scholarly journals The genome of Leishmania adleri from a mammalian host highlights chromosome fission in Sauroleishmania

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Simone Coughlan ◽  
Peter Mulhair ◽  
Mandy Sanders ◽  
Gabriele Schonian ◽  
James A. Cotton ◽  
...  
Keyword(s):  
Mammalian Host ◽  
Chromosome Fission

The zoonotic potential of bat-borne coronaviruses

2020 ◽  
Vol 4 (4) ◽  
pp. 365-381
Author(s):  
Ny Anjara Fifi Ravelomanantsoa ◽  
Sarah Guth ◽  
Angelo Andrianiaina ◽  
Santino Andry ◽  
Anecia Gentles ◽  
...  
Keyword(s):  
Genetic Material ◽  
Field Research ◽  
Sympatric Species ◽  
Animal Origin ◽  
Mammalian Host ◽  
Past Century ◽  
The Past ◽  
Novel Host ◽  
Horseshoe Bat ◽  
Human Infections

Seven zoonoses — human infections of animal origin — have emerged from the Coronaviridae family in the past century, including three viruses responsible for significant human mortality (SARS-CoV, MERS-CoV, and SARS-CoV-2) in the past twenty years alone. These three viruses, in addition to two older CoV zoonoses (HCoV-229E and HCoV-NL63) are believed to be originally derived from wild bat reservoir species. We review the molecular biology of the bat-derived Alpha- and Betacoronavirus genera, highlighting features that contribute to their potential for cross-species emergence, including the use of well-conserved mammalian host cell machinery for cell entry and a unique capacity for adaptation to novel host environments after host switching. The adaptive capacity of coronaviruses largely results from their large genomes, which reduce the risk of deleterious mutational errors and facilitate range-expanding recombination events by offering heightened redundancy in essential genetic material. Large CoV genomes are made possible by the unique proofreading capacity encoded for their RNA-dependent polymerase. We find that bat-borne SARS-related coronaviruses in the subgenus Sarbecovirus, the source clade for SARS-CoV and SARS-CoV-2, present a particularly poignant pandemic threat, due to the extraordinary viral genetic diversity represented among several sympatric species of their horseshoe bat hosts. To date, Sarbecovirus surveillance has been almost entirely restricted to China. More vigorous field research efforts tracking the circulation of Sarbecoviruses specifically and Betacoronaviruses more generally is needed across a broader global range if we are to avoid future repeats of the COVID-19 pandemic.

Investigation of Tickborne Pathogens within Naturally Infected Brown Dog Tick (Ixodidae: Rhipicephalus Sanguineus) in Egypt by Light and Electron Microscopy

2020 ◽  
Keyword(s):  
Electron Microscopy ◽  
Salivary Gland ◽  
Light And Electron Microscopy ◽  
Rhipicephalus Sanguineus ◽  
Mammalian Host ◽  
Babesia Canis ◽  
Brown Dog Tick ◽  
Transmission Electron ◽  
Dog Tick ◽  
Theileria Spp

Tick borne pathogens present a significant health challenge to animals and human because a single tick may transmit multiple pathogens to a mammalian host during feeding. The present study detected tick-borne pathogens from pet dogs. A total of 666 ticks were collected from 144 pet and sheltered dogs in Egypt from April to September 2018. For hemolymph, midgut and salivary gland smears 546 ticks were used as well as 360 egg smears from 120 female tick were examined by light microscope. The infected ticks were prepared for transmission electron microscopy (TEM). Ticks were identified; Rhipicephalus sanguineus. Light microscopy showed infection rates of 44.69%, 68.50% & 15.75%, in hemolymph, midgut and salivary gland, respectively. H. canis recorded the highest rates in hemolymph and midgut (35.89% & 49.82%, respectively), but Theileria spp. was the lowest (0.73% & 2.93%, respectively). In salivary gland smears, Babesia canis. was detected in 13.55% and Theileria spp. in 1.83%. Mixed infection in same tick was recorded in 4.76% &0.37% in midgut and salivary gland smears, respectively. Babesia canis stages were recovered from 15% of egg smears. R. sanguineus was natural infected by Babesia, Theileria, Hepatozoon and Anaplasma phagocytophilum as well as mixed infections of protozoa accompanied by a complicated sign of diseases and failure in accurate diagnosis.

Polyamines and Related Nitrogen Compounds in the Chemotherapy of Neglected Diseases Caused by Kinetoplastids

2018 ◽  
Vol 18 (5) ◽  
pp. 321-368 ◽  
Author(s):  
Juan A. Bisceglia ◽  
Maria C. Mollo ◽  
Nadia Gruber ◽  
Liliana R. Orelli
Keyword(s):  
Drug Targets ◽  
Redox Homeostasis ◽  
Cost Effective ◽  
Structural Features ◽  
Mammalian Host ◽  
Neglected Diseases ◽  
Nitrogen Compounds ◽  
Chemical Structures

Neglected diseases due to the parasitic protozoa Leishmania and Trypanosoma (kinetoplastids) affect millions of people worldwide, and the lack of suitable treatments has promoted an ongoing drug discovery effort to identify novel nontoxic and cost-effective chemotherapies. Polyamines are ubiquitous small organic molecules that play key roles in kinetoplastid parasites metabolism, redox homeostasis and in the normal progression of cell cycles, which differ from those found in the mammalian host. These features make polyamines attractive in terms of antiparasitic drug development. The present work provides a comprehensive insight on the use of polyamine derivatives and related nitrogen compounds in the chemotherapy of kinetoplastid diseases. The amount of literature on this subject is considerable, and a classification considering drug targets and chemical structures were made. Polyamines, aminoalcohols and basic heterocycles designed to target the relevant parasitic enzyme trypanothione reductase are discussed in the first section, followed by compounds directed to less common targets, like parasite SOD and the aminopurine P2 transporter. Finally, the third section comprises nitrogen compounds structurally derived from antimalaric agents. References on the chemical synthesis of the selected compounds are reported together with their in vivo and/or in vitro IC50 values, and structureactivity relationships within each group are analyzed. Some favourable structural features were identified from the SAR analyses comprising protonable sites, hydrophobic groups and optimum distances between them. The importance of certain pharmacophoric groups or amino acid residues in the bioactivity of polyamine derived compounds is also discussed.

Development of Mucosal Immunity: Functional Interactions with Mucosal Microbiome in Health and Disease

2019 ◽  
Vol 15 (2) ◽  
pp. 154-165
Author(s):  
Oscar G. Gómez-Duarte ◽  
Pearay L. Ogra
Keyword(s):  
Adaptive Immunity ◽  
Mucosal Immunity ◽  
Plasma Cells ◽  
External Environment ◽  
Mammalian Host ◽  
Immune Functions ◽  
Principal Mechanism ◽  
Functional Development ◽  
Mucosal Surfaces ◽  
Specific Pathogen

The mucosal surfaces and the skin are the primary sites of interactions between the mammalian host and the external environment. These sites are exposed continuously to the diverse components of the environment, including subcellular, unicellular and multicellular organisms, dietary agents and food products; and numerous other soluble or cellular air or water borne products. The development of innate and adaptive immunity in the mucosal surfaces and the skin are the principal mechanism of mammalian defense evolved to date, in order to maintain effective homeostatic balance between the host and the external environment. The innate immune functions are mediated by a number of host specific Pathogen Recognition Receptors (PRR), designed to recognize unique Pathogen Associated Molecular Patterns (PAMP), essential to the molecular structure of the microorganism. The major components of specific adaptive immunity in the mucosal surfaces include the organized antigen-reactive lymphoid follicles in different inductive mucosal sites and the effector sites of the lamina propria and sub-epithelial regions, which contain lymphoid and plasma cells, derived by the homing of antigen sensitized cells from the inductive sites. The acquisition of environmental microbiome by the neonate in its mucosal surfaces and the skin, which begins before or immediately after birth, has been shown to play a critical and complex role in the development of mucosal immunity. This report provides an overview of the mammalian microbiome and highlights its role in the evolution and functional development of immunologic defenses in the mucosal surface under normal physiologic conditions and during infectious and non-infectious inflammatory pathologic states associated with altered microbiota.

scholarly journals Metabolic reprogramming during the Trypanosoma brucei life cycle

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 683 ◽  
Author(s):  
Terry K. Smith ◽  
Frédéric Bringaud ◽  
Derek P. Nolan ◽  
Luisa M. Figueiredo
Keyword(s):  
Life Cycle ◽  
Trypanosoma Brucei ◽  
Model Organism ◽  
Protozoan Parasite ◽  
Tsetse Fly ◽  
Metabolic Reprogramming ◽  
Mammalian Host ◽  
Insect Vector ◽  
Environmental Signals ◽  
Cellular Metabolic Activity

Cellular metabolic activity is a highly complex, dynamic, regulated process that is influenced by numerous factors, including extracellular environmental signals, nutrient availability and the physiological and developmental status of the cell. The causative agent of sleeping sickness, Trypanosoma brucei, is an exclusively extracellular protozoan parasite that encounters very different extracellular environments during its life cycle within the mammalian host and tsetse fly insect vector. In order to meet these challenges, there are significant alterations in the major energetic and metabolic pathways of these highly adaptable parasites. This review highlights some of these metabolic changes in this early divergent eukaryotic model organism.

scholarly journals Isolation of viable Babesia bovis merozoites to study parasite invasion

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hassan Hakimi ◽  
Masahito Asada ◽  
Takahiro Ishizaki ◽  
Shinichiro Kawazu
Keyword(s):  
Control Strategies ◽  
Specific Inhibitor ◽  
Babesia Bovis ◽  
Parasite Development ◽  
Mammalian Host ◽  
Bovine Babesiosis ◽  
Binary Forms ◽  
Parasite Invasion ◽  
Dependent Protein ◽  
Basic Biology

AbstractBabesia parasite invades exclusively red blood cell (RBC) in mammalian host and induces alterations to host cell for survival. Despite the importance of Babesia in livestock industry and emerging cases in humans, their basic biology is hampered by lack of suitable biological tools. In this study, we aimed to develop a synchronization method for Babesia bovis which causes the most pathogenic form of bovine babesiosis. Initially, we used compound 2 (C2), a specific inhibitor of cyclic GMP-dependent protein kinase (PKG), and a derivative of C2, ML10. While both inhibitors were able to prevent B. bovis egress from RBC and increased percentage of binary forms, removal of inhibitors from culture did not result in a synchronized egress of parasites. Because using PKG inhibitors alone was not efficient to induce a synchronized culture, we isolated viable and invasive B. bovis merozoites and showed dynamics of merozoite invasion and development in RBCs. Using isolated merozoites we showed that BbVEAP, VESA1-export associated protein, is essential for parasite development in the RBC while has no significant role in invasion. Given the importance of invasion for the establishment of infection, this study paves the way for finding novel antigens to be used in control strategies against bovine babesiosis.

scholarly journals The fibrinolytic system enables the onset of Plasmodium infection in the mosquito vector and the mammalian host

2021 ◽  
Vol 7 (6) ◽  
pp. eabe3362 ◽  
Author(s):  
Thiago Luiz Alves e Silva ◽  
Andrea Radtke ◽  
Amanda Balaban ◽  
Tales Vicari Pascini ◽  
Zarna Rajeshkumar Pala ◽  
...  
Keyword(s):  
Plasminogen Activators ◽  
Fibrinolytic System ◽  
Matrix Proteins ◽  
Parasite Development ◽  
Mammalian Host ◽  
Mosquito Vector ◽  
Plasminogen Activation ◽  
Plasmodium Infection ◽  
Human Plasminogen ◽  
Vertebrate Hosts

Plasmodium parasites must migrate across proteinaceous matrices to infect the mosquito and vertebrate hosts. Plasmin, a mammalian serine protease, degrades extracellular matrix proteins allowing cell migration through tissues. We report that Plasmodium gametes recruit human plasminogen to their surface where it is processed into plasmin by corecruited plasminogen activators. Inhibition of plasminogen activation arrests parasite development early during sexual reproduction, before ookinete formation. We show that increased fibrinogen and fibrin in the blood bolus, which are natural substrates of plasmin, inversely correlate with parasite infectivity of the mosquito. Furthermore, we show that sporozoites, the parasite form transmitted by the mosquito to humans, also bind plasminogen and plasminogen activators on their surface, where plasminogen is activated into plasmin. Surface-bound plasmin promotes sporozoite transmission by facilitating parasite migration across the extracellular matrices of the dermis and of the liver. The fibrinolytic system is a potential target to hamper Plasmodium transmission.

scholarly journals The novel Dbl homology/BAR domain protein, MsgA, of Talaromyces marneffei regulates yeast morphogenesis during growth inside host cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Harshini Weerasinghe ◽  
Hayley E. Bugeja ◽  
Alex Andrianopoulos
Keyword(s):  
Pathogenic Fungi ◽  
Host Cells ◽  
Microbial Pathogens ◽  
Mammalian Host ◽  
Host Immune System ◽  
Nucleotide Exchange ◽  
Phagocytic Cells ◽  
Macrophage Infection ◽  
Bar Domain ◽  
Talaromyces Marneffei

AbstractMicrobial pathogens have evolved many strategies to evade recognition by the host immune system, including the use of phagocytic cells as a niche within which to proliferate. Dimorphic pathogenic fungi employ an induced morphogenetic transition, switching from multicellular hyphae to unicellular yeast that are more compatible with intracellular growth. A switch to mammalian host body temperature (37 °C) is a key trigger for the dimorphic switch. This study describes a novel gene, msgA, from the dimorphic fungal pathogen Talaromyces marneffei that controls cell morphology in response to host cues rather than temperature. The msgA gene is upregulated during murine macrophage infection, and deletion results in aberrant yeast morphology solely during growth inside macrophages. MsgA contains a Dbl homology domain, and a Bin, Amphiphysin, Rvs (BAR) domain instead of a Plekstrin homology domain typically associated with guanine nucleotide exchange factors (GEFs). The BAR domain is crucial in maintaining yeast morphology and cellular localisation during infection. The data suggests that MsgA does not act as a canonical GEF during macrophage infection and identifies a temperature independent pathway in T. marneffei that controls intracellular yeast morphogenesis.

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