scholarly journals Influence of environmental factors on the presence of Vibrio cholerae in the marine environment: a climate link

2007 ◽  
Vol 1 (03) ◽  
pp. 224-241 ◽  
Author(s):  
Violeta Trinidad Pardío Sedas
Keyword(s):  
Environmental Factors ◽  
Vibrio Cholerae ◽  
Marine Environment ◽  
Environmental Changes ◽  
Three Dimensional ◽  
Economic Loss ◽  
Natural Systems ◽  
Filamentous Green Algae ◽  
Tropical Areas ◽  
El Tor

Evidence indicates that the atmospheric and oceanic processes that occur in response to increased greenhouse gases in the broad-scale climate system may already be changing the ecology of infectious diseases. Recent studies have shown that climate also influences the abundance and ecology of pathogens, and the links between pathogens and changing ocean conditions, including human diseases such as cholera. Vibrio cholerae is well recognized as being responsible for significant mortality and economic loss in developing countries, most often centered in tropical areas of the world. Within the marine environment, V. cholerae is found attached to surfaces provided by plants, filamentous green algae, copepods, crustaceans, and insects. The specific environmental changes that amplified plankton and associated bacterial proliferation and govern the location and timing of plankton blooms have been elucidated. Several studies have demonstrated that environmental non-O1 and non-O139 V. cholerae strains and V. cholerae O1 El Tor and O139 are able to form a three-dimensional biofilm on surfaces which provides a microenvironment, facilitating environmental persistence within natural aquatic habitats during interepidemic periods. Revealing the influence of climatic/environmental factors in seasonal patterns is critical to understanding temporal variability of cholera at longer time scales to improve disease forecasting. From an applied perspective, clarifying the mechanisms that link seasonal environmental changes to diseases’ dynamics will aid in developing strategies for controlling diseases across a range of human and natural systems.

scholarly journals Molecular MLVA Typing of Typical and Genetically Altered Natural Strains of Vibrio cholerae El Tor Biovar

2012 ◽  
pp. 39-43 ◽  
Author(s):  
T. A. Kul’Shan’ ◽  
Ya. M. Krasnov ◽  
Yu. V. Lozovsky ◽  
N. I. Smirnova
Keyword(s):  
Genetic Diversity ◽  
Environmental Factors ◽  
Vibrio Cholerae ◽  
Gene Variants ◽  
El Tor ◽  
Mlva Typing ◽  
Natural Strains

Displayed is the possibility of differentiation between typical and genetically altered strains of Vibrio cholerae biovar El Tor, which vary in their virulence and epidemic potential, by means of MLVA. Determined is a significant genetic diversity of the gene-variants, probably, due to their polyclonal origin and continuous alterations within genome under the influence of varying environmental factors.

scholarly journals The Vibrio cholerae VarS/VarA two-component system controls the expression of virulence proteins through ToxT regulation

Microbiology ◽  
2011 ◽  
Vol 157 (5) ◽  
pp. 1466-1473 ◽  
Author(s):  
Jeyoun Jang ◽  
Kyung-Tae Jung ◽  
Jungchan Park ◽  
Cheon-Kwon Yoo ◽  
Gi-Eun Rhie
Keyword(s):  
Vibrio Cholerae ◽  
Environmental Changes ◽  
Transcription Activator ◽  
Two Component System ◽  
Component System ◽  
Virulence Proteins ◽  
Two Component ◽  
Virulence Protein ◽  
El Tor

Although the conditions for inducing virulence protein expression in vitro are different, both classical and El Tor biotypes of Vibrio cholerae have been reported to regulate the expression of virulence proteins such as cholera toxin (CT) and toxin-coregulated pili (Tcp) through the ToxR/S/T system. The transcription activator ToxR responds to environmental stimuli such as pH and temperature and activates the second transcriptional regulator ToxT, which upregulates expression of virulence proteins. In addition to the ToxR/S/T signalling system, V. cholerae has been proposed to utilize another two-component system VarS/VarA to modulate expression of virulence genes. Previous study has shown that VarA of the VarS/VarA system is involved in the regulation of virulence proteins in the classical V. cholerae O395 strain; however, no further analysis was performed concerning VarS. In this study, we constructed varS mutants derived from the classical O395 and El Tor C6706 strains and demonstrated that VarS is also involved in the expression of the virulence proteins CT and Tcp from the V. cholerae classical and El Tor strains. This expression is through regulation of ToxT expression in response to environmental changes due to different toxin-inducing conditions.

HOPS

2011 ◽  
pp. 840-847
Author(s):  
Stefano Cagnoni ◽  
Monica Mordonini ◽  
Luca Mussi ◽  
Giovanni Adorni
Keyword(s):  
Machine Vision ◽  
Environmental Changes ◽  
Peripheral Vision ◽  
Three Dimensional ◽  
Human Perception ◽  
Dimensional Structure ◽  
Biological Vision ◽  
Natural Systems ◽  
Binocular Stereo Vision ◽  
Binocular Stereo

Biological vision processes are usually characterized by the following different phases: • Awareness: natural or artificial agents operating in dynamic environments can benefit from a, possibly rough, global description of the surroundings. In human this is referred to as peripheral vision, since it derives from stimuli coming from the edge of the retina. • Attention: once an interesting object/event has been detected, higher resolution is required to set focus on it and plan an appropriate reaction. In human this corresponds to the so-called foveal vision, since it originates from the center of the retina (fovea). • Analysis: extraction of detailed information about objects of interest, their three-dimensional structure and their spatial relationships completes the vision process. Achievement of these goals requires at least two views of the surrounding scene with known geometrical relations. In humans, this function is performed exploiting binocular (stereo) vision. Computer Vision has often tried to emulate natural systems or, at least, to take inspiration from them. In fact, different levels of resolution are useful also in machine vision. In the last decade a number of studies dealing with multiple cameras at different resolutions have appeared in literature. Furthermore, the ever-growing computer performances and the ever-decreasing cost of video equipment make it possible to develop systems which rely mostly, or even exclusively, on vision for navigating and reacting to environmental changes in real time. Moreover, using vision as the unique sensory input makes artificial perception closer to human perception, unlike systems relying on other kinds of sensors and allows for the development of more direct biologically-inspired approaches to interaction with the external environment (Trullier 1997). This article presents HOPS (Hybrid Omnidirectional Pin-hole Sensor), a class of dual camera vision sensors that try to exalt the connection between machine vision and biological vision.

scholarly journals Identification and Characterization of a Vibrio cholerae Gene, mbaA, Involved in Maintenance of Biofilm Architecture

2003 ◽  
Vol 185 (4) ◽  
pp. 1384-1390 ◽  
Author(s):  
Natalia Bomchil ◽  
Paula Watnick ◽  
Roberto Kolter
Keyword(s):  
Vibrio Cholerae ◽  
Matrix Material ◽  
Three Dimensional ◽  
Microscopic Analysis ◽  
Typical Structure ◽  
Abiotic Surfaces ◽  
Biofilm Architecture ◽  
El Tor ◽  
Identification And Characterization

ABSTRACT The formation of biofilms is thought to play a key role in the environmental survival of the marine bacterium Vibrio cholerae. Although the factors involved in V. cholerae attachment to abiotic surfaces have been extensively studied, relatively little is known about the mechanisms involved in the subsequent maturation of the biofilms. Here we report the identification of a novel gene, which we have named mbaA (for maintenance of biofilm architecture), that plays a role in the formation and maintenance of the highly organized three-dimensional architecture of V. cholerae El Tor biofilms. We demonstrate that although the absence of mbaA does not significantly affect the initial attachment of cells onto the surface, it leads to the formation of biofilms that lack the typical structure, including the pillars of cells separated by fluid-filled channels that are evident in mature wild-type biofilms. Microscopic analysis indicates that the absence of mbaA leads to an increase in the amount of extracellular matrix material in the biofilms. The predicted mbaA product is a member of a family of regulatory proteins, containing GGDEF and EAL domains, suggesting that MbaA regulates the synthesis of some component of the biofilm matrix.

Genomic Variability of Pathogenicity Islands in Nontoxigenic Strains of Vibrio cholerae O1 Biotype El Tor

2020 ◽  
Vol 56 (9) ◽  
pp. 1055-1069
Author(s):  
N. I. Smirnova ◽  
A. A. Kritsky ◽  
J. V. Alkhova ◽  
E. Yu. Agafonova ◽  
E. Yu. Shchelkanova ◽  
...  
Keyword(s):  
Vibrio Cholerae ◽  
Pathogenicity Islands ◽  
Genomic Variability ◽  
Vibrio Cholerae O1 ◽  
El Tor

Three-dimensional stromatolites from Maastrichtian–Danian Yacoraite Formation, Argentina: modelling and assessing hydrodynamic controls on growth patterns

2021 ◽  
pp. 1-17
Author(s):  
Patricio Guillermo Villafañe ◽  
Carlos Cónsole-Gonella ◽  
Paolo Citton ◽  
Ignacio Díaz-Martínez ◽  
Silvina de Valais
Keyword(s):  
Environmental Factors ◽  
Methodological Approach ◽  
Three Dimensional ◽  
Growth Patterns ◽  
External Morphology ◽  
Water Dynamics ◽  
Microbial Composition ◽  
Depositional Processes ◽  
Run Off ◽  
Internal Arrangement

Abstract Stromatolites are biogenic sedimentary structures formed by the interplay of biological (microbial composition) and environmental factors (local hydrodynamic conditions, clastic input and/or water chemistry). Well-preserved, three-dimensional (3D) fossil stromatolites are key to assessing the environmental factors controlling their growth and resulting morphology in space and time. Here, we report the detailed analysis of well-exposed, highly informative stromatolite build-ups from a single stratigraphic horizon within the Maastrichtian–Danian Yacoraite Formation (Argentina). This study focuses on the analysis of depositional processes driving intertidal to shallow subtidal stromatolites. Overall depositional architecture, external morphology and internal arrangement (mega, macro, meso and microstructures) of stromatolite build-ups were analysed and combined with 3D photogrammetric models, allowing us to decipher the links between stromatolite structure and tidal dynamics. Results suggest that external morphology and architecture of elongated and parallel clusters grew under the influence of run-off channels. The internal morphology exhibits columnar structures where the space between columns is interpreted as recharge or discharge channels. This work supports the theory that stromatolites can be used as a high-resolution tool in the assessment of water dynamics, and provides a new methodological approach and data for the dynamic reconstruction of intertidal stromatolite systems through the geological record.

scholarly journals Validation of a three-dimensional model about sleep: Habits, personal factors and environmental factors

Sleep Science ◽  
2014 ◽  
Vol 7 (4) ◽  
pp. 197-202 ◽  
Author(s):  
Teresa Rebelo-Pinto ◽  
Joana Carneiro Pinto ◽  
Helena Rebelo-Pinto ◽  
Teresa Paiva
Keyword(s):  
Environmental Factors ◽  
Three Dimensional ◽  
Personal Factors ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Sleep Habits

scholarly journals Environmental factors influence the detection probability in acoustic telemetry in a marine environment: results from a new setup

Hydrobiologia ◽  
2018 ◽  
Vol 845 (1) ◽  
pp. 81-94 ◽  
Author(s):  
Jan Reubens ◽  
Pieterjan Verhelst ◽  
Inge van der Knaap ◽  
Klaas Deneudt ◽  
Tom Moens ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Marine Environment ◽  
Detection Probability ◽  
Acoustic Telemetry

scholarly journals Enhancing the resilience of coupled human and natural systems of alpine rangelands on the Qinghai-Tibetan Plateau

2015 ◽  
Vol 37 (1) ◽  
pp. i ◽  
Author(s):  
Shikui Dong ◽  
Ruth Sherman
Keyword(s):  
Tibetan Plateau ◽  
Science Policy ◽  
Sustainable Management ◽  
Environmental Changes ◽  
Policy Design ◽  
Rangeland Management ◽  
Special Issue ◽  
Natural Systems ◽  
Wide Range ◽  
Science Policy Interface

This special issue covers a wide range of topics on the protection and sustainable management of alpine rangelands on the Qinghai-Tibetan Plateau (QTP), including Indigenous knowledge of sustainable rangeland management, science-policy interface for alpine rangeland biodiversity conservation, adaptations of local people to social and environmental changes and policy design for managing coupled human-natural systems of alpine rangelands.

RESISTANT VIBRIO CHOLERÆ EL TOR IN TANZANIA

The Lancet ◽  
1979 ◽  
Vol 314 (8134) ◽  
pp. 147-148 ◽  
Author(s):  
K.J. Towner ◽  
N.J. Pearson ◽  
F. O'Grady
Keyword(s):  
Vibrio Cholerae ◽  
El Tor
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