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Parasites & Vectors Jun 2021Parasites, including viruses, bacteria, fungi, protists, helminths, and arthropods, are ubiquitous in the animal kingdom. Consequently, hosts are frequently infected... (Review)
Review
Parasites, including viruses, bacteria, fungi, protists, helminths, and arthropods, are ubiquitous in the animal kingdom. Consequently, hosts are frequently infected with more than one parasite species simultaneously. The assessment of such co-infections is of fundamental importance for disease ecology, but relevant studies involving non-domesticated animals have remained scarce. Many amphibians are in decline, and they generally have a highly diverse parasitic fauna. Here we review the literature reporting on field surveys, veterinary case studies, and laboratory experiments on co-infections in amphibians, and we summarize what is known about within-host interactions among parasites, which environmental and intrinsic factors influence the outcomes of these interactions, and what effects co-infections have on hosts. The available literature is piecemeal, and patterns are highly diverse, so that identifying general trends that would fit most host-multiparasite systems in amphibians is difficult. Several examples of additive, antagonistic, neutral, and synergistic effects among different parasites are known, but whether members of some higher taxa usually outcompete and override the effects of others remains unclear. The arrival order of different parasites and the time lag between exposures appear in many cases to fundamentally shape competition and disease progression. The first parasite to arrive can gain a marked reproductive advantage or induce cross-reaction immunity, but by disrupting the skin and associated defences (i.e., skin secretions, skin microbiome) and by immunosuppression, it can also pave the way for subsequent infections. Although there are exceptions, detrimental effects to the host are generally aggravated with increasing numbers of co-infecting parasite species. Finally, because amphibians are ectothermic animals, temperature appears to be the most critical environmental factor that affects co-infections, partly via its influence on amphibian immune function, partly due to its direct effect on the survival and growth of parasites. Besides their importance for our understanding of ecological patterns and processes, detailed knowledge about co-infections is also crucial for the design and implementation of effective wildlife disease management, so that studies concentrating on the identified gaps in our understanding represent rewarding research avenues.
Topics: Amphibians; Animals; Animals, Wild; Coinfection; Host-Parasite Interactions; Parasites; Parasitic Diseases, Animal
PubMed: 34082796
DOI: 10.1186/s13071-021-04796-1 -
Current Drug Targets 2023Parasitic human infectious diseases are a worldwide health problem due to the increased resistance to conventional drugs. For this reason, the identification of novel... (Review)
Review
BACKGROUND
Parasitic human infectious diseases are a worldwide health problem due to the increased resistance to conventional drugs. For this reason, the identification of novel molecular targets and the discovery of new chemotherapeutic agents are urgently required. Metalo- aminopeptidases are promising targets in parasitic infections. They participate in crucial processes for parasite growth and pathogenesis.
OBJECTIVE
In this review, we describe the structural, functional and kinetic properties, and inhibitors, of several parasite metalo-aminopeptidases, for their use as targets in parasitic diseases.
CONCLUSION
M1 and M17 aminopeptidases are essential enzymes for parasite development, and M18 aminopeptidase could be involved in hemoglobin digestion and erythrocyte invasion and egression. and acidic M17 aminopeptidases can play a nutritional role. T. brucei basic M17 aminopeptidase down-regulation delays the cytokinesis. The inhibition of Leishmania basic M17 aminopeptidase could affect parasite viability. methionyl aminopeptidase inhibition prevents apoptosis but not the parasite death. Decrease in M17 aminopeptidase activity produces cell wall structural modifications and encystation inhibition. Inhibition of growth is probably related to the inhibition of the parasite M17 aminopeptidase, probably involved in host hemoglobin degradation. M17 aminopeptidases inhibition may affect parasite development, since they could participate in hemoglobin degradation, surface membrane remodeling and eggs hatching. M17 aminopeptidase inhibition could attenuate parasite virulence, since it is apparently involved in the hydrolysis of cathepsin Cs- or proteasome-produced dipeptides and/or cell attachment/invasion processes. These data are relevant to validate these enzymes as targets.
Topics: Animals; Humans; Aminopeptidases; Parasites; Plasmodium falciparum; Toxoplasma; Communicable Diseases
PubMed: 36825701
DOI: 10.2174/1389450124666230224140724 -
Parasitology Dec 2022Fish (Elasmobranchia and Actinopterygii) inhabit the majority of aquatic habitats globally. They are crucial for human nutrition but they may be negatively affected by...
Fish (Elasmobranchia and Actinopterygii) inhabit the majority of aquatic habitats globally. They are crucial for human nutrition but they may be negatively affected by parasitic protists and metazoan parasites. Fish parasites are also an extraordinary group of animals because of their ecological and evolutionary importance and unique adaptations to parasitism. They also play a key role in ecosystem functioning. In the present special issue, 13 review and research articles on major groups of fish parasites are provided to document the current advancement in our understanding of different aspects of their biology, ecology and associations with their fish hosts. The existing gaps in our knowledge of these peculiar animals are mapped and future trends in their research outlined.
Topics: Animals; Humans; Parasites; Ecosystem; Host-Parasite Interactions; Fishes; Biological Evolution; Fish Diseases
PubMed: 36226653
DOI: 10.1017/S0031182022001433 -
Parasitology Research Nov 2022Global change in the Anthropocene has modified the environment of almost any species on earth, be it through climate change, habitat modifications, pollution, human... (Review)
Review
Global change in the Anthropocene has modified the environment of almost any species on earth, be it through climate change, habitat modifications, pollution, human intervention in the form of mass drug administration (MDA), or vaccination. This can have far-reaching consequences on all organisational levels of life, including eco-physiological stress at the cell and organism level, individual fitness and behaviour, population viability, species interactions and biodiversity. Host-parasite interactions often require highly adapted strategies by the parasite to survive and reproduce within the host environment and ensure efficient transmission among hosts. Yet, our understanding of the system-level outcomes of the intricate interplay of within host survival and among host parasite spread is in its infancy. We shed light on how global change affects host-parasite interactions at different organisational levels and address challenges and opportunities to work towards better-informed management of parasite control. We argue that global change affects host-parasite interactions in wildlife inhabiting natural environments rather differently than in humans and invasive species that benefit from anthropogenic environments as habitat and more deliberate rather than erratic exposure to therapeutic drugs and other control efforts.
Topics: Animals; Animals, Wild; Biodiversity; Ecosystem; Host-Parasite Interactions; Humans; Parasites
PubMed: 36066742
DOI: 10.1007/s00436-022-07649-7 -
Seminars in Immunology Mar 2021A wealth of research is dedicated to understanding how resistance against parasites is conferred and how parasite-driven pathology is regulated. This research is in part... (Review)
Review
A wealth of research is dedicated to understanding how resistance against parasites is conferred and how parasite-driven pathology is regulated. This research is in part driven by the hope to better treatments for parasitic diseases of humans and livestock, and in part by immunologists who use parasitic infections as biomedical tools to evoke physiological immune responses. Much of the current mechanistic knowledge has been discovered in laboratory studies using model organisms, especially the laboratory mouse. However, wildlife are also hosts to a range of parasites. Through the study of host-parasite interactions in these non-laboratory systems we can gain a deeper understanding of parasite immunology in a more natural, complex environment. With a focus on helminth parasites, we here explore the insights gained into parasite-induced immune responses through (for immunologists) non-conventional experimental systems, and how current core findings from laboratory studies are reflected in these more natural conditions. The quality of the immune response is undoubtedly a central player in susceptibility versus resistance, as many laboratory studies have shown. Yet, in the wild, parasite infections tend to be chronic diseases. Whilst reading our review, we encourage the reader to consider the following questions which may (only) be answered by studying naturally occurring parasites in the wild: a) what type of immune responses are mounted against parasites in different hosts in the wild, and how do they vary within an individual over time, between individuals of the same species and between species? b) can we use wild or semi-wild study systems to understand the evolutionary drivers for tolerance versus resistance towards a parasite? c) what determines the ability of the host to cope with an infection and is there a link with the type of immune response mounted? d) can we modulate environmental factors to manipulate a wild animal's immune response to parasitic infections, with translation potential for humans, wildlife, and livestock? and e) in context of this special issue, what lessons for Type 2 immunity can we glean from studying animals in their natural environments? Further, we aim to integrate some of the knowledge gained in semi-wild and wild settings with knowledge gained from traditional laboratory-based research, and to raise awareness for the opportunities (and challenges) that come with integrating a multitude of naturally-occurring variables into immunoparasitological research.
Topics: Animals; Animals, Wild; Biological Evolution; Host-Parasite Interactions; Humans; Mice; Parasites
PubMed: 34785137
DOI: 10.1016/j.smim.2021.101525 -
Trends in Parasitology Mar 2023Imaging of parasites is central to diagnosis of many parasitic diseases and has thus far played an important role in the development of antiparasitic strategies. The... (Review)
Review
Imaging of parasites is central to diagnosis of many parasitic diseases and has thus far played an important role in the development of antiparasitic strategies. The development of novel imaging technologies has revolutionized medicine in fields other than parasitology and has also opened up new avenues for the visualization of parasites. Here we review the role imaging technology has played so far in parasitology and how it may spur further advancement. We point out possibilities to improve current microscopy-based diagnostic methods and how to extend them with radiological imaging modalities. We also highlight in vivo tracking of parasites as a readout for efficacy of new antiparasitic strategies and as a source of fundamental insights for rational design.
Topics: Animals; Humans; Parasitic Diseases; Parasites; Antiparasitic Agents; Diagnostic Imaging; Parasitology
PubMed: 36641293
DOI: 10.1016/j.pt.2022.12.008 -
Infection, Genetics and Evolution :... Jun 2022Because parasite data reveal essential information about the behavior and history of their hosts, it is possible to use them as tracers of host evolution. A table built...
Because parasite data reveal essential information about the behavior and history of their hosts, it is possible to use them as tracers of host evolution. A table built from the analysis of the data contained in the book by Ashford and Crewe "The Parasites of Homo sapiens" allows counting and cross comparing the parasites according to the main descriptors used by the authors: Taxonomic groups, for each group number of parasites species identified in humans; Status, numbers of reported human cases and their dispersion; Geographic distribution, parasite specific richness recorded in biogeographic regions; Habitat, parasite location in or on the human body; Transmission, contamination pathways to man; Hosts, non-human hosts, which have a role in the maintenance of a parasite; Host-specificity status, relative role of man or other hosts in the maintenance of parasite populations. A strong positive correlation is observed between the number of parasites species recorded in humans and the global parasite species richness for each taxonomic group. About 74% of the parasites recorded in humans are rare, sporadic or nowhere common; 10% only are common or abundant worldwide. The Palearctic exhibits the highest parasite species diversity; the Oriental, Nearctic, Neotropical and Aethiopian regions have roughly similar richness values; the Australian Region is the poorest. Earliest domesticated animals, such as dog, cat, cattle or pig, share more parasite species with Humans than tardily domesticated as horse, rabbit or camel. More than one third of our parasites have elected our alimentary canal as a home and about two third are using the digestive tract path for contamination. Time of occupancy of new territories, diversity in feeding habits and commensalism with other animals, widely explain Human particular parasite richness. As suggested by the authors: "There must be few parasitic species which have never had the opportunity to infect a human".
Topics: Animals; Australia; Cattle; Dogs; Ecosystem; Horses; Host Specificity; Host-Parasite Interactions; Humans; Parasites; Rabbits; Swine
PubMed: 35245684
DOI: 10.1016/j.meegid.2022.105262 -
Frontiers in Cellular and Infection... 2023Parasitic diseases pose a significant threat to global public health, particularly in developing countries. Host genetic factors play a crucial role in determining... (Review)
Review
Parasitic diseases pose a significant threat to global public health, particularly in developing countries. Host genetic factors play a crucial role in determining susceptibility and resistance to infection. Recent advances in molecular and biological technologies have enabled significant breakthroughs in understanding the impact of host genes on parasite adaptation. In this comprehensive review, we analyze the host genetic factors that influence parasite adaptation, including hormones, nitric oxide, immune cells, cytokine gene polymorphisms, parasite-specific receptors, and metabolites. We also establish an interactive network to better illustrate the complex relationship between host genetic factors and parasite-host adaptation. Additionally, we discuss future directions and collaborative research priorities in the parasite-host adaptation field, including investigating the impact of host genes on the microbiome, developing more sophisticated models, identifying and characterizing parasite-specific receptors, utilizing patient-derived sera as diagnostic and therapeutic tools, and developing novel treatments and management strategies targeting specific host genetic factors. This review highlights the need for a comprehensive and systematic approach to investigating the underlying mechanisms of parasite-host adaptation, which requires interdisciplinary collaborations among biologists, geneticists, immunologists, and clinicians. By deepening our understanding of the complex interactions between host genetics and parasite adaptation, we can develop more effective and targeted interventions to prevent and treat parasitic diseases. Overall, this review provides a valuable resource for researchers and clinicians working in the parasitology field and offers insights into the future directions of this critical research area.
Topics: Humans; Animals; Parasites; Host Adaptation; Cytokines; Microbiota; Nitric Oxide
PubMed: 37637465
DOI: 10.3389/fcimb.2023.1228206 -
Acta Parasitologica Mar 2022Liquid biopsy refers to the sampling and molecular analysis of body fluids such as blood, saliva, and urine in contrast to conventional tissue biopsies. Liquid biopsy... (Review)
Review
BACKGROUND
Liquid biopsy refers to the sampling and molecular analysis of body fluids such as blood, saliva, and urine in contrast to conventional tissue biopsies. Liquid biopsy approach can offer powerful non-invasive biomarkers (circulating markers) for diagnosis and monitoring treatment response of a variety of diseases, including parasitic infections.
METHODS
In this review, we concentrate on cell-free DNA (cfDNA), microRNA (miRNA), and exosomes in the published literature.
RESULTS
Considering the high prevalence and severity of parasitic infections worldwide, circulating biomarkers can provide a new insight into the diagnosis and prognosis of parasites in the near future. Moreover, identifying and characterizing parasite- or host-derived circulating markers are important for a better understanding of the pathogenesis of parasite infection and host-parasite relationship at the molecular level. Profiling of biomarkers for parasitic diseases is a promising potential field, though further studies and optimization strategies are required, both in vitro and in vivo.
CONCLUSION
In this review, we discuss three approaches in the liquid biopsy including circulating cfDNA, miRNAs, and exosomes for diagnosis and evaluation of parasites and summarize circulating biomarkers in non-invasive samples during parasitic infections.
Topics: Animals; Biomarkers; Cell-Free Nucleic Acids; Exosomes; Humans; Liquid Biopsy; MicroRNAs; Parasites; Parasitic Diseases
PubMed: 34176040
DOI: 10.1007/s11686-021-00444-x -
How colonization bottlenecks, tissue niches, and transmission strategies shape protozoan infections.Trends in Parasitology Dec 2023Protozoan pathogens such as Plasmodium spp., Leishmania spp., Toxoplasma gondii, and Trypanosoma spp. are often associated with high-mortality, acute and chronic... (Review)
Review
Protozoan pathogens such as Plasmodium spp., Leishmania spp., Toxoplasma gondii, and Trypanosoma spp. are often associated with high-mortality, acute and chronic diseases of global health concern. For transmission and immune evasion, protozoans have evolved diverse strategies to interact with a range of host tissue environments. These interactions are linked to disease pathology, yet our understanding of the association between parasite colonization and host homeostatic disruption is limited. Recently developed techniques for cellular barcoding have the potential to uncover the biology regulating parasite transmission, dissemination, and the stability of infection. Understanding bottlenecks to infection and the in vivo tissue niches that facilitate chronic infection and spread has the potential to reveal new aspects of parasite biology.
Topics: Animals; Humans; Host-Parasite Interactions; Protozoan Infections; Parasites; Toxoplasma; Plasmodium
PubMed: 37839913
DOI: 10.1016/j.pt.2023.09.017