scholarly journals Metabarcoding: A Powerful Yet Still Underestimated Approach for the Comprehensive Study of Vector-Borne Pathogen Transmission Cycles and Their Dynamics

2020 ◽  
Author(s):  
Anette Hernández-Andrade ◽  
Joel Moo-Millan ◽  
Nohemi Cigarroa-Toledo ◽  
Angel Ramos-Ligonio ◽  
Claudia Herrera ◽  
...  
Keyword(s):  
Pathogen Transmission ◽  
Vector Borne ◽  
Transmission Cycles ◽  
Comprehensive Study

scholarly journals World Association for the Advancement of Veterinary Parasitology (W.A.A.V.P.) guidelines for studies evaluating the efficacy of parasiticides in reducing the risk of vector-borne pathogen transmission in dogs and cats

2021 ◽  
Vol 290 ◽  
pp. 109369
Author(s):  
Domenico Otranto ◽  
Filipe Dantas-Torres ◽  
Josephus J. Fourie ◽  
Vincenzo Lorusso ◽  
Marie Varloud ◽  
...  
Keyword(s):  
Pathogen Transmission ◽  
Veterinary Parasitology ◽  
World Association ◽  
Vector Borne

scholarly journals Host Associations Of Biting Midges (Diptera: Ceratopogonidae: Culicoides) Near Sentinel Chicken Surveillance Locations In Florida, USA

2019 ◽  
Vol 35 (3) ◽  
pp. 200-206 ◽  
Author(s):  
Kristin E. Sloyer ◽  
Carolina Acevedo ◽  
Alfred E. Runkel ◽  
Nathan D. Burkett-Cadena
Keyword(s):  
Mosquito Control ◽  
Pathogen Transmission ◽  
Host Use ◽  
Culicoides Species ◽  
Biting Midges ◽  
Total Blood ◽  
Avian Blood ◽  
Vector Borne ◽  
Arbovirus Surveillance ◽  
Blood Meals

ABSTRACT Quantifying host use is important for understanding transmission of vector-borne pathogens. Despite the importance of biting midges (Diptera: Ceratopogonidae) in pathogen transmission, the vector–host relationships of most Culicoides species are poorly documented, even in locations where active arbovirus surveillance is conducted. Polymerase chain reaction–based blood-meal analysis was performed on 663 blood-engorged Culicoides females collected by 7 Florida mosquito control districts at 24 sentinel chicken arbovirus surveillance sites in 2017. A total of 638 blood meals were successfully analyzed to determine host species source, representing 11 Culicoides species. The most commonly bitten host was domestic chicken (Gallus gallus) (presumably sentinel chickens), constituting 565 of 638 (88.6%) the total blood meals. Other common hosts included humans (5.8%), white-tailed deer (Odoocoileus virginianus) (2.5%), and brown basilisk (Basiliscus vittatus) (1.6%). Significant differences in distribution of mammal and avian blood meals were found for a number of Culicoides species, and these patterns did not vary across locations. These results indicate that sentinel chickens are exposed to bites by Culicoides, potentially exposing them to Culicoides-borne pathogens. The findings that vertebrate host use was consistent across locations suggests that each Culicoides species has affinity for one or more specific animal groups, and does not feed randomly upon available animals.

Promising Role of Wolbachia as Anti-parasitic Drug Target and Eco-Friendly Biocontrol Agent

2019 ◽  
Vol 14 (1) ◽  
pp. 69-79 ◽  
Author(s):  
Tooran Nayeri Chegeni ◽  
Mahdi Fakhar
Keyword(s):  
Drug Target ◽  
Biocontrol Agent ◽  
Pathogen Transmission ◽  
Parasitic Diseases ◽  
Pests And Diseases ◽  
Filarial Nematodes ◽  
Reproductive Incompatibility ◽  
Vector Borne ◽  
Potential Strategy

Background: Wolbachia is the most common endosymbiotic bacteria in insectborne parasites and it is the most common reproductive parasite in the world. Wolbachia has been found worldwide in numerous arthropod and parasite species, including insects, terrestrial isopods, spiders, mites and filarial nematodes. There is a complicated relationship between Wolbachia and its hosts and in some cases, they create a mutual relationship instead of a parasitic relationship. Some species are not able to reproduce in the absence of infection with Wolbachia. Thus, the use of existing strains of Wolbachia bacteria offers a potential strategy for the control of the population of mosquitoes and other pests and diseases. Methods: We searched ten databases and reviewed published papers regarding the role of Wolbachia as a promising drug target and emerging biological control agents of parasitic diseases between 1996 and 2017 (22 years) were considered eligible. Also, in the current study several patents (WO008652), (US7723062), and (US 0345249 A1) were reviewed. Results: Endosymbiotic Wolbachia bacteria, which are inherited from mothers, is transmitted to mosquitoes and interferes with pathogen transmission. They can change the reproduction of their host. Wolbachia is transmitted through the cytoplasm of eggs and have evolved different mechanisms for manipulating the reproduction of its hosts, including the induction of reproductive incompatibility, parthenogenesis, and feminization. The extensive effects of Wolbachia on reproduction and host fitness have made Wolbachia the issue of growing attention as a potential biocontrol agent. Conclusion: Wolbachia has opened a new window to design a costly, potent and ecofriendly drug target for effective treatment and elimination of vector-borne parasitic diseases.

scholarly journals Efficient population modification gene-drive rescue system in the malaria mosquito Anopheles stephensi

2020 ◽  
Author(s):  
Adriana Adolfi ◽  
Valentino M. Gantz ◽  
Nijole Jasinskiene ◽  
Hsu-Feng Lee ◽  
Kristy Hwang ◽  
...  
Keyword(s):  
Anopheles Stephensi ◽  
Pathogen Transmission ◽  
Gene Drive ◽  
Initial Release ◽  
Genetic Technologies ◽  
Rescue System ◽  
Vector Borne ◽  
Kynurenine Hydroxylase ◽  
Drive Systems ◽  
Population Suppression

ABSTRACTThe development of Cas9/gRNA-mediated gene-drive systems has bolstered the advancement of genetic technologies for controlling vector-borne pathogen transmission. These include population suppression approaches, genetic analogs of insecticidal techniques that reduce the number of vector insects, and population modification (replacement/alteration) approaches, which interfere with competence to transmit pathogens. We developed a recoded gene-drive rescue system for population modification in the malaria vector, Anopheles stephensi, that relieves the load in females caused by integration of the drive into the kynurenine hydroxylase gene by rescuing its function. Non-functional resistant alleles are eliminated via a dominantly-acting maternal effect combined with slower-acting standard negative selection, and a functional resistant allele does not prevent drive invasion. Small cage trials show that single releases of gene-drive males robustly result in efficient population modification with ≥95% of mosquitoes carrying the drive within 5-11 generations over a range of initial release ratios.

scholarly journals The seal louse (Echinophthirius horridus) in the Dutch Wadden Sea: investigation of vector-borne pathogens

2021 ◽  
Author(s):  
Jörg Hirzmann ◽  
David Ebmer ◽  
Guillermo J. Sánchez Contreras ◽  
Ana Rubio-García ◽  
Gerd Magdowski ◽  
...  
Keyword(s):  
Wadden Sea ◽  
Vector Competence ◽  
Pathogen Transmission ◽  
Grey Seal ◽  
Harbour Seals ◽  
Wide Range ◽  
Rehabilitation Period ◽  
Phocid Seals ◽  
Vector Borne

Abstract Background: Belonging to the anopluran family Echinophthiriidae, Echinophthirius horridus, the seal louse, has been reported to parasitize a broad range of representatives of phocid seals. So far, only few studies focused on vector function of echinophthiriid lice and knowledge on their role in pathogen transmission is still scarce. The current study aims to investigate the possible vector role of E. horridus parasitizing seals in the Dutch Wadden Sea.Methods: E. horridus seal lice were collected from 54 harbour seals (Phoca vitulina) and one grey seal (Halichoerus grypus) during their rehabilitation period at the Sealcentre Pieterburen, the Netherlands. DNA was extracted from pooled seal lice of individual seals for molecular detection of the seal heartworm Acanthocheilonema spirocauda, the rickettsial intracellular bacterium Anaplasma phagocytophilum, and the cell wall-less bacteria Mycoplasma spp. using PCR assays.Results: Seal lice from 35% of the harbour seals (19/54) and from the grey seal proved positive for A. spirocauda. The seal heartworm was molecularly characterised and phylogenetically analysed (rDNA, cox1). A nested PCR was developed for the cox1 gene to detect A. spirocauda stages in seal lice. A. phagocytophilum and a Mycoplasma species previously identified from a patient with disseminated ‘seal finger’ mycoplasmosis were detected the first time in seal lice. Conclusions: Our findings support the potential vector role of seal lice in transmission of A. spirocauda, and reveal new insights into the spectrum of pathogens occurring in seal lice. Studies on vector competence of E. horridus, especially for bacterial pathogens, are essentially needed in the future as these pathogens might have detrimental effects on the health of seal populations. Further, studies on the vector role of different echinophthiriid species infecting a wide range of pinniped hosts should be conducted to extend the knowledge of vector borne pathogens in seal lice.

scholarly journals Predators affect a plant virus through direct and trait-mediated indirect effects on vectors

2021 ◽  
Author(s):  
Benjamin W. Lee ◽  
Robert E. Clark ◽  
Saumik Basu ◽  
David W. Crowder
Keyword(s):  
Plant Pathogens ◽  
Virus Transmission ◽  
Pathogen Transmission ◽  
Risk Of Predation ◽  
Predation Effects ◽  
Antipredator Behaviors ◽  
Vector Borne ◽  
Predator Risk ◽  
Aphid Movement ◽  
And Behavior

AbstractArthropods that vector plant pathogens often interact with predators within food webs. Predators affect vectors by eating them (consumptive effects) and by inducing antipredator behaviors (non-consumptive effects), and these interactions may affect transmission of vector-borne pathogens. However, it has proven difficult to experimentally tease apart the effects of predators on vector fitness and behavior as they are often correlated. We addressed this problem by assessing how both aphids and an aphid-borne pathogen were affected by variable predation risk. Specifically, we experimentally manipulated ladybeetle predators’ mouthparts to isolate consumptive, and non-consumptive, effects of predators on aphid fitness, movement, and virus transmission. We show that although lethal predators decreased aphid vector abundance, they increased pathogen transmission by increasing aphid movement among hosts. Moreover, aphids responded to risk of predation by moving to younger plant tissue that was more susceptible to the pathogen. Aphids also responded to predator risk through compensatory reproduction, which offset direct consumptive effects. Our results support predictions of disease models showing alterations of vector movement due to predators can have greater effects on transmission of pathogens than vector consumption. Broadly, our study shows isolating direct and indirect predation effects can reveal novel pathways by which predators affect vector-borne pathogens.

scholarly journals Regulation of midgut cell proliferation impacts Aedes aegypti susceptibility to dengue virus

2018 ◽  
Author(s):  
Mabel L. Taracena ◽  
Vanessa Bottino-Rojas ◽  
Octavio A.C. Talyuli ◽  
Ana Beatriz Walter-Nuno ◽  
José Henrique M. Oliveira ◽  
...  
Keyword(s):  
Virus Infection ◽  
Aedes Aegypti ◽  
Dengue Virus ◽  
Denv Infection ◽  
Pathogen Transmission ◽  
Intestinal Lumen ◽  
Midgut Cell ◽  
Vector Borne Diseases ◽  
Cellular Processes ◽  
Vector Borne

AbstractAedes aegypti is the vector of some of the most important vector-borne diseases like Dengue, Chikungunya, Zika and Yellow fever, affecting millions of people worldwide. The cellular processes that follow a blood meal in the mosquito midgut are directly associated with pathogen transmission. We studied the homeostatic response of the midgut against oxidative stress, as well as bacterial and dengue virus (DENV) infections, focusing on the proliferative ability of the intestinal stem cells (ISC). Inhibition of the peritrophic matrix (PM) formation led to an increase in ROS production by the epithelial cells in response to contact with the resident microbiota, suggesting that maintenance of low levels of ROS in the intestinal lumen is key to keep ISCs division in balance. We show that dengue virus infection induces midgut cell division in both DENV susceptible (Rockefeller) and refractory (Orlando) mosquito strains. However, the susceptible strain delays the activation of the regeneration process compared with the refractory strain. Impairment of the Delta/Notch signaling, by silencing the Notch ligand Delta using RNAi, significantly increased the susceptibility of the refractory strains to DENV infection of the midgut. We propose that this cell replenishment is essential to control viral infection in the mosquito. Our study demonstrates that the intestinal epithelium of the blood fed mosquito is able to respond and defend against different challenges, including virus infection. In addition, we provide unprecedented evidence that the activation of a cellular regenerative program in the midgut is important for the determination of the mosquito vectorial competence.

scholarly journals IMPORTANT VECTOR-BORNE DISEASES WITH THEIR ZOONOTIC POTENTIAL: PRESENT SITUATION AND FUTURE PERSPECTIVE

2016 ◽  
Vol 13 (2) ◽  
pp. 1-14
Author(s):  
MAHNA Khan
Keyword(s):  
Public Health ◽  
Animal Welfare ◽  
Human Life ◽  
Habitat Change ◽  
Zoonotic Diseases ◽  
Pathogen Transmission ◽  
Future Perspective ◽  
Vector Borne Diseases ◽  
Pathogen Invasion ◽  
Vector Borne

Vector-borne diseases (VBDs) of zoonotic importance are the global threat in the human life and on animal welfare as well. Many vector-borne pathogens (VBPs) have appeared in new regions in the past two decades, while many endemic diseases have increased in incidence. Although introductions and emergence of endemic pathogens are often considered to be distinct processes, many endemic pathogens are actually spreading at a local scale coincident with habitat change. Key differences between dynamics and diseases burden result from increased pathogen transmission following habitat change, deforestation and introduction life into new regions. Local emergence of VBPs are commonly driven by changing in ecology (deforestation, massive natural calamities, civil wares etc.), altered human behavior, enhanced enzootic cycles, pathogen invasion from anthropogenic trade and travel, genomic changes of pathogens to coup up with the new hosts, vectors, and climatic conditions and adaptability in wildlife reservoirs. Once a pathogen is established, ecological factors related to vector and host characteristics can shape the evolutionary selective pressure and result in increased use of people as transmission hosts. West Nile virus (WNV), Nipah virus and Chikungunya virus (CHIKV) are among the best-understood zoonotic vector-borne pathogens (VBPs) to have emerged in the last two decades and showed just how explosive epidemics can be in new regions. Zoonotic VBPs that are likely introduced into new regions include Rift Valley Fever and Japanese Encephalitis viruses (JEV) in the Americas, Venezuelan equine encephalitis virus in Eurasia or Africa, Crimean-Congo Hemorrhagic Fever virus (CCHFV) in new parts of Eurasia. Vector-borne diseases currently impose global burden on public health and animal welfare including widespread formerly zoonotic human diseases, such as malaria, leishmania and dengue fever, as well as zoonotic diseases for which humans are dead end hosts, such as Lyme disease, WNV and CCHF. It requires highly equipped laboratory facilities and technical manpower to address emergence and re-emergence of vector-borne zoonotic diseases. Financial and technological hurdles persist in developing countries, making diagnosis and control facility difficult where these diseases are stubbornly most prevalent. Development of technological and highly knowledgeable manpower is the key to protect public health and eco-health. An awareness building about the changing risk of VBPs to prevent introduction foreign pathogens is far more difficult because this is commonly an inevitable consequence of the globalization of trade and travel and in most cases is accidental. Designing of active surveillance of the deadly infectious pathogens by combining the expertise of veterinary and human health could play pivotal roles towards reducing burden of VBPs. History suggests that successful control of VBPs requires prompt identification, swift action, mobilization of fund for developing technical expertise and occasionally by using draconian social measures.DOI: http://dx.doi.org/10.3329/bjvm.v13i2.26614Bangl. J. Vet. Med. (2015). 13 (2): 1-14

scholarly journals The seal louse (Echinophthirius horridus) in the Dutch Wadden Sea: investigation of vector-borne pathogens 

2020 ◽  
Author(s):  
Jörg Hirzmann ◽  
David Ebmer ◽  
Guillermo J. Sánchez Contreras ◽  
Ana Rubio-García ◽  
Gerd Magdowski ◽  
...  
Keyword(s):  
Wadden Sea ◽  
Pathogen Transmission ◽  
Grey Seal ◽  
Potential Vector ◽  
Harbour Seals ◽  
Rehabilitation Period ◽  
Phocid Seals ◽  
Vector Borne ◽  
First Time

Abstract Background: Belonging to the anopluran family Echinophthiriidae, Echinophthirius horridus, the seal louse, has been reported to parasitize a broad range of representatives of phocid seals. So far, only few studies focused on vector function of echinophthiriid lice and knowledge on their role in pathogen transmission is still scarce. The current study aims to investigate the possible vector role of E. horridus parasitizing seals in the Dutch Wadden Sea.Methods: More than 1200 E. horridus seal lice were collected from 54 harbour seals (Phoca vitulina) and one grey seal (Halichoerus grypus) during their rehabilitation period in the Sealcentre Pieterburen, the Netherlands. DNA was extracted from pooled seal lice of individual seals for molecular detection of the seal heartworm Acanthocheilonema spirocauda, the rickettsial intracellular bacterium Anaplasma phagocytophilum, and Mycoplasma spp. using PCR assays.Results: Seal lice from 35% of the harbour seals (19/54) and from the grey seal proved positive for A. spirocauda. The seal heartworm was molecularly characterised and phylogenetically analysed for the first time (rDNA, cox1). A nested PCR was developed for the cox1 gene to detect A. spirocauda stages in seal lice. A. phagocytophilum and a Mycoplasma species previously identified from a patient with disseminated ‘seal finger’ mycoplasmosis were detected the first time in seal lice. Conclusions: Our findings support the potential vector role of seal lice in transmission of A. spirocauda, and reveal new insights into the spectrum of pathogens occurring in seal lice. As these pathogens might have detrimental effects on the health of seal populations further epidemiological investigations on infections due to these pathogens in seals should be conducted.

Ecological Interactions Influencing the Emergence, Abundance, and Human Exposure to Tick-Borne Pathogens

2020 ◽  
pp. 135-154
Author(s):  
Maria A. Diuk-Wasser ◽  
Maria del Pilar Fernandez ◽  
Stephen Davis
Keyword(s):  
Nonlinear Effects ◽  
The United States ◽  
Pathogen Transmission ◽  
Tick Feeding ◽  
Disease Agent ◽  
Vector Borne ◽  
Key Aspects ◽  
Transmission Pathways ◽  
Lyme Disease Agent ◽  
Effective Public Health

Tick-borne pathogens pose the greatest vector-borne disease burden in temperate areas of Europe and North America. We synthesize key aspects of tick life history that enable ticks to persist, spread and impact human health, including a two-year life cycle, multiple transmission pathways and dependence on hosts for tick feeding, movement and pathogen transmission. We discuss modeling advances that incorporate these traits in the context of climate-driven variation in tick feeding phenology. For established pathogens, such as the Lyme disease agent in the United States, we disentangle the linkages between land use change, habitat fragmentation and host diversity influencing human risk of infection along an urbanization gradient. We propose a coupled natural-human system framework for tick-borne pathogens that accounts for nonlinear effects and feedbacks between the enzootic cycle and human spillover. A deeper understanding of the eco-bio-social determinants of these diseases is required to develop more effective public health interventions.

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