The Role of Melanin in Fungal Pathogenesis for Animal Hosts

Author(s):  
Daniel F. Q. Smith ◽  
Arturo Casadevall
2020 ◽  
Vol 375 (1808) ◽  
pp. 20190593 ◽  
Author(s):  
Spencer V. Nyholm

Microorganisms are associated with the eggs of many animals. For some hosts, the egg serves as the ideal environment for the vertical transmission of beneficial symbionts between generations, while some bacteria use the egg to parasitize their hosts. In a number of animal groups, egg microbiomes often perform other essential functions. The eggs of aquatic and some terrestrial animals are especially susceptible to fouling and disease since they are exposed to high densities of microorganisms. To overcome this challenge, some hosts form beneficial associations with microorganisms, directly incorporating microbes and/or microbial products on or in their eggs to inhibit pathogens and biofouling. Other functional roles for egg-associated microbiomes are hypothesized to involve oxygen and nutrient acquisition. Although some egg-associated microbiomes are correlated with increased host fitness and are essential for successful development, the mechanisms that lead to such outcomes are often not well understood. This review article will discuss different functions of egg microbiomes and how these associations have influenced the biology and evolution of animal hosts. This article is part of the theme issue ‘The role of the microbiome in host evolution’.


2019 ◽  
Vol 34 (10) ◽  
pp. 2045-2054 ◽  
Author(s):  
Javier Campo ◽  
David Bass ◽  
Patrick J. Keeling
Keyword(s):  

2006 ◽  
Vol 5 (12) ◽  
pp. 1941-1949 ◽  
Author(s):  
Adrienne C. Sexton ◽  
Barbara J. Howlett

2020 ◽  
Vol 2 (1) ◽  
pp. 28-35
Author(s):  
Aline Koch ◽  
Timo Schlemmer ◽  
Richard Lischka

Fusarium graminearum (Fg) is a necrotrophic fungal pathogen that causes devastating diseases on its crop hosts barley and wheat. Recently, small RNAs (sRNAs) were identified as mobile communication signals between eukaryotes and their pathogens, symbionts or parasites. It has been shown that pathogens secrete sRNAs as effectors to suppress plant immunity and plants use endogenous sRNAs to resist infection, a phenomenon termed cross-kingdom RNAi; ckRNAi. However, little is known about the transport of fungus- or plant produced sRNAs to silence genes that contribute to immunity. Extracellular vesicles (EVs) are predicted playing a key role in the bidirectional transfer of sRNAs that mediate ckRNAi. To address this knowledge gap, we investigated the effects of EVs isolated from barley and Fg on their counterparts during plant-fungal interaction. Towards this, we developed a protocol for the isolation of EVs from Fg liquid cultures and assessed how Fg EVs contribute to fungal pathogenesis in barley using infiltration assays. To test the interdependence of EVs during Barley-Fg interaction, we treated Fg cultures with barley EVs. We found that infiltration of Fg EVs caused host specific phytotoxic effects in barley and barley EVs impaired Fg growth. Of note, Fg cultures showed an increase in purple pigmentation upon inoculation with barley EVs, suggesting a stress-induced premature formation of fruiting bodies. Together, our results demonstrate that EVs contribute to the Barley-Fg interaction, however, further studies are needed to unravel the nature of EV cargoes (e.g. protein and/or sRNA) responsible for affecting its plant/fungus counterpart.


Pathogens ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 529 ◽  
Author(s):  
Ahmed S. Abdel-Moneim ◽  
Elsayed M. Abdelwhab

COVID-19 is the first known pandemic caused by a coronavirus, SARS-CoV-2, which is the third virus in the family Coronaviridae to cause fatal infections in humans after SARS-CoV and MERS-CoV. Animals are involved in the COVID-19 pandemic. This review summarizes the role of animals as reservoirs, natural hosts and experimental models. SARS-CoV-2 originated from animal reservoir, most likely bats and/or pangolins. Anthroponotic transmission has been reported in cats, dogs, tigers, lions and minks. As of now, there is no a strong evidence for natural animal-to-human transmission or sustained animal-to-animal transmission of SARS-CoV-2. Experimental infections conducted by several research groups have shown that monkeys, hamsters, ferrets, cats, tree shrews, transgenic mice and fruit bats were permissive, while dogs, pigs and poultry were resistant. There is an urgent need to understand the zoonotic potential of different viruses in animals, particularly in bats, before they transmit to humans. Vaccines or antivirals against SARS-CoV-2 should be evaluated not only for humans, but also for the protection of companion animals (particularly cats) and susceptible zoo and farm animals.


Chemotherapy ◽  
2021 ◽  
pp. 1-9
Author(s):  
Cristina Parolin ◽  
Sara Virtuoso ◽  
Marta Giovanetti ◽  
Silvia Angeletti ◽  
Massimo Ciccozzi ◽  
...  

Viruses arise through cross-species transmission and can cause potentially fatal diseases in humans. This is the case of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which recently appeared in Wuhan, China, and rapidly spread worldwide, causing the outbreak of coronavirus disease 2019 (COVID-19) and posing a global health emergency. Sequence analysis and epidemiological investigations suggest that the most likely original source of SARS-CoV-2 is a spillover from an animal reservoir, probably bats, that infected humans either directly or through intermediate animal hosts. The role of animals as reservoirs and natural hosts in SARS-CoV-2 has to be explored, and animal models for COVID-19 are needed as well to be evaluated for countermeasures against SARS-CoV-2 infection. Experimental cells, tissues, and animal models that are currently being used and developed in COVID-19 research will be presented.


Author(s):  
Pengfei Zhai ◽  
Landan Shi ◽  
Guowei Zhong ◽  
Jihong Jiang ◽  
Jingwen Zhou ◽  
...  

An efficient reactive oxygen species (ROS) detoxification system is vital for the survival of the pathogenic fungus Aspergillus fumigatus within the host high ROS environment of the host. Therefore, identifying and targeting factors essential for oxidative stress response is one approach to develop novel treatments for fungal infections. Oxidation resistance 1 (Oxr1) protein is essential for protection against oxidative stress in mammals, but its functions in pathogenic fungi remain unknown. The present study aimed to characterize the role of an Oxr1 homolog in A. fumigatus . The results indicated that the OxrA protein plays an important role in oxidative stress resistance by regulating the catalase function in A. fumigatus , and overexpression of catalase can rescue the phenotype associated with OxrA deficiency. Importantly, the deficiency of oxrA decreased the virulence of A. fumigatus and altered the host immune response. Using the Aspergillus -induced lung infection model, we demonstrated that the ΔoxrA mutant strain induced less tissue damage along with decreased levels of LDH and albumin release. Additionally, the ΔoxrA mutant caused inflammation at a lower degree, along with a markedly reduced influx of neutrophils to the lungs and a decreased secretion of cytokine usually associated with recruitment of neutrophils in mice. These results characterize for the role of OxrA in A. fumigatus , as a core regulator of oxidative stress resistance and fungal pathogenesis. Importance Knowledge of reactive oxygen species (ROS) detoxification in fungal pathogens is useful in the design of new antifungal drugs and could aid in the study of oxidative stress resistance mechanisms. In this study, we demonstrate that OxrA protein localize to the mitochondria and function to protect against oxidative damage. We demonstrate that OxrA contributes to oxidative stress resistance by regulating catalase function, and overexpression of catalase (CatA or CatB) can rescue the phenotype that is associated with OxrA deficiency. Remarkably, a loss of OxrA attenuated the fungal virulence in a mouse model of invasive pulmonary aspergillosis and altered the host immune response. Therefore, our finding indicates that inhibition of OxrA might be an effective approach for alleviating A. fumigatus infection. The present study is, to the best of our knowledge, a pioneer in reporting the vital role of Oxr1 protein in pathogenic fungi.


2008 ◽  
Vol 2 (3) ◽  
pp. 308-320 ◽  
Author(s):  
David M. Arana ◽  
Daniel Prieto ◽  
Elvira Román ◽  
César Nombela ◽  
Rebeca Alonso-Monge ◽  
...  

2006 ◽  
Vol 1 (2) ◽  
pp. 219-227 ◽  
Author(s):  
John R Erb-Downward ◽  
Gary B Huffnagle

Biology ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 274
Author(s):  
Mónica Mazorra-Alonso ◽  
Gustavo Tomás ◽  
Juan José Soler

Microbial symbionts are nowadays considered of pivotal importance for animal life. Among the many processes where microorganisms are involved, an emerging research avenue focuses on their major role in driving the evolution of chemical communication in their hosts. Volatiles of bacterial origin may underlie chemical communication and the transfer of social information through signals, as well as inadvertent social information. We reviewed the role of microorganisms in animal communication between conspecifics, and, because the microbiome may cause beneficial as well as deleterious effects on their animal hosts, we also reviewed its role in determining the outcome of the interactions with parasites and predators. Finally, we paid special attention to the hypothetical role of predation and parasitism in driving the evolution of the animal microbiome. We highlighted the novelty of the theoretical framework derived from considering the microbiota of animals in scenarios of communication, parasitism, and predation. We aimed to encourage research in these areas, suggesting key predictions that need to be tested to better understand what is one of the main roles of bacteria in animal biology.


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