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ELife Sep 2021The parasite that causes African sleeping sickness can be transmitted from mammals to tsetse flies in two stages of its lifecycle, rather than one as was previously...
The parasite that causes African sleeping sickness can be transmitted from mammals to tsetse flies in two stages of its lifecycle, rather than one as was previously thought.
Topics: Animals; Life Cycle Stages; Trypanosomiasis, African; Tsetse Flies
PubMed: 34534076
DOI: 10.7554/eLife.72980 -
ELife Oct 2016Trypanosome parasites are hiding in human skin, a discovery that may undermine efforts to eliminate sleeping sickness by 2020.
Trypanosome parasites are hiding in human skin, a discovery that may undermine efforts to eliminate sleeping sickness by 2020.
Topics: Animals; Humans; Skin; Trypanosoma brucei gambiense; Trypanosomiasis, African; Tsetse Flies
PubMed: 27740910
DOI: 10.7554/eLife.21506 -
Nature Communications Nov 2022Approximately 20% of sleeping sickness patients exhibit respiratory complications, however, with a largely unknown role of the parasite. Here we show that tsetse...
Approximately 20% of sleeping sickness patients exhibit respiratory complications, however, with a largely unknown role of the parasite. Here we show that tsetse fly-transmitted Trypanosoma brucei parasites rapidly and permanently colonize the lungs and occupy the extravascular spaces surrounding the blood vessels of the alveoli and bronchi. They are present as nests of multiplying parasites exhibiting close interactions with collagen and active secretion of extracellular vesicles. The local immune response shows a substantial increase of monocytes, macrophages, dendritic cells and γδ and activated αβ T cells and a later influx of neutrophils. Interestingly, parasite presence results in a significant reduction of B cells, eosinophils and natural killer cells. T. brucei infected mice show no infection-associated pulmonary dysfunction, mirroring the limited pulmonary clinical complications during sleeping sickness. However, the substantial reduction of the various immune cells may render individuals more susceptible to opportunistic infections, as evident by a co-infection experiment with respiratory syncytial virus. Collectively, these observations provide insights into a largely overlooked target organ, and may trigger new diagnostic and supportive therapeutic approaches for sleeping sickness.
Topics: Mice; Animals; Trypanosomiasis, African; Tsetse Flies; Trypanosoma brucei brucei; Thorax; Pulmonary Alveoli
PubMed: 36400767
DOI: 10.1038/s41467-022-34757-w -
Virulence Dec 2023African trypanosomes are vector-borne protozoa, which cause significant human and animal disease across sub-Saharan Africa, and animal disease across Asia and South... (Review)
Review
African trypanosomes are vector-borne protozoa, which cause significant human and animal disease across sub-Saharan Africa, and animal disease across Asia and South America. In humans, infection is caused by variants of , and is characterized by varying rate of progression to neurological disease, caused by parasites exiting the vasculature and entering the brain. Animal disease is caused by multiple species of trypanosome, primarily , and . These trypanosomes also infect multiple species of mammalian host, and this complexity of trypanosome and host diversity is reflected in the spectrum of severity of disease in animal trypanosomiasis, ranging from hyperacute infections associated with mortality to long-term chronic infections, and is also a main reason why designing interventions for animal trypanosomiasis is so challenging. In this review, we will provide an overview of the current understanding of trypanosome determinants of infection progression and severity, covering laboratory models of disease, as well as human and livestock disease. We will also highlight gaps in knowledge and capabilities, which represent opportunities to both further our fundamental understanding of how trypanosomes cause disease, as well as facilitating the development of the novel interventions that are so badly needed to reduce the burden of disease caused by these important pathogens.
Topics: Animals; Humans; Trypanosomiasis, African; Virulence; Tsetse Flies; Trypanosoma; Trypanosomiasis; Mammals
PubMed: 36419235
DOI: 10.1080/21505594.2022.2150445 -
Frontiers in Cellular and Infection... 2013Tsetse flies are the primary vectors of African trypanosomes, which cause Human and Animal African trypanosomiasis in 36 countries in sub-Saharan Africa. These flies... (Review)
Review
Tsetse flies are the primary vectors of African trypanosomes, which cause Human and Animal African trypanosomiasis in 36 countries in sub-Saharan Africa. These flies have also established symbiotic associations with bacterial and viral microorganisms. Laboratory-reared tsetse flies harbor up to four vertically transmitted organisms-obligate Wigglesworthia, commensal Sodalis, parasitic Wolbachia and Salivary Gland Hypertrophy Virus (SGHV). Field-captured tsetse can harbor these symbionts as well as environmentally acquired commensal bacteria. This microbial community influences several aspects of tsetse's physiology, including nutrition, fecundity and vector competence. This review provides a detailed description of tsetse's microbiome, and describes the physiology underlying host-microbe, and microbe-microbe, interactions that occur in this fly.
Topics: Animals; Host-Parasite Interactions; Microbiota; Symbiosis; Tsetse Flies
PubMed: 24195062
DOI: 10.3389/fcimb.2013.00069 -
Parasitology Today (Personal Ed.) Mar 2000Arthropods are involved in the transmission of parasitic and viral agents that cause devastating diseases in animals and plants. Effective control strategies for many of... (Review)
Review
Arthropods are involved in the transmission of parasitic and viral agents that cause devastating diseases in animals and plants. Effective control strategies for many of these diseases still rely on the elimination or reduction of vector insect populations. In addition to these pathogenic organisms, arthropods are rich in microbes that are symbiotic in their associations and are often necessary for the fecundity and viability of their hosts. Because the viability of the host often depends on these obligate symbionts, and because these organisms often live in close proximity to disease-causing pathogens, they have been of interest to applied biologists as a potential means to genetically manipulate populations of pest species. As knowledge on these symbiotic associations accumulates from distantly related insect taxa, conserved mechanisms for their transmission and evolutionary histories are beginning to emerge. Here, Serap Aksoy summarizes current knowledge on the functional and evolutionary biology of the multiple symbionts harbored in the medically and agriculturally important insect group, tsetse, and their potential role in the control of trypanosomiasis.
Topics: Animals; Bacterial Physiological Phenomena; Insect Vectors; Pest Control, Biological; Symbiosis; Trypanosomiasis; Tsetse Flies
PubMed: 10689331
DOI: 10.1016/s0169-4758(99)01606-3 -
Journal of Medical Entomology Mar 2021The effect of human-associated habitat degradation on tsetse populations is well established. However, more insights are needed into how gradual human encroachment into...
Effects of Human Settlements and Spatial Distribution of Wing Vein Length, Wing Fray Categories and Hunger Stages in Glossina morsitans morsitans (Diptera: Glossinidae) and Glossina pallidipes (Diptera: Glossinidae) in Areas Devoid of Cattle in North-Eastern Zambia.
The effect of human-associated habitat degradation on tsetse populations is well established. However, more insights are needed into how gradual human encroachment into tsetse fly belts affect tsetse populations. This study investigated how wing vein length, wing fray categories, and hunger stages, taken as indicators of body size, age, and levels of access to hosts, respectively, in Glossina morsitans morsitans Westwood (Diptera: Glossinidae) and Glossina pallidipes Austen (Diptera: Glossinidae), varied along a transect from the edge into inner parts of the tsetse belt, in sites that had human settlement either concentrated at the edge of belt or evenly distributed along transect line, in north-eastern Zambia. Black-screen fly round and Epsilon traps were used in a cross-sectional survey on tsetse flies at three sites, following a transect line marked by a road running from the edge into the inner parts of the tsetse belt, per site. Two sites had human settlement concentrated at or close to the edge of the tsetse belt, whereas the third had human settlement evenly distributed along the transect line. Where settlements were concentrated at the edge of tsetse belt, increase in distance from the settlements was associated with increase in wing vein length and a reduction in the proportion of older, and hungry, tsetse flies. Increase in distance from human settlements was associated with improved tsetse well-being, likely due to increase in habitat quality due to decrease in effects of human activities.
Topics: Animals; Body Size; Cattle; Cross-Sectional Studies; Ecosystem; Glossinidae; Humans; Hunger; Insect Control; Insect Vectors; Rural Population; Tsetse Flies; Wings, Animal; Zambia
PubMed: 33118036
DOI: 10.1093/jme/tjaa228 -
Parasites & Vectors Jan 2019The discovery and development of fluorescent proteins for the investigation of living cells and whole organisms has been a major advance in biomedical research. This... (Review)
Review
The discovery and development of fluorescent proteins for the investigation of living cells and whole organisms has been a major advance in biomedical research. This approach was quickly exploited by parasitologists, particularly those studying single-celled protists. Here we describe some of our experiments to illustrate how fluorescent proteins have helped to reveal what trypanosomes get up to inside the tsetse fly. Fluorescent proteins turned the tsetse fly from a "black box" into a bright showcase to track trypanosome migration and development within the insect. Crosses of genetically modified red and green fluorescent trypanosomes produced yellow fluorescent hybrids and established the "when" and "where" of trypanosome sexual reproduction inside the fly. Fluorescent-tagging endogenous proteins enabled us to identify the meiotic division stage and gametes inside the salivary glands of the fly and thus elucidate the mechanism of sexual reproduction in trypanosomes. Without fluorescent proteins we would still be in the "dark ages" of understanding what trypanosomes get up to inside the tsetse fly.
Topics: Animals; Germ Cells; Insect Vectors; Meiosis; Reproduction; Salivary Glands; Trypanosoma; Tsetse Flies
PubMed: 30609932
DOI: 10.1186/s13071-018-3204-y -
Nature Communications Jul 2023African trypanosomes are dixenous eukaryotic parasites that impose a significant human and veterinary disease burden on sub-Saharan Africa. Diversity between species and...
African trypanosomes are dixenous eukaryotic parasites that impose a significant human and veterinary disease burden on sub-Saharan Africa. Diversity between species and life-cycle stages is concomitant with distinct host and tissue tropisms within this group. Here, the spatial proteomes of two African trypanosome species, Trypanosoma brucei and Trypanosoma congolense, are mapped across two life-stages. The four resulting datasets provide evidence of expression of approximately 5500 proteins per cell-type. Over 2500 proteins per cell-type are classified to specific subcellular compartments, providing four comprehensive spatial proteomes. Comparative analysis reveals key routes of parasitic adaptation to different biological niches and provides insight into the molecular basis for diversity within and between these pathogen species.
Topics: Humans; Animals; Trypanosomiasis, African; Tsetse Flies; Proteome; Proteomics; Trypanosoma brucei brucei; Trypanosoma congolense
PubMed: 37479728
DOI: 10.1038/s41467-023-40125-z -
Parasite Immunology Aug 2011The diseases caused by trypanosomes are medically and economically devastating to the population of Sub-Saharan Africa. Parasites of the genus Trypanosoma infect both... (Review)
Review
The diseases caused by trypanosomes are medically and economically devastating to the population of Sub-Saharan Africa. Parasites of the genus Trypanosoma infect both humans, causing African sleeping sickness, and livestock, causing Nagana. The development of effective treatment strategies has suffered from severe side effects of approved drugs, resistance and major difficulties in delivering drugs. Antimicrobial peptides (AMPs) are ubiquitous components of immune defence and are being rigorously pursued as novel sources of new therapeutics for a variety of pathogens. Here, we review the role of AMPs in the innate immune response of the tsetse fly to African trypanosomes, catalogue trypanocidal AMPs from diverse organisms and highlight the susceptibility of bloodstream form African trypanosomes to killing by unconventional toxic peptides.
Topics: Alamethicin; Animals; Antimicrobial Cationic Peptides; Cell Membrane; Cell Membrane Permeability; Humans; Lipopeptides; Peptides; Peptides, Cyclic; Trypanocidal Agents; Trypanosoma; Tsetse Flies
PubMed: 21517904
DOI: 10.1111/j.1365-3024.2011.01294.x