Intestinal cell diversity and treatment responses in a parasitic nematode at single cell resolution.

BACKGROUND: Parasitic nematodes, significant pathogens for humans, animals, and plants, depend on diverse organ systems for intra-host survival. Understanding the cellular diversity and molecular variations underlying these functions holds promise for developing novel therapeutics, with specific emphasis on the neuromuscular system's functional diversity. The nematode intestine, crucial for anthelmintic therapies, exhibits diverse cellular phenotypes, and unraveling this diversity at the single-cell level is essential for advancing knowledge in anthelmintic research across various organ systems. RESULTS: Here, using novel single-cell transcriptomics datasets, we delineate cellular diversity within the intestine of adult female Ascaris suum, a parasitic nematode species that infects animals and people. Gene transcripts expressed in individual nuclei of untreated intestinal cells resolved three phenotypic clusters, while lower stringency resolved additional subclusters and more potential diversity. Clusters 1 and 3 phenotypes displayed variable congruence with scRNA phenotypes of C. elegans intestinal cells, whereas the A. suum cluster 2 phenotype was markedly unique. Distinct functional pathway enrichment characterized each A. suum intestinal cell cluster. Cluster 2 was distinctly enriched for Clade III-associated genes, suggesting it evolved within clade III nematodes. Clusters also demonstrated differential transcriptional responsiveness to nematode intestinal toxic treatments, with Cluster 2 displaying the least responses to short-term intra-pseudocoelomic nematode intestinal toxin treatments. CONCLUSIONS: This investigation presents advances in knowledge related to biological differences among major cell populations of adult A. suum intestinal cells. For the first time, diverse nematode intestinal cell populations were characterized, and associated biological markers of these cells were identified to support tracking of constituent cells under experimental conditions. These advances will promote better understanding of this and other parasitic nematodes of global importance, and will help to guide future anthelmintic treatments.

Surveys on Baylisascaris procyonis in two of the three French wild raccoon populations.

Human infection by Baylisascaris procyonis can result in larva migrans syndromes, which can cause severe neurological sequelae and fatal cases. The raccoon serves as the definitive host of the nematode, harboring adult worms in its intestine and excreting millions of eggs into the environment via its feces. Transmission to paratenic hosts (such as rodents, birds and rabbits) or to humans occurs by accidental ingestion of eggs. The occurrence of B. procyonis in wild raccoons has been reported in several Western European countries. In France, raccoons have currently established three separate and expanding populations as a result of at least three independent introductions. Until now the presence of B. procyonis in these French raccoon populations has not been investigated. Between 2011 and 2021, 300 raccoons were collected from both the south-western and north-eastern populations. The core parts of the south-western and north-eastern French raccoon populations were free of B. procyonis. However, three worms (molecularly confirmed) were detected in a young raccoon found at the edge of the north-eastern French raccoon population, close to the Belgian and Luxemburg borders. Population genetic structure analysis, genetic exclusion tests and factorial correspondence analysis all confirmed that the infected raccoon originated from the local genetic population, while the same three approaches showed that the worms were genetically distinct from the two nearest known populations in Germany and the Netherlands. The detection of an infected raccoon sampled east of the northeastern population raises strong questions about the routes of introduction of the roundworms. Further studies are required to test wild raccoons for the presence of B. procyonis in the area of the index case and further east towards the border with Germany.

Pinworm (Enterobius Vermicularis) Infestation: An Updated Review.

BACKGROUND: Pinworm infestation is an important public health problem worldwide, especially among children 5 to 10 years of age in developing countries with temperate climates. The problem is often overlooked because of its mild or asymptomatic clinical manifestations. OBJECTIVE: The purpose of this article was to familiarize pediatricians with the diagnosis and management of pinworm infestation. METHODS: A search was conducted in August 2023 in PubMed Clinical Queries using the key terms "Enterobius vermicularis," OR "enterobiasis," OR "pinworm." The search strategy included all clinical trials, observational studies, and reviews published within the past 10 years. Only papers published in the English literature were included in this review. The information retrieved from the above search was used in the compilation of the present article. RESULTS: Enterobiasis is a cosmopolitan parasitosis caused by Enterobius vermicularis. It affects approximately 30% of children worldwide and up to 60% of children in some developing countries. Predisposing factors include poor socioeconomic conditions, inadequate sanitation, poor personal hygiene, and overcrowding. Children aged 5 to 14 years have shown the highest prevalence of enterobiasis.. Egg transmission is mainly by the fecal-oral route. Approximately 30 to 40% of infested patients do not show any clinical symptoms of the disease. For symptomatic patients, the most common presenting symptom is nocturnal pruritus ani. The diagnosis of E. vermicularis infection is best established by the cellophane tape test. The sensitivity of one single test is around 50%; however, the sensitivity increases to approximately 90% with tests performed on three different mornings. If a worm is visualized in the perianal area or the stool, a pathological examination of the worm will yield a definitive diagnosis. As pinworms and eggs are not usually passed in the stool, examination of the stool is not recommended. The drugs of choice for the treatment of pinworm infestation are mebendazole (100 mg), pyrantel pamoate (11 mg/kg, maximum 1 g), and albendazole (400 mg), all of the above-mentioned drugs are given in a single dose and repeated in two weeks. Mebendazole and albendazole are both adulticidal and ovicidal, whereas pyrantel pamoate is only adulticidal. Given their safety and effectiveness, mebendazole and albendazole are currently the best available drugs for the treatment of pinworm infestation. For pregnant women, pyrantel is preferred to mebendazole and albendazole. Treatment of all household members should be considered, especially if there are multiple or repeated symptomatic infections because reinfection is common even when effective medication is given. CONCLUSION: In spite of effective treatment of pinworm infestation, recurrences are common. Recurrences are likely due to repeated cycles of reinfection (particularly, autoinfection) because of the short life span of adult pinworms. Good personal hygiene, such as frequent handwashing, especially after bowel movements and before meals, clipping of fingernails, avoidance of finger-sucking, nail-biting, and scratching in the anogenital area, are important preventive measures. Treatment of all household members should be considered, especially if there are multiple or repeated symptomatic infections.

Ascaridia galli - An old problem that requires new solutions.

Reports of Ascaridia galli in laying hens in Europe have increased since the ban on conventional battery cages in 2012. As this parasite is transmitted directly via the faecal-oral route by parasite eggs containing a larva, it is reasonable to assume that the escalating problem is related to the increased exposure now occurring in modern welfare-friendly cage-free housing systems. On many farms, A. galli reappears in subsequent flocks, even though the birds have no access to the outdoors, biosecurity is high and empty houses are cleaned and disinfected during downtime. Since the egg production cycle lasts only ≈80 weeks and recombinant antigen production for helminth vaccines has not yet been solved, the development of a vaccine seems to be an unrealistic option. Therefore, disrupting the life cycle of the parasite by other means, including the strategic use of dewormers, appears to be the key to controlling infection. Of concern is that only one class of anthelmintics is licenced for poultry in Europe and that are usually administered indiscriminately through the birds' drinking water and often too late when the parasite is already established. If current calendar-based parasite control strategies are not changed, there is a risk that resistance to anthelmintics may develop, as has already been demonstrated with nematodes in livestock. We insist that treatments can be more effective and the risk of developing drug resistance can be mitigated if we invest in a better understanding of A. galli responses to more prudent and judicious use of anthelmintics. This review identifies knowledge gaps and highlights aspects of sustainable parasite control that require further research to support commercial egg producers.

Baylisascaris procyonis Roundworm Infection in Child with Autism Spectrum Disorder, Washington, USA, 2022.

We describe a case of Baylisascaris procyonis roundworm infection in a child in Washington, USA, with autism spectrum disorder. Environmental assessment confirmed nearby raccoon habitation and B. procyonis eggs. B. procyonis infections should be considered a potential cause of human eosinophilic meningitis, particularly among young children and persons with developmental delays.

Using Google Trends to Estimate the Geographic Distribution of Soil-Transmitted Helminthiasis in the United States from 2016 to 2021.

Soil-transmitted helminth infections are assumed to be uncommon in the US, despite numerous studies in the past few decades showing high burdens in Appalachia and the southern states. We assessed trends of interest in the Google search engine to gauge spatiotemporal patterns of potential soil-transmitted helminth transmission. We conducted a further ecological study comparing Google search trends to risk factors for soil-transmitted helminth transmission. Google search trends for terms related to soil-transmitted helminths were clustered in Appalachia and the south, with seasonal surges suggestive of endemic transmission for hookworm, roundworm (Ascaris), and threadworm. Furthermore, lower access to plumbing, increased septic tank use, and more rural environments were associated with increased soil-transmitted helminth-related Google search terms. Together, these results suggest that soil-transmitted helminthiasis remains endemic in parts of Appalachia and the south.

Distribution of Baylisascaris procyonis in Raccoons (Procyon lotor) in Florida, USA.

Baylisascaris procyonis, or raccoon roundworm, is an intestinal nematode parasite of raccoons (Procyon lotor) that is important to public and wildlife health. Historically, the parasite was uncommon in the southeastern US; however, the range of B. procyonis has expanded to include Florida, US. From 2010 to 2016, we opportunistically sampled 1,030 raccoons statewide. The overall prevalence was 3.7% (95% confidence interval=2.5-4.8%) of sampled individuals, and infection intensity ranged from 1 to 48 (mean±standard deviation 9.9±4.0). We found raccoon roundworm in 9/56 (16%) counties sampled, and the percent positive ranged from 1.1% to 13.3% of specimens collected per county. Including previously published data, B. procyonis was detected in 11 Florida counties. We used logistic regression to estimate the contribution of raccoon demographic variables and the presence of the endoparasite Macracanthorhynchus ingens to B. procyonis detection in Florida. Following the model selection process we found housing density, M. ingens presence, and urbanicity to be predictive of raccoon roundworm presence. We also found substantial among-county variation. Raccoon sex and age were not useful predictors. Public health officials, wildlife rehabilitators, wildlife managers, and others should consider any Florida raccoon to be potentially infected with B. procyonis, particularly in areas where housing density is high.

Prescribed fire alters nematode communities in an old-field grassland.

Fire is a common disturbance in many biomes, with both beneficial and detrimental effects on soil biology, which largely depend on fire intensity. However, little is known about the impact of fire on soil nematode communities in terrestrial ecosystem. In the present study, we investigated the effects of short-term prescribed fire on soil nematode communities and soil properties in an old-field grassland in Northern China. The results showed that burning significantly increased soil nematode abundance by 77% and genus richness by 49% compared to the control. Burning also decreased taxon dominance by 45% (Simpson's D) and increased nematode diversity by 31% (Shannon-Weaver H'). However, burning increased plant parasites (particularly genera Cephalenchus and Pratylenchus) and shifted community to more bacterial-feeding genera (i.e., decreased Channel Index). Generally, burning increased soil bio-available nitrogen (NH4 +-N and NO3 --N) content, which would be the main drivers causing nematode community to flourish via a "bottom-up" effect. These results suggest that prescribed fire increases nematode diversity and alters community composition toward more plant parasites and bacterial feeders. Our findings highlight the importance of prescribed fire management in shaping short-term nematode community structure and function, but the long-term effects and impacts of these changes on soil nutrient and carbon cycling remain unknown.

Phytochemical Analysis and Anti-Ascaris suum Activity of Different Zanthoxylum Species In Vitro and In Vivo.

Zanthoxylum plants (ZPs), including multiple Chinese prickly ash species, are dual-purpose functional foods favored by the general population around the world in foods, cosmetics, and traditional medicines and have antipruritic, insecticidal, and fungicidal bioactivities. For the first time, the anti-roundworm bioactivity of ZPs and the active ingredients were compared and investigated. Through nontarget metabolomics following targeted quantitative analysis, qinbunamides, sanshools, sanshooel, asarinin, and sesamin were found to be the main different components of Zanthoxylum species. Coincidentally, the 12 chemical components were also the dominant anti-roundworm ingredients of ZP extracts. The extracts of three species of Chinese prickly ash (1 mg/mL) decreased the hatchability of roundworm eggs significantly, and the ChuanJiao seed killed roundworms (insecticidal rate 100%) and alleviated the symptoms of pneumonia in mice. Furthermore, retention time-accurate mass-tandem mass spectrometry-ion ratio (RT-AM-MS/MS-IR) were modeled by assaying 108 authentic compounds of ZP extracts, and 20 metabolites were confidently identified in biological samples from ZP extract-treated mice by analyzing the m/z values and the empirical substructures. This study provides a good reference for the proper application of ZPs.

Continuity in intestinal parasite infection in Aalst (Belgium) from the medieval to the early modern period (12th-17th centuries).

OBJECTIVE: To characterize patterns in the taxonomic diversity of parasites infecting the population of Aalst, Belgium, between the 12th and 17th centuries. MATERIALS: 14 sediment samples from seven cesspits dated 1100-1700 CE. METHODS: Digital light microscopy and Enzyme-linked immunosorbent assay (ELISA). RESULTS: We identified eggs of four species of helminths: whipworm (Trichuris trichiura), roundworm (Ascaris lumbricoides), Echinostoma fluke and Dicrocoelium fluke. ELISA results for protozoal parasites were negative. CONCLUSIONS: Taxonomic diversity of parasite infections remained constant from the 12th to the 17th centuries. Roundworm and whipworm, spread by poor sanitation, were dominant. Two species of zoonotic parasites were also identified, including for the first time ever in the Low Countries the Echinostoma fluke, which may have been spread by eating uncooked freshwater animal foods. SIGNIFICANCE: Analysis of sediment samples spanning such a broad chronology (six centuries) from a single city offers the opportunity to track diachronic change, which is rare in paleoparasitological studies. LIMITATIONS: We were unable to acquire samples from cesspits dating to the 14th century. SUGGESTIONS FOR FURTHER RESEARCH: Additional data from other Low Countries towns may strengthen the patterns identified in this paper. A similar approach can be used to investigate towns in different regions of the world.

Fatal visceral larva migrans from Toxocara catis infection of the heart and liver in a child.

We discuss the pathophysiology and epidemiology of Toxocara catis infection complicated by visceral larval migrans . We describe a previously healthy 19-month-old white male child found dead in bed by his mother. He had what was thought to be an upper respiratory infection for several days.The child had eosinophilic hepatitis and myocarditis complicating visceral larval migrans due to Toxocara catis infection from the family cat. We discuss the pathologic and clinical aspects of visceral larval migrans due to of Toxocara catis infection.

Iron deficiency and soil-transmitted helminth infection: classic and neglected connections.

Beyond participating in the oxygen transport by red blood cells, iron is an essential micronutrient and contributes to different physiological pathways and processes, such as cell proliferation, DNA repair, and other homeostatic functions. Iron deficiency affects millions of people, especially children and pregnant women. The consequences of iron deficiency are diverse, including inadequate child development, impaired cognition, and reduced productivity. Several factors contribute to iron deficiency, such as iron-poor diet, genetic factors, and infection with soil-transmitted helminths (STHs), especially roundworms (Ascaris lumbricoides), hookworms (Necator americanus and Ancylostoma duodenale), and whipworms (Trichuris trichiura). This review updates and summarizes the role of STHs as drivers of iron deficiency. Also, the poorly explored connections between STH infection, geophagia (a pica manifestation), immune response, and iron deficiency are discussed, highlighting how iron deficiency may act as a risk factor for infections by STHs, in addition to being a consequence of intestinal parasitic infections. Finally, strategies for control and management of iron deficiency and STH infection are described.

First Report of Sarconema eurycerca Heart Infection in Mute Swans in Serbia.

BACKGROUND: The Sarconema eurycerca heart infection may be one of the main causes of death in swans and geese due to severe heart lesions. To date, there have been no reports of Sarconema eurycerca in mute swans (Cygnus olor) in Serbia and this parasite has never been morphologically characterized in wild birds from this region. METHODS: In spring 2021, eight dead mute swans (Cygnus olor) were collected during avian influenza surveillance on the territory of the Province of Vojvodina and submitted to Scientific Veterinary Institute "Novi Sad" to determine the cause of death. The presence of highly pathogenic avian influenza subtype H5N1 was determined in all swans using molecular methods. RESULTS: Necropsy of the swans revealed changes characteristic for highly pathogenic avian influenza infection, such as severe haemorrhages and necrosis in different organs. Three of the eight swans showed massive subepicardial haemorrhages and myocarditis with intralesional 2-4 cm long whitish roundworms. Histopathologically, haemorrhages and many adult heart worms were observed in the myocardium. Based on morphological features of parasites, infection by Sarconema eurycerca was concluded. CONCLUSION: According to the available scientific literature, the presence of heart roundworms in swans has not yet been confirmed in our country. This report is the first published case of cardiac filariasis associated with S. eurycerca infection in mute swans in the Republic of Serbia.

Intestinal parasite infection in the Augustinian friars and general population of medieval Cambridge, UK.

OBJECTIVE: To investigate how lifestyle may have impacted the risk of contracting intestinal parasites in medieval England . Regular clergy (such as those living in monasteries) and the lay population form interesting groups for comparison as diet and lifestyle varied significantly. Monasteries were built with latrine blocks and hand washing facilities, unlike houses of the poor. MATERIALS: Sediment samples from the pelvis, along with control samples from feet and skull, of 19 burials of Augustinian Friars (13th-16th century), and 25 burials from All Saints by the Castle parish cemetery (10th-14th century), Cambridge. METHODS: We analysed the sediment using micro-sieving and digital light microscopy to identify the eggs of intestinal parasites. RESULTS: Parasite prevalence (roundworm and whipworm) in the Augustinian friars was 58%, and in the All Saints by the Castle parishioners just 32% (Barnards Test score statistic 1.7176, p-value 0.092). CONCLUSIONS: It is interesting that the friars had nearly double the infection rate of parasites spread by poor hygiene, compared with the general population. We consider options that might explain this difference, and discuss descriptions and treatment of intestinal worms in medical texts circulating in Cambridge during the medieval period. SIGNIFICANCE: This is the first study to compare prevalence of parasite infection between groups with different socioeconomic status from the same location. LIMITATIONS: Quality of egg preservation was suboptimal, so our data may under-represent the true prevalence. SUGGESTIONS FOR FURTHER RESEARCH: Larger studies with greater statistical power, covering different time periods and regions.

Dive into the sea: first molecular phylogenetic evidence of host expansion from terrestrial/freshwater to marine organisms in Mermithidae (Nematoda: Mermithida).

We report the first mermithid nematode found to be parasitic in a marine tanaidacean crustacean. Ten host tanaidaceans were collected from a depth of 52 m in Otsuchi Bay, Iwate, Japan, north-western Pacific, and identified as a species in the tanaidid genus Zeuxo Templeton, 1840. Nematodes occurred in the host's body cavity; in one case, at least two individuals inhabited a single host. We provide a brief description and illustrations of the morphology of the nematode. In a phylogenetic reconstruction based on the 18S ribosomal RNA gene, the nematode nested in a clade otherwise containing mermithids from terrestrial or freshwater hosts, showing an expansion in host utilization in Mermithidae Braun, 1883 from terrestrial/freshwater hosts to a marine organism.

Soil-Transmitted Helminths and Anaemia: A Neglected Association Outside the Tropics.

Anaemia is an important cause of morbidity and mortality globally. Among infectious agents responsible for anaemia, helminthic infections are often neglected, particularly in non-endemic countries. However, they should not be neglected in this setting, as international travel and migration are on the rise. In this narrative review, we aimed to describe soil-transmitted helminths as a cause of or contributing factor to anaemia, focusing on hookworms (Necator americanus and Ancylostoma duodenale), the whipworm (Trichuris trichiura), the roundworm (Ascaris lumbricoides), and the threadworm (Strongyloides stercoralis). A general review on the epidemiology, lifecycle, and clinical spectrum of anaemia is proposed, with a special focus on helminthic infections' association with anaemia as well as the diagnostic approach, which are both particularly important in non-endemic settings.

Ivermectin-induced gene expression changes in adult Parascaris univalens and Caenorhabditis elegans: a comparative approach to study anthelminthic metabolism and resistance in vitro.

BACKGROUND: The nematode Parascaris univalens is one of the most prevalent parasitic pathogens infecting horses but anthelmintic resistance undermines treatment approaches. The molecular mechanisms underlying drug activity and resistance remain poorly understood in this parasite since experimental in vitro models are lacking. The aim of this study was to evaluate the use of Caenorhabditis elegans as a model for P. univalens drug metabolism/resistance studies by a comparative gene expression approach after in vitro exposure to the anthelmintic drug ivermectin (IVM). METHODS: Twelve adult P. univalens worms in groups of three were exposed to ivermectin (IVM, 10-13 M, 10-11 M, 10-9 M) or left unexposed for 24 h at 37 °C, and total RNA, extracted from the anterior end of the worms, was sequenced using Illumina NovaSeq. Differentially expressed genes (DEGs) involved in metabolism, transportation, or gene expression with annotated Caernorhabditis elegans orthologues were identified as candidate genes to be involved in IVM metabolism/resistance. Similarly, groups of 300 adult C. elegans worms were exposed to IVM (10-9 M, 10-8 M and 10-7 M) or left unexposed for 4 h at 20 °C. Quantitative RT-PCR of RNA extracted from the C. elegans worm pools was used to compare against the expression of selected P. univalens candidate genes after drug treatment. RESULTS: After IVM exposure, 1085 DEGs were found in adult P. univalens worms but the relative gene expression changes were small and large variabilities were found between different worms. Fifteen of the DEGs were chosen for further characterization in C. elegans after comparative bioinformatics analyses. Candidate genes, including the putative drug target lgc-37, responded to IVM in P. univalens, but marginal to no responses were observed in C. elegans despite dose-dependent behavioral effects observed in C. elegans after IVM exposure. Thus, the overlap in IVM-induced gene expression in this small set of genes was minor in adult worms of the two nematode species. CONCLUSION: This is the first time to our knowledge that a comparative gene expression approach has evaluated C. elegans as a model to understand IVM metabolism/resistance in P. univalens. Genes in P. univalens adults that responded to IVM treatment were identified. However, identifying conserved genes in P. univalens and C. elegans involved in IVM metabolism/resistance by comparing gene expression of candidate genes proved challenging. The approach appears promising but was limited by the number of genes studied (n = 15). Future studies comparing a larger number of genes between the two species may result in identification of additional candidate genes involved in drug metabolism and/or resistance.

Low exposure of urban dogs in metropolitan Sydney, Australia to Toxocara canis demonstrated by ELISA using T. canis excretory-secretory (E/S) larval antigens.

Canine roundworm, Toxocara canis, is considered ubiquitous but patent infections are rare in adult owned urban dogs. Hepato-pulmonary migration of T. canis is common in young dogs, but in adult dogs, the migration of T. canis is arrested in tissues and larvae are inhibited. During this somatic migration, T. canis release excretory-secretory (E/S) larval antigens against which the host mounts an immune response. Detection of anti-T. canis E/S immunoglobulins is considered a proxy for the presence of arrested somatic T. canis larvae. By screening several cohorts of dogs in New South Wales (NSW), Australia, we determined the seroprevalence of anti-T. canis E/S in urban owned dogs visiting a veterinary teaching hospital in Sydney to be 3.8 % (n = 53), which was significantly lower (two-proportion z-test, P < 0.05) than the seroprevalence in pet dogs in regional western NSW (22.2 %, n = 63), and rehomed greyhounds (53.6 %, n = 28). Using a logistic regression model, the risk of testing positive in regional pet dogs (odds ratio [OR] = 37.0) and rehomed greyhounds (OR = 81.0) was significantly higher than in urban dogs (P < 0.05). Although routine deworming of dogs eliminates patent infection, our data show a low number of urban dogs with anti-T. canis E/S antibodies, which implies that the majority of these dogs were not exposed to T. canis previously, do not possess inhibited T. canis larvae, and in the case of intact females, will not transmit it to their puppies.

An Overview of Ascariasis Involvement in Gallbladder Disease: A Systematic Review of Case Reports.

Ascaris lumbricoides is the most common type of helminth infection in humans. It affects more than one billion of the world's population. Children living in developing nations are prone to ascariasis, presenting with obstructive biliary illnesses. Migration of Ascaris worms through the major duodenal papilla to the hepatobiliary system leads to symptoms of biliary colic and complications along the biliary tree. In April 2022, we performed a systematic review of case reports to identify and examine cases of gallbladder ascariasis worldwide. A methodical search using PubMed, Semantic Scholar, ScienceDirect, and Directory of Open Access Journals yielded 2773 studies. After duplicate removal, title, abstract, and content screening, retrieval, and quality assessment, 13 studies met the criteria for this systematic review of case reports. The cases and results from these 13 studies revealed gallbladder ascariasis in different age groups worldwide. This systematic review discusses ascariasis, explicitly highlighting its presence in the gallbladder, symptomatic presentation, laboratory/imaging findings, complications, and approach to management.