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Parasitology Research Mar 2022The use of fertilizers based on sewage sludge is common practice. Due to the possible presence of pathogens and eggs of intestinal parasites like Ascaris sp., Toxocara...
The use of fertilizers based on sewage sludge is common practice. Due to the possible presence of pathogens and eggs of intestinal parasites like Ascaris sp., Toxocara sp., and Trichuris sp. in these products, it is necessary to control them. The aim of the study was to determine the presence of parasite eggs in commercial organic fertilizers available on the market. Selected commercial products were tested using the Quinn flotation method and a method dedicated to the study of dewatered sewage sludge. Assessment of the viability of helminth eggs was carried out on the basis of staining with calcein and propidium iodide. In 57% of the tested samples, the presence of live eggs of the abovementioned parasites was detected, and in 21% of samples, the eggs with live larvae were detected. Eggs of Trichuris sp. (50%) and Ascaris sp. (36%) were the most common. The obtained results clearly indicate that the process of hygienization of the sewage sludge before the production of fertilizers was not effective enough and it is necessary to standardize the prophylaxis against the spread of parasitic nematodes in commercially available products.
Topics: Animals; Ascaris; Fertilizers; Parasites; Sewage; Toxocara; Trichuris
PubMed: 35118511
DOI: 10.1007/s00436-022-07451-5 -
Parasitology Research Apr 2021The mechanistic (or mammalian) target of rapamycin (mTOR) is considered as a critical regulatory enzyme involved in essential signaling pathways affecting cell growth,... (Review)
Review
The mechanistic (or mammalian) target of rapamycin (mTOR) is considered as a critical regulatory enzyme involved in essential signaling pathways affecting cell growth, cell proliferation, protein translation, regulation of cellular metabolism, and cytoskeletal structure. Also, mTOR signaling has crucial roles in cell homeostasis via processes such as autophagy. Autophagy prevents many pathogen infections and is involved on immunosurveillance and pathogenesis. Immune responses and autophagy are therefore key host responses and both are linked by complex mTOR regulatory mechanisms. In recent years, the mTOR pathway has been highlighted in different diseases such as diabetes, cancer, and infectious and parasitic diseases including leishmaniasis, toxoplasmosis, and malaria. The current review underlines the implications of mTOR signals and intricate networks on pathogen infections and the modulation of this master regulator by parasites. Parasitic infections are able to induce dynamic metabolic reprogramming leading to mTOR alterations in spite of many other ways impacting this regulatory network. Accordingly, the identification of parasite effects and interactions over such a complex modulation might reveal novel information regarding the biology of the abovementioned parasites and might allow the development of therapeutic strategies against parasitic diseases. In this sense, the effects of inhibiting the mTOR pathways are also considered in this context in the light of their potential for the prevention and treatment of parasitic diseases.
Topics: Animals; Autophagy; Cell Cycle; Cell Proliferation; Humans; Immunity; Leishmaniasis; Malaria; Parasites; Parasitic Diseases; Phosphorylation; Protein Biosynthesis; Signal Transduction; Sirolimus; TOR Serine-Threonine Kinases; Toxoplasmosis
PubMed: 33534053
DOI: 10.1007/s00436-021-07070-6 -
Parasites & Vectors Apr 2023The use of polymerase chain reaction (PCR)-based diagnostic approaches has steadily increased in the field of parasitology in recent decades. The most recent large-scale... (Review)
Review
The use of polymerase chain reaction (PCR)-based diagnostic approaches has steadily increased in the field of parasitology in recent decades. The most recent large-scale technological modification of the PCR formula, also known as third-generation PCR, came in the form of digital PCR (dPCR). Currently, the most common form of dPCR on the market is digital droplet PCR (ddPCR). Unlike quantitative real-time PCR (qPCR), the digital format allows for highly sensitive, absolute quantification of nucleic acid targets and does not require external standards to be included in the developed assays. Dividing each sample into thousands of compartments and using statistical models also eliminates the need for technical replicates. With unprecedented sensitivity and enforcement of binary endpoint reactions, ddPCR not only allows the use of tiny sample volumes (especially important when working with limited amounts of DNA) but also minimises the impact of variations in amplification efficiency and the presence of inhibitors. As ddPCR is characterised by excellent features such as high throughput, sensitivity and robust quantification, it is widely used as a diagnostic tool in clinical microbiology. Due to recent advances, both the theoretical background and the practical, current applications related to the quantification of nucleic acids of eukaryotic parasites need to be updated. In this review, we present the basics of this technology (particularly useful for new users) and consolidate recent advances in the field with a focus on applications to the study of helminths and protozoan parasites.
Topics: Animals; Parasites; Real-Time Polymerase Chain Reaction; DNA; Phenotype
PubMed: 37098569
DOI: 10.1186/s13071-023-05756-7 -
PloS One 2023Associations between genetic variants and susceptibility to infections have long been studied in free-living hosts so as to infer the contemporary evolutionary forces...
Associations between genetic variants and susceptibility to infections have long been studied in free-living hosts so as to infer the contemporary evolutionary forces that shape the genetic polymorphisms of immunity genes. Despite extensive studies of proteins interacting with pathogen-derived ligands, such as MHC (major histocompatilbility complex) or TLR (Toll-like receptors), little is known about the efferent arm of the immune system. Cytokines are signalling molecules that trigger and modulate the immune response, acting as a crucial link between innate and adaptive immunity. In the present study we investigated how genetic variation in cytokines in bank voles Myodes glareolus affects their susceptibility to infection by parasites (nematodes: Aspiculuris tianjensis, Heligmosomum mixtum, Heligmosomoides glareoli) and microparasites (Cryptosporidium sp, Babesia microti, Bartonella sp.). We focused on three cytokines: tumour necrosis factor (TNF), lymphotoxin alpha (LTα), and interferon beta (IFNβ1). Overall, we identified four single nucleotide polymorphisms (SNPs) associated with susceptibility to nematodes: two located in LTα and two in IFNβ1. One of those variants was synonymous, another located in an intron. Each SNP associated with parasite load was located in or next to a codon under selection, three codons displayed signatures of positive selection, and one of purifying selection. Our results indicate that cytokines are prone to parasite-driven selection and that non-coding variants, although commonly disregarded in studies of the genetic background of host-parasite co-evolution, may play a role in susceptibility to infections in wild systems.
Topics: Animals; Parasites; Cytokines; Cryptosporidiosis; Cryptosporidium; Polymorphism, Genetic; Nematoda
PubMed: 36693052
DOI: 10.1371/journal.pone.0258009 -
Virology Journal Sep 2020Infections caused by protozoan parasites burden the world with huge costs in terms of human and animal health. Most parasitic diseases caused by protozoans are... (Review)
Review
Infections caused by protozoan parasites burden the world with huge costs in terms of human and animal health. Most parasitic diseases caused by protozoans are neglected, particularly those associated with poverty and tropical countries, but the paucity of drug treatments and vaccines combined with increasing problems of drug resistance are becoming major concerns for their control and eradication. In this climate, the discovery/repurposing of new drugs and increasing effort in vaccine development should be supplemented with an exploration of new alternative/synergic treatment strategies. Viruses, either native or engineered, have been employed successfully as highly effective and selective therapeutic approaches to treat cancer (oncolytic viruses) and antibiotic-resistant bacterial diseases (phage therapy). Increasing evidence is accumulating that many protozoan, but also helminth, parasites harbour a range of different classes of viruses that are mostly absent from humans. Although some of these viruses appear to have no effect on their parasite hosts, others either have a clear direct negative impact on the parasite or may, in fact, contribute to the virulence of parasites for humans. This review will focus mainly on the viruses identified in protozoan parasites that are of medical importance. Inspired and informed by the experience gained from the application of oncolytic virus- and phage-therapy, rationally-driven strategies to employ these viruses successfully against parasitic diseases will be presented and discussed in the light of the current knowledge of the virus biology and the complex interplay between the viruses, the parasite hosts and the human host. We also highlight knowledge gaps that should be addressed to advance the potential of virotherapy against parasitic diseases.
Topics: Animals; Host-Parasite Interactions; Humans; Oncolytic Virotherapy; Parasites; Parasitic Diseases; Phage Therapy
PubMed: 32993724
DOI: 10.1186/s12985-020-01410-1 -
Cell Chemical Biology May 2023Artemisinins (ART) are critical anti-malarials and despite their use in combination therapy, ART-resistant Plasmodium falciparum is spreading globally. To counter ART...
Artemisinins (ART) are critical anti-malarials and despite their use in combination therapy, ART-resistant Plasmodium falciparum is spreading globally. To counter ART resistance, we designed artezomibs (ATZs), molecules that link an ART with a proteasome inhibitor (PI) via a non-labile amide bond and hijack parasite's own ubiquitin-proteasome system to create novel anti-malarials in situ. Upon activation of the ART moiety, ATZs covalently attach to and damage multiple parasite proteins, marking them for proteasomal degradation. When damaged proteins enter the proteasome, their attached PIs inhibit protease function, potentiating the parasiticidal action of ART and overcoming ART resistance. Binding of the PI moiety to the proteasome active site is enhanced by distal interactions of the extended attached peptides, providing a mechanism to overcome PI resistance. ATZs have an extra mode of action beyond that of each component, thereby overcoming resistance to both components, while avoiding transient monotherapy seen when individual agents have disparate pharmacokinetic profiles.
Topics: Animals; Antimalarials; Proteasome Endopeptidase Complex; Parasites; Pharmacophore; Ubiquitin; Plasmodium; Artemisinins; Drug Resistance
PubMed: 37148884
DOI: 10.1016/j.chembiol.2023.04.006 -
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 -
Temporal dynamics of freshwater planktonic parasites inferred using a DNA metabarcoding time-series.Parasitology Nov 2021Parasites are important components of biodiversity and contributors to ecosystem functioning, but are often neglected in ecological studies. Most studies examine model...
Parasites are important components of biodiversity and contributors to ecosystem functioning, but are often neglected in ecological studies. Most studies examine model parasite systems or single taxa, thus our understanding of community composition is lacking. Here, the seasonal and annual dynamics of parasites was quantified using a 5-year metabarcoding time-series of freshwater plankton, collected weekly. We first identified parasites in the dataset using literature searches of the taxonomic match and using sequence metadata from the National Center for Biotechnology Information (NCBI) nucleotide database. In total, 441 amplicon sequence variants (belonging to 18 phyla/clades) were classified as parasites. The four phyla/clades with the highest relative read abundance and richness were Chytridiomycota, Dinoflagellata, Oomycota and Perkinsozoa. Relative read abundance of total parasite taxa, Dinoflagellata and Perkinsozoa significantly varied with season and was highest in summer. Parasite richness varied significantly with season and year, and was generally lowest in spring. Each season had distinct parasite communities, and the difference between summer and winter communities was most pronounced. Combining DNA metabarcoding with searches of the literature and NCBI metadata allowed us to characterize parasite diversity and community dynamics and revealed the extent to which parasites contribute to the diversity of freshwater plankton communities.
Topics: Animals; Biodiversity; DNA Barcoding, Taxonomic; Ecosystem; Fresh Water; Parasites; Plankton; RNA, Ribosomal, 18S
PubMed: 35060465
DOI: 10.1017/S0031182021001293 -
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