particular, remote-sensed
three-hourly wave height estimations) for the daily skill assessment of the IBI-WAV model product.
Special attention was focused on monitoring Ophelia—one of the major hurricanes on record in
the easternmost Atlantic—during its 3-day track over Ireland and the UK (15–17 October 2017).
Overall, the results reveal the significant accuracy of IBI-WAV forecasts and prove that a combined
observational and modeling approach can provide a comprehensive characterization of severe wave
conditions in coastal areas and shows the benefits from the complementary nature of both systems.The authors also would like to thank the support by Interreg Atlantic Area project MyCOAST (EAPA 285/2016) co-funded by the ERDF (EU)S
Extreme wave height events in NW Spain: a combined multi-sensor and model approach
The Galician coast (NW Spain) is a region that is strongly influenced by the presence of low pressure systems in the mid-Atlantic Ocean and the periodic passage of storms that give rise to severe sea states. Since its wave climate is one of the most energetic in Europe, the objectives of this paper were twofold. The first objective was to characterize the most extreme wave height events in Galicia over the wintertime of a two-year period (2015–2016) by using reliable high-frequency radar wave parameters in concert with predictions from a regional wave (WAV) forecasting system running operationally in the Iberia-Biscay-Ireland (IBI) area, denominatedIBI-WAV. The second objective was to showcase the application of satellite wave altimetry (in particular, remote-sensed three-hourly wave height estimations) for the daily skill assessment of the IBI-WAV model product. Special attention was focused on monitoring Ophelia—one of the major hurricanes on record in the easternmost Atlantic—during its 3-day track over Ireland and the UK (15–17 October 2017). Overall, the results reveal the significant accuracy of IBI-WAV forecasts and prove that a combined observational and modeling approach can provide a comprehensive characterization of severe wave conditions in coastal areas and shows the benefits from the complementary nature of both systems
Onchocerciasis transmission in Ghana: Persistence under different control strategies and the role of the simuliid vectors
Background:
The World Health Organization (WHO) aims at eliminating onchocerciasis by 2020 in selected African countries. Current control focuses on community-directed treatment with ivermectin (CDTI). In Ghana, persistent transmission has been reported despite long-term control. We present spatial and temporal patterns of onchocerciasis transmission in relation to ivermectin treatment history.
Methodology/Principal Findings:
Host-seeking and ovipositing blackflies were collected from seven villages in four regions of Ghana with 3–24 years of CDTI at the time of sampling. A total of 16,443 flies was analysed for infection; 5,812 (35.3%) were dissected for parity (26.9% parous). Heads and thoraces of 12,196 flies were dissected for Onchocerca spp. and DNA from 11,122 abdomens was amplified using Onchocerca primers. A total of 463 larvae (0.03 larvae/fly) from 97 (0.6%) infected and 62 (0.4%) infective flies was recorded; 258 abdomens (2.3%) were positive for Onchocerca DNA. Infections (all were O. volvulus) were more likely to be detected in ovipositing flies. Transmission occurred, mostly in the wet season, at Gyankobaa and Bosomase, with transmission potentials of, respectively, 86 and 422 L3/person/month after 3 and 6 years of CDTI. The numbers of L3/1,000 parous flies at these villages were over 100times the WHO threshold of one L3/1,000 for transmission control. Vector species influenced transmission parameters. At Asubende, the number of L3/1,000 ovipositing flies (1.4, 95% CI = 0–4) also just exceeded the threshold despite extensive vector control and 24 years of ivermectin distribution, but there were no infective larvae in host-seeking flies.
Conclusions/Significance:
Despite repeated ivermectin treatment, evidence of O. volvulus transmission was documented in all seven villages and above the WHO threshold in two. Vector species influences transmission through biting and parous rates and vector competence, and should be included in transmission models. Oviposition traps could augment vector collector methods for monitoring and surveillance
Evidence of an Antimicrobial-Immunomodulatory Role of Atlantic Salmon Cathelicidins during Infection with Yersinia ruckeri
Cathelicidins are a family of antimicrobial peptides that act as effector molecules of the innate immune system with broad-spectrum antimicrobial properties. These evolutionary conserved cationic host-defence peptides are integral components of the immune response of fish, which are generally believed to rely heavily on innate immune defences to invading pathogens. In this study we showed that Atlantic salmon cathelicidin 1 and 2 (asCATH1 and asCATH2) stimulated peripheral blood leukocytes increasing the transcription of the chemokine interleukin-8. Further, functional differences were identified between the two cathelicidins. In the presence of serum, asCATH1 displayed greatly diminished host haemolytic activity, while the constitutively expressed asCATH2 had no haemolytic activity with or without serum. These findings support our hypothesis that fish cathelicidins exert their primary antimicrobial action at the site of pathogen invasion such as epithelial surfaces. Further, we hypothesise that like their mammalian counterparts in the presence of serum they act as mediators of the innate and adaptive immune response via the release of cytokines thus indirectly protecting against a variety of pathogens. We highlight the importance of this immunomodulatory role from the involvement of asCATHs during an infection with the fish pathogen Yersinia ruckeri. While we were able to demonstrate in vitro that asCATH1 and 2, possessed direct microbicidal activity against the fish pathogen, Vibrio anguillarum, and a common gram negative bacterium, Escherichia coli, little or no bactericidal activity was found against Y. ruckeri. The contribution of either asCATH in the immune response or as a potential virulence factor during yersiniosis is highlighted from the increased expression of asCATH1 and 2 mRNA during an in vivo challenge with Y. ruckeri . We propose that Atlantic salmon cathelicidins participate in the interplay between the innate and adaptive immune systems via the release of cytokines enabling a more effective response to invading pathogens
Venezuela's humanitarian crisis, resurgence of vector-borne diseases, and implications for spillover in the region.
In the past 5-10 years, Venezuela has faced a severe economic crisis, precipitated by political instability and declining oil revenue. Public health provision has been affected particularly. In this Review, we assess the impact of Venezuela's health-care crisis on vector-borne diseases, and the spillover into neighbouring countries. Between 2000 and 2015, Venezuela witnessed a 359% increase in malaria cases, followed by a 71% increase in 2017 (411 586 cases) compared with 2016 (240 613). Neighbouring countries, such as Brazil, have reported an escalating trend of imported malaria cases from Venezuela, from 1538 in 2014 to 3129 in 2017. In Venezuela, active Chagas disease transmission has been reported, with seroprevalence in children (<10 years), estimated to be as high as 12·5% in one community tested (n=64). Dengue incidence increased by more than four times between 1990 and 2016. The estimated incidence of chikungunya during its epidemic peak is 6975 cases per 100 000 people and that of Zika virus is 2057 cases per 100 000 people. The re-emergence of many vector-borne diseases represents a public health crisis in Venezuela and has the possibility of severely undermining regional disease elimination efforts. National, regional, and global authorities must take action to address these worsening epidemics and prevent their expansion beyond Venezuelan borders
L'Institut de Cibernètica: organització i línies de recerca
Aquest treball vol ésser una breu presentació de l'Institut de Cibernètica i de la seva tasca de recerca. A la primera part s'exposen eIs antecedents sobre els inicis i creació de l'Institut, els seus objectius i la seva estructura funcional. Pel que fa a l'estructura es descriuen les diferents Seccions amb el seu contingut, així com els Serveis que constitueixen l'imprescindible suport operatiu per a la tasca de recerca. A la segona part es presenten les principals línies de recerca de l'Institut, tot i fent una relació dels projectes concrets mes importants que comprenen. Finalment, es presenta la relaci6 de les publicacions corres ponents als anys 1978, 1979, i de les tesis doctoraIs Ilegides
Minimalist Model Systems Reveal Similarities and Differences between Membrane Interaction Modes of MCL1 and BAK
Proteins belonging to the BCL2 family are key modulators of apoptosis that establish a complex network of interactions among themselves and with other cellular factors to regulate cell fate. It is well established that mitochondrial membranes are the main locus of action of all BCL2 family proteins, but it is difficult to obtain a precise view of how BCL2 family members operate at the native mitochondrial membrane environment during apoptosis. Here, we used minimalist model systems and multiple fluorescence-based techniques to examine selected membrane activities of MCL1 and BAK under apoptotic-like conditions. We show that three distinct apoptosis-related factors (i.e. the BCL2 homology 3 ligand cBID, the mitochondrion-specific lipid cardiolipin, and membrane geometrical curvature) all promote membrane association of BCL2-like structural folds belonging to both MCL1 and BAK. However, at the same time, the two proteins exhibited distinguishing features in their membrane association modes under apoptotic-like conditions. In addition, scanning fluorescence cross-correlation spectroscopy and FRET measurements revealed that the BCL2-like structural fold of MCL1, but not that of BAK, forms stable heterodimeric complexes with cBID in a manner adjustable by membrane cardiolipin content and curvature degree. Our results add significantly to a growing body of evidence indicating that the mitochondrial membrane environment plays a complex and active role in the mode of action of BCL2 family proteins
PB1-F2, an Influenza A Virus-Encoded Proapoptotic Mitochondrial Protein, Creates Variably Sized Pores in Planar Lipid Membranes
A frameshifted region of the influenza A virus PB1 gene encodes a novel protein, termed PB1-F2, a mitochondrial protein that can induce cell death. Many proapoptotic proteins are believed to act at the mitochondrial outer membrane to form an apoptotic pore with lipids. We studied the interaction of isolated, synthetic PB1-F2 (sPB1-F2) peptide with planar phospholipid bilayer membranes. The presence of nanomolar concentrations of peptide in the bathing solution induced a transmembrane conductance that increased in a potential-dependent manner. Positive potential on the side of protein addition resulted in a severalfold increase in the rate of change of membrane conductance. sPB1-F2-treated membranes became permeable to monovalent cations, chloride, and to a lesser extent, divalent ions. Despite various experimental conditions, we did not detect the distinctive conductance levels typical of large, stable pores, protein channels, or even pores that are partially proteinaceous. Rather, membrane conductance induced by sPB1-F2 fluctuated and visited almost all conductance values. sPB1-F2 also dramatically decreased bilayer stability in an electric field, consistent with a decrease in the line tension of a lipidic pore. Since similar membrane-destabilizing profiles are seen with proapoptotic proteins (e.g., Bax) and the cytoplasmic helix of human immunodeficiency virus gp41, we suggest that the basis for sPB1-F2-induced cell death may be the permeabilization and destabilization of mitochondrial membranes, leading to macromolecular leakage and apoptosis