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Glycoconjugate Journal Feb 2020Parasitic helminths and pest insects are organisms with great ecological importance, having direct or indirect detrimental effects on people's lives worldwide. Several... (Review)
Review
Parasitic helminths and pest insects are organisms with great ecological importance, having direct or indirect detrimental effects on people's lives worldwide. Several reports in literature indicate that the glycan repertoire of parasites plays important roles in host-parasite interactions and modulation and evasion of the host immune system, while insect glycans are essential for their survival, growth and development. Although glycosylation is the result of a highly conserved machinery, differences between species and between different stages of one organism's life cycle occur. This review provides insight into recent glycomics studies both for helminths and insects, focussing on sex differences and the role of carbohydrate structures in reproduction. Information on the differential N-glycosylation process between males and females can generate a better understanding of the biology and physiology of these economic important organisms, and can contribute to the discovery of novel anti-fecundity vaccine candidates and drug targets, as well as in the elaboration of innovative pest management strategies.
Topics: Animals; Female; Glycosylation; Helminths; Insecta; Male; Parasites; Polysaccharides; Reproduction; Sex Differentiation
PubMed: 30941612
DOI: 10.1007/s10719-019-09866-2 -
Trends in Parasitology Jun 2022γ-aminobutyric acid (GABA) is a nonstructural amino acid that serves diverse functions in unicellular and multicellular organisms. Besides its widely established role... (Review)
Review
γ-aminobutyric acid (GABA) is a nonstructural amino acid that serves diverse functions in unicellular and multicellular organisms. Besides its widely established role in mammals as an inhibitory neurotransmitter, the diverse biological roles and metabolism of GABA in protozoan parasites have begun to be unveiled. GABA acts as either the intracellular signal or cell-to-cell messenger to mediate a variety of cellular responses that protect the parasites from environmental and host-derived stress. Moreover, GABA metabolism was found to be tightly regulated, involving protein machinery confined to the protozoa lineage. Meanwhile, host-parasite GABAergic interaction plays a role in the pathogenesis and disease manifestation of protozoan infections. Therefore, the GABAergic system apparently is broadly involved in essential biological and pathophysiological processes and is well conserved in parasitic and free-living protozoa.
Topics: Animals; Host-Parasite Interactions; Mammals; Parasites; Protozoan Infections; gamma-Aminobutyric Acid
PubMed: 35264298
DOI: 10.1016/j.pt.2022.02.004 -
Frontiers in Immunology 2020
Topics: Animals; Host-Parasite Interactions; Humans; Infection Control; Infections; Parasites
PubMed: 32457761
DOI: 10.3389/fimmu.2020.00880 -
Journal of Clinical Microbiology Nov 2022Advances in laboratory techniques have revolutionized parasitology diagnostics over the past several decades. Widespread implementation of rapid antigen detection tests...
Advances in laboratory techniques have revolutionized parasitology diagnostics over the past several decades. Widespread implementation of rapid antigen detection tests has greatly expanded access to tests for global parasitic threats such as malaria, while next-generation amplification and sequencing methods allow for sensitive and specific detection of human and animal parasites in complex specimen matrices. Recently, the introduction of multiplex panels for human gastrointestinal infections has enhanced the identification of common intestinal protozoa in feces along with bacterial and viral pathogens. Despite the benefits provided by novel diagnostics, increased reliance on nonmicroscopy-based methods has contributed to the progressive, widespread loss of morphology expertise for parasite identification. Loss of microscopy and morphology skills has the potential to negatively impact patient care, public health, and epidemiology. Molecular- and antigen-based diagnostics are not available for all parasites and may not be suitable for all specimen types and clinical settings. Furthermore, inadequate morphology experience may lead to missed and inaccurate diagnoses and erroneous descriptions of new human parasitic diseases. This commentary highlights the need to maintain expert microscopy and morphological parasitology diagnostic skills within the medical and scientific community. We proposed that light microscopy remains an important part of training and practice in the diagnosis of parasitic diseases and that efforts should be made to train the next generation of morphological parasitologists before the requisite knowledge, skills, and capacity for this complex and important mode of diagnosis are lost. In summary, the widespread, progressive loss of morphology expertise for parasite identification negatively impacts patient care, public health, and epidemiology.
Topics: Animals; Humans; Parasitic Diseases; Parasites; Microscopy; Feces; Bacteria
PubMed: 36314793
DOI: 10.1128/jcm.00986-22 -
Tropical Medicine & International... Dec 2022Ova and parasite (O&P) examination is recommended for the laboratory diagnosis of agents causing parasitic infections; however, this exam requires scientific and...
OBJECTIVE
Ova and parasite (O&P) examination is recommended for the laboratory diagnosis of agents causing parasitic infections; however, this exam requires scientific and technological improvements to enhance its diagnostic validity. Dissolved air flotation (DAF) is an efficient technical principle separating suspended solids in a liquid medium. We aimed to develop and validate a new procedure for intestinal parasite detection with DAF.
METHODS
In this study, we collected samples from 500 volunteers, screened them by direct examination, and transferred the material to tubes using the Three Faecal Test (TF-Test) for triplicate DAF tests. We evaluated physical-chemical parameters and DAF prototype components through quantifying parasites recovered from floated and non-floated regions of the flotation column. The DAF operation protocol was validated with the gold standard results.
RESULTS
The 10% saturated volume proportion and cationic surfactant showed regularity and high parasite recovery (80%). Modifications of the needle device did not influence parasite recovery (p > 0.05). Sensitivity, specificity, accuracy and kappa agreement obtained with the DAF protocol were 91%, 100%, 93% and substantial (k = 0.64), respectively.
CONCLUSION
The DAF principle could be used to process faecal samples in routine laboratory exams, enabling intestinal parasite detection.
Topics: Animals; Humans; Parasites; Intestinal Diseases, Parasitic; Feces; Clinical Laboratory Techniques
PubMed: 36261920
DOI: 10.1111/tmi.13827 -
Trends in Ecology & Evolution Aug 2020Infectious disease outbreaks emerged across the globe during the recent 2015-2016 El Niño event, re-igniting research interest in how climate events influence disease... (Review)
Review
Infectious disease outbreaks emerged across the globe during the recent 2015-2016 El Niño event, re-igniting research interest in how climate events influence disease dynamics. While the relationship between long-term warming and the transmission of disease-causing parasites has received substantial attention, we do not yet know how pulse heat events - common phenomena in a warming world - will alter parasite transmission. The effects of pulse warming on ecological and evolutionary processes are complex and context dependent, motivating research to understand how climate oscillations drive host health and disease. Here, we develop a framework for evaluating and predicting the effects of pulse warming on parasitic infection. Specifically, we synthesize how pulse heat stress affects hosts, parasites, and the ecological interactions between them.
Topics: Animals; Climate; Climate Change; Heat-Shock Response; Host-Parasite Interactions; Parasites
PubMed: 32439076
DOI: 10.1016/j.tree.2020.04.002 -
Trends in Parasitology Aug 2020Reptiles are reservoirs of a wide range of pathogens, including many protozoa, helminths, pentastomids, and arthropod parasitic species, some of which may be of public... (Review)
Review
Reptiles are reservoirs of a wide range of pathogens, including many protozoa, helminths, pentastomids, and arthropod parasitic species, some of which may be of public health concern. In this review we discuss the zoonotic risks associated with human-reptile interactions. Increased urbanization and introduction of exotic species of reptile may act as drivers for the transmission of zoonotic parasites through the environment. In addition, being a part of human diet, reptiles can be a source of life-threatening parasitoses, such as pentastomiasis or sparganosis. Finally, reptiles kept as pets may represent a risk to owners given the possibility of parasites transmitted by direct contact or fecal contamination. Awareness of reptile-borne zoonotic parasitoses is important to advocate control, prevention, and surveillance of these neglected diseases.
Topics: Animals; Food Parasitology; Humans; Parasites; Parasitic Diseases; Pets; Reptiles; Zoonoses
PubMed: 32448703
DOI: 10.1016/j.pt.2020.04.014 -
Annual Review of Marine Science Jan 2021Climate change affects ecological processes and interactions, including parasitism. Because parasites are natural components of ecological systems, as well as agents of... (Review)
Review
Climate change affects ecological processes and interactions, including parasitism. Because parasites are natural components of ecological systems, as well as agents of outbreak and disease-induced mortality, it is important to summarize current knowledge of the sensitivity of parasites to climate and identify how to better predict their responses to it. This need is particularly great in marine systems, where the responses of parasites to climate variables are less well studied than those in other biomes. As examples of climate's influence on parasitism increase, they enable generalizations of expected responses as well as insight into useful study approaches, such as thermal performance curves that compare the vital rates of hosts and parasites when exposed to several temperatures across a gradient. For parasites not killed by rising temperatures, some simple physiological rules, including the tendency of temperature to increase the metabolism of ectotherms and increase oxygen stress on hosts, suggest that parasites' intensity and pathologies might increase. In addition to temperature, climate-induced changes in dissolved oxygen, ocean acidity, salinity, and host and parasite distributions also affect parasitism and disease, but these factors are much less studied. Finally, because parasites are constituents of ecological communities, we must consider indirect and secondary effects stemming from climate-induced changes in host-parasite interactions, which may not be evident if these interactions are studied in isolation.
Topics: Animals; Aquatic Organisms; Climate Change; Ecosystem; Host-Parasite Interactions; Parasites; Parasitic Diseases; Temperature
PubMed: 32520636
DOI: 10.1146/annurev-marine-031920-100429 -
Parasite (Paris, France) 2022Helminth parasitoses are among the most prevalent health issues worldwide. Their control depends largely on unravelling host-parasite interactions, including parasitic... (Review)
Review
Helminth parasitoses are among the most prevalent health issues worldwide. Their control depends largely on unravelling host-parasite interactions, including parasitic exploitation of the host haemostatic system. The present study undertakes a scoping review of the research carried out in this field with the aim of unifying and updating concepts. Multiple keywords combined with Boolean operators were employed to design the literature search strategy. Two online databases were used to identify original peer-reviewed articles written in English and published before 1st January 2020 describing molecular interactions between helminth parasites and the host haemostatic system. Relevant data from the selected sources of evidence were extracted and analysed. Ninety-six publications reporting 259 interactions were selected. Fifty-three proteins belonging to 32 species of helminth parasites were involved in interactions with components of the host haemostatic system. Many of these proteins from both parasite and host were conserved among the different interactions identified. Most of these interactions were related to the inhibition of the coagulation system and the activation of fibrinolysis. This was associated mainly with a potential of parasites to reduce the formation of blood clots in the host and attributed to biological processes, such as parasite nutrition, survival, invasion, evasion and migration or the appearance of pathological mechanisms in the host. A wide range of helminth parasites have developed similar strategies to exploit the haemostatic system of their hosts, which could be regarded as an evolutionary conserved mechanism that could confer benefits to parasites in terms of survival and establishment in their vertebrate hosts.
Topics: Animals; Helminths; Hemostatics; Host-Parasite Interactions; Parasites; Vertebrates
PubMed: 35833785
DOI: 10.1051/parasite/2022034 -
Journal of Helminthology Jan 2024Acanthocephalans constitute a small taxonomic group related to rotifers and specialized in a parasitic lifestyle. Anurans act as paratenic and definitive hosts and... (Review)
Review
Acanthocephalans constitute a small taxonomic group related to rotifers and specialized in a parasitic lifestyle. Anurans act as paratenic and definitive hosts and infections always occur trophically. Our objective is to describe and summarize the richness of acanthocephalans in Neotropical anurans. We conducted a literature review in the main research databases, compiling data published until August 2021. We identified 66 articles with records of acanthocephalan-anuran association, 53.03% were carried out in Brazil. We detected 108 species of anurans from 11 families parasitized by acanthocephalans. With the exception of Bufonidae, Hylidae and Leptodactylidae, which are relatively well-studied families, interaction with acanthocephalans remains largely unexplored for most anuran species. We found six families of acanthocephalans: Centrorhynchidae, Echinorhynchidae, Oligacanthorhynchidae, Cavisomidae, Neoechinorhynchidae and Plagiorhynchidae. Centrorhynchidae and Echinorhynchidae presented the largest number of taxa associated with anurans. The largest number of records corresponded to acanthocephalans in the larval stage (cystacanths), for which anurans act as paratenic hosts. We observed a lack of specific taxonomic resolution in the identifications of most reports, because a large part of the records in the larval stage make morphological identification difficult. Brazil, Mexico, Paraguay, Argentina, Ecuador and Peru are the countries with the most records, while Costa Rica, Venezuela, Colombia, Chile and Uruguay exhibited the lowest publication numbers, resulting in gaps in the distribution of acanthocephalans. We expanded the known number of anuran species parasitized by acanthocephalans, compared to the last published review. Overall, we aim to contribute to the understanding of diversity within this intriguing but understudied group.
Topics: Animals; Acanthocephala; Parasites; Anura; Bufonidae; Argentina; Larva
PubMed: 38263742
DOI: 10.1017/S0022149X23000986