Let it glow: genetically encoded fluorescent reporters in Plasmodium

The use of fluorescent proteins (FPs) in Plasmodium parasites has been key to understand the biology of this obligate intracellular protozoon. FPs like the green fluorescent protein (GFP) enabled to explore protein localization, promoter activity as well as dynamic processes like protein export and endocytosis. Furthermore, FP biosensors have provided detailed information on physiological parameters at the subcellular level, and fluorescent reporter lines greatly extended the malariology toolbox. Still, in order to achieve optimal results, it is crucial to know exactly the properties of the FP of choice and the genetic scenario in which it will be used. This review highlights advantages and disadvantages of available landing sites and promoters that have been successfully applied for the ectopic expression of FPs in Plasmodium berghei and Plasmodium falciparum. Furthermore, the properties of newly developed FPs beyond DsRed and EGFP, in the visualization of cells and cellular structures as well as in the sensing of small molecules are discussed.

Babesia duncani, A Model Organism for Investigating Intraerythrocytic Parasitism and Novel Anti-Parasitic Therapeutic Strategies

Pathogens such as Plasmodium, Babesia, and Theileria invade and multiply within host red blood cells, leading to the pathological consequences of malaria, babesiosis and theileriosis. Establishing continuous in vitro culture systems and suitable animal models is crucial for studying these pathogens. This review spotlights the B. duncani "in culture-in mouse (ICIM)" model as a promising resource for advancing research on the biology, pathogenicity, and virulence of intraerythrocytic parasites. The model offers practical benefits, encompassing well-defined culture conditions, ease of manipulation and a well-annotated genome. Moreover, B. duncani serves as a surrogate system for drug discovery, facilitating the evaluation of new antiparasitic drugs in vitro and in animals, elucidating their modes of action, and uncovering potential resistance mechanisms. The B. duncani ICIM model thus emerges as a multifaceted tool with profound implications, promising advancements in our understanding of parasitic biology and shaping the development of future therapies.

Mangrove sediments are environmental hotspots for pathogenic protists

Mangrove sediments are unique ecosystems providing habitats for diverse organisms, especially microbial communities. However, little is known about the diversity and environmental risk of a critical group of microorganisms, the protists. To address this gap, we employed metagenome sequencing technologies to provide the first comprehensive view of the protistan community in the mangrove sediment. Our results surprisingly showed that parasitic protists dominated the protistan community in mangrove sediments, with an average abundance of 59.67%, one of the highest in all ecosystems on Earth. We also found that the relative abundance of protists decreased significantly (R = -0.21, p = 0.045) with latitude but increased with depths (R = 0.7099, p < 0.001). The parasitic communities were positively influenced by microbial (bacteria, fungi, and archaea) communities, including horizontal-scale and vertical-scale. In addition, sulfate and salinity had the most significant influence on the protistan community. Our findings provide new insights into our understanding of protistan variation in mangrove sediments, including abundance, composition, and possible functions, and indicate that mangrove sediments are hotspots for environmental pathogens, posing a potential risk to human health.

A potential role of protein extractions from Metagonimus yokogawai in amelionating inflammation in patients with ankylosing spondylitis

Helminth infections and their components has been recognized to have a positive impact on the immune system. This study aimed to investigate the potential of Metagonimus yokogawai-derived proteins (MYp) to provide protection against ankylosing spondylitis (AS) through modulation of immune responses. The cytotoxicity of MYp at various doses was first assessed using MTS and flow cytometry. Peripheral blood mononuclear cells (PBMCs) were collected from AS patients, and the production of inflammatory cytokines was analyzed through flow cytometry. In the experiments with SKG mice, MYp or vehicle was administered and inflammation was evaluated through immunohistochemistry and enzyme-linked immunosorbent assay. The results showed that MYp did not decrease cell viability of PBMCs even after 48 h. Additionally, the frequencies of IFN-γ and IL-17A producing cells were significantly reduced after MYp treatment in the PBMC cultures. Furthermore, MYp treatment significantly suppressed arthritis and enthesitis in the SKG mouse model. The results suggest the first evidence that MYp can effectively alleviate clinical symptoms and restore cytokine balance in patients with AS.

Marine Natural Products as Novel Treatments for Parasitic Diseases

Parasitic diseases including malaria, leishmaniasis, and trypanosomiasis have received significant attention due to their severe health implications, especially in developing countries. Marine natural products from a vast and diverse range of marine organisms such as sponges, corals, molluscs, and algae have been found to produce unique bioactive compounds that exhibit promising potent properties, including antiparasitic, anti-Plasmodial, anti-Leishmanial, and anti-Trypanosomal activities, providing hope for the development of effective treatments. Furthermore, various techniques and methodologies have been used to investigate the mechanisms of these antiparasitic compounds. Continued efforts in the discovery and development of marine natural products hold significant promise for the future of novel treatments against parasitic diseases.

Complex effects of testosterone level on ectoparasite load in a ground squirrel: an experimental test for the immunocompetence handicap hypothesis

BACKGROUND

The immunocompetence handicap hypothesis suggests that males with a higher testosterone level should be better at developing male secondary traits, but at a cost of suppressed immune performance. As a result, we should expect that males with an increased testosterone level also possess a higher parasite load. However, previous empirical studies aimed to test this prediction have generated mixed results. Meanwhile, the effect of testosterone level on parasite load in female hosts remains poorly known.

METHODS

In this study, we tested this prediction by manipulating testosterone level in Daurian ground squirrels (Spermophilus dauricus), a medium-sized rodent widely distributed in northeast Asia. S. dauricus is an important host of ticks and fleas and often viewed as a considerable reservoir of plague. Live-trapped S. dauricus were injected with either tea oil (control group) or testosterone (treatment group) and then released. A total of 10 days later, the rodents were recaptured and checked for ectoparasites. Fecal samples were also collected to measure testosterone level of each individual.

RESULTS

We found that testosterone manipulation and sex of hosts interacted to affect tick load. At the end of the experiment, male squirrels subjected to testosterone implantation had an averagely higher tick load than males from the control group. However, this pattern was not found in females. Moreover, testosterone manipulation did not significantly affect flea load in S. dauricus.

CONCLUSIONS

Our results only lent limited support for the immunocompetence handicap hypothesis, suggesting that the role of testosterone on regulating parasite load is relatively complex, and may largely depend on parasite type and gender of hosts.

[Progress of researches on the antiparasitic activity of antimicrobial peptide LL-37]

Parasitic diseases caused by protozoan and helminth infections are still widespread across the world, notably in tropical and subtropical areas, which threaten the children and adult health. Long-term use of anti-parasitic drugs may result in reduced drug susceptibility and even drug resistance. Antimicrobial peptides have been demonstrated to inhibit parasite growth and development, which has potential antiparasitic values. LL-37, the only human antimicrobial peptide in the cathelicidin family, has been widely investigated. This paper reviews the progress of researches on the antiparasitic activity of LL-37, and discusses the prospects of LL-37 in the research of parasites.

Mouse model of secondary cystic echinococcosis

Cystic echinococcosis (CE) is a parasitic zoonosis caused by the larval stage of the cestode Echinococcus granulosus sensu lato (s. l.), a genetic complex composed of five species: E. granulosus sensu stricto (s. s.), E. equinus, E. ortleppi, E. canadensis, and E. felidis. The parasite requires two mammalian hosts to complete its life cycle: a definitive host (mainly dogs) harboring the adult parasite in its intestines, and an intermediate host (mostly farm and wild ungulates) where hydatid cysts develop mainly in the liver and lungs. Humans are accidental intermediate hosts, being susceptible to either primary or secondary forms of CE; the first one due to the ingestion of oncospheres, and the second one because of the spillage of protoscoleces (PSC) contained within a primary cyst. Secondary CE is a serious medical problem, and can be modeled in immunocompetent mice (a non-natural intermediate host) through the intraperitoneal inoculation of viable PSC from E. granulosus s. l. This model is useful to study not only the immunobiology of CE, but also to test new chemotherapeutics or therapeutical protocols, to explore novel vaccine candidates, and to evaluate alternative diagnostic and/or follow-up tools. The mouse model of secondary CE involves two sequential stages: an early stage of parasite pre-encystment (PSC develop into hydatid cysts in the peritoneal cavity of mice), and a late or chronic stage of parasite post-encystment (already differentiated cysts slowly grow during the whole host lifespan). This model is a time-consuming infection, whose outcome depends on several factors like the parasite infective dose, the mouse strain, and the parasite species/genotype. Thus, such variables should always be adjusted according to the research objectives. Herein, the general materials and procedures needed to establish secondary CE in mice are described, as well as several useful tips and recommendations.

Parallel functional reduction in the mitochondria of apicomplexan parasites

Extreme functional reduction of mitochondria has taken place in parallel in many distantly related lineages of eukaryotes, leading to a number of recurring metabolic states with variously lost electron transport chain (ETC) complexes, loss of the tricarboxylic acid (TCA) cycle, and/or loss of the mitochondrial genome. The resulting mitochondria-related organelles (MROs) are generally structurally reduced and in the most extreme cases barely recognizable features of the cell with no role in energy metabolism whatsoever (e.g., mitosomes, which generally only make iron-sulfur clusters). Recently, a wide diversity of MROs were discovered to be hiding in plain sight: in gregarine apicomplexans. This diverse group of invertebrate parasites has been known and observed for centuries, but until recent applications of culture-free genomics, their mitochondria were unremarkable. The genomics, however, showed that mitochondrial function has reduced in parallel in multiple gregarine lineages to several different endpoints, including the most reduced mitosomes. Here we review this remarkable case of parallel evolution of MROs, and some of the interesting questions this work raises.

MicroCT illuminates the unique morphology of Shiinoidae (Copepoda: Cyclopoida), an unusual group of fish parasites

The copepod family Shiinoidae Cressey, 1975 currently comprises nine species of teleost parasites with unusual morphology and a unique attachment mechanism. Female shiinoids possess greatly enlarged antennae that oppose a rostrum, an elongate outgrowth of cuticle that originates between the antennules. The antennae form a moveable clasp against the rostrum which they use to attach to their host. In this study, we use micro-computed tomography (microCT) to examine specimens of Shiinoa inauris Cressey, 1975 in situ attached to host tissue in order to characterize the functional morphology and specific muscles involved in this novel mode of attachment and to resolve uncertainty regarding the segmental composition of the regions of the body. We review the host and locality data for all reports of shiinoids, revise the generic diagnoses for both constituent genera Shiinoa Kabata, 1968 and Parashiinoa West, 1986, transfer Shiinoa rostrata Balaraman, Prabha & Pillai, 1984 to Parashiinoa as Parashiinoa rostrata (Balaraman, Prabha & Pillai, 1984) n. comb., and present keys to the females and males of both genera.

Identification of Cryptosporidium parvum and Blastocystis hominis subtype ST3 in Cholga mussel and treated sewage: Preliminary evidence of fecal contamination in harvesting area

Cryptosporidium parvum and Blastocystis hominis are foodborne parasites known for causing diarrhea. They accumulate in mussels grown on contaminated water bodies, due to the discharge of treated sewage from sewage treatment plants (STP). Despite this, some countries like Chile do not include these parasites in the control or monitoring of sewage water. The objective of this research was to evaluate the contamination of C. parvum. and B. hominis from treated sewage (disinfected by chlorination) and Cholga mussels in a touristic rural cove from the bay of Concepción. Cholga mussels from commercial stores and a treated sewage sample were analyzed. Cryptosporidium spp. was identified by Ziehl-Neelsen-Staining (ZNS) and C. parvum by direct-immunofluorescence assay (IFA) from ZNS-positive samples. Blastocystis hominis was identified by PCR using locus SSU rDNA. C. parvum and B. hominis subtype ST3 were found in 40% and 45% of Cholga mussel samples, respectively, and both parasites were identified in the treated sewage. Blastocystis hominis SSU rDNA gene alignment from Cholga mussels and treated sewage showed 89% of similarity, indicating that could be the same parasite in both samples. We describe the first evidence of possible contamination with these parasites from treated sewage to Cholga mussel suggesting an environmental contamination with high human risk. Based on these results, further studies will consider all the rural coves and STP from the bay to prevent possible contamination of these parasites.

Hard ticks (Acari: Ixodidae) parasitizing bushbabies (Mammalia: Galagidae) in a biodiversity hotspot of northern South Africa

South Africa has six species of primates, three of which are bushbabies (family Galagidae). Very little information is available on their parasites due to the lack of longitudinal studies, although Rhipicephalus appendiculatus, Amblyomma hebraeum and Haemaphysalis elliptica were previously reported from the brown greater galago (Otolemur crassicaudatus) in South Africa. During 2014-2019, 83 O. crassicaudatus (70 live-trapped and 13 deceased animals) were checked for the presence of hard ticks, all from Limpopo Province, South Africa. Seventy-three of 83 (88 %) galagos were found to be tick-infested. Among ixodid genera, Haemaphysalis had the highest prevalence (46 % of the bushbabies), followed by Rhipicephalus (25 %) and Ixodes (18 %). In total, ten tick species were identified. Importantly, all infestations were monospecific. Ticks occurred on various body parts of bushbabies, thus no predilection site was noted. In conclusion, while previously only three ixodid species were known to infest bushbabies in South Africa, the present study showed that these animals can be parasitized by a much broader range of hard ticks.

Halocercus lagenorhynchi infection in a stranded striped dolphin Stenella coeruleoalba (Meyen, 1833) on the Southwest coastline of India

Necropsy on a striped dolphin Stenella coeruleoalba (Meyen, 1833) entangled in ghost fishing net and dead while rescuing yielded some helminth parasites, later identified as Halocercus lagenorhynchi. DNA barcoding of the host and parasite and the phylogenetic analysis of the parasite was conducted. This study provides valuable information towards establishing basal data of marine mammal parasite diversity and distribution in the Indian waters. We believe this is the first report of the occurrence of Halocercus lagenorhynchi in marine mammals in India.

Vector species richness predicts local mortality rates from Chagas disease

Vector species richness may drive the prevalence of vector-borne diseases by influencing pathogen transmission rates. The dilution effect hypothesis predicts that higher biodiversity reduces disease prevalence, but with inconclusive evidence. In contrast, the amplification effect hypothesis suggests that higher vector diversity may result in greater disease transmission by increasing and diversifying the transmission pathways. The relationship between vector diversity and pathogen transmission remains unclear and requires further study. Chagas disease is a vector-borne disease most prevalent in Brazil and transmitted by multiple species of insect vectors of the subfamily Triatominae, yet the drivers of spatial variation in its impact on human populations remain unresolved. We tested whether triatomine species richness, latitude, bioclimatic variables, human host population density, and socioeconomic variables predict Chagas disease mortality rates across over 5000 spatial grid cells covering all of Brazil. Results show that species richness of triatomine vectors is a good predictor of mortality rates caused by Chagas disease, which supports the amplification effect hypothesis. Vector richness and the impact of Chagas disease may also be driven by latitudinal components of climate and human socioeconomic factors. We provide evidence that vector diversity is a strong predictor of disease prevalence and give support to the amplification effect hypothesis.

Production of Escovopsis conidia and the potential use of this parasitic fungus as a biological control agent of leaf-cutting ant fungus gardens

This study was carried out to investigate the use of different substrates for the production of Escovopsis conidia and verify the virulence of four different isolates cultured on four types of substrates using a novel bioassay. Escovopsis isolates were molecularly identified, based on Internal Transcribed Spacer (ITS) nucleotide sequences. To evaluate conidial production, suspensions (1 × 106 conidia mL-1) of each Escovopsis isolate were inoculated onto four substrates (parboiled rice, white rice, rolled oats, and corn grits). After 14 days, conidial yields were assessed. The virulence of each isolate cultured on the four substrates was tested against Leucoagaricus fungus garden fragments, by directly applying 500 µL of each conidial suspension (1 × 107 conidia mL-1), and the development of the parasite was monitored daily until it completely colonized the fungus garden. It was observed that rolled oats were the best substrate for conidial production, with a yield of 1.7 × 107 to 2.0 × 108 conidia mL-1. Furthermore, isolate AT-01 produced the highest number of conidia when compared with the other isolates. Regardless of the substrate used to produce AT-01 conidia, this isolate completely colonized the fungus garden 6 days post inoculation (dpi), followed by AT-02, AC-01, and AC-2. High levels of both conidial production and virulence against the leaf-cutting ant fungus garden were observed here.

Separation of evolutionary timescales in coevolving species

Many coevolutionary processes, including host-parasite and host-symbiont interactions, involve one species or trait which evolves much faster than the other. Whether or not a coevolutionary trajectory converges depends on the relative rates of evolutionary change in the two species, and so current adaptive dynamics approaches generally either determine convergence stability by considering arbitrary (often comparable) rates of evolutionary change or else rely on necessary or sufficient conditions for convergence stability. We propose a method for determining convergence stability in the case where one species is expected to evolve much faster than the other. This requires a second separation of timescales, which assumes that the faster evolving species will reach its evolutionary equilibrium (if one exists) before a new mutation arises in the more slowly evolving species. This method, which is likely to be a reasonable approximation for many coevolving species, both provides straightforward conditions for convergence stability and is less computationally expensive than traditional analysis of coevolution models, as it reduces the trait space from a two-dimensional plane to a one-dimensional manifold. In this paper, we present the theory underlying this new separation of timescales and provide examples of how it could be used to determine coevolutionary outcomes from models.

First report of Besnoitia bennetti in Irish donkeys: an emerging parasitic disease in Europe

BACKGROUND

This is the first report of Besnoitia bennetti in donkeys in Ireland. B. bennetti, an apicomplexan protozoan parasite specific to equids, is an emerging pathogen in Europe. This parasite forms chronic intracytoplasmic cysts in cells of the mesenchymal lineage, mainly fibroblasts, in the skin, sclera and mucosa. Clinical signs in affected equine hosts vary from mild to severe debilitating disease. Little is known of the phylogeny, epidemiology or transmission of B. bennetti infection in donkeys, mules or horses.

CASE PRESENTATION

Two cases of besnoitiosis in donkeys are presented. Both donkeys were born and raised in theSouthwest of Ireland. The first case was a 2.5-year-old donkey that had a suspect sarcoid removed, while the second case,a 2-year-old donkey, had a biopsy of nodular dermatitis of the muzzle. Diagnosis was made by histopathology and the parasite species, B. bennetti, was confirmed by PCR followed by sequencing and microsatellite analysis. Both donkeys had high antibody titres against Besnoitia spp. Small (0.5 mm) scleral, conjunctival and dermal cysts over the muzzle were subsequently observed in both animals. Treatment with trimethoprim sulfadiazine for 30 days did not lead to clinical resolution. The findings are compared to the cases of besnoitiosis in donkeys reported in the past 10 years throughout Europe.

CONCLUSIONS

Besnoitiosis should be considered as a differential diagnosis for chronic skin disease particularly in cases of cutaneous masses, non-pruritic dermatitis, and dermatitis that is not responsive to treatment in donkeys and other equids. Future studies are needed to investigate the prevalence of the disease in Irish donkeys, the spread of the disease and the potential impact on the health and welfare of the donkeys.

Improved 18S rDNA profiling of parasite communities in salmonid tissues using a host blocking primer

Sensitive screening of eukaryotic communities in aquaculture for research and management is limited by the availability of technologies that can detect invading pathogens in an unbiased manner. Amplicon sequencing of 18S ribosomal DNA (rDNA) provides a potential pan-diagnostic test to overcome these biases; however, this technique is limited by a swamping effect of host DNA on low abundance parasite DNA. In this study, we have adapted a host 18S rDNA blocking assay to amplify eukaryotic DNA from salmonid tissue for amplicon sequencing. We demonstrate that effective salmonid 18S rDNA blocking enables sensitive detection of parasite genera in salmonid gill swabs. Furthermore, 18S rDNA amplicon sequencing with host blocking identified enriched pathogen communities in gill swabs from Atlantic salmon suffering from severe clinical gill infections compared to those exhibiting no clinical signs of gill infection. Application of host 18S rDNA blocking in salmonid samples led to improved detection of the amoebic parasite Neoparamoeba perurans, a parasite of significant threat to the Atlantic salmon aquaculture industry. These results reveal host 18S rDNA blocking as an effective strategy to improve the profiling and detection of parasitic communities in aquaculture species. This assay can be readily adapted to any animal species for improved eukaryotic profiling across agricultural and veterinary industries.

Strategies for describing myxozoan pathogens, dreadful fish diseases in aquaculture

Myxozoans are obligate endoparasites, cosmopolitan in distribution with both vertebrate and invertebrate hosts. Their myxospores consist of shell valves, polar capsules with coiled polar tubules that are extrudible, and infective amoeboid germs. Myxozoan parasites are most abundant, and due to their increasing number in recent years, they can pose an emerging threat to the fish industry worldwide. Hence, the immediate need is to devise a strategy to understand and detect parasites and parasitism. They may proliferate to different organs with the advancement of infection. This all warrants the development/devising of strategies and results of integrative studies in order to identify these dreadful parasites and resolve taxonomic issues. Different methods whether classical methods including gross morphology or advanced methods such as electron microscopy (SEM, TEM, STEM), Confocal laser scanning microscopy (CLSM), histopathological studies, site preference, host and tissue specificity, a molecular approach using new markers can be clubbed for identification because these parasites are hidden and are difficult to recognize. This group was earlier classified only on the basis of myxospores morphology, but due to the high structural variability of this group advanced methods and approaches have to be implied which can minimize the problems in assigning new species.

The first record of Brachylaima ezohelicis (Trematoda: Brachylaimidae) in the red fox (Vulpes vulpes schrencki)

Brachylaima spp. are trematodes that have a unique life cycle as they exclusively use land snails as the intermediate host. Although their intermediate host has been well studied, very little information is available about their definitive host, partly as isolation of its adult stage from wild animals is rare. We found three trematodes in the small intestine of a red fox (Vulpes vulpes schrencki) in Hokkaido, the northernmost island of Japan. The trematodes were identified as Brachylaima ezohelicis based on morphological features and genetic analysis, which is believed to have a definitive avian host. The morphological features of the isolated trematodes were consistent with B. ezohelicis samples grown in the definitive host except for body length. Our study suggests that B. ezohelicis uses mammals as definitive hosts as well as birds.

Mysterious microsporidians: springtime outbreaks of disease in Daphnia communities in shallow pond ecosystems

Parasites can play key roles in ecosystems, especially when they infect common hosts that play important ecological roles. Daphnia are critical grazers in many lentic freshwater ecosystems and typically reach peak densities in early spring. Daphnia have also become prominent model host organisms for the field of disease ecology, although most well-studied parasites infect them in summer or fall. Here, we report field patterns of virulent microsporidian parasites that consistently infect Daphnia in springtime, in a set of seven shallow ponds in Georgia, USA, sampled every 3-4 weeks for 18 months. We detected two distinct parasite taxa, closely matching sequences of Pseudoberwaldia daphniae and Conglomerata obtusa, both infecting all three resident species of Daphnia: D. ambigua, D. laevis, and D. parvula. To our knowledge, neither parasite has been previously reported in any of these host species or anywhere in North America. Infection prevalence peaked consistently in February-May, but the severity of these outbreaks differed substantially among ponds. Moreover, host species differed markedly in terms of their maximum infection prevalence (5% [D. parvula] to 72% [D. laevis]), mean reduction of fecundity when infected (70.6% [D. ambigua] to 99.8% [D. laevis]), mean spore yield (62,000 [D. parvula] to 377,000 [D. laevis] per host), and likelihood of being infected by each parasite. The timing and severity of the outbreaks suggests that these parasites could be impactful members of these shallow freshwater ecosystems, and that the strength of their effects is likely to hinge on the composition of ponds' zooplankton communities.

A web-based microbiological hazard identification tool for infant foods

An integrated approach to identify and assess Microbiological Hazards (MHs) and mitigate risks in infant food chains is crucial to ensure safe foods for infants and young children. A systematic procedure was developed to identify MHs in specific infant foods. This includes five major steps: 1) relevant hazard-food pairing, 2) process inactivation efficiency, 3) recontamination possibility after processing, 4) MHs growth opportunity, and 5) MHs-food association level. These steps were integrated into an online tool called the Microbiological Hazards IDentification (MiID) decision support system (DSS), targeting food companies, governmental agencies and academia users, and is accessible at https://foodmicrobiologywur.shinyapps.io/Microbial_hazards_ID/. The MiID DSS was validated in four case studies, focussing on infant formula, fruit puree, cereal-based meals, and fresh fruits, each representing distinct products and processing characteristics. The results obtained through the application of the MiID DSS, compared with identification by food safety experts, consistently identified the top MHs in these food products. This process affirms its effectiveness in systematic hazard identification. The introduction of the MiID DSS helps to structure the first steps in HACCP (hazard analysis) and in risk assessment (hazard identification) to follow a structured and well-documented procedure, balancing the risk of overlooking relevant MHs or including too many irrelevant MHs. It is a valuable addition to risk analysis/assessment in infant food chains and has the potential for future extension. This includes the incorporation of newly acquired data related to infant foods via a semi-publicly hosted platform, or it can be adapted for hazard identification in general food products using a similar framework.

Beach volleyball and Cutaneous Larva Migrans

Cutaneous larva migrans can affect even athletes who travelled to play beach volleyball in Zanzibar. We describe a cluster of CLM infections in travellers who contracted the disease during their trip to Africa, rather than bringing a volleyball trophy. Despite presenting typical changes, all of them were misdiagnosed.

Changes in saliva protein profile throughout Rhipicephalus microplus blood feeding

BACKGROUND

When feeding on a vertebrate host, ticks secrete saliva, which is a complex mixture of proteins, lipids, and other molecules. Tick saliva assists the vector in modulating host hemostasis, immunity, and tissue repair mechanisms. While helping the vector to feed, its saliva modifies the site where pathogens are inoculated and often facilitates the infection process. The objective of this study is to uncover the variation in protein composition of Rhipicephalus microplus saliva during blood feeding.

METHODS

Ticks were fed on calves, and adult females were collected, weighed, and divided in nine weight groups, representing the slow and rapid feeding phases of blood feeding. Tick saliva was collected, and mass spectrometry analyses were used to identify differentially secreted proteins. Bioinformatic tools were employed to predict the structural and functional features of the salivary proteins. Reciprocal best hit analyses were used to identify conserved families of salivary proteins secreted by other tick species.

RESULTS

Changes in the protein secretion profiles of R. microplus adult female saliva during the blood feeding were observed, characterizing the phenomenon known as "sialome switching." This observation validates the idea that the switch in protein expression may serve as a mechanism for evading host responses against tick feeding. Cattle tick saliva is predominantly rich in heme-binding proteins, secreted conserved proteins, lipocalins, and protease inhibitors, many of which are conserved and present in the saliva of other tick species. Additionally, another remarkable observation was the identification of host-derived proteins as a component of tick saliva.

CONCLUSIONS

Overall, this study brings new insights to understanding the dynamics of the proteomic profile of tick saliva, which is an important component of tick feeding biology. The results presented here, along with the disclosed sequences, contribute to our understanding of tick feeding biology and might aid in the identification of new targets for the development of novel anti-tick methods.

Assessing the microbiota of the snail intermediate host of trematodes, Galba truncatula

BACKGROUND

The microbiome is known to play key roles in health and disease, including host susceptibility to parasite infections. The freshwater snail Galba truncatula is the intermediate host for many trematode species, including the liver and rumen flukes Fasciola hepatica and Calicophoron daubneyi, respectively. The snail-parasite system has previously been investigated. However, the specific interaction between the snail-associated microbiota and intra-snail developmental stages of trematodes has yet to be explored.

METHODS

Galba truncatula snails were collected from farms in Northern Ireland and trematode infection was diagnosed using PCR. High-throughput sequencing analysis of the bacterial 16S ribosomal DNA V3-V4 hypervariable regions was subsequently applied to characterise the microbiota of both uninfected and infected snails.

RESULTS

We first showed that the snail harboured microbiota that was distinct for its environment. The microbiota of infected snails was found to differ significantly from that of uninfected snails. In particular, the bacterial genera Mycoplasma and Methylotenera were significantly more abundant in infected snails, while genera Sphingomonas and Nocardioides were predominantly associated with uninfected snails.

CONCLUSION

These findings pave the way to future studies on the functional roles of bacteria in host-parasite relationships.

Drivers of infection with Toxoplasma gondii genotype type II in Eurasian red squirrels (Sciurus vulgaris)

BACKGROUND

In September 2014, there was sudden upsurge in the number of Eurasian red squirrels (Sciurus vulgaris) found dead in the Netherlands. High infection levels with the parasite Toxoplasma gondii were demonstrated, but it was unclear what had caused this increase in cases of fatal toxoplasmosis. In the present study, we aimed to gain more knowledge on the pathology and prevalence of T. gondii infections in Eurasian red squirrels in the Netherlands, on the T. gondii genotypes present, and on the determinants of the spatiotemporal variability in these T. gondii infections. The presence of the closely related parasite Hammondia hammondi was also determined.

METHODS

Eurasian red squirrels that were found dead in the wild or that had died in wildlife rescue centres in the Netherlands over a period of seven years (2014-2020) were examined. Quantitative real-time polymerase chain reaction was conducted to analyse tissue samples for the presence of T. gondii and H. hammondi DNA. Toxoplasma gondii-positive samples were subjected to microsatellite typing and cluster analysis. A mixed logistic regression was used to identify climatic and other environmental predictors of T. gondii infection in the squirrels.

RESULTS

A total of 178 squirrels were examined (49/178 T. gondii positive, 5/178 H. hammondi positive). Inflammation of multiple organs was the cause of death in 29 squirrels, of which 24 were also T. gondii polymerase chain reaction positive. Toxoplasma gondii infection was positively associated with pneumonia and hepatitis. Microsatellite typing revealed only T. gondii type II alleles. Toxoplasma gondii infection rates showed a positive correlation with the number of days of heavy rainfall in the previous 12 months. Conversely, they showed a negative association with the number of hot days within the 2-week period preceding the sampling date, as well as with the percentage of deciduous forest cover at the sampling site.

CONCLUSIONS

Toxoplasma gondii infection in the squirrels appeared to pose a significant risk of acute mortality. The T. gondii genotype detected in this study is commonly found across Europe. The reasons for the unusually high infection rates and severe symptoms of these squirrels from the Netherlands remain unclear. The prevalence of T. gondii in the deceased squirrels was linked to specific environmental factors. However, whether the increase in the number of dead squirrels indicated a higher environmental contamination with T. gondii oocysts has yet to be established.

Green synthesis of silver and iron oxide nanoparticles mediated photothermal effects on Blastocystis hominis

The evolution of parasite resistance to antiparasitic agents has become a serious health issue indicating a critical and pressing need to develop new therapeutics that can conquer drug resistance. Nanoparticles are novel, promising emerging drug carriers that have demonstrated efficiency in treating many parasitic diseases. Lately, attention has been drawn to a broad-spectrum nanoparticle capable of converting absorbed light into heat via the photothermal effect phenomenon. The present study is the first to assess the effect of silver nanoparticles (Ag NPs) and iron oxide nanoparticles (Fe3O4 NPs) as sole agents and with the combined action of the light-emitting diode (LED) on Blastocystis hominins (B. hominis) in vitro. Initially, the aqueous synthesized nanoparticles were characterized by UV-Vis spectroscopy, zeta potential, and transmission electron microscopy (TEM). The anti-blastocyst efficiency of these NPs was tested separately in dark conditions. As these NPs have a wide absorption spectrum in the visible regions, they were also excited by a continuous wave LED of wavelength band (400-700 nm) to test the photothermal effect. The sensitivity of B. hominis cysts was evaluated using scanning laser confocal microscopy whereas the live and dead cells were accurately segmented based on superpixels and the k-mean clustering algorithm. Our findings showed that this excitation led to hyperthermia that induced a significant reduction in the number of cysts treated with photothermally active NPs. The results of this study elucidate the potential role of photothermally active NPs as an effective anti-blastocystis agent. By using this approach, new therapeutic antiparasitic agents can be developed.

Palaeoparasitology confirms Early Lapita evidence of pig and dog at Kamgot, Bismarck Archipelago

Little is known about helminth parasites of the Bismarck Archipelago, in either archaeological or modern contexts. This study presents a parasitological analysis of soil samples from Early Lapita habitation layers at Kamgot (3300-3000 BP). Evidence for the presence of pigs and dogs and the timing of their arrival in Early Lapita contexts have been contested in the literature. The finding of parasite eggs in samples from Kamgot supports the presence of pigs and dogs at the site. Six types of helminth eggs were identified: pig nematode Trichuris suis, dog nematode Toxocara canis, and cestode Dipylidium caninum, as well as two unknown trematodes and a possible anoplocephalid cestode, thereby indicating the local presence of other mammals or birds. This study represents the first confirmed record of ancient helminth parasites in tropical Oceania.

Inhibition of Plasmodium falciparum plasmepsins by drugs targeting HIV-1 protease: A way forward for antimalarial drug discovery

Plasmodium species are causative agents of malaria, a disease that is a serious global health concern. FDA-approved HIV-1 protease inhibitors (HIV-1 PIs) have been reported to be effective in reducing the infection by Plasmodium parasites in the population co-infected with both HIV-1 and malaria. However, the mechanism of HIV-1 PIs in mitigating Plasmodium pathogenesis during malaria/HIV-1 co-infection is not fully understood. In this study we demonstrate that HIV-1 drugs ritonavir (RTV) and lopinavir (LPV) exhibit the highest inhibition activity against plasmepsin II (PMII) and plasmepsin X (PMX) of P. falciparum. Crystal structures of the complexes of PMII with both drugs have been determined. The inhibitors interact with PMII via multiple hydrogen bonding and hydrophobic interactions. The P4 moiety of RTV forms additional interactions compared to LPV and exhibits conformational flexibility in a large S4 pocket of PMII. Our study is also the first to report inhibition of P. falciparum PMX by RTV and the mode of binding of the drug to the PMX active site. Analysis of the crystal structures implies that PMs can accommodate bulkier groups of these inhibitors in their S4 binding pockets. Structurally similar active sites of different vacuolar and non-vacuolar PMs suggest the potential of HIV-1 PIs in targeting these enzymes with differential affinities. Our structural investigations and biochemical data emphasize PMs as crucial targets for repurposing HIV-1 PIs as antimalarial drugs.

Causes of infectious pediatric uveitis: A review

Infectious pediatric uveitis is a rare disease that can cause severe ocular damage if not detected rapidly and treated properly. Additionally, early identification of an infection can protect the child from life-threatening systemic infection. Infectious uveitis can be congenital or acquired and may manifest as a primary ocular infection or as a reactivation. Nevertheless, publications on infectious paediatric uveitis are usually limited to a small number of patients or a case report. So far, most studies on uveitis in children have focused primarily on noninfectious uveitis, and a systematic study on infectious uveitis is lacking. In this review, we summarize the literature on infectious uveitis in pediatric populations and report on the epidemiology, pathophysiology, clinical signs, diagnostic tests, and treatment. We will describe the different possible pathogens causing uveitis in childhood by microbiological group (i.e. parasites, viruses, bacteria, and fungi). We aim to contribute to early diagnosis and management of infectious pediatric uveitis, which in turn might improve not only visual outcome, but also the general health outcome.

The co-infection of pulmonary hydatid cyst, lophomoniasis and tuberculosis in a patient with resistant respiratory symptoms; a case report study

BACKGROUND

Lophomonas blattarum is a rare protozoan that causes opportunistic infections, and the co-infection of lophomonas with tuberculosis and human hydatidosis is a serious public problem in the co-endemic areas of developing countries.

CASE REPORT

We presented a 58-year-old female with fever, losing weight, and cough with whitish-yellow sputum that started one month ago. Increasing inflammatory markers and hypereosinophilia in laboratory tests, and a cavity with thick, regular walls and undulating air-fluid levels measuring 43 × 30, evident in the upper segment of the right lower lobe (RLL), along with consolidation and the ground glass opacity of the upper segment and posterior basal of the RLL is apparent in CT scan were reported. Then, a bronchoscopy was requested, and the BAL specimen reported a negative fungal and bacterial infection in the samples. Several live and oval flagellated lophomonas protozoa, hydatid cyst protoscoleces (the larval forms of the parasites), and M. tuberculosis were observed in microscopic evaluation. The patient was treated with metronidazole, oral albendazole, and a combination of TB regimen.

CONCLUSION

Physicians should always consider the possibility of co-infections of lophomonas with tuberculosis and human hydatidosis and investigate patients with risk factors such as immunodeficiency conditions or treated with immunosuppressive medications.

Effect of macrophage polarization on parasitic protection against type 1 diabetes mellitus

Type 1 diabetes mellitus is a chronic disease caused by the destruction of pancreatic beta cells. Based on the hygiene hypothesis, a growing body of evidence suggests a negative association between parasitic infections and diabetes in humans and animal models. The mechanism of parasite-mediated prevention of type 1 diabetes mellitus may be related to the adaptive and innate immune systems. Macrophage polarization is a new paradigm for the treatment of type 1 diabetes mellitus, and different host macrophage subsets play various roles during parasite infection. Proinflammatory cytokines are released by M1 macrophages, which are important in the development of type 1 diabetes mellitus. Parasite-activated M2 macrophages prevent the development of type 1 diabetes mellitus and can influence the development of adaptive immune responses through several mechanisms, including Th2 cells and regulatory T cells. Here, we review the role and mechanism of macrophage polarization in parasitic protection against type 1 diabetes mellitus.

Rapid, automated quantification of Haemonchus contortus ova in sheep faecal samples

Haemonchus contortus is one of the most pathogenic nematodes affecting small ruminants globally and is responsible for large economic losses in the sheep and goat industry. Anthelmintic resistance is rampant in this parasite and thus parasite control programs must account for drug efficacy on individual farms and, sometimes, whether H. contortus is the most prevalent trichostrongylid. Historically, coproculture has been the main way to determine the prevalence of H. contortus in faecal samples due to the inability to morphologically differentiate between trichostrongylid egg types, but this process requires a skilled technician and takes multiple days to complete. Fluoresceinated peanut agglutinin (PNA) has been shown to specifically bind H. contortus and thus differentiate eggs based on whether they fluoresce, but this method has not been widely adopted. The ParasightTM System (PS) fluorescently stains helminth eggs in order to identify and quantify them, and the H. contortus PNA staining method was therefore adapted to this platform using methodology requiring only 20 min to obtain results. In this study, 74 fecal samples were collected from sheep and analyzed for PNA-stained H. contortus, using both PS and manual fluorescence microscopy. The percentage of H. contortus was determined based on standard total strongylid counts with PS or brightfield microscopy. Additionally, 15 samples were processed for coproculture with larval identification, and analyzed with both manual and automated PNA methods. All methods were compared using the coefficient of determination (R2) and the Lin's concordance correlation coefficient (ρc). ParasightTM and manual PNA percent H. contortus results were highly correlated with R2 = 0.8436 and ρc = 0.9100 for all 74 fecal samples. Coproculture versus PS percent H. contortus were also highly correlated with R2 = 0.8245 and ρc = 0.8605. Overall, this system provides a rapid and convenient method for determining the percentage of H. contortus in sheep and goat fecal samples without requiring specialized training.

Comparison of methods to detect interspecific competition among parasites in depauperate communities

Because conducting experimental coinfections is intractable in most parasite systems, inferences about the presence and strength of interspecific interactions in parasite communities are often made from analyses of field data. It is unclear whether methods used to test for competition are able to detect competition in field-collected datasets. Data from a study of the intestinal helminth communities of creek chub (Semotilus atromaculatus) were used to explore the potential of commonly available methods to detect negative interactions among parasite species in species-poor, low-intensity communities. Model communities were built in the absence of competition and then modified by four modes of competition. Both parametric and null model approaches were utilized to analyze modelled parasite communities to determine the conditions under which competitive interactions were discerned. Correlations had low Type I error rates but did not reliably detect competition, when present, at a statistically significant level. Results from logistical regressions were similar but showed improved statistical power. Results from null model approaches varied. Envelope analyses had near ideal properties when parasite prevalence was high but had high Type I error rates in low prevalence communities. Co-occurrence analyses demonstrated promising results with certain co-occurrence metrics and randomization algorithms, but also had many more cases of failure to detect competition when present and/or reject competition when it was absent. No analytical approach was clearly superior, and the variability observed in the present investigation mirrors similar efforts, suggesting that clear guidelines for detecting competition in parasite communities with observational data will be elusive.

DNA Aptamer-Based Staining and Fluorescence Microscopy for Rapid Detection of Cyclospora Cayetanensis Oocysts

There are no commercial antibodies for detection of Cyclospora cayetanensis, only a relatively slow polymerase chain reaction (PCR) test developed by the U.S. Food and Drug Administration (FDA). However, DNA aptamers have recently been developed by our group against known proteins and whole oocysts of C. cayetanensis and shown to specifically detect the oocysts when attached on their 5' ends to red-emitting fluorophores and used as probes for fluorescence microscopy. Aptamers developed against recombinant wall protein 2 and TA4 antigen-like protein as well as whole oocysts specifically stained C. cayetanensis oocysts while exhibiting little, if any, staining of numerous other waterborne parasite species. Interestingly, the aptamers stained both exterior cell wall moieties and internal structures, suggesting that the aptamers penetrate the oocysts even without added detergents.

Prevalence of the scuticociliate Orchitophrya stellarum in seastars from the Pacific and Atlantic oceans

As part of a study to investigate the use of the scuticociliate Orchitophrya stellarum as a biological control for the invasive seastar Asterias amurensis in Australia, we collected prevalence data for O. stellarum from 3 seastar species (A. amurensis, A. rubens, Pisaster ochraceus) between 1996 and 1999 from the Pacific (Australia, Japan, Korea, Canada) and Atlantic (France, Netherlands, Canada) oceans. In the Pacific Ocean, for the first time, we found O. stellarum in male A. amurensis in Korea and female A. amurensis in Japan. The parasite was not detected in the invasive A. amurensis from Australia. There was no significant difference between size of infected and uninfected male seastars, nor a correlation between biased sex ratio and parasite prevalence in populations in the Pacific or Atlantic oceans. Therefore, unlike other studies, we found size and sex ratio in seastar populations in the field are unreliable indicators of parasite impacts. Regular monitoring of infected seastar populations in the field would be useful to better understand how sex ratio varies with parasite prevalence. We recommend laboratory studies under controlled conditions to determine the effect of O. stellarum on seastar populations.

First report of Dactylogyrus formosus from India: a case of co-existence with Paradactylogyrus catlaius causing mass mortality in Indian major carp, Catla catla

The family Dactylogyridae, known for its role as a frequent pathogen in Cyprinids, was identified in a case of mass mortality involving Catla catla fingerlings (measuring 6.5 ± 2.0 cm and weighing 40.5 ± 10 g) in West Bengal, India. Microscopic examination revealed the presence of two co-existing parasites, Dactylogyrus formosus and Paradactylogyrus catlaius, attached to different sections of the gill filament. Despite their coexistence, these parasites exhibited marked differences in their haptoral hard parts, genital organs, and preferred habitats. Molecular analysis of the Internal Transcribed Spacer 1 and 4 genes indicated more than 90% similarity between the detected parasite and D. formosus previously reported in China. Histopathological observations illustrated the parasites' specific attachment to the distal end of the primary gill lamellae, gradually causing destruction to a maximum number of secondary lamellae. Internally, infiltration of eosinophilic granular cells was observed in gill and kidney blood vessels, while the liver exhibited hepatocytes filled with hemosiderin. The infected fish were treated for 24 h with a safe dose of common salt (5.6 ppt) and albendazole (62 ppm). The survivability rate was significantly higher (p < 0.05) in both treated groups compared to the control. Interestingly, the group treated with common salt showed superior results compared to the albendazole-treated fish. This study presents the sympatric speciation of D. formosus in a new host (C. catla) and explores its host specificity, histopathology, and treatment methods. This case marks the first report of D. formosus causing substantial mortality in cultured Catla in India, alongside the coexistence with Paradactylogyrus catlaius.

The cestode Stringopotaenia psittacea (Fuhrmann, 1904) (Cestoda: Anoplocephalidae) from a critically endangered New Zealand bird: New evidence from ancient coprolites

New Zealand's kākāpō parrot, once widespread, is now critically endangered due to habitat loss and introduced mammalian predators. Prior to major population decline, a unique kākāpō cestode, Stringopotaenia psittacea, was found in the 1880s and first described in 1904. Here we report the discovery of eggs of this cestode in kākāpō coprolites of pre-human settlement age from the Honeycomb Hill cave system, north-west Nelson. Analysis of 52 samples, including coprolites of post-human settlement age, from nine sites within six South Island locations across a wide geographic range, yielded only eight infected samples in this single cave system. Results suggest that prior to human settlement, S.psittacea was not widespread within and between kākāpō populations, in marked contrast to other parasite types of the extinct moa spp. Intense management of the last remaining kākāpō has endangered or possibly caused the extinction of this cestode. This is the first confirmed record of S.psittacea since its discovery in 1884.

PCR-Based Screening of Pathogens in Bombus terrestris Populations of Turkey

PURPOSE

Bumblebees are an important group of insects in the pollination of various vegetables, fruits, oilseeds, legumes, and the fodder crops. Compared to honeybees, they have a wider choice of hosts and a longer flight period. These bees are used especially for the pollination of plants in greenhouses and are commercially produced for this purpose. Recently, serious decreases have been occurring in bumblebee populations due to various reasons such as pathogens, and some of species are even threatened with extinction. Due to the worldwide decline in pollinator insects, determining the distribution and prevalence of bumblebee pathogens is of great importance. Therefore, this study was conducted to determine the incidence and prevalence of pathogens in Turkish bumblebee populations and how much of each pathogen was in bumblebee samples.

METHODS

A total of 172 Bombus terrestris (Linnaeus,1758) samples (21 samples from commercial enterprises, 79 samples from greenhouses and 72 samples from nature) were randomly collected from 3 provinces (Antalya, Mersin and İzmir) where greenhouse cultivation is intensively carried out in Turkey. Eighty-nine of these samples were collected in the spring and eighty-three in the autumn. The presence of four pathogens (Nosema bombi, Crithidia bombi, Apicystis bombi, and Locustacarus buchneri) was investigated by PCR using universal primers.

RESULTS

The overall prevalence of Nosema bombi, Crithidia bombi, Apicystis bombi, and Locustacarus buchneri was determined as 7.55%, 9.3%, 11.62%, and 4.65%, respectively. Co-infections (5.81%) were only detected in wild-caught (nature) samples. C. bombi and A. bombi infections were detected at higher rates in the spring samples than in the autumn samples (p < 0.05). There was no significant difference between the spring and autumn samples with respect to the presence of N. bombi and L. buchneri (p > 0.05).

CONCLUSION

The results obtained could be important in determining the prevalence and spread rates of the bumblebee diseases in Turkey and to determine appropriate protection measures. The information gathered should increase our knowledge about the presence of these pathogens in Turkey and could contribute to improve apiarist's practice. More studies are needed to determine the transmission pathways of these pathogens between the populations. Also, complex pathogen interactions in bumblebee populations should be considered in the future to improve bumblebee health.

[Anticancer effect of parasites and its underlying mechanisms: a review]

Both parasitic diseases and cancers are disorders that seriously threaten human health. A strong correlation has been recently found between parasitic infections and cancers, and multiple species of parasites and their derived products have shown effective to suppress cancer development, progression and metastasis. Therefore, deciphering the interaction among parasites, cancers and hosts not only provides new insights into the development of cancer therapy, but also provides the basis for screening of parasites-derived active anticancer molecules. This review summarizes the latest advances in the anticancer activity of parasites and underlying mechanisms.

TEMPERATURE AND SALINITY AFFECT DEVELOPMENT OF THE PARASITIC SEA ANEMONE EDWARDSIELLA LINEATA POTENTIALLY LIMITING ITS IMPACT AS A BIOLOGICAL CONTROL ON THE CTENOPHORE MNEMIOPSIS LEIDYI

The lined sea anemone, Edwardsiella lineata, parasitizes the ctenophore Mnemiopsis leidyi, which is one of the most destructive marine invasive species in the world. Mnemiopsis leidyi is known to tolerate a wide range of environmental conditions. However, the environmental tolerances of its most prominent parasite have never been characterized. Here we determined the effects of temperature (18, 22, 26, and 30 C) and salinity (6, 15, 24, and 33 ppt) on the survival and development of E. lineata from a vermiform parasite to a free-living polyp. At higher temperatures and lower salinities, E. lineata experienced significantly higher mortality, and it failed to develop into an adult polyp at the highest temperature (30 C) and lowest salinities we tested (6 ppt or 15 ppt). While such temperature and salinity restrictions would not currently prevent E. lineata from infecting M. leidyi in many of the European waters where it has become a destructive invasive species, these environmental limitations may be reducing overlap between host and parasite within the host's native range, a situation that could be exacerbated by climate change.

Does Anisakis spp. infestation affect the proximate composition, fatty acids, and minerals contents of its host Merluccius merlucccius?

Fish play an important role in human nutrition. They are not only a great source of protein and healthy fats, but also a unique source of essential nutrients such as omega-3 fatty acids. Moreover, most fish are parasitized, and some of these parasites are able to influence the reallocation of resources in their favor and thus reduce the nutritional quality of the fish. The present study was conducted to investigate the impact of the third stage larvae (L3) of Anisakis spp. on the proximate composition, macro-minerals (potassium, calcium, and sodium), and fatty acids of European hake (Merluccius merluccius Linnaeus, 1758). In parasitized female group, our results revealed a decrease (p< 0.005) in the amount of carbohydrate by 6.5%, of calcium by 17%, and of 2 polyunsaturated fatty acids (arachidonic acid (C20: 4w-6), and eicosapentaenoic acid (C20: 5w-3) with 33% and 15% respectively. Simultaneously, an increase by 25% in the level of a single saturated fatty acid C10:0 was noticed. According to the principal component analysis, the parasitized female was wealthy of saturated fatty acids and monounsaturated fatty acids and contains less of polyunsaturated fatty acids, omega-3 fatty acids, and omega-6 fatty acids than the unparasitized female and male. No significant changes were observed in the biochemical composition of male hake, probably due to the low mean intensity of L3 larvae of Anisakis spp. in this group.

Plastics in an endemic fish species (Alburnus sellal) and its parasite (Ligula intestinalis) in the Upper Tigris River, Türkiye

Occurrence of micro-, meso- and macroplastics in Alburnus sellal and its parasite Ligula intestinalis is reported for the first time in the Tigris River, one of the two large rivers that defines Mesopotamia. Plastic occurrence was assessed from museum fish materials collected in the upper Tigris River between 2007 and 2021. Plastics were found in 57 % of A. sellal specimens (536 individuals) and in 74 % of L. intestinalis specimens (57 individuals). Mean plastic ingestion was 1.27 ± 1.30 items. fish-1 and 1.77 ± 1.79 items. parasite-1 considering all the fish and parasites analysed. Fibres were the most common types of plastics, comprising 96.2 % and 81 % of plastics in A. sellal and L. intestinalis, respectively. Black was the most common colour of plastics found in both fish (37 %) and parasite specimens (58 %). Microplastics comprised 95.5 % and 100 % of plastics found in A. sellal and L. intestinalis, respectively. In both specimens acrylic (PAN) was the most common polymer as confirmed by FTIR spectroscopy. Differences in plastic ingestion were not significantly over time and among regions. No significant correlation was found between plastics ingestion by fish and by parasites. The present assessment shows that native fish species of the Tigris River have been contaminated by plastics by more than a decade. Our results contribute to a better understanding of the status of plastic pollution in fish and parasites, provide plastic pollution baseline data for the Tigris River and highlight the urgent need to elucidate on the distribution and fate of plastics in freshwater environments and their effects on the ecosystem and humans.

Identification of proteins that bind extracellular microRNAs secreted by the parasitic nematode Trichinella spiralis

Small non-coding RNAs such as microRNAs (miRNAs) are conserved across eukaryotes and play key roles in regulating gene expression. In many organisms, miRNAs are also secreted from cells, often encased within vesicles such as exosomes, and sometimes extravesicular. The mechanisms of miRNA secretion, how they are stabilised outside of cells and their functional importance are poorly understood. Recently, we characterised the parasitic nematode Trichinella spiralis as a model to study miRNA secretion. T. spiralis muscle-stage larvae (MSL) secrete abundant miRNAs which are largely extravesicular. Here, we investigated how T. spiralis miRNAs might remain stable outside of cells. Using proteomics, we identified two RNA binding proteins secreted by T. spiralis larvae and characterised their RNA binding properties. One, a homologue of the known RNA binding protein KSRP, binds miRNA in a selective and sequence-specific fashion. Another protein, which is likely a novel RNA binding protein, binds to miRNA without exhibiting sequence specificity. Our results suggest a possible mechanism for miRNA secretion by T. spiralis and may have relevance for understanding the biology of extracellular miRNA more widely.

The SUN-like protein TgSLP1 is essential for nuclear division in the apicomplexan parasite Toxoplasma gondii

Connections between the nucleus and the cytoskeleton are important for positioning and division of the nucleus. In most eukaryotes, the linker of nucleoskeleton and cytoskeleton (LINC) complex spans the outer and inner nuclear membranes and connects the nucleus to the cytoskeleton. In opisthokonts, it is composed of Klarsicht, ANC-1 and Syne homology (KASH) domain proteins and Sad1 and UNC-84 (SUN) domain proteins. Given that the nucleus is positioned at the posterior pole of Toxoplasma gondii, we speculated that apicomplexan parasites must have a similar mechanism that integrates the nucleus and the cytoskeleton. Here, we identified three UNC family proteins in the genome of the apicomplexan parasite T. gondii. Whereas the UNC-50 protein TgUNC1 localised to the Golgi and appeared to be not essential for the parasite, the SUN domain protein TgSLP2 showed a diffuse pattern throughout the parasite. The second SUN domain protein, TgSLP1, was expressed in a cell cycle-dependent manner and was localised close to the mitotic spindle and, more detailed, at the kinetochore. We demonstrate that conditional knockout of TgSLP1 leads to failure of nuclear division and loss of centrocone integrity.

Antagonism between co-infecting gastrointestinal nematodes: A meta-analysis of experimental infections in Sheep

Gastrointestinal nematodes (GIN) have enormous global impacts in humans, wildlife and grazing livestock. Within grazing livestock, sheep are of particular global importance and the economics and sustainability of sheep production are greatly constrained by GIN infections. Natural infections are composed of co-infections with multiple species, and while some past work suggests species can interact negatively with one another within the same host, there is wide variation in reported patterns. Here, we undertook a systematic literature search and meta-analysis of experimental GIN co-infections of sheep to determine whether these experimental studies support the hypothesis of antagonistic interactions between different co-infecting GIN, and test whether aspects of parasite biology or experimental design influence the observed effects. A systematic search of the literature yielded 4848 studies, within which, we identified 19 experimental sheep studies comparing post-mortem worm counts across two co-infecting GIN species. Meta-analysis of 67 effects obtained from these studies provides strong evidence for interactions between GIN species. There was wide variation in the strength and direction of these interactions, but the global effect was significantly antagonistic. On average, there was a decrease in the number of worms of one species when a co-infecting species was also present, relative to a mono-infection with that species alone. This effect was dependent on the infectious dose and was rapidly lost after anthelmintic treatment, suggesting that live worms are required for the effect to occur. Individual parasite species varied in the extent to which they both exerted, and were subject to, these interspecies interactions, and these differences are more complex than simply co-localisation within the gastrointestinal tract. Antagonistic interactions between co-infecting GIN may feedback into their epidemiology as well as potentially affecting the clinical impacts of infection. Furthermore, the consequences of these interactions may be heightened when clinical interventions affect only one species within the co-infecting network. Whilst it was not possible to identify the causes of variation between GIN species in the impact of co-infection, these findings point to new avenues for epidemiological, clinical and mechanistic research on GIN co-infections.

In vitro evaluation of the effect of galectins on Schistosoma mansoni motility

OBJECTIVE

Galectins are sugar-binding proteins that participate in many biological processes, such as immunity, by regulating host immune cells and their direct interaction with pathogens. They are involved in mediating infection by Schistosoma mansoni, a parasitic trematode that causes schistosomiasis. However, their direct effects on schistosomes have not been investigated.

RESULTS

We found that galectin-2 recognizes S. mansoni glycoconjugates and investigated whether galectin-1, 2, and 3 can directly affect S. mansoni in vitro. Adult S. mansoni were treated with recombinant galectin-1, 2, and 3 proteins or praziquantel, a positive control. Treatment with galectin-1, 2, and 3 had no significant effect on S. mansoni motility, and no other differences were observed under a stereoscopic microscope. Hence, galectin-1, 2, and 3 may have a little direct effect on S. mansoni. However, they might play a role in the infection in vivo via the modulation of the host immune response or secretory molecules from S. mansoni. To the best of our knowledge, this is the first study to investigate the direct effect of galectins on S. mansoni and helps in understanding the roles of galectins in S. mansoni infection in vivo.

mRNA cap-binding protein eIF4E1 is a novel regulator of Toxoplasma gondii latency

The protozoan parasite Toxoplasma gondii causes serious opportunistic disease due to its ability to persist in patients as latent tissue cysts. The molecular mechanisms coordinating conversion between proliferative parasites (tachyzoites) and dormant cysts (bradyzoites) are not fully understood. We previously showed that phosphorylation of eIF2α accompanies bradyzoite formation, suggesting that this clinically relevant process involves regulation of mRNA translation. In this study, we investigated the composition and role of eIF4F multi-subunit complexes in translational control. Using CLIPseq, we find that the cap-binding subunit, eIF4E1, localizes to the 5'-end of all tachyzoite mRNAs, many of which show evidence of stemming from heterogenous transcriptional start sites. We further show that eIF4E1 operates as the predominant cap-binding protein in two distinct eIF4F complexes. Using genetic and pharmacological approaches, we found that eIF4E1 deficiency triggers efficient spontaneous formation of bradyzoites without stress induction. Consistent with this result, we also show that stress-induced bradyzoites exhibit reduced eIF4E1 expression. Overall, our findings establish a novel role for eIF4F in translational control required for parasite latency and microbial persistence.

Effects of Cryptosporidium parvum infection on intestinal fungal microbiota in yaks (Bos grunniens)

During the last decade, researchers had started to focus on the relationship between intestinal parasitic infection and variation of intestinal microflora. Cryptosporidium is a widely known opportunistic and zoonotic pathogen. Several studies have shown that Cryptosporidium infection has impact to alter the gut microflora. However, there are only few studies referring to the fungal microflora changes in response to Cryptosporidium infection in highland ruminants. Therefore, the present study was performed for exploring the alternations of intestinal fungal microbiota in yaks after exposure to Cryptosporidium infection. In present study, Amplicon sequencing of ITS regions was used to study the variations of fungal microflora in yaks. After filtering the raw data, over 45 000 and 62 000 clean data were obtained in uninfected and infected yaks, respectively. By using alpha diversity analysis, it was found that there is no significant difference in the richness and evenness when positive samples were compared with negative ones, whereas intestinal fungal communities in different taxa in yaks were changed. The results of present study depicted that 2-phyla and 21-genera in the infected animals had significantly (P < 0.05) changed. These genera were Septoria, Coniothyrium, Cleistothelebolus, Bensingtonia, Cystobasidium, Filobasidium, Coprotus, Carex, Blumeria, Coprinellus, Leucosporidium, Phialophora, Isolepis, Ascobolus, Thecaphora, Mortierella, Urocystis, Symmetrospora and Lasiobolus. In addition, we found variations in 28 enzymes suggesting that the function of microbiota was also affected. It is concluded that there are drastic changes in the fungal microflora and microbiota functions after exposure to Cryptosporidium infection in yak. Our results help to focus on the prompt way for the development of new therapies to control Cryptosporidiosis.