-
Clinical Microbiology Reviews Jan 2002Malaria presents a diagnostic challenge to laboratories in most countries. Endemic malaria, population movements, and travelers all contribute to presenting the... (Review)
Review
Malaria presents a diagnostic challenge to laboratories in most countries. Endemic malaria, population movements, and travelers all contribute to presenting the laboratory with diagnostic problems for which it may have little expertise available. Drug resistance and genetic variation has altered many accepted morphological appearances of malaria species, and new technology has given an opportunity to review available procedures. Concurrently the World Health Organization has opened a dialogue with scientists, clinicians, and manufacturers on the realistic possibilities for developing accurate, sensitive, and cost-effective rapid diagnostic tests for malaria, capable of detecting 100 parasites/microl from all species and with a semiquantitative measurement for monitoring successful drug treatment. New technology has to be compared with an accepted "gold standard" that makes comparisons of sensitivity and specificity between different methods. The majority of malaria is found in countries where cost-effectiveness is an important factor and ease of performance and training is a major consideration. Most new technology for malaria diagnosis incorporates immunochromatographic capture procedures, with conjugated monoclonal antibodies providing the indicator of infection. Preferred targeted antigens are those which are abundant in all asexual and sexual stages of the parasite and are currently centered on detection of HRP-2 from Plasmodium falciparum and parasite-specific lactate dehydrogenase or Plasmodium aldolase from the parasite glycolytic pathway found in all species. Clinical studies allow effective comparisons between different formats, and the reality of nonmicroscopic diagnoses of malaria is considered.
Topics: Animals; Antigens, Protozoan; Humans; Malaria; Microscopy, Fluorescence; Parasitemia; Parasitology; Plasmodium; Polymerase Chain Reaction; Reagent Kits, Diagnostic; Serologic Tests; Time Factors
PubMed: 11781267
DOI: 10.1128/CMR.15.1.66-78.2002 -
ELife Jul 2023Mermithid nematodes are obligate invertebrate parasites dating back to the Early Cretaceous. Their fossil record is sparse, especially before the Cenozoic, thus little...
Mermithid nematodes are obligate invertebrate parasites dating back to the Early Cretaceous. Their fossil record is sparse, especially before the Cenozoic, thus little is known about their early host associations. This study reports 16 new mermithids associated with their insect hosts from mid-Cretaceous Kachin amber, 12 of which include previously unknown hosts. These fossils indicate that mermithid parasitism of invertebrates was already widespread and played an important role in the mid-Cretaceous terrestrial ecosystem. Remarkably, three hosts (bristletails, barklice, and perforissid planthoppers) were previously unknown to be parasitized by mermithids both past and present. Furthermore, our study shows that in contrast to their Cenozoic counterparts, Cretaceous nematodes including mermithids are more abundant in non-holometabolous insects. This result suggests that nematodes had not completely exploited the dominant Holometabola as their hosts until the Cenozoic. This study reveals what appears to be a vanished history of nematodes that parasitized Cretaceous insects.
Topics: Animals; Mermithoidea; Ecosystem; Nematoda; Insecta; Parasites; Fossils; Amber
PubMed: 37449724
DOI: 10.7554/eLife.86283 -
Parasitology Jan 2022Although it is generally known that a combination of abiotic and biotic drivers shapes the distribution and abundance of parasites, our understanding of the interplay of...
Although it is generally known that a combination of abiotic and biotic drivers shapes the distribution and abundance of parasites, our understanding of the interplay of these factors remains to be assessed for most marine host species. The present field survey investigated spatial patterns of richness, prevalence and abundance of parasites in Mytilus galloprovincialis along the coast of the northern Adriatic Sea. Herein, the relationships between biotic (host size, density and local parasite richness of mussel population) and abiotic (eutrophication and salinity) drivers and parasite richness of mussel individuals, prevalence and abundance were analysed. Local parasite richness was the most relevant factor driving parasite species richness in mussel individuals. Prevalence was mainly driven by eutrophication levels in three out of four parasite species analysed. Similarly, abundance was driven mainly by eutrophication in two parasite species. Mussel size, density and salinity had only minor contributions to the best fitting models. This study highlights that the influence of abiotic and biotic drivers on parasite infections in mussels can be differentially conveyed, depending on the infection measure applied, i.e. parasite richness, prevalence or abundance. Furthermore, it stresses the importance of eutrophication as a major factor influencing parasite prevalence and abundance in mussels in the Adriatic Sea.
Topics: Animals; Humans; Mytilus; Parasites; Parasitic Diseases; Prevalence; Salinity
PubMed: 34380583
DOI: 10.1017/S0031182021001438 -
Clinical Microbiology Reviews Jul 2017In the last 2 decades, renewed attention to neglected tropical diseases (NTDs) has spurred the development of antiparasitic agents, especially in light of emerging drug... (Review)
Review
In the last 2 decades, renewed attention to neglected tropical diseases (NTDs) has spurred the development of antiparasitic agents, especially in light of emerging drug resistance. The need for new drugs has required screening methods using parasite culture. Furthermore, clinical laboratories sought to correlate susceptibility methods with treatment outcomes, most notably with malaria. Parasites with their various life cycles present greater complexity than bacteria, for which standardized susceptibility methods exist. This review catalogs the state-of-the-art methodologies used to evaluate the effects of drugs on key human parasites from the point of view of drug discovery as well as the need for laboratory methods that correlate with clinical outcomes.
Topics: Animals; Antiparasitic Agents; Drug Discovery; Humans; Neglected Diseases; Parasites
PubMed: 28446445
DOI: 10.1128/CMR.00111-16 -
PLoS Neglected Tropical Diseases May 2022Insect-vectored Leishmania are responsible for loss of more disability-adjusted life years than any parasite besides malaria. Elucidation of the environmental factors... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Insect-vectored Leishmania are responsible for loss of more disability-adjusted life years than any parasite besides malaria. Elucidation of the environmental factors that affect parasite transmission by vectors is essential to develop sustainable methods of parasite control that do not have off-target effects on beneficial insects or environmental health. Many phytochemicals that inhibit growth of sand fly-vectored Leishmania-which have been exhaustively studied in the search for phytochemical-based drugs-are abundant in nectars, which provide sugar-based meals to infected sand flies.
PRINCIPLE FINDINGS
In a quantitative meta-analysis, we compare inhibitory phytochemical concentrations for Leishmania to concentrations present in floral nectar and pollen. We show that nectar concentrations of several flowering plant species exceed those that inhibit growth of Leishmania cell cultures, suggesting an unexplored, landscape ecology-based approach to reduce Leishmania transmission.
SIGNIFICANCE
If nectar compounds are as effective against parasites in the sand fly gut as predicted from experiments in vitro, strategic planting of antiparasitic phytochemical-rich floral resources or phytochemically enriched baits could reduce Leishmania loads in vectors. Such interventions could provide an environmentally friendly complement to existing means of disease control.
Topics: Animals; Insect Vectors; Leishmania; Parasites; Phlebotomus; Phytochemicals; Plant Nectar; Psychodidae
PubMed: 35551517
DOI: 10.1371/journal.pntd.0010373 -
Biochimica Et Biophysica Acta. General... Jan 2017Resistance against antibiotics is unfortunately still a major biomedical challenge for a wide range of pathogens responsible for potentially fatal diseases. (Review)
Review
BACKGROUND
Resistance against antibiotics is unfortunately still a major biomedical challenge for a wide range of pathogens responsible for potentially fatal diseases.
SCOPE OF REVIEW
In this study, we aim at providing a critical assessment of the recent advances in design and use of drugs targeting genome integrity by perturbation of thymidylate biosynthesis.
MAJOR CONCLUSION
We find that research efforts from several independent laboratories resulted in chemically highly distinct classes of inhibitors of key enzymes within the routes of thymidylate biosynthesis. The present article covers numerous studies describing perturbation of this metabolic pathway in some of the most challenging pathogens like Mycobacterium tuberculosis, Plasmodium falciparum, and Staphylococcus aureus.
GENERAL SIGNIFICANCE
Our comparative analysis allows a thorough summary of the current approaches to target thymidylate biosynthesis enzymes and also include an outlook suggesting novel ways of inhibitory strategies. This article is part of a Special Issue entitled "Science for Life" Guest Editor: Dr. Austen Angell, Dr. Salvatore Magazù and Dr. Federica Migliardo.
Topics: Animals; Bacteria; Enzyme Inhibitors; Genomic Instability; Parasites; Viruses
PubMed: 27217086
DOI: 10.1016/j.bbagen.2016.05.024 -
PLoS Pathogens Nov 2023Signalling pathways in malaria parasite remain poorly defined and major reason for this is the lack of understanding of the function of majority of parasite protein...
Signalling pathways in malaria parasite remain poorly defined and major reason for this is the lack of understanding of the function of majority of parasite protein kinases and phosphatases in parasite signalling and its biology. In the present study, we have elucidated the function of Protein Kinase 2 (PfPK2), which is known to be indispensable for the survival of human malaria parasite Plasmodium falciparum. We demonstrate that it is involved in the invasion of host erythrocytes, which is critical for establishing infection. In addition, PfPK2 may also be involved in the maturation of the parasite post-invasion. PfPK2 regulates the release of microneme proteins like Apical Membrane Antigen 1 (AMA1), which facilitates the formation of Tight Junction between the merozoite and host erythrocyte- a key step in the process of invasion. Comparative phosphoproteomics studies revealed that PfPK2 may be involved in regulation of several key proteins involved in invasion and signalling. Furthermore, PfPK2 regulates the generation of cGMP and the release of calcium in the parasite, which are key second messengers for the process of invasion. These and other studies have shed light on a novel signalling pathway in which PfPK2 acts as an upstream regulator of important cGMP-calcium signalling, which plays an important role in parasite invasion.
Topics: Animals; Humans; Protein Kinases; Protozoan Proteins; Parasites; Calcium; Plasmodium falciparum; Erythrocytes
PubMed: 37988347
DOI: 10.1371/journal.ppat.1011770 -
Parasitology Dec 2022Interest in local environmental conditions and the occurrence and behaviour of parasites has increased over the last 3 decades, leading to the discipline of... (Review)
Review
Interest in local environmental conditions and the occurrence and behaviour of parasites has increased over the last 3 decades, leading to the discipline of Environmental Parasitology. The aim of this discipline is to investigate how anthropogenically altered environmental factors influence the occurrence of parasites and how the combined effects of pollutants and parasites affect the health of their hosts. Accordingly, in this paper, we provide an overview of the direct and indirect effects of pollutants on the occurrence and distribution of fish parasites. However, based on current knowledge, it is difficult to draw general conclusions about these interdependencies, as the effects of pollutants on free-living (larval) parasite stages, as well as their effects on ectoparasites, depend on the pollutant–host–parasite combination as well as on other environmental factors that can modulate the harmful effects of pollutants. Furthermore, the question of the combined effects of the simultaneous occurrence of parasites and pollutants on the physiology and health of the fish hosts is of interest. For this purpose, we differentiate between the dominance effects of individual stressors over other, additive or synergistically reinforcing effects as well as combined antagonistic effects. For the latter, there are only very few studies, most of which were also carried out on invertebrates, so that this field of research presents itself as very promising for future investigations.
Topics: Animals; Parasites; Fishes; Environmental Pollutants; Fish Diseases; Host-Parasite Interactions
PubMed: 35993340
DOI: 10.1017/S0031182022001172 -
Diseases of Aquatic Organisms Oct 2019Amphipods are commonly used test organisms in ecotoxicological studies. Nevertheless, their naturally occurring parasites have mostly been neglected in these... (Review)
Review
Amphipods are commonly used test organisms in ecotoxicological studies. Nevertheless, their naturally occurring parasites have mostly been neglected in these investigations, even though several groups of parasites can have a multitude of effects, e.g. on host survival, physiology, or behavior. In the present review, we summarize the knowledge on the effects of Microsporidia and Acanthocephala, 2 common and abundant groups of parasites in amphipods, on the outcome of ecotoxicological studies. Parasites can have significant effects on toxicological endpoints (e.g. mortality, biochemical markers) that are unexpected in some cases (e.g. down-regulation of heat shock protein 70 response in infected individuals). Therefore, parasites can bias the interpretation of results, for example if populations with different parasite profiles are compared, or if toxicological effects are masked by parasite effects. With the present review, we would like to encourage ecotoxicologists to consider parasites as an additional factor if field-collected test organisms are analyzed for biomarkers. Additionally, we suggest intensification of research activities on the effects of parasites in amphipods in connection with other stressors to disentangle parasite and pollution effects and to improve our understanding of parasite effects in this host taxon.
Topics: Acanthocephala; Amphipoda; Animals; Host-Parasite Interactions; Microsporidia; Parasites
PubMed: 31575839
DOI: 10.3354/dao03355 -
Journal of Clinical Microbiology Oct 2021Acanthocephala is a phylum of parasitic pseudocoelomates that infect a wide range of vertebrate and invertebrate hosts and can cause zoonotic infections in humans. The... (Review)
Review
Acanthocephala is a phylum of parasitic pseudocoelomates that infect a wide range of vertebrate and invertebrate hosts and can cause zoonotic infections in humans. The zoologic literature is quite rich and diverse; however, the human-centric literature is sparse, with sporadic reports over the past 70 years. Causal agents of acanthocephaliasis in humans are reviewed as well as their biology and life cycle. This review provides the first consolidated and summarized report of human cases of acanthocephaliasis based on English language publications, including epidemiology, clinical presentation, treatment, and diagnosis and identification.
Topics: Acanthocephala; Animals; Helminthiasis; Host-Parasite Interactions; Humans; Intestinal Diseases, Parasitic; Parasites
PubMed: 34076470
DOI: 10.1128/JCM.02691-20