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Disease Vectors (disease + vector)

Distribution by Scientific Domains
Life Sciences70%

Selected Abstracts

Disease Vectors and International Transport

JOURNAL OF TRAVEL MEDICINE, Issue 4 2003
Norman Gratz
No abstract is available for this article. [source]

Sequence and organization of the mitochondrial genome of the Chagas disease vector, Triatoma dimidiata

INSECT MOLECULAR BIOLOGY, Issue 3 2001
E. M. Dotson
Abstract The 17 019 bp mitochondrial genome of Triatoma dimidiata is composed of thirteen protein coding sequences, twenty-two tRNAs, small and large ribosomal units, and a control region. The gene order and orientation are identical to that of Drosophila yakuba. The nucleotide composition is biased toward adenine and thymine (69.5% A + T). The 2.1 kb putative control region, known as the A + T rich region in most insects, has an A + T bias of 66%, but contains a 400 bp sequence that is 77.5% A + T and two other distinct regions: (1) one with a lower A + T bias (60.1%) and (2) a region of eight tandem repeat units. The identified 1.4 kb nuclear copy of mitochondrial sequences encompasses the string of Gs and the beginning of the cytochrome c oxidase 1 gene but lacks the 1.8 kb region spanning the eight tandem repeats and the 5, end of the NADH dehydrogenase subunit II gene. [source]

Seasonal effects and fine-scale population dynamics of Aedes taeniorhynchus, a major disease vector in the Galapagos Islands

MOLECULAR ECOLOGY, Issue 20 2010
ARNAUD BATAILLE
Abstract Characterization of the fine-scale population dynamics of the mosquito Aedes taeniorhynchus is needed to improve our understanding of its role as a disease vector in the Galapagos Islands. We used microsatellite data to assess the genetic structure of coastal and highland mosquito populations and patterns of gene flow between the two habitats through time on Santa Cruz Island. In addition, we assessed possible associations of mosquito abundance and genetic diversity with environmental variables. The coastal and highland mosquito populations were highly differentiated from each other all year round, with some gene flow detected only during periods of increased precipitation. The results support the hypothesis that selection arising from ecological differences between habitats is driving adaptation and divergence in A. taeniorhynchus, and maintaining long-term genetic differentiation of the populations against gene flow. The highland and lowland populations may constitute an example of incipient speciation in progress. Highland populations were characterized by lower observed heterozygosity and allelic richness, suggesting a founder effect and/or lower breeding site availability in the highlands. A lack of reduction in genetic diversity over time in highland populations suggests that they survive dry periods as dormant eggs. Association between mosquito abundance and precipitation was strong in the highlands, whereas tide height was the main factor affecting mosquito abundance on the coast. Our findings suggests differences in the infection dynamics of mosquito-borne parasites in the highlands compared to the coast, and a higher risk of mosquito-driven disease spread across these habitats during periods of increased precipitation. [source]

The neuropeptidome of Rhodnius prolixus brain

PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 3 2009
Sheila Ons
Abstract We show a sensitive and straightforward off-line nano-LC-MALDI-MS/MS workflow that allowed the first comprehensive neuropeptidomic analysis of an insect disease vector. This approach was applied to identify neuropeptides in the brain of Rhodnius prolixus, a vector of Chagas disease. This work will contribute to the annotation of genes in the ongoing R. prolixus genome sequence project. Peptides were identified by de novo sequencing and comparisons to known neuropeptides from different organisms by database search. By these means, we were able to identify 42 novel neuropeptides from R. prolixus. The peptides were classified as extended FMRF-amide-related peptides, sulfakinins, myosuppressins, short neuropeptide F, long neuropeptide F, SIF-amide-related peptides, tachykinins, orcokinins, allatostatins, allatotropins, calcitonin-like diuretic hormones, corazonin, and pyrokinin. Some of them were detected in multiple isoforms and/or truncated fragments. Interestingly, some of the R. prolixus peptides, as myosuppressin and sulfakinins, are unique in their characteristic C-terminal domain among insect neuropeptides identified so far. [source]

Prairie dog presence affects occurrence patterns of disease vectors on small mammals

ECOGRAPHY, Issue 5 2008
R. Jory Brinkerhoff
Wildlife disease is recognized as a burgeoning threat to imperiled species and aspects of host and vector community ecology have been shown to have significant effects on disease dynamics. The black-tailed prairie dog is a species of conservation concern that is highly susceptible to plague, a flea-transmitted disease. Prairie dogs (Cynomys) alter the grassland communities in which they exist and have been shown to affect populations of small rodents, which are purported disease reservoirs. To explore potential ecological effects of black-tailed prairie dogs on plague dynamics, we quantified flea occurrence patterns on small mammals in the presence and absence of prairie dogs at 8 study areas across their geographic range. Small mammals sampled from prairie dog colonies showed significantly higher flea prevalence, flea abundance, and relative flea species richness than those sampled from off-colony sites. Successful plague transmission likely is dependent on high prevalence and abundance of fleas that can serve as competent vectors. Prairie dogs may therefore facilitate the maintenance of plague by increasing flea occurrence on potential plague reservoir species. Our data demonstrate the previously unreported ecological influence of prairie dogs on vector species assemblages, which could influence disease dynamics. [source]

Functional genomics studies on the innate immunity of disease vectors

INSECT SCIENCE, Issue 1 2008
Luke A. Baton
Abstract The increasing availability of genome sequences and the development of high-throughput techniques for gene expression profiling and functional characterization are transforming the study of innate immunity and other areas of insect biology. Already, functional genomic approaches have enabled a quantum advance in the characterization of mosquito immune responses to malaria parasite infection, and similar high-throughput functional genomic studies of other vector-pathogen interactions can be expected in the near future. The application of microarray-based and other expression analyses provide genome-wide transcriptional profiles that can be used to identify insect immune system components that are differentially regulated upon exposure to various classes of pathogens, including many important etiologic agents of human and animal diseases. The role of infection-responsive or other candidate immune genes identified through comparative genomic approaches can then be functionally characterized, either in vivo, for instance in adult mosquitoes, or in vitro using cell lines. In most insect vectors of human pathogens, germ-line transgenesis is still technically difficult and maintenance of multiple transgenic lines logistically demanding. Consequently, transient RNA interference (RNAi)-mediated gene-silencing has rapidly become the method of choice for functional characterization of candidate innate immune genes. The powerful combination of transcriptional profiling in conjunction with assays using RNAi to determine gene function, and identify regulatory pathways, together with downstream cell biological approaches to determine protein localization and interactions, will continue to provide novel insights into the role of insect innate immunity in a variety of vector-pathogen interactions. Here we review advances in functional genomics studies of innate immunity in the insect disease vectors, over the past decade, with a particular focus on the Anopheles mosquito and its responses to malaria infection. [source]

The Revised International Health Regulations and Their Relevance to Travel Medicine

JOURNAL OF TRAVEL MEDICINE, Issue 3 2007
MFPHM, MRCGP, Max Hardiman MBChB
The revised International Health Regulations 2005 (IHR 2005) will enter into force in June 2007. Here we give an overview of the IHR (2005) and their relevance to the travel medicine practitioner. The two specific applications of the IHR (2005) most likely to be encountered by travelers are the disinsection of aircraft to prevent importation of disease vectors and the yellow fever vaccination requirements imposed by certain countries. A model of the revised international certificate of vaccination or prophylaxis will be shown. The IHR (2005) has moved away from the definition of fixed maximum measures relating to specific diseases and in their place focus on the issuance of context-specific recommendations, made either on a temporary emergency basis or established for routine application in respect of ongoing risks of disease spread. [source]

Natural hybridization and the evolution of domesticated, pest and disease organisms

MOLECULAR ECOLOGY, Issue 5 2004
Michael L. Arnold
Abstract The role of natural hybridization in the evolutionary history of numerous species is well recognized. The impact of introgressive hybridization and hybrid speciation has been documented especially in plant and animal assemblages. However, there remain certain areas of investigation for which natural hybridization and its consequences remain under-studied and under-appreciated. One such area involves the evolution of organisms that positively or negatively affect human populations. In this review, I highlight exemplars of how natural hybridization has contributed to the evolution of (i) domesticated plants and animals; (ii) pests; (iii) human disease vectors; and (iv) human pathogens. I focus on the effects from genetic exchange that may lead to the acquisition of novel phenotypes and thus increase the beneficial or detrimental (to human populations) aspects of the various taxa. [source]