Host–Pathogen Evolution and Coevolution in Avian Systems

2021 ◽  
pp. 77-98
Author(s):  
Camille Bonneaud
Keyword(s):  
Disease Transmission ◽  
Natural Populations ◽  
Transmission Dynamics ◽  
Phenotypic Change ◽  
Avian Host ◽  
Future Directions ◽  
Pathogen Evolution ◽  
Host Pathogen ◽  
Theoretical Predictions ◽  
Mechanistic Basis

The significance of studying birds and their pathogens goes far beyond the applied conservation or epidemiological implications of their interactions. Evidence suggests that avian host–pathogen systems can be used to test fundamental theoretical predictions about adaptive evolution and coevolution in natural populations. This chapter highlights recent advances in the field of bird–pathogen evolution and coevolution, how these advances have come about, and future directions of research. Further, it shows that, while there is a growing body of work that provides support for both avian host and pathogen evolution, evidence for their antagonistic coevolution, the process of adaptation and counter-adaptation in response to the reciprocal selection pressures that they impose on each other, remains rare. Rigorously demonstrating the processes of evolution and coevolution is complex in natural populations and doing so necessarily requires borrowing methodological approaches from a range of disciplines to fully characterize phenotypic change, its genetic and mechanistic basis, as well as its adaptive benefits. Overcoming the challenge of such a task will, however, generate important insights into a range of processes, from disease transmission dynamics and pathogenesis to the maintenance of biodiversity.

scholarly journals Application of Mathematical Modeling in Prediction of COVID-19 Transmission Dynamics

2022 ◽  
Author(s):  
Ali AlArjani ◽  
Md Taufiq Nasseef ◽  
Sanaa M. Kamal ◽  
B. V. Subba Rao ◽  
Mufti Mahmud ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Models ◽  
Disease Transmission ◽  
Transmission Dynamics ◽  
New Disease ◽  
Intrinsic Properties ◽  
Future Directions ◽  
Entire World ◽  
Second Wave

AbstractThe entire world has been affected by the outbreak of COVID-19 since early 2020. Human carriers are largely the spreaders of this new disease, and it spreads much faster compared to previously identified coronaviruses and other flu viruses. Although vaccines have been invented and released, it will still be a challenge to overcome this disease. To save lives, it is important to better understand how the virus is transmitted from one host to another and how future areas of infection can be predicted. Recently, the second wave of infection has hit multiple countries, and governments have implemented necessary measures to tackle the spread of the virus. We investigated the three phases of COVID-19 research through a selected list of mathematical modeling articles. To take the necessary measures, it is important to understand the transmission dynamics of the disease, and mathematical modeling has been considered a proven technique in predicting such dynamics. To this end, this paper summarizes all the available mathematical models that have been used in predicting the transmission of COVID-19. A total of nine mathematical models have been thoroughly reviewed and characterized in this work, so as to understand the intrinsic properties of each model in predicting disease transmission dynamics. The application of these nine models in predicting COVID-19 transmission dynamics is presented with a case study, along with detailed comparisons of these models. Toward the end of the paper, key behavioral properties of each model, relevant challenges and future directions are discussed.

Simulating disease transmission dynamics at a multi-scale level

2007 ◽  
Vol 1 (1) ◽  
pp. 26-34 ◽  
Author(s):  
Moshe B Hoshen ◽  
Anthony H Burton ◽  
Themis J V Bowcock
Keyword(s):  
Disease Transmission ◽  
Transmission Dynamics ◽  
Scale Level ◽  
Multi Scale

scholarly journals Heritability of DNA methylation in threespine stickleback (Gasterosteus aculeatus)

Genetics ◽  
2021 ◽  
Vol 217 (1) ◽  
Author(s):  
Juntao Hu ◽  
Sara J S Wuitchik ◽  
Tegan N Barry ◽  
Heather A Jamniczky ◽  
Sean M Rogers ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Genetic Architecture ◽  
Gasterosteus Aculeatus ◽  
Additive Genetic Variance ◽  
Natural Populations ◽  
Threespine Stickleback ◽  
Phenotypic Change ◽  
Cpg Sites ◽  
Cis And Trans ◽  
Methylation Variation

Abstract Epigenetic mechanisms underlying phenotypic change are hypothesized to contribute to population persistence and adaptation in the face of environmental change. To date, few studies have explored the heritability of intergenerationally stable methylation levels in natural populations, and little is known about the relative contribution of cis- and trans-regulatory changes to methylation variation. Here, we explore the heritability of DNA methylation, and conduct methylation quantitative trait loci (meQTLs) analysis to investigate the genetic architecture underlying methylation variation between marine and freshwater ecotypes of threespine stickleback (Gasterosteus aculeatus). We quantitatively measured genome-wide DNA methylation in fin tissue using reduced representation bisulfite sequencing of F1 and F2 crosses, and their marine and freshwater source populations. We identified cytosines (CpG sites) that exhibited stable methylation levels across generations. We found that additive genetic variance explained an average of 24–35% of the methylation variance, with a number of CpG sites possibly autonomous from genetic control. We also detected both cis- and trans-meQTLs, with only trans-meQTLs overlapping with previously identified genomic regions of high differentiation between marine and freshwater ecotypes. Finally, we identified the genetic architecture underlying two key CpG sites that were differentially methylated between ecotypes. These findings demonstrate a potential role for DNA methylation in facilitating adaptation to divergent environments and improve our understanding of the heritable basis of population epigenomic variation.

scholarly journals The effects of flooding and weather conditions on leptospirosis transmission in Thailand

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sudarat Chadsuthi ◽  
Karine Chalvet-Monfray ◽  
Anuwat Wiratsudakul ◽  
Charin Modchang
Keyword(s):  
Sensitivity Analysis ◽  
Public Education ◽  
Mathematical Models ◽  
Disease Transmission ◽  
Transmission Rate ◽  
Weather Conditions ◽  
Transmission Dynamics ◽  
Multiplication Rate ◽  
High Degree ◽  
Transmission Models

AbstractThe epidemic of leptospirosis in humans occurs annually in Thailand. In this study, we have developed mathematical models to investigate transmission dynamics between humans, animals, and a contaminated environment. We compared different leptospire transmission models involving flooding and weather conditions, shedding and multiplication rate in a contaminated environment. We found that the model in which the transmission rate depends on both flooding and temperature, best-fits the reported human data on leptospirosis in Thailand. Our results indicate that flooding strongly contributes to disease transmission, where a high degree of flooding leads to a higher number of infected individuals. Sensitivity analysis showed that the transmission rate of leptospires from a contaminated environment was the most important parameter for the total number of human cases. Our results suggest that public education should target people who work in contaminated environments to prevent Leptospira infections.

scholarly journals Contrasting Patterns of Virus Protection and Functional Incompatibility Genes in Two ConspecificWolbachiaStrains fromDrosophila pandora

2018 ◽  
Vol 85 (5) ◽  
Author(s):  
Angelique K. Asselin ◽  
Simon Villegas-Ospina ◽  
Ary A. Hoffmann ◽  
Jeremy C. Brownlie ◽  
Karyn N. Johnson
Keyword(s):  
Disease Transmission ◽  
Cytoplasmic Incompatibility ◽  
Natural Populations ◽  
Differential Protection ◽  
Content Type ◽  
Infection Dynamics ◽  
Modification Factor ◽  
Control Disease ◽  
Multiple Strains ◽  
High Degree

ABSTRACTWolbachiainfections can present different phenotypes in hosts, including different forms of reproductive manipulation and antiviral protection, which may influence infection dynamics within host populations. In populations ofDrosophila pandoratwo distinctWolbachiastrains coexist, each manipulating host reproduction: strainwPanCI causes cytoplasmic incompatibility (CI), whereas strainwPanMK causes male killing (MK). CI occurs when aWolbachia-infected male mates with a female not infected with a compatible type ofWolbachia, leading to nonviable offspring.wPanMK can rescuewPanCI-induced CI but is unable to induce CI. The antiviral protection phenotypes provided by thewPanCI andwPanMK infections were characterized; the strains showed differential protection phenotypes, whereby cricket paralysis virus (CrPV)-induced mortality was delayed in flies infected withwPanMK but enhanced in flies infected withwPanCI compared to their respectiveWolbachia-cured counterparts. Homologs of thecifAandcifBgenes involved in CI identified inwPanMK andwPanCI showed a high degree of conservation; however, the CifB protein inwPanMK is truncated and is likely nonfunctional. The presence of a likely functional CifA inwPanMK andwPanMK’s ability to rescuewPanCI-induced CI are consistent with the recent confirmation of CifA’s involvement in CI rescue, and the absence of a functional CifB protein further supports its involvement as a CI modification factor. Taken together, these findings indicate thatwPanCI andwPanMK have different relationships with their hosts in terms of their protective and CI phenotypes. It is therefore likely that different factors influence the prevalence and dynamics of these coinfections in naturalDrosophila pandorahosts.IMPORTANCEWolbachiastrains are common endosymbionts in insects, with multiple strains often coexisting in the same species. The coexistence of multiple strains is poorly understood but may rely onWolbachiaorganisms having diverse phenotypic effects on their hosts. AsWolbachiais increasingly being developed as a tool to control disease transmission and suppress pest populations, it is important to understand the ways in which multipleWolbachiastrains persist in natural populations and how these might then be manipulated. We have therefore investigated viral protection and the molecular basis of cytoplasmic incompatibility in two coexistingWolbachiastrains with contrasting effects on host reproduction.

scholarly journals Estimasi Reproduction Number Model Matematika Penyebaran Malaria di Sumba Tengah, Indonesia

2021 ◽  
Vol 2 (1) ◽  
pp. 13-19
Author(s):  
Ervin Mawo Banni ◽  
Maria A Kleden ◽  
Maria Lobo ◽  
Meksianis Zadrak Ndii
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Health Center ◽  
Disease Transmission ◽  
Reproduction Number ◽  
Transmission Dynamics ◽  
Awareness Program ◽  
Awareness Programs ◽  
Malaria Eradication

Malaria is transmitted via a bite of mosquitoes and it is dangerous if it is not properly treated. Mathematical modeling can be formulated to understand the disease transmission dynamics. In this paper, a mathematical model with an awareness program has been formulated and the reproduction number has been estimated against the data from Weeluri Health Center, Mamboro District, Central Sumba. The calculation showed that the reproduction number is R0 = 1.2562. Results showed that if the efficacy of the awareness program is lower than 20%, the reproduction number is still above unity. If the efficacy of the awareness program is higher than 20%, the reproduction number is lower than unity. This implies that the efficacy of awareness programs is the key to the success of Malaria eradication.

scholarly journals AFM-Based Correlative Microscopy Illuminates Human Pathogens

2021 ◽  
Vol 11 ◽  
Author(s):  
Supriya V. Bhat ◽  
Jared D. W. Price ◽  
Tanya E. S. Dahms
Keyword(s):  
Optical Microscopy ◽  
Disease Transmission ◽  
Fitness Landscape ◽  
Host Cells ◽  
Full Potential ◽  
Correlative Microscopy ◽  
Human Pathogens ◽  
Host Pathogen Interactions ◽  
Host Pathogen ◽  
The Many

Microbes have an arsenal of virulence factors that contribute to their pathogenicity. A number of challenges remain to fully understand disease transmission, fitness landscape, antimicrobial resistance and host heterogeneity. A variety of tools have been used to address diverse aspects of pathogenicity, from molecular host-pathogen interactions to the mechanisms of disease acquisition and transmission. Current gaps in our knowledge include a more direct understanding of host-pathogen interactions, including signaling at interfaces, and direct phenotypic confirmation of pathogenicity. Correlative microscopy has been gaining traction to address the many challenges currently faced in biomedicine, in particular the combination of optical and atomic force microscopy (AFM). AFM, generates high-resolution surface topographical images, and quantifies mechanical properties at the pN scale under physiologically relevant conditions. When combined with optical microscopy, AFM probes pathogen surfaces and their physical and molecular interaction with host cells, while the various modes of optical microscopy view internal cellular responses of the pathogen and host. Here we review the most recent advances in our understanding of pathogens, recent applications of AFM to the field, how correlative AFM-optical microspectroscopy and microscopy have been used to illuminate pathogenicity and how these methods can reach their full potential for studying host-pathogen interactions.

scholarly journals Relatedness and genetic structure of big brown bat (Eptesicus fuscus) maternity colonies in an urban-wildland interface provides insight into rabies transmission dynamics

2020 ◽  
Author(s):  
Faith M. Walker ◽  
Colin J. Sobek ◽  
Camille E. Platts-McPharlin ◽  
Carol L. Chambers
Keyword(s):  
Genetic Structure ◽  
Disease Transmission ◽  
Urban Areas ◽  
Genetic Relatedness ◽  
Radio Telemetry ◽  
Eptesicus Fuscus ◽  
Geographic Mobility ◽  
Transmission Dynamics ◽  
Urocyon Cinereoargenteus ◽  
Disease Exposure

AbstractBig brown bats (Eptesicus fuscus) are the bat species most frequently found to be rabid in North America and are a key source of sylvatic rabies in wildlife. Females can form summer maternity colonies in urban areas, often using access holes in the exterior of buildings to roost in relatively large numbers. In Flagstaff, Arizona, these roosts are commonly found in houses adjacent to golf courses, where habitat quality (food, water, shelter) is high for bats and for mesocarnivores such as striped skunks (Mephitis mephitis) and gray foxes (Urocyon cinereoargenteus). Periodic rabies outbreaks in Flagstaff involving all three of these mammals are primarily caused by an E. fuscus variant of the disease. However, little is known about E. fuscus social behavior during the summer months and how it may drive space use and hence disease exposure to conspecifics and mesocarnivores. To address this knowledge gap, we collected 88 unique genetic samples via buccal swabs from E. fuscus captured at four maternity roosts surrounding a golf course during summer of 2013. We used 7 microsatellite loci to estimate genetic relatedness among individuals and genetic structure within and among colonies in order to infer whether females selected roosts based on kinship, and used genetics and radio telemetry to determine the frequency of roost switching. We found roost switching through genetics (two mother and adult daughter pairs at the same and different roosts) and telemetry, and no evidence of elevated genetic relatedness within colonies or genetic structure between colonies. These results have important implications for disease transmission dynamics in that social cohesion based on relatedness does not act to constrain the virus to a particular roost area. Instead, geographic mobility may increase disease exposure to neighboring areas. We discuss mitigating actions for bat conservation and public health.

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