Parasitic contamination in vegetables for human consumption: a systematic review and meta-analysis.

The study conducted a review of the parasitological profile of vegetables from 2001 to 2021, considering the type, consumption, and cultivation, globally. The databases searched included MEDLINE, SciELO, Web of Science, Science Direct, and Scopus using the terms "Detection OR Prevalence OR Incidence OR occurrence OR contamination AND vegetable OR fruit AND Helminth OR egg OR Parasite OR cysts OR protozoa". A total of 16,600 articles were found, 117 of which were reviewed. Of the 391,291 samples, 3.85% (15,095) were contaminated by parasites. Among those positive, 30.10% (4,543/15,095) contained enteroparasites commonly of human origin and 58.78% (8,873/15,095) came from markets. Few articles mentioned the cultivation type, but among those, conventional cultivation showed more contamination (42.34%; 224/529). Herbaceous vegetables were the most contaminated (56.84%; 8,580/15,095. Ascaris lumbricoides was found in 10.16% (1,535/15,095) of the samples. Lettuce was the most contaminated (20.43%; 3,084/15,095).

First record of metazoan parasites of hybrids between the genera Colossoma and Piaractus in natural environments.

The practice of hybridization is carried out globally in fish farms. Here, we present the first record of the parasitic fauna of hybrids among genus Colossoma and Piaractus in natural environments. We identified a total of 48 hybrids, nine F1 hybrids (nuclear DNA from both species present in the cross) and 38 advanced hybrids (nuclear DNA from one species), both from crosses between Piaractus brachypomus and Piaractus mesopotamicus, and one F1 "tambacu" corresponding to cross between Colossoma macropomum and Piaractus mesopotamicus. This is the first record of Anacanthorus penilabiatus, Anacanthorus toledoensis, Mymarothecium viatorum, Mymarothecium ianwhittington, Haementeria sp., Dadaytrema oxycephala, Rondonia rondoni, and Echinorhynchus gomesi parasitizing hybrids collected in a natural environment. With this, we expand knowledge about the diversity of fish and parasites in the upper Paraná River and warn about the risk that fish escapes can cause in the basin.

Metazoan endoparasites of snakes from Argentina: Review and checklist with distributional notes and remarks.

This article presents a checklist of metazoan parasites of snakes from Argentina, along with a comprehensive review of the relevant literature published between 1922 and June 2023, covering various aspects of interest. We compiled 34 species of metazoan endoparasites from 28 studies. The subclass Digenea showed the highest number of species (n = 22 species), followed by the phylum Nematoda (n = 8 species), and the subclass Pentastomida (n = 3 species and 1 taxa inquirenda). Dipsadidae was the family of snakes with the most species examined for metazoan endoparasites (n = 20 species). In contrast, Viperidae had the largest number of specimens surveyed (n = 343). Of 23 provinces, 15 (65.2%) presented at least one report of metazoan endoparasites in snakes. The northeastern provinces showed the highest richness of metazoan endoparasites and host diversity. Many articles focused on taxonomy, but studies on parasite ecology were not found. Although taxonomic accuracy was high in most reports, some records were correctly deposited in zoological collections or geo-referenced. This is the first attempt to include all groups of metazoan endoparasites of snakes from Argentina in a single checklist in the last century.

Fish ectoparasite detection, collection and curation.

Fish parasitology is a dynamic and internationally important discipline with numerous biological, ecological and practical applications. We reviewed optimal fish and parasite sampling methods for key ectoparasite phyla (i.e. Ciliophora, Platyhelminthes, Annelida and Arthropoda) as well as recent advances in molecular detection of ectoparasites in aquatic environments. Ideally, fish capture and anaesthesia as well as parasite recovery methods should be validated to eliminate potential sampling bias and inaccuracy in determining ectoparasite population parameters. There are considerable advantages to working with fresh samples and live parasites, when combined with appropriate fixation methods, as sampling using dead or decaying materials can lead to rapid decomposition of soft-bodied parasites and subsequent challenges for identification. Sampling methods differ between target phyla, and sometimes genera, with optimum techniques largely associated with identification of parasite microhabitat and the method of attachment. International advances in fish parasitology can be achieved through the accession of whole specimens and/or molecular voucher specimens (i.e. hologenophores) in curated collections for further study. This approach is now critical for data quality because of the increased application of environmental DNA (eDNA) for the detection and surveillance of parasites in aquatic environments where the whole organism may be unavailable. Optimal fish parasite sampling methods are emphasised to aid repeatability and reliability of parasitological studies that require accurate biodiversity and impact assessments, as well as precise surveillance and diagnostics.

Parasitic Contamination of Soil in the Southern United States.

Parasites are generally associated with lower income countries in tropical and subtropical areas. Still, they are also prevalent in low-income communities in the southern United States. Studies characterizing the epidemiology of parasites in the United States are limited, resulting in little comprehensive understanding of the problem. This study investigated the environmental contamination of parasites in the southern United States by determining each parasite's contamination rate and burden in five low-income communities. A total of 499 soil samples of approximately 50 g were collected from public parks and private residences in Alabama, Louisiana, Mississippi, South Carolina, and Texas. A technique using parasite floatation, filtration, and bead-beating was applied to dirt samples to concentrate and extract parasite DNA from samples and detected via multiparallel quantitative polymerase chain reaction (qPCR). qPCR detected total sample contamination of Blastocystis spp. (19.03%), Toxocara cati (6.01%), Toxocara canis (3.61%), Strongyloides stercoralis (2.00%), Trichuris trichiura (1.80%), Ancylostoma duodenale (1.42%), Giardia intestinalis (1.40%), Cryptosporidium spp. (1.01%), Entamoeba histolytica (0.20%), and Necator americanus (0.20%). The remaining samples had no parasitic contamination. Overall parasite contamination rates varied significantly between communities: western Mississippi (46.88%), southwestern Alabama (39.62%), northeastern Louisiana (27.93%), southwestern South Carolina (27.93%), and south Texas (6.93%) (P <0.0001). T. cati DNA burdens were more significant in communities with higher poverty rates, including northeastern Louisiana (50.57%) and western Mississippi (49.60%) compared with southwestern Alabama (30.05%) and southwestern South Carolina (25.01%) (P = 0.0011). This study demonstrates the environmental contamination of parasites and their relationship with high poverty rates in communities in the southern United States.

Spatial invasion of cooperative parasites.

In this paper we study invasion probabilities and invasion times of cooperative parasites spreading in spatially structured host populations. The spatial structure of the host population is given by a random geometric graph on [0,1]n, n∈N, with a Poisson(N)-distributed number of vertices and in which vertices are connected over an edge when they have a distance of at most rN with rN of order N(ß-1)/n for some 0<ß<1. At a host infection many parasites are generated and parasites move along edges to neighbouring hosts. We assume that parasites have to cooperate to infect hosts, in the sense that at least two parasites need to attack a host simultaneously. We find lower and upper bounds on the invasion probability of the parasites in terms of survival probabilities of branching processes with cooperation. Furthermore, we characterize the asymptotic invasion time. An important ingredient of the proofs is a comparison with infection dynamics of cooperative parasites in host populations structured according to a complete graph, i.e. in well-mixed host populations. For these infection processes we can show that invasion probabilities are asymptotically equal to survival probabilities of branching processes with cooperation. Furthermore, we build on proof techniques developed in Brouard and Pokalyuk (2022), where an analogous invasion process has been studied for host populations structured according to a configuration model. We substantiate our results with simulations.

Can Parasites be Useful?

Parasites are commonly associated with harm, but they also have beneficial aspects that are still being discovered. It is important to acknowledge both the harmful and beneficial aspects of parasites. They have been found to have positive effects on non-healing wounds, surgical wounds, obesity, glucose metabolism disorders, nerve repair, cancer treatments, and fertility. Research has shown that helminths, protozoa, and arthropods have the ability to correct, prevent, and cure certain disorders through the use of the parasite itself, its molecules, or even its eggs. This article includes studies on the beneficial aspects of parasites. However, further research is needed to fully understand the mechanisms by which parasites stimulate or affect the immune system and how they can be used therapeutically.

Mining parasites for their potential as novel therapeutic agents against cancer.

Despite recent advances in the management and therapeutic of cancer, the treatment of the disease is limited by its high cost and severe side effects. In this scenario, there is an unmet need to identify novel treatment alternatives for this dreaded disease. Recently there is growing evidence that parasites may cause anticancer effects because of a negative correlation between parasitic infections and tumour growth despite some parasites that are known to exhibit pro-carcinogenic effects. It has been observed that parasites exert an anticancer effect either by activating the host's immune response or by secreting certain molecules that exhibit anticancer potential. The activation of the immune response by these parasitic organisms results in the inhibition of some of the hallmarks of cancer such as tumour proliferation, angiogenesis, and metastasis. This review summarizes the current advances as well as the mechanisms underlying the possible implications of this diverse group of organisms as anticancer agents.

Unveiling risks in healthy food: Vegetables and fruits are linked to the distribution chain of protozoan parasites.

Vegetable and fruit contamination is recognized as a significant parasite transmission route. This review presents the current state of vegetables ad fruits contamination with food-borne parasitic protozoa worldwide. We consider the methodologies and strategies for detecting parasitic stages developed in the last decade and the contamination data. Asia had the highest number of reports (94 studies), followed by Africa (74 studies). At the country level, with 41 studies, Iran had the most reports among other countries, followed by Nigeria (28 studies). According to the studies included in the current review, 41.22% of vegetables and fruits were contaminated with different species of protozoan parasites. Among different continents, Asia accounted for the highest contamination rate of protozoan parasites (57.12%). Giardia spp. (10%) had the highest contamination rate in vegetables and fruits, followed by Entamoeba coli (8%), E. histolytica/dispar (7%), and Cryptosporidium spp. (6%). This study provides essential data for health authorities to develop food safety programs. The presence of protozoan parasites in fruits and vegetables highlights the critical need for maintaining rigorous food safety measures across the entire production and distribution process, particularly in countries that are major producers and distributors of these food items.

Temporal change in the parasite community of an invasive fish Trachelyopterus galeatus (Siluriformes: Auchenipteridae) in a neotropical floodplain.

The construction of dams and hydroelectric plants affects biodiversity in aquatic environments and can facilitate the invasion of species. Few studies assess the long-term response of parasite fauna under these events. The aim of this study was to investigate possible changes in the endoparasite composition of the invasive catfish Trachelyopterus galeatus (Linnaeus, 1766) in the floodplain of the upper Paraná River over a 27-year study period. A total of 79 fish were collected in period 1 (1993) and 31 in period 2 (2019/2020) at the same sampling points, and the endoparasites were located in the gastrointestinal system using a stereomicroscope. It was found that the development of the fish and the composition of their endoparasitic fauna changed over time. In the second period, the fish presented smaller values for mass (g) and standard length (cm) when compared to period 1. It was found that three species of endoparasites were found per period, but although the richness was the same, the composition differed, and only one digenean (Microrchis oligovitellum Lunaschi, 1987 (Trematoda: Paramphistomidae)) was shared. The Porto Primavera Dam was built upstream of the site between the sampling periods (1999) and caused a number of environmental changes, possibly being the main factor responsible for changes in components of the parasite community. Anthropic modification to an environment can cause loss of diversity and loss of ecological interactions. Through our results, we emphasize the importance of including parasite fauna in studies that assess environmental impacts.

Gastrointestinal parasites of Wolffsohn's viscacha (Chinchillidae: Lagidium wolffsohni), an endemic rodent species from the wild Patagonia.

Parasites are ubiquitous in wildlife populations and have a profound impact on population dynamics. Interest in parasites of wildlife has increased significantly in recent years, particularly in those with relevant conservation status. Patagonia is one of the wildest and remote areas of the world. The Wolffsohn's viscacha lives in a small mountainous area of Patagonia. Until now, little is known about the biology and ecology of this species. The aim of this research was to study the gastrointestinal parasite diversity in this rodent from a coprological survey. A total of 125 fecal samples from 25 colonies were examined. Each sample was rehydrated, homogenized, and analyzed using three parasitological techniques: spontaneous sedimentation, Mini-FLOTAC, and centrifugation-flotation in sucrose-saturated solution, followed by examination under optical microscopy. The samples, eggs, and oocysts of parasites were described, measured, and photographed. All colonies were positive for at least one parasite species. A total of 10 parasitic species were identified: Viscachataenia sp., possibly V. quadrata, Monoecocestus sp., an unidentified anoplocephalid, Heteroxynema sp., possibly H. (Cavioxyura) viscaciae, Helminthoxys sp., possibly H. effilatus, an unidentified strongylid-type egg, Trichuris sp., two morphologies of unidentified coccidians and Eimeria sp. This is the first exhaustive study of gastrointestinal parasites in L. wolffsohni and a large number of eggs and oocysts of parasites were found. Our results highlight the use of noninvasive techniques for the study of parasites of wildlife hosts; as in the case of this rodent with a remote habitat, which makes sampling difficult. The results of our study provide baseline information on gastrointestinal parasite infections in this species.

Parasite prevalence is determined by infection state- and risk-dependent dispersal of the host.

The spread of parasites and the emergence of disease are currently threatening global biodiversity and human welfare. To address this threat, we need to better understand those factors that determine parasite persistence and prevalence. It is known that dispersal is central to the spatial dynamics of host-parasite systems. Yet past studies have typically assumed that dispersal is a species-level constant, despite a growing body of empirical evidence that dispersal varies with ecological context, including the risk of infection and aspects of host state such as infection status (parasite-dependent dispersal; PDD). Here, we develop a metapopulation model to understand how different forms of PDD shape the prevalence of a directly transmitted parasite. We show that increasing host dispersal rate can increase, decrease or cause a non-monotonic change in regional parasite prevalence, depending on the type of PDD and characteristics of the host-parasite system (transmission rate, virulence, and dispersal mortality). This result contrasts with previous studies with parasite-independent dispersal which concluded that prevalence increases with host dispersal rate. We argue that accounting for host dispersal responses to parasites is necessary for a complete understanding of host-parasite dynamics and for predicting how parasite prevalence will respond to changes such as human alteration of landscape connectivity. This article is part of the theme issue 'Diversity-dependence of dispersal: interspecific interactions determine spatial dynamics'.

Parasite infection in a cell population: role of the partitioning kernel.

We consider a cell population subject to a parasite infection. Cells divide at a constant rate and, at division, share the parasites they contain between their two daughter cells. The sharing may be asymmetric, and its law may depend on the number of parasites in the mother. Cells die at a rate which may depend on the number of parasites they carry, and are also killed when this number explodes. We study the survival of the cell population as well as the mean number of parasites in the cells, and focus on the role of the parasites partitioning kernel at division.

Modern Strategies for Diagnosis and Treatment of Parasitic Diseases.

Parasites are very widely distributed in the environment and form complex relationships with their hosts, forming host-parasite systems [...].

Glyphosate-environmental variables interaction: How does it affect the parasite Chordodes nobilii?

The worldwide used herbicide Glyphosate can interact with environmental variables, but there is limited information on the influence of environmental stressors on its toxicity. Environmental changes could modify glyphosate effects on non-target organisms, including parasites such as gordiids. The freshwater microscopic larvae of the gordiid Chordodes nobilii are sensitive to several pollutants and environmental variables, but their combined effect has not been evaluated yet. The aim of this study was to evaluate the impact of temperature, pH and exposure time on the toxicity of Glyphosate to C. nobilii larvae. A protocol was followed to evaluate the infectivity of larvae treated with factorial combinations of concentration (0 and 0.067 mg/L), exposure time (24 and 48 h), temperature (18, 23 and 28 °C), and pH (7, 8 and 9). The reference values were 23 °C, pH 8 and 48 h. The interaction effect on the infectivity of gordiid larvae was assessed post-exposure using Aedes aegyptii larvae as host. Results were evaluated using GLMM, which does not require data transformation. The modeling results revealed three highly significant triple interactions. Glyphosate toxicity varied depending on the combination of variables, with a decrease being observed after 24 h-exposure at pH 7 and 23 °C. Glyphosate and 28 °C combination led to slightly reduced infectivity compared to temperature alone. This study is the first to report the combined effects of glyphosate, temperature, pH and time on a freshwater animal. It demonstrates that a specific combination of factors determines the effect of glyphosate on a non-target organism. The potential use of C. nobilli as a bioindicator is discussed. In the context of global warming and considering that the behavioral manipulation of terrestrial hosts by gordiids can shape community structure and the energy flow through food webs, our results raise concerns about possible negative effects of climate change on host-parasite dynamics.

Annotation and visualization of parasite, fungi and arthropod genomes with Companion.

As sequencing genomes has become increasingly popular, the need for annotation of the resulting assemblies is growing. Structural and functional annotation is still challenging as it includes finding the correct gene sequences, annotating other elements such as RNA and being able to submit those data to databases to share it with the community. Compared to de novo assembly where contiguous chromosomes are a sign of high quality, it is difficult to visualize and assess the quality of annotation. We developed the Companion web server to allow non-experts to annotate their genome using a reference-based method, enabling them to assess the output before submitting to public databases. In this update paper, we describe how we have included novel methods for gene finding and made the Companion server more efficient for annotation of genomes of up to 1 Gb in size. The reference set was increased to include genomes of interest for human and animal health from the fungi and arthropod kingdoms. We show that Companion outperforms existing comparable tools where closely related references are available.

HOST SWITCHING IN DICYEMIDS (PHYLUM DICYEMIDA).

Dicyemids (phylum Dicyemida) are the most common and most characteristic endosymbionts in the renal sacs of benthic cephalopod molluscs: octopuses and cuttlefishes. Typically, 2 or 3 dicyemid species are found in a single specimen of the host, and most dicyemids have high host specificity. Host-specific parasites are restricted to a limited range of host species by ecological barriers that impede dispersal and successful establishment; therefore, phylogenies of interacting groups are often congruent due to repeated co-speciation. Most frequently, however, host and parasite phylogenies are not congruent, which can be explained by processes such as host switching and other macro-evolutionary events. Here, the history of dicyemids and their host cephalopod associations were studied by comparing their phylogenies. Dicyemid species were collected from 8 decapodiform species and 12 octopodiform species in Japanese waters. Using whole mitochondrial cytochrome c oxidase subunit 1 (COI) sequences, a phylogeny of 37 dicyemid species, including 4 genera representing the family Dicyemidae, was reconstructed. Phylogenetic trees derived from analyses of COI genes consistently suggested that dicyemid species should be separated into 3 major clades and that the most common genera, Dicyema and Dicyemennea, are not monophyletic. Thus, morphological classification does not reflect the phylogenetic relationships of these 2 genera. Divergence (speciation) of dicyemid species seems to have occurred within a single host species. Possible host-switching events may have occurred between the Octopodiformes and Decapodiformes or within the Octopodiformes or the Decapodiformes. Therefore, the mechanism of dicyemid speciation may be a mixture of host switching and intra-host speciation. This is the first study in which the process of dicyemid diversification involving cephalopod hosts has been evaluated with a large number of dicyemid species and genera.