scholarly journals Using Remote Biomonitoring to Understand Heterogeneity in Immune-Responses and Disease-Dynamics in Small, Free-Living Animals

2014 ◽  
Vol 54 (3) ◽  
pp. 377-386 ◽  
Author(s):  
J. S. Adelman ◽  
S. C. Moyers ◽  
D. M. Hawley
2012 ◽  
Vol 82 (3) ◽  
pp. 200-208 ◽  
Author(s):  
Emilio Jirillo ◽  
Felicita Jirillo ◽  
Thea Magrone

Pre-, pro-, and symbiotics are endowed with a broad spectrum of beneficial effects when administered to animals and humans. A series of experimental and clinical studies have clearly demonstrated that prebiotics, probiotics, or their combination are very effective in attenuating chronic inflammatory conditions such as inflammatory bowel disease or obesity. In addition, these natural products are able to prevent or arrest tumor development, acting on the intestinal microbiota as well as potentiating the immune response.Aging is characterized by a dramatic reduction of both innate and adaptive immune responses, the so-called immunosenescence. This leads to an increased incidence of infections, autoimmune diseases, and cancer in the elderly. Pre-, pro-, and symbiotic administration has been shown to ameliorate the immune response in aging. In particular, administration of a symbiotic to free-living elderly was able to potentiate the release of interleukin-8, thus increasing neutrophils in the host, perhaps explaining the reduced frequency of winter infections in the elderly.


2019 ◽  
Vol 92 (1) ◽  
pp. 106-114 ◽  
Author(s):  
Emily Cornelius Ruhs ◽  
François Vézina ◽  
William H. Karasov

Author(s):  
C. Brandon Ogbunugafor ◽  
Miles Miller-Dickson ◽  
Victor A. Meszaros ◽  
Lourdes M. Gomez ◽  
Anarina L. Murillo ◽  
...  

ABSTRACTCOVID-19 has circled the globe, rapidly expanding into a pandemic within a matter of weeks. While early studies revealed important features of SARS-CoV-2 transmission, the role of variation in free-living virus survival in modulating the dynamics of outbreaks remains unclear and controversial. Using an empirically determined understanding of the natural history of SARS-CoV-2 infection and detailed, country-level case data, we elucidate how variation in free-living virus survival influences key features of COVID-19 epidemics. Our findings suggest that environmental transmission can have a subtle, yet significant influence on COVID-19’s basic reproductive number () and other key signatures of outbreak intensity. Summarizing, we propose that variation in environmental transmission may explain some observed differences in disease dynamics from setting to setting, and can inform public health interventions.


2020 ◽  
Author(s):  
Lourdes M. Gomez ◽  
Victor A Meszaros ◽  
Wendy C. Turner ◽  
C. Brandon Ogbunugafor

ABSTRACTThe relationship between parasite virulence and transmission is a pillar of evolutionary theory that has specific implications for public health. Part of this canon involves the idea that virulence and free-living survival (a key component of transmission) may have different relationships in different host-parasite systems. Most examinations of the evolution of virulence-transmission relationships—theoretical or empirical in nature—tend to focus on the evolution of virulence, with transmission a secondary consideration. And even within transmission studies, the focus on free-living survival is a smaller subset, though recent studies have examined its importance in the ecology of infectious diseases. Few studies have examined the epidemic-scale consequences of variation in survival across different virulence-survival relationships. In this study, we utilize a mathematical model motivated by aspects of SARS-CoV-2 natural history to investigate how evolutionary changes in survival may influence several aspects of disease dynamics at the epidemiological scale. Across virulence-survival relationships (where these traits are positively or negatively correlated), we found that small changes (5% above and below the nominal value) in survival can have a meaningful effect on certain outbreak features, including the R0, and the size of the infectious peak in the population. These results highlight the importance of properly understanding the mechanistic relationship between virulence and parasite survival, as evolution of increased survival across different relationships with virulence will have considerably different epidemiological signatures.


2020 ◽  
Vol 15 (10) ◽  
pp. 919-936
Author(s):  
Paula Guzmán-Téllez ◽  
Moisés Martínez-Castillo ◽  
Nadia Flores-Huerta ◽  
Gabriela Rosales-Morgan ◽  
Judith Pacheco-Yépez ◽  
...  

Currently, there is growing interest in the identification and purification of microbial lectins due to their involvement in the pathogenicity mechanisms of pathogens, such as Entamoeba histolytica and free-living amoebae. The Gal/GalNAc lectin from E. histolytica participates in adhesion, cytotoxicity and regulation of immune responses. Furthermore, mannose- and galactose-binding protein have been described in Acanthamoeba castellanii and Balamuthia mandrillaris, respectively and they also contribute to host damage. Finally, in Naegleria fowleri, molecules containing mannose and fucose are implicated in adhesion and cytotoxicity. Considering their relevance in the pathogenesis of the diseases caused by these protozoa, lectins appear to be promising targets in the diagnosis, vaccination and treatment of these infections.


2020 ◽  
Author(s):  
Hazel N. Farthing ◽  
Jiamei Jiang ◽  
Alexandra J. Henwood ◽  
Andy Fenton ◽  
Trent Garner ◽  
...  

AbstractFree-living eukaryotic microbes may reduce animal diseases. We evaluated the dynamics by which micrograzers (primarily protozoa) apply top-down control on the chytrid Batrachochytrium dendrobatidis (Bd) a devastating, panzootic pathogen of amphibians. Although micrograzers consumed zoospores (∼3 µm), the dispersal stage of chytrids, not all species grew monoxenically on zoospores. However, the ubiquitous ciliate Tetrahymena pyriformis, which likely co-occurs with Bd, grew at near its maximum rate (r = 1.7 d-1). A functional response (ingestion vs. prey abundance) for T. pyriformis, measured using spore-surrogates (microspheres) revealed maximum ingestion (Imax) of 1.63 × 103 zoospores d-1, with a half saturation constant (k) of 5.75 × 103 zoospores ml-1. Using these growth and grazing data we developed and assessed a population model that incorporated chytrid-host and micrograzer dynamics. Simulations using our data and realistic parameters obtained from the literature suggested that micrograzers could control Bd and potentially prevent chytridiomycosis (defined as 104 sporangia host-1). However, simulated inferior micrograzers (0.7 x Imax and 1.5 x k) did not prevent chytridiomycosis, although they ultimately reduced pathogen abundance to below levels resulting in disease. These findings indicate how micrograzer responses can be applied when modelling disease dynamics for Bd and other zoosporic fungi.


Fire Ecology ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Gregory F. Albery ◽  
Isabella Turilli ◽  
Maxwell B. Joseph ◽  
Janet Foley ◽  
Celine H. Frere ◽  
...  

Abstract Background Fire strongly affects animals’ behavior, population dynamics, and environmental surroundings, which in turn are likely to affect their immune systems and exposure to pathogens. However, little work has yet been conducted on the effects of wildfires on wildlife disease. This research gap is rapidly growing in importance because wildfires are becoming globally more common and more severe, with unknown impacts on wildlife disease and unclear implications for livestock and human health in the future. Results Here, we discussed how wildfires could influence susceptibility and exposure to infection in wild animals, and the potential consequences for ecology and public health. In our framework, we outlined how habitat loss and degradation caused by fire affect animals’ immune defenses, and how behavioral and demographic responses to fire affect pathogen exposure, spread, and maintenance. We identified relative unknowns that might influence disease dynamics in unpredictable ways (e.g., through altered community composition and effects on free-living parasites). Finally, we discussed avenues for future investigations of fire-disease links. Conclusions We hope that this review will stimulate much-needed research on the role of wildfire in influencing wildlife disease, providing an important source of information on disease dynamics in the wake of future wildfires and other natural disasters, and encouraging further integration of the fields of fire and disease ecology.


Viruses ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1055 ◽  
Author(s):  
Lourdes M. Gomez ◽  
Victor A. Meszaros ◽  
Wendy C. Turner ◽  
C. Brandon Ogbunugafor

The relationship between parasite virulence and transmission is a pillar of evolutionary theory that has implications for public health. Part of this canon involves the idea that virulence and free-living survival (a key component of transmission) may have different relationships in different host–parasite systems. Most examinations of the evolution of virulence-transmission relationships—Theoretical or empirical in nature—Tend to focus on the evolution of virulence, with transmission being a secondary consideration. Even within transmission studies, the focus on free-living survival is a smaller subset, though recent studies have examined its importance in the ecology of infectious diseases. Few studies have examined the epidemic-scale consequences of variation in survival across different virulence–survival relationships. In this study, we utilize a mathematical model motivated by aspects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) natural history to investigate how evolutionary changes in survival may influence several aspects of disease dynamics at the epidemiological scale. Across virulence–survival relationships (where these traits are either positively or negatively correlated), we found that small changes (5% above and below the nominal value) in survival can have a meaningful effect on certain outbreak features, including R0, and on the size of the infectious peak in the population. These results highlight the importance of properly understanding the mechanistic relationship between virulence and parasite survival, as the evolution of increased survival across different relationships with virulence may have considerably different epidemiological signatures.


2021 ◽  
Vol 11 ◽  
Author(s):  
Hazel N. Farthing ◽  
Jiamei Jiang ◽  
Alexandra J. Henwood ◽  
Andy Fenton ◽  
Trent W. J. Garner ◽  
...  

Free-living eukaryotic microbes may reduce animal diseases. We evaluated the dynamics by which micrograzers (primarily protozoa) apply top-down control on the chytrid Batrachochytrium dendrobatidis (Bd) a devastating, panzootic pathogen of amphibians. Although micrograzers consumed zoospores (∼3 μm), the dispersal stage of chytrids, not all species grew monoxenically on zoospores. However, the ubiquitous ciliate Tetrahymena pyriformis, which likely co-occurs with Bd, grew at near its maximum rate (r = 1.7 d–1). A functional response (ingestion vs. prey abundance) for T. pyriformis, measured using spore-surrogates (microspheres) revealed maximum ingestion (Imax) of 1.63 × 103 zoospores d–1, with a half saturation constant (k) of 5.75 × 103 zoospores ml–1. Using these growth and grazing data we developed and assessed a population model that incorporated chytrid-host and micrograzer dynamics. Simulations using our data and realistic parameters obtained from the literature suggested that micrograzers could control Bd and potentially prevent chytridiomycosis (defined as 104 sporangia host–1). However, simulated inferior micrograzers (0.7 × Imax and 1.5 × k) did not prevent chytridiomycosis, although they ultimately reduced pathogen abundance to below levels resulting in disease. These findings indicate how micrograzer responses can be applied when modeling disease dynamics for Bd and other zoosporic fungi.


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