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BACKGROUND: One-fifth of the global population is infected with soil-transmitted helminths (STH). Mass drug administration (MDA) with deworming medication is widely implemented to control morbidity associated with STH infections. However, surveillance of human infection prevalence by collecting individual stool samples is time-consuming, costly, often stigmatized, and logistically challenging. Current methods of STH detection are poorly sensitive, particularly in low-intensity and low-prevalence populations. METHODOLOGY/PRINCIPAL FINDINGS: We aimed to develop a sensitive and specific molecular method for detecting STH DNA in large volumes of soil (20 g) by conducting laboratory and proof of concept studies across field sites in Kenya, Benin, and India. We collected human stool (n = 669) and soil (n = 478) from 322 households across the three study sites. We developed protocols for DNA extraction from 20 g of soil and qPCR to detect Ascaris lumbricoides, Trichuris trichiura, Necator americanus, and Ancylostoma duodenale. Agreement between detection of STH via qPCR, digital droplet PCR (ddPCR), and microscopy-based methods was assessed using the Cohens Kappa statistic. Finally, we estimated associations between soil characteristics and detection of STH in soil by qPCR, as well as between STH detected in soil and STH detected in stool from matched households, adjusting for soil characteristics. The overall prevalence of STH in soil by qPCR was 31% for A. lumbricoides, 3% for T. trichiura, and 13% for any hookworm species. ddPCR and qPCR performed similarly. However, there was poor agreement between STH detected in soil by qPCR versus light microscopy. Microscopy underestimated the prevalence of A. lumbricoides and N. americanus and overestimated T. trichiura. Detection of an STH species in household soil was strongly associated with increased odds of a household member being infected with that same species. CONCLUSIONS/SIGNIFICANCE: Soil surveillance for STH has several benefits over stool-based surveillance, including lower cost and higher success rates for sample collection. Considering that delivery of MDA occurs at the community level, environmental surveillance using molecular methods could be a cost-effective alternate strategy for monitoring STH in these populations.

Helminth infections are a major public health problem as they can cause long-term chronic infections in their hosts for which there is no effective vaccine. During the long-term interaction between helminths and their hosts, helminth-derived extracellular vesicles (EVs) can participate in host immunomodulatory processes by secreting bioactive molecules (BMAs). Growing data suggests that microRNAs (miRNAs) in helminth EVs have a significant impact on the host's immune system. The let-7 family is highly conserved among helminth EVs and highly homologous in the host, and its function in host–parasite crosstalk may reflect active selection for compatibility with the host miRNA machinery. In-depth studies targeting this aspect may better elucidate the mechanism of parasite-host interactions. Hence, this review summarizes the current studies on the cross-species involvement of helminth EV-derived let-7 in host immune regulation and discusses the barriers to related research and potential applications of helminth EVs. [ABSTRACT FROM AUTHOR]

Introduction: Ascaris lumbricoides infection is one of the most common soil-transmitted helminthiasis and IgE response to this helminth may increase the risk of asthma, bronchial hyperreactivity and atopy. There is not enough evidence showing the role of group-2 innate lymphoid cells (ILC2) in the pathogenesis of helminth infections in humans. Here, we aimed to investigate and characterize the influence of Ascaris lumbricoides infection on circulating ILCs in endemically exposed subjects. Methods: Non-infected (NI; n=16) and Ascaris-infected (AI; n=16) subjects from an endemic area were included. Two consecutive stool samples from each subject were examined by Kato-Katz to define parasite infection. Antibodies to the ABA-1 antigen of Ascaris and Ascaris extract were measured by ELISA. ILC subsets and their activation markers (CD25, CD69, thymic stromal lymphopoietin receptor (TSLPR) were evaluated in its PBMC by flow cytometry. Proximity extension assay (PEA) was performed to explore plasma proteins associated to infection. Results: No significant differences in the relative or absolute frequencies of total ILCs, ILC1, ILC2 and ILC3 cells were observed regarding the infection status. However, within AI group, IgE-sensitized subjects to ABA-1 had higher frequencies and counts of ILC2 (p<0.05). Frequencies of CD25+, CD69+ and TSLPR+ ILC2 were higher in AI compared to the NI (p<0.01). Additionally, egg burden was positively correlated with CD69+ ILC2 frequencies (r=0.67; p=0.005). Tryptase alpha/beta 1 (TPSAB1), GP6 and several plasma proteins associated with cell growth and granulocyte chemotaxis were highly expressed in the AI group (p<0.05). Interestingly, TPSAB1 levels were positively correlated with ILC2 expressing activation markers frequencies, egg burden and IgE levels against Ascaris. Discussion: Ascaris infection is associated with increased expression of ILC2 activation markers and TPSAB1, which may contribute to the type-2 response. [ABSTRACT FROM AUTHOR]

Introduction: Live microfilariae (mf) and mf-derived extracellular vesicles (EVs) have been shown to modulate human antigen presenting cell (APC) function, most notably by suppressing the induction of IL-12 (and other pro-inflammatory cytokines) following activation with LPS and interferon-y. Methods: To explore further how EVs alter human APC function, we studied the effect of mf and EVs on human elutriated monocyte-derived dendritic cells (DC) following exposure to Mf, mf-derived excretory/secretory (E/S) products, E/S depleted of EVs through ultracentrifugation and purified EVs. After demonstrating that the measurable responses induced by live mf could be recapitulated by EVs and EV-containing E/S, we next performed RNAseq analysis of human DC following exposure to live mf, EVs, E/S, or EV-depleted E/S. Results: In our analyses of the data for the DC, using a false discovery rate (FDR) <0.05, EV-exposed DC had induced the expression of 212 differentially expressed genes (DEGs) when compared to unexposed DC and 157 when compared to E/Sdepleted EVs. These genes were enriched in GO biological processes associated with neutrophil degranulation and 15 DEGs associated with KEGG Lysosome pathways. IPA analysis point to immune dysregulation. We next aimed to understand the intracellular processes altered by EVs and the effect these have on effector T cells. When SARS CoV-2 Membrane-specific CD4+ TCLs were assessed following EV conditioning of autologous DC and activation with the SARS CoV-2-Membrane peptide pool, we found conditioning reduced the frequency of SARS CoV-2 Membrane-specific CD3+ CD4+ CD154+ cells (p=.015). Similarly, EV-conditioning of SARS CoV-2 Membrane-specific CD3+ CD4+ cells induced fewer cell capable of producing IFN-g (p=.045). Discussion: Taken together, our data suggest a modulatory role of EVs on APC function that likely leads to defects in T cell effector function. [ABSTRACT FROM AUTHOR]

Little is known of helminth parasites in Micronesia in archaeological contexts. This study presents a parasitological analysis of soil and sediment samples from Ebon Atoll in the Marshall Islands, eastern Micronesia. Microscopic eggs of the dog (Canis lupus familiaris) nematode Toxocara canis, which could have adversely affected the health of local people as well as their dogs, were found at two sites, in one example in habitation layers dated to 1830–1625 calBP (95% CI), extending the date for the known presence of dogs in the Marshall Islands by at least 600 years. This study represents the first confirmed evidence of pre‐European helminth parasites in Micronesia. As similar Melanesian and Polynesian studies have previously been reported, the study also completes the initial, pre‐contact helminth record for the three main island regions of Oceania. [ABSTRACT FROM AUTHOR]

The host/parasite relationship is a key tool for understanding the role of parasitism in the feeding ecology of Antarctic seabirds. Especially, birds with extensive migratory routes through isolated regions are particularly sensitive to new infections. Although research on parasitic diSseases in Antarctic birds is sparse and information is fragmentary, an increasing number of studies are currently underway in this area. The present study aims to provide new information on parasitic helminths in the Southern Giant Petrel Macronectes giganteus in some nesting areas from South Shetland Island and Antárctic Península, integrating different parasitological techniques. A total of 126 faecal samples, 16 regurgitates and six dead individuals (five adults and one chick) were analysed for helminth parasites. Members of four helminth groups (Cestoda, Digenea, Nematoda, Acanthocephala) represented the parasitic diversity of the Southern Giant Petrel in the studied localities. All dead birds analysed (P = 100%) harboured helminth parasites, additionally P = 49.2% of the faecal samples and P = 6.25% of the regurgitated individuals presented at least one of the different helminth groups found in the viscera. The combination of three diagnostic techniques allowed us to determine the presence of nine helminth species (Cosmocephalus obvelatus, Stegophorus macronectes, Stegophorus diomedeae, Contracaecum sp., Parorchites zederi, Tetrabothrius heteroclitus, Diphylobotrium sp., Corynosoma shackletoni, and Renicolidae). In addition, juvenile specimens of Tetrameres sp. and Anisakis sp. were found in the eviscerated host. We discuss the trophic relationships of the hosts and their influence in the helminth infestations. This study provides new knowledge about the parasitic diversity of the Southern Giant Petrel in its nestling areas with new records of helminth species in Antarctica. [ABSTRACT FROM AUTHOR]

For this molecular genetic research, helminthological samples were collected from the lungs of 17 samples of Pelophylax terentievi (Mezhzherin, 1992) distributed in Kashkadarya and Surkhondarya regions in the spring and summer of 2024. The difference between the nucleotides of the R. engelbrechti_uz (PQ219671) sample belonging to the Rhabdias genus collected from the southern regions of our republic and the R. engelbrechti (MG428406) sample obtained from the NCBI database was 0.4%. Nucleotide sequence obtained as a result of molecular-genetic study of engelbrechti belonging to Rhabdias genus was placed in the National Center for Biotechnology Information. This species was recorded for the first time to the best of our knowledge in the territory of the Republic of Uzbekistan. [ABSTRACT FROM AUTHOR]

Parasitic otitis is an inflammatory process that can affect the external to internal cattle ear, causing discomfort in animals, impairing performance, and even leading to animal death. The infection was initially associated with nematodes of the Rhabditis genus in tropical and subtropical regions. Currently, the nematode species described as associated with bovine otitis are Metarhabditis costai, Metarhabditis freitasi, and, more recently, M. blumi. It is worth highlighting that there is still a lack of robust information regarding the morphological details, ultrastructural aspects, and molecular biology data of these species. The Metarhabditis genus is composed of seven species and two more have recently been added. The objective of this study is to update the morphological data using advanced microscopy techniques to emphasize and clarify the main morphological differences between three species of Metarhabditis currently associated with parasitic otitis. Samples of inflammatory exudate were collected from four adult female Gir cattle (Bos taurus indicus) on a farm in Itabira, Minas Gerais state, Brazil. Specimens were analyzed using light microscopy and scanning electron microscopy. Two species, M. costai and M. freitasi, were morphologically identified, consistent with previous reports. Scanning electron microscopy revealed new structural characteristics of the nematode species involved in parasitic otitis compared with M. blumi obtained from the CGC Center. Significant differences were observed in the male posterior region, bursa, and tail. Molecular analysis was conducted to differentiate these three species, and it was observed that the species first associated with otitis formed distinct clusters compared to M. blumi. However, it is important to note that further studies are needed to genetically characterize species of the Metarhabditis genus. [ABSTRACT FROM AUTHOR]

Zoo conditions are unique for reindeer, since domestic reindeer are not kept in captive facilities like cattle. In the zoo, reindeer are usually surrounded by many different animals that they would never encounter naturally. Thus, they might be infected with new helminths. Numerous petting zoos raise concerns about the safety of tactile interactions for human visitors. Our study is the first large-scale one. Qualitative and quantitative fecal analyses were carried out for 233 reindeer distributed over 50 Russian zoos according to the National Standard of the Russian Federation (GOST R 54627-2011) Ruminant animals—Methods of Laboratory Helminthological Diagnostics. Where possible, DNA analyses of helminths were performed targeting internal transcribed spacer region. As a result, F. hepatica, Paramphistomum sp., Moniezia sp. (including M. expansa), gastrointestinal strongylids (including Nematodirus spp.), Dictyocaulus sp., E. rangiferi, Trichuris sp., and Capillaria sp. were found in 106 (45%) zoo reindeer. All these helminths were previously reported in reindeer and pose no direct danger for humans. The intensity of invasions was mostly low. Fecal examination might be considered as an indirect method for mange diagnostics, as Chorioptes and Demodex mites were found in reindeer fecal samples. The latter may represent a novel species of mite specific for reindeer. [ABSTRACT FROM AUTHOR]

Fisheries and aquaculture are crucial for ensuring food security and are significant sources of income and social advancement in developing nations. Parasitic infections among fish in natural and artificial culture systems are detrimental to their health and growth. Epidemiological studies are a prerequisite to understanding the dynamics of the disease in a fish population. In the present study, we have evaluated the prevalence and seasonal variation of the digenetic trematode parasite Isoparorchis hypselobagri infecting the catfish Wallago attu from the Aligarh region of Uttar Pradesh. To perform epidemiological studies, regular sampling of fish was carried out from March 2018 to February 2023. A total of 1110 fish were examined, of which 293 were infected with I. hypselobagri. The total number of parasites recovered from the fish host W. attu was 1297 and the prevalence and mean intensity were 26.39% and 4.42, respectively. The highest prevalence of infection, with a value of 34.94%, was observed during the winter season, while the summer season exhibited the lowest prevalence of 12.78%. The findings suggest that the prevalence of the parasite is highest during the late monsoon to early winter months and lowest during the summer to early monsoon months. This variation in prevalence may be attributed to environmental conditions, particularly temperature fluctuations. The necessity to assess parasite infection arises because parasitic infection or sickness in fish causes significant damage to the fishing industry, and as a consequence, livelihoods in poor or developing countries are affected. [ABSTRACT FROM AUTHOR]

The present study is aimed to investigate potential in vitro anthelmintic efficacy of two phenolic compounds Ferulic acid and Sinapic acid against the parasite H. diminuta. Adult parasites collected from infected rat's intestine (maintained in our laboratory) were treated with 1, 2.5, 5, 10 and 20 mg/mL concentrations of both the compounds in RPMI-1640 media containing 1% Tween 20. Further, one group was treated in Praziquantel as a reference drug and another group of parasites were kept as control. The efficacy was evaluated on the basis of motility and mortality of the parasites. The paralyzed worms were further processed for the morphological and ultrastructural studies and observed through light and scanning electron microscopy. A significant dose-dependent efficacy was found in all treatment and decrease in relative movability value was also recorded in all the concentrations of two compounds treated parasites. The time taken for paralysis in 5 mg/mL of Ferulic acid and 10 mg/mL of Sinapic acid were 1.47 ± 0.04 h and 0.88 ± 0.03 h respectively which is accorded with the standard concentration of Praziquantel. Morphological micrographs revealed pronounced distortion and altered topography of scolex and tegument while histological study showed loss of uniform tegumental integrity with folds and cracks in the treated parasites. Further, extensive alteration in the scolex and irrevocable disruption all over the body surface with loss of trapezoid shape, shrinkage of tegument and sloughing off microtriches were observed in electron microscopic study. The study indicated that both the compounds possess strong activity against H. diminuta and further studies are required to understand their detailed mode of action to exploit them as potential alternative candidates for curing helminthiases. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To investigate the prevalence of parasitic infections in the human population and identify the related risk factors of Gonabad city, southeast of Khorasan Razavi province, northeastern Iran. METHODOLOGY: This cross-sectional study was performed from March to April 2019 in Gonabad city in Khorasan Razavi province in northeastern Iran. One thousand thirty-eight stool samples were examined using parasitological methods like direct wet-mounting, formalin-ether concentration and Gomori's trichrome staining. Moreover, the socio-demographic data of inhabitants were recorded. All statistical analyses were performed using SPSS software (version 16). Qualitative variables were reported as numbers and percentages. RESULTS: The overall intestinal parasitic infection prevalence was 18.1 %, whereas this value for protozoan agents was 16.7% (95% CI 14.14 to 19) and 1.3% (95% CI 0.7 to 2) for helminth parasites. The highest parasitic agent prevalence belongs to Blastocystis sp (12.4 %), Entamoeba coli (1.8%) and Enterobius vermicularis (1.2%), respectively. Giardia lamblia (1.1%) Entamoeba histolytica /dispar (0.3%), Iodamoeba butschlii (0.3%), Chilomastix mesnili (0.3%), Hymenolepis nana (0.2 %) Dientamoeba fragilis (0.2%) and Trichomonas hominis (0.3%) were other identified parasites. Multivariate logistic regression analysis revealed a significant association of parasitic intestinal infections with factors such as age, residency status and source of drinking water (P

Parasitic worms (helminths) establish chronic infection within mammalian hosts by strategically regulating their host’s immune responses. Deciphering the mechanisms by which host non-coding RNAs (ncRNA) co-ordinate the activation and regulation of immune cells is essential to understanding host immunity and immune-related pathology. It is also important to comprehend how pathogens secrete specific ncRNAs to manipulate gene expression of host immune cells and influence their response to infection. To investigate the contribution of both host and helminth derived ncRNAs to the activation and/or regulation of innate immune responses during a parasite infection, we examined ncRNA expression in the peritoneal macrophages from mice infected with Fasciola hepatica. We discovered the presence of several parasitic-derived miRNAs within host macrophages at 6 hrs and 18 hrs post infection. Target prediction analysis showed that these Fasciola miRNAs regulate host genes associated with the activation of host pro-inflammatory macrophages. Concomitantly, there was a distinct shift in host ncRNA expression, which was significant at 5 days post-infection. Prediction analysis suggested that these host ncRNAs target a different cohort of host genes compared to the parasite miRNAs, although the functional outcome was predicted to be similar i.e. reduced pro-inflammatory response and the promotion of a reparative/tolerant phenotype. Taken together, these observations uncover the interplay between host and parasitic ncRNAs and reveal a complementary regulation of the immune response that allows the parasite to evade immune detection and promote tissue repair for the host. These findings will provide a new understanding of the molecular interaction between parasites and host.

Zoo conditions are unique for reindeer, since domestic reindeer are not kept in captive facilities like cattle. In the zoo, reindeer are usually surrounded by many different animals that they would never encounter naturally. Thus, they might be infected with new helminths. Numerous petting zoos raise concerns about the safety of tactile interactions for human visitors. Our study is the first large-scale one. Qualitative and quantitative fecal analyses were carried out for 233 reindeer distributed over 50 Russian zoos according to the National Standard of the Russian Federation (GOST R 54627-2011) Ruminant animals—Methods of Laboratory Helminthological Diagnostics. Where possible, DNA analyses of helminths were performed targeting internal transcribed spacer region. As a result, F. hepatica, Paramphistomum sp., Moniezia sp. (including M. expansa), gastrointestinal strongylids (including Nematodirus spp.), Dictyocaulus sp., E. rangiferi, Trichuris sp., and Capillaria sp. were found in 106 (45%) zoo reindeer. All these helminths were previously reported in reindeer and pose no direct danger for humans. The intensity of invasions was mostly low. Fecal examination might be considered as an indirect method for mange diagnostics, as Chorioptes and Demodex mites were found in reindeer fecal samples. The latter may represent a novel species of mite specific for reindeer.

Parasitic otitis is an inflammatory process that can affect the external to internal cattle ear, causing discomfort in animals, impairing performance, and even leading to animal death. The infection was initially associated with nematodes of the Rhabditis genus in tropical and subtropical regions. Currently, the nematode species described as associated with bovine otitis are Metarhabditis costai, Metarhabditis freitasi, and, more recently, M. blumi. It is worth highlighting that there is still a lack of robust information regarding the morphological details, ultrastructural aspects, and molecular biology data of these species. The Metarhabditis genus is composed of seven species and two more have recently been added. The objective of this study is to update the morphological data using advanced microscopy techniques to emphasize and clarify the main morphological differences between three species of Metarhabditis currently associated with parasitic otitis. Samples of inflammatory exudate were collected from four adult female Gir cattle (Bos taurus indicus) on a farm in Itabira, Minas Gerais state, Brazil. Specimens were analyzed using light microscopy and scanning electron microscopy. Two species, M. costai and M. freitasi, were morphologically identified, consistent with previous reports. Scanning electron microscopy revealed new structural characteristics of the nematode species involved in parasitic otitis compared with M. blumi obtained from the CGC Center. Significant differences were observed in the male posterior region, bursa, and tail. Molecular analysis was conducted to differentiate these three species, and it was observed that the species first associated with otitis formed distinct clusters compared to M. blumi. However, it is important to note that further studies are needed to genetically characterize species of the Metarhabditis genus.

Abstract Background Estimation of prevalence of Strongyloides stercoralis infection is required in endemic areas, in order to identify areas in need of control programmes. Data on prevalence of strongyloidiasis in Madagascar are scant. Aim of this work was to estimate prevalence of S. stercoralis in four districts of Madagascar. Methods Fecal and serum samples collected in the context of a previous study on schistosomiasis were tested with S. stercoralis real-time PCR and serology, respectively. A multiplex real-time PCR for Ascaris lumbricoides, Ancylostoma duodenalis, Necator americanus, and Trichuris trichiura was done on fecal samples collected in the areas demonstrating higher prevalence of strongyloidiasis. Comparisons between proportions were made using Fisher exact test, with false discovery rate correction used for post-hoc comparisons. A multivariable Firth logistic regression model was used to assess potential risk factors for S. stercoralis infection. Results Overall, 1775 serum samples were tested, of which 102 of 487 (20.9%) and 104 of 296 (35.2%) were serological-positive in Marovoay and in Vatomandry districts (both coastal areas), respectively, compared to 28 of 496 (5.6%) and 30 of 496 (6.1%) in Tsiroanomandidy and in Ambositra districts (both highlands), respectively (adj. p

Helminth infections are prevalent in poverty-stricken areas and developing countries with warm, humid climates and poor sanitary conditions. The limited availability of anthelmintic drugs and the emergence of drug resistance have prompted the search for new treatment options. Medicinal plants, traditionally used for treating various ailments, including parasitic infections, have been explored as sources of novel anthelmintic compounds. To evaluate the preliminary phytochemical analysis and in vitro anthelmintic activity of Colchicum autumnale L. corm extract. The anthelmintic activity of C. autumnale corm extract was tested against Pheretima posthuma (earthworms). Five different concentrations (20, 40, 60, 80, and 100 mg/ml) of the C. autumnale extract were used, alongside the standard drug albendazole at the same concentrations. The time taken for paralysis and death of the worms was recorded. The preliminary phytochemical qualitative analysis of the ethanolic extract showed the presence of alkaloids, carbohydrates, glycosides, saponins, phenols, tannins, and steroids. The study highlighted the potential of C. autumnale extract as a natural anthelmintic agent. The dose-dependent activity suggested that higher concentrations of the extract provided more effective anthelmintic action. However, further research is necessary to establish the optimal dosing, safety, and in vivo efficacy of the extract.

Members of the genus Scaphanocephalus mature in accipitrids, particularly osprey, Pandion haliaetus, with metacercaria causing Black Spot Syndrome in reef fishes. In most of the world, only the type species, Scaphanocephalus expansus (Creplin, 1842) has been reported. Recent molecular studies in the Western Atlantic, Mediterranean and Persian Gulf reveal multiple species of Scaphanocephalus, but have relied on 28S rDNA, mainly from metacercariae, which limits both morphological identification and resolution of closely related species. Here we combine nuclear rDNA with mitochondrial sequences from adult worms collected in osprey across North America and the Caribbean to describe species and elucidate life cycles in Scaphanocephalus. A new species described herein can be distinguished from S. expansus based on overall body shape and size. Phylogenetic analysis of the whole mitochondrial genome of Scaphanocephalus indicates a close relationship with Cryptocotyle. We conclude that at least 3 species of Scaphanocephalus are present in the Americas and 2 others are in the Old World. Specimens in the Americas have similar or identical 28S to those in the Mediterranean and Persian Gulf, but amphi-Atlantic species are unlikely in light of divergence in cytochrome c oxidase I and the lack of amphi-Atlantic avian and fish hosts. Our results provide insight into the geographic distribution and taxonomy of a little-studied trematode recently linked to an emerging pathology in ecologically important reef fishes.

Extracellular vesicles (EVs) have emerged as key intercellular communication and pathogenesis mediators. Parasitic organisms' helminths, causewidespread infections with significant health impacts worldwide. Recent research has shed light on the role of EVs in the lifecycle, immune evasion, and disease progression of these parasitic organisms. These tiny membrane-bound organelles including microvesicles and exosomes, facilitate the transfer of proteins, lipids, mRNAs, and microRNAs between cells. EVs have been isolated from various bodily fluids, offering a potential diagnostic and therapeutic avenue for combating infectious agents. According to recent research, EVs from helminths hold great promise in the diagnosis of parasitic infections due to their specificity, early detection capabilities, accessibility, and the potential for staging and monitoring infections, promote intercellular communication, and are a viable therapeutic tool for the treatment of infectious agents. Exploring host-parasite interactions has identified promising new targets for diagnostic, therapy, and vaccine development against helminths. This literature review delves into EVS's origin, nature, biogenesis, and composition in these parasitic organisms. It also highlights the proteins and miRNAs involved in EV release, providing a comprehensive summary of the latest findings on the significance of EVs in the biology of helminths, promising targets for therapeutic and diagnostic biomarkers. [ABSTRACT FROM AUTHOR]

The global prevalence of type 2 diabetes mellitus (T2D) is increasing rapidly, with an anticipated 600 million cases by 2035. While infectious diseases such as helminth infections have decreased due to improved sanitation and health care, recent research suggests a link between helminth infections and T2D, with helminths such as Schistosoma, Nippostrongylus, Strongyloides, and Heligmosomoides potentially mitigating or slowing down T2D progression in human and animal models. Helminth infections enhance host immunity by promoting interactions between innate and adaptive immune systems. In T2D, type 1 immune responses are suppressed and type 2 responses are augmented, expanding regulatory T cells and innate immune cells, particularly type 2 immune cells and macrophages. This article reviews recent research shedding light on the favorable effects of helminth infections on T2D. The potential defense mechanisms identified include heightened insulin sensitivity and reduced inflammation. The synthesis of findings from studies investigating parasitic helminths and their derivatives underscores promising avenues for defense against T2D. [ABSTRACT FROM AUTHOR]

Background: Respiratory syncytial virus (RSV) infection in infants is a major cause of viral bronchiolitis and hospitalisation. We have previously shown in a murine model that ongoing infection with the gut helminth Heligmosomoides polygyrus protects against RSV infection through type I interferon (IFN‐I) dependent reduction of viral load. Yet, the cellular basis for this protection has remained elusive. Given that recruitment of mononuclear phagocytes to the lung is critical for early RSV infection control, we assessed their role in this coinfection model. Methods: Mice were infected by oral gavage with H. polygyrus. Myeloid immune cell populations were assessed by flow cytometry in lung, blood and bone marrow throughout infection and after secondary infection with RSV. Monocyte numbers were depleted by anti‐CCR2 antibody or increased by intravenous transfer of enriched monocytes. Results: H. polygyrus infection induces bone marrow monopoiesis, increasing circulatory monocytes and lung mononuclear phagocytes in a IFN‐I signalling dependent manner. This expansion causes enhanced lung mononuclear phagocyte counts early in RSV infection that may contribute to the reduction of RSV load. Depletion or supplementation of circulatory monocytes prior to RSV infection confirms that these are both necessary and sufficient for helminth induced antiviral protection. Conclusions: H. polygyrus infection induces systemic monocytosis contributing to elevated mononuclear phagocyte numbers in the lung. These cells are central to an anti‐viral effect that reduces the peak viral load in RSV infection. Treatments to promote or modulate these cells may provide novel paths to control RSV infection in high risk individuals. [ABSTRACT FROM AUTHOR]

Background: Estimation of prevalence of Strongyloides stercoralis infection is required in endemic areas, in order to identify areas in need of control programmes. Data on prevalence of strongyloidiasis in Madagascar are scant. Aim of this work was to estimate prevalence of S. stercoralis in four districts of Madagascar. Methods: Fecal and serum samples collected in the context of a previous study on schistosomiasis were tested with S. stercoralis real-time PCR and serology, respectively. A multiplex real-time PCR for Ascaris lumbricoides, Ancylostoma duodenalis, Necator americanus, and Trichuris trichiura was done on fecal samples collected in the areas demonstrating higher prevalence of strongyloidiasis. Comparisons between proportions were made using Fisher exact test, with false discovery rate correction used for post-hoc comparisons. A multivariable Firth logistic regression model was used to assess potential risk factors for S. stercoralis infection. Results: Overall, 1775 serum samples were tested, of which 102 of 487 (20.9%) and 104 of 296 (35.2%) were serological-positive in Marovoay and in Vatomandry districts (both coastal areas), respectively, compared to 28 of 496 (5.6%) and 30 of 496 (6.1%) in Tsiroanomandidy and in Ambositra districts (both highlands), respectively (adj. p < 0.001). PCR for S. stercoralis was positive in 15 of 210 (7.1%) and in 11 of 296 (3.7%) samples from Marovoay from Vatomandry, respectively, while was negative for all samples tested in the other two districts. High prevalence of A. lumbricoides (45.9%), hookworm (44.6%) and T. trichiura (32.1%) was found in Vatomandry. In the multivariable analysis, strongyloidiasis was associated with hookworm infection. Hookworm infection was also associated with male sex and lower education level. Conclusions: S. stercoralis prevalence proved higher in coastal areas compared to highlands. Different climatic conditions may explain this distribution, along with previous rounds of anthelminthics distributed in the country, which may have reduced the parasite load in the population. The high prevalence of the other soil-transmitted helminths (STH) in Vatomandry was unexpected, given the good coverage with benzimidazole in control campaigns. Further studies are needed to explore the risk factors for STH and S. stercoralis infections in Madagascar, in order to align with the WHO recommendations. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To investigate the prevalence of parasitic infections in the human population and identify the related risk factors of Gonabad city, southeast of Khorasan Razavi province, northeastern Iran. METHODOLOGY: This cross-sectional study was performed from March to April 2019 in Gonabad city in Khorasan Razavi province in northeastern Iran. One thousand thirty-eight stool samples were examined using parasitological methods like direct wet-mounting, formalin-ether concentration and Gomori's trichrome staining. Moreover, the socio-demographic data of inhabitants were recorded. All statistical analyses were performed using SPSS software (version 16). Qualitative variables were reported as numbers and percentages. RESULTS: The overall intestinal parasitic infection prevalence was 18.1 %, whereas this value for protozoan agents was 16.7% (95% CI 14.14 to 19) and 1.3% (95% CI 0.7 to 2) for helminth parasites. The highest parasitic agent prevalence belongs to Blastocystis sp (12.4 %), Entamoeba coli (1.8%) and Enterobius vermicularis (1.2%), respectively. Giardia lamblia (1.1%) Entamoeba histolytica/dispar (0.3%), Iodamoeba butschlii (0.3%), Chilomastix mesnili (0.3%), Hymenolepis nana (0.2 %) Dientamoeba fragilis (0.2%) and Trichomonas hominis (0.3%) were other identified parasites. Multivariate logistic regression analysis revealed a significant association of parasitic intestinal infections with factors such as age, residency status and source of drinking water (P<0.05). CONCLUSION: Our findings approved that the protozoan agents have a relatively high prevalence among the studied population. So, it could be severe enough to alarm the entities implementing healthcare services measures for parasitic intestinal infection control. [ABSTRACT FROM AUTHOR]

We report a case of infection with the zoonotic nematode Gongylonema sp. in a 24-year-old woman from Varna, Bulgaria. Two days before seeking medical attention, the patient had noticed a filamentous mass in her buccal mucosa that migrated when touched with the tongue. She manually removed a thread-like worm from the mucosa near her lower lip. Albendazole was prescribed for three days. The patient had no history of travelling abroad or contact with animals. To our knowledge, this is the sixth case that has been reported in the country. [ABSTRACT FROM AUTHOR]

Ethiopian wolves (EWs), Canis simensis, are the rarest canids in the world and Africa's most endangered carnivore, found in only six isolated habitat fragments in the highlands of Ethiopia. Previous reports on the prevalence of parasites in the EW in Bale Mountains National Park (BMNP) are limited, with little information on their helminth fauna. This study seeks to understand the prevalence of helminth parasites in the EW in BMNP, Ethiopia. In this study, fecal samples were collected from 43 EWs in Web Valley (WV), BMNP, from June to October 2020, and the presence of helminth eggs was assessed using fecal sedimentation and centrifugal floatation methods with microscopy. Forty‐two out of 43 fecal samples from wolves (98%) contained eggs from two taxonomic groups of helminths. Eggs from Capillaria spp. and Trichuris vulpis were found most frequently, followed by Toxocara canis, Diphyllobothrium spp., Toxascaris leonina, and Capillaria aerophila. One EW (2%) was recorded for harboring the cestode Moniezia expansa. About 9 of the 43 EWs (21%) presented monospecific infection: 9 EWs (21%) harbored 2 parasite species, 9 EWs (21%) hosted 3 parasite species, 11 EWs (26%) had infection involving 4 parasite species, 2 EWs (5%) were infected with 5 parasite species, 1 EW (2%) presented 6 parasite species, 1 EW (2%) harbored 7 parasite species, and 1 EW (2%) was diagnosed without parasite species. Concurrent helminth infection was highly associated with female EW. Megeti 3 was associated with a low level of concurrent helminth infection. The prevalence of helminth parasites found in wolves in the study area suggests that the environment is highly contaminated with intestinal parasites. Regular control of parasite transmission in EW, domestic dogs, and humans in and around BMNP, public education, and further parasite epidemiological studies must be conducted. [ABSTRACT FROM AUTHOR]

Introduction: Intestinal roundworms cause chronic debilitating disease in animals, including humans. Traditional experimental models of these types of infection use a large single-dose infection. However, in natural settings, hosts are exposed to parasites on a regular basis and when mice are exposed to frequent, smaller doses of Heligmosomoides polygyrus, the parasites are cleared more quickly. Whether this more effective host response has any negative consequences for the host is not known. Results: Using a trickle model of infection, we found that worm clearance was associated with known resistance-related host responses: increased granuloma and tuft cell numbers, increased levels of granuloma IgG and decreased intestinal transit time, as well as higher serum IgE levels. However, we found that the improved worm clearance was also associated with an inflammatory phenotype in and around the granuloma, increased smooth muscle hypertrophy/ hyperplasia, and elevated levels of Adamts gene expression. Discussion: To our knowledge, we are the first to identify the involvement of this protein family of matrix metalloproteinases (MMPs) in host responses to helminth infections. Our results highlight the delicate balance between parasite clearance and host tissue damage, which both contribute to host pathology. When continually exposed to parasitic worms, improved clearance comes at a cost. [ABSTRACT FROM AUTHOR]

Organisms have evolved diverse strategies to manage parasite infections. Broadly, hosts may avoid infection by altering behaviour, resist infection by targeting parasites or tolerate infection by repairing associated damage. The effectiveness of a strategy depends on interactions between, for example, resource availability, parasite traits (virulence, life‐history) and the host itself (nutritional status, immunopathology). To understand how these factors shape host parasite‐mitigation strategies, we developed a mathematical model of within‐host, parasite‐immune dynamics in the context of helminth infections. The model incorporated host nutrition and resource allocation to different mechanisms of immune response: larval parasite prevention; adult parasite clearance; damage repair (tolerance). We also considered a non‐immune strategy: avoidance via anorexia, reducing intake of infective stages. Resources not allocated to immune processes promoted host condition, whereas harm due to parasites and immunopathology diminished it. Maximising condition (a proxy for fitness), we determined optimal host investment for each parasite‐mitigation strategy, singly and combined, across different environmental resource levels and parasite trait values. Which strategy was optimal varied with scenario. Tolerance generally performed well, especially with high resources. Success of the different resistance strategies (larval prevention or adult clearance) tracked relative virulence of larval and adult parasites: slowly maturing, highly damaging larvae favoured prevention; rapidly maturing, less harmful larvae favoured clearance. Anorexia was viable only in the short term, due to reduced host nutrition. Combined strategies always outperformed any lone strategy: these were dominated by tolerance, with some investment in resistance. Choice of parasite mitigation strategy has profound consequences for hosts, impacting their condition, survival and reproductive success. We show that the efficacy of different strategies is highly dependent on timescale, parasite traits and resource availability. Models that integrate such factors can inform the collection and interpretation of empirical data, to understand how those drivers interact to shape host immune responses in natural systems. [ABSTRACT FROM AUTHOR]

Helminth infections are prevalent in poverty-stricken areas and developing countries with warm, humid climates and poor sanitary conditions. The limited availability of anthelmintic drugs and the emergence of drug resistance have prompted the search for new treatment options. Medicinal plants, traditionally used for treating various ailments, including parasitic infections, have been explored as sources of novel anthelmintic compounds. To evaluate the preliminary phytochemical analysis and in vitro anthelmintic activity of Colchicum autumnale L. corm extract. The anthelmintic activity of C. autumnale corm extract was tested against Pheretima posthuma (earthworms). Five different concentrations (20, 40, 60, 80, and 100 mg/ml) of the C. autumnale extract were used, alongside the standard drug albendazole at the same concentrations. The time taken for paralysis and death of the worms was recorded. The preliminary phytochemical qualitative analysis of the ethanolic extract showed the presence of alkaloids, carbohydrates, glycosides, saponins, phenols, tannins, and steroids. The study highlighted the potential of C. autumnale extract as a natural anthelmintic agent. The dose-dependent activity suggested that higher concentrations of the extract provided more effective anthelmintic action. However, further research is necessary to establish the optimal dosing, safety, and in vivo efficacy of the extract. [ABSTRACT FROM AUTHOR]

Complex cross-talk occurs between gastrointestinal nematodes and gut symbiotic microbiota, with consequences for animal metabolism. To investigate the connection between methane production and endoparasites, this study evaluated the effect of mixed infection with Haemonchus contortus and Trichostrongylus colubriformis on methanogenic and methanotrophic community in rumen microbiota of lambs using shotgun metagenomic and real-time quantitative PCR (qPCR). The rumen content was collected from six Santa Inês lambs, (7 months old) before and after 42 days infection by esophageal tube. The metagenomic analysis showed that the infection affected the microbial community structure leading to decreased abundance of methanotrophs bacteria, i.e. α-proteobacteria and β-proteobacteria, anaerobic methanotrophic archaea (ANME), protozoa, sulfate-reducing bacteria, syntrophic bacteria with methanogens, geobacter, and genes related to pyruvate, fatty acid, nitrogen, and sulfur metabolisms, ribulose monophosphate cycle, and Entner–Doudoroff Pathway. Additionally, the abundance of methanogenic archaea and the mcrA gene did not change. The co-occurrence networks enabled us to identify the interactions between each taxon in microbial communities and to determine the reshaping of rumen microbiome associations by gastrointestinal nematode infection. Besides, the correlation between ANMEs was lower in the animal's postinfection. Our findings suggest that gastrointestinal parasites potentially lead to decreased methanotrophic metabolism-related microorganisms and genes. [ABSTRACT FROM AUTHOR]

IntroductionThe coronavirus disease 2019 (COVID-19) pandemic has resulted in devastating health and economic consequences worldwide. Vaccination has been a central pillar for COVID-19 prevention and control. Understanding the immunomodulatory effects of helminth infections on COVID-19 vaccine-induced immune responses and vaccine efficacy is crucial to the development and deployment of effective vaccination strategies in low- and middle-income countries with a high prevalence of worms.MethodsIn September 2022, we conducted a cross-sectional, population-based survey in five Schistosoma mansoni endemic villages in Mayuge District, Uganda (n = 450). The prevalence of schistosomiasis and soil-transmitted helminths was determined by the Kato-Katz (KK) technique on two stool samples collected from each participant. A subset of individuals (n = 204) were interviewed in a COVID-19 vaccination survey. IgG levels against the SARS-CoV-2 spike S1 subunit (anti-S1 IgG) were measured by enzyme-linked immunosorbent assay (ELISA) in collected serum samples.ResultsThe overall schistosomiasis and hookworm prevalence rates in the five villages were 36.4% (166/450) and 36.9% (168/450), respectively. Within the cohort, 69.78% (314/450) of the subjects had a positive anti-S1 IgG response. COVID-19 vaccination coverage among the interviewed participants was 93.14% (190/204; 95% CI, 88.8% − 95.9%). However, 81% (154/190) of COVID-19 vaccinees had an anti-S1 IgG titre ≤200. In an adolescent group receiving a single dose of the BNT162b2 mRNA vaccine (n = 23), an inverse correlation was observed between anti-S1 IgG antibody level/titre and faecal egg count. Within the above group, anti-S1 IgG levels/titres were significantly lower in subjects with moderate or heavy S. mansoni infection (n = 5) than those in KK-negative individuals (n = 9).ConclusionAlthough the acceptance rate of COVID-19 vaccination was high, the majority of participants received only a single vaccine dose and the overall anti-S1 IgG titres in confirmed vaccinees were low. Moderate-to-heavy schistosome infections blunted the antibody responses following vaccination with a single dose of BNT162b2. These observations confirm the necessity for a second COVID-19 vaccine dose for two-dose primary immunization series and call for implementation research that may inform the development of a ‘treat and vaccinate’ policy during vaccination roll-out in regions with heavy worm burdens.

Helminth infections are a major public health problem as they can cause long-term chronic infections in their hosts for which there is no effective vaccine. During the long-term interaction between helminths and their hosts, helminth-derived extracellular vesicles (EVs) can participate in host immunomodulatory processes by secreting bioactive molecules (BMAs). Growing data suggests that microRNAs (miRNAs) in helminth EVs have a significant impact on the host’s immune system. The let-7 family is highly conserved among helminth EVs and highly homologous in the host, and its function in host–parasite crosstalk may reflect active selection for compatibility with the host miRNA machinery. In-depth studies targeting this aspect may better elucidate the mechanism of parasite-host interactions. Hence, this review summarizes the current studies on the cross-species involvement of helminth EV-derived let-7 in host immune regulation and discusses the barriers to related research and potential applications of helminth EVs.

IntroductionAscaris lumbricoides infection is one of the most common soil-transmitted helminthiasis and IgE response to this helminth may increase the risk of asthma, bronchial hyperreactivity and atopy. There is not enough evidence showing the role of group-2 innate lymphoid cells (ILC2) in the pathogenesis of helminth infections in humans. Here, we aimed to investigate and characterize the influence of Ascaris lumbricoides infection on circulating ILCs in endemically exposed subjects.MethodsNon-infected (NI; n=16) and Ascaris-infected (AI; n=16) subjects from an endemic area were included. Two consecutive stool samples from each subject were examined by Kato-Katz to define parasite infection. Antibodies to the ABA-1 antigen of Ascaris and Ascaris extract were measured by ELISA. ILC subsets and their activation markers (CD25, CD69, thymic stromal lymphopoietin receptor (TSLPR) were evaluated in its PBMC by flow cytometry. Proximity extension assay (PEA) was performed to explore plasma proteins associated to infection.ResultsNo significant differences in the relative or absolute frequencies of total ILCs, ILC1, ILC2 and ILC3 cells were observed regarding the infection status. However, within AI group, IgE-sensitized subjects to ABA-1 had higher frequencies and counts of ILC2 (p

IntroductionLive microfilariae (mf) and mf-derived extracellular vesicles (EVs) have been shown to modulate human antigen presenting cell (APC) function, most notably by suppressing the induction of IL-12 (and other pro-inflammatory cytokines) following activation with LPS and interferon-y. MethodsTo explore further how EVs alter human APC function, we studied the effect of mf and EVs on human elutriated monocyte-derived dendritic cells (DC) following exposure to Mf, mf-derived excretory/secretory (E/S) products, E/S depleted of EVs through ultracentrifugation and purified EVs. After demonstrating that the measurable responses induced by live mf could be recapitulated by EVs and EV-containing E/S, we next performed RNAseq analysis of human DC following exposure to live mf, EVs, E/S, or EV-depleted E/S. ResultsIn our analyses of the data for the DC, using a false discovery rate (FDR)

Abstract Background Parasitic helminths influence the composition of the gut microbiome. However, the microbiomes of individuals living in helminth-endemic regions are understudied. The Orang Asli, an indigenous population in Malaysia with high burdens of the helminth Trichuris trichiura, display microbiotas enriched in Clostridiales, an order of spore-forming obligate anaerobes with immunogenic properties. We previously isolated novel Clostridiales that were enriched in these individuals and found that a subset promoted the Trichuris life cycle. In this study, we aimed to further characterize the functional properties of these bacteria. Results Clostridiales isolates were profiled for their ability to perform 57 enzymatic reactions and produce short-chain fatty acids (SCFAs) and hydrogen sulfide, revealing that these bacteria were capable of a range of activities associated with metabolism and host response. Consistent with this finding, monocolonization of mice with individual isolates identified bacteria that were potent inducers of regulatory T-cell (Treg) differentiation in the colon. Comparisons between variables revealed by these studies identified enzymatic properties correlated with Treg induction and Trichuris egg hatching. Conclusion We identified Clostridiales species that are sufficient to induce high levels of Tregs. We also identified a set of metabolic activities linked with Treg differentiation and Trichuris egg hatching mediated by these newly isolated bacteria. Altogether, this study provides functional insights into the microbiotas of individuals residing in a helminth-endemic region. Video Abstract

With many non-human primates (NHPs) showing continued population decline, there is an ongoing need to better understand their ecology and conservation threats. One such threat is the risk of disease, with various bacterial, viral and parasitic infections previously reported to have damaging consequences for NHP hosts. Strongylid nematodes are one of the most commonly reported parasitic infections in NHPs. Current knowledge of NHP strongylid infections is restricted by their typical occurrence as mixed infections of multiple genera, which are indistinguishable through traditional microscopic approaches. Here, modern metagenomics approaches were applied for insight into the genetic diversity of strongylid infections in South-East and East Asian NHPs. We hypothesized that strongylid nematodes occur in mixed communities of multiple taxa, dominated by Oesophagostomum, matching previous findings using single-specimen genetics. Utilizing the Illumina MiSeq platform, ITS-2 strongylid metabarcoding was applied to 90 samples from various wild NHPs occurring in Malaysian Borneo and Japan. A clear dominance of Oesophagostomum aculeatum was found, with almost all sequences assigned to this species. This study suggests that strongylid communities of Asian NHPs may be less species-rich than those in African NHPs, where multi-genera communities are reported. Such knowledge contributes baseline data, assisting with ongoing monitoring of health threats to NHPs.

Polyphenols are phytochemicals commonly found in plant-based diets which have demonstrated immunomodulatory and anti-inflammatory properties. However, the interplay between polyphenols and pathogens at mucosal barrier surfaces has not yet been elucidated in detail. Here, we show that proanthocyanidin (PAC) polyphenols interact with gut parasites to influence immune function and gut microbial-derived metabolites in mice. PAC intake inhibited mastocytosis during infection with the small intestinal roundworm Heligmosomoides polygyrus, and altered the host tissue transcriptome at the site of infection with the large intestinal whipworm Trichuris muris, with a notable enhancement of type-1 inflammatory and interferon-driven gene pathways. In the absence of infection, PAC intake promoted the expansion of Turicibacter within the gut microbiota, increased fecal short chain fatty acids, and enriched phenolic metabolites such as phenyl-γ-valerolactones in the cecum. However, these putatively beneficial effects were reduced in PAC-fed mice infected with T. muris, suggesting concomitant parasite infection can attenuate gut microbial-mediated PAC catabolism. Collectively, our results suggest an inter-relationship between a phytonutrient and infection, whereby PAC may augment parasite-induced inflammation (most prominently with the cecum dwelling T. muris), and infection may abrogate the beneficial effects of health-promoting phytochemicals.

ABSTRACTThe gut microbiota has coevolved with the host for hundreds of millions of years, playing a beneficial role in host health. Human parasitic helminths are widespread and pose a pervasive global public health issue. Although Type 2 immunity provides partial resistance to helminth infections, the composition of the gut microbiota can change correspondingly. Therefore, it raises the question of what role the gut microbiota plays during helminth infection. Akkermansia muciniphila has emerged as a notable representative of beneficial microorganisms in the gut microbiota. Recent studies indicate that A. muciniphila is not merely associated with helminth infection but is also causally linked to infection. Here, we provide an overview of the crosstalk between A. muciniphila and enteric helminth infection. Our goal is to enhance our understanding of the interplay among A. muciniphila, helminths, and their hosts while also exploring the potential underlying mechanisms.

Species of Pterygodermatites are spirurid nematodes that have expanded their geographic distribution worldwide. They infect a variety of mammalian definitive hosts with few reports of potential paratenic infections in amphibian and reptile hosts. In this study, we report Pterygodermatites sp. larvae identified in free-ranging, invasive Cuban treefrogs (Osteopilus septentrionalis), from central Florida, United States. Encysted larvae were recovered from the skeletal muscle and/or the coelomic cavity of three frogs; molecular characterization of the small subunit (18S) ribosomal RNA and cytochrome oxidase I genes of the parasites matched reported sequences of Pterygodermatites (Mesopectines) whartoni (Tubangui, 1931). This is a parasite native to Southeastern Asia and to the best of the authors' knowledge, it is the first report of the species in the New World. The recovery of invasive Pterygodermatites from invasive Cuban treefrogs in North America highlights the growing concern regarding the potential impact non-native parasites and invasive species may have on native wildlife populations. [ABSTRACT FROM AUTHOR]

There is rapidly growing awareness of microbiome assembly and function in early-life gut health. Although many factors, such as antibiotic use and highly processed diets, impinge on this process, most research has focused on people residing in high-income countries. However, much of the world's population lives in low- and middle-income countries (LMICs), where, in addition to erratic antibiotic use and suboptimal diets, these groups experience unique challenges. Indeed, many children in LMICs are infected with intestinal helminths. Although helminth infections are strongly associated with diverse developmental co-morbidities and induce profound microbiome changes, few studies have directly examined whether intersecting pathways between these components of the holobiont shape health outcomes in early life. Here, we summarize microbial colonization within the first years of human life, how helminth-mediated changes to the gut microbiome may affect postnatal growth, and why more research on this relationship may improve health across the lifespan. Intestinal helminth infection and delayed gut microbiome maturation have known individual developmental and long-term adverse health outcomes. Yet, their combined effects in early life remain poorly described. Here, Bogza et al. detail these complex interactions and suggest experimental models to explore their emergent properties on immune, microbial, and infant development. [ABSTRACT FROM AUTHOR]

Background: Parasitic helminths influence the composition of the gut microbiome. However, the microbiomes of individuals living in helminth-endemic regions are understudied. The Orang Asli, an indigenous population in Malaysia with high burdens of the helminth Trichuris trichiura, display microbiotas enriched in Clostridiales, an order of spore-forming obligate anaerobes with immunogenic properties. We previously isolated novel Clostridiales that were enriched in these individuals and found that a subset promoted the Trichuris life cycle. In this study, we aimed to further characterize the functional properties of these bacteria. Results: Clostridiales isolates were profiled for their ability to perform 57 enzymatic reactions and produce short-chain fatty acids (SCFAs) and hydrogen sulfide, revealing that these bacteria were capable of a range of activities associated with metabolism and host response. Consistent with this finding, monocolonization of mice with individual isolates identified bacteria that were potent inducers of regulatory T-cell (Treg) differentiation in the colon. Comparisons between variables revealed by these studies identified enzymatic properties correlated with Treg induction and Trichuris egg hatching. Conclusion: We identified Clostridiales species that are sufficient to induce high levels of Tregs. We also identified a set of metabolic activities linked with Treg differentiation and Trichuris egg hatching mediated by these newly isolated bacteria. Altogether, this study provides functional insights into the microbiotas of individuals residing in a helminth-endemic region. -EyM7p7tfAvrAjtAePB85J Video Abstract [ABSTRACT FROM AUTHOR]

Parasites represent a ubiquitous threat for most organisms, requiring potential hosts to invest in a range of strategies to defend against infection—these include both behavioural and physiological mechanisms. Avoidance is an essential first line of defence, but this behaviour may show a trade-off with host investment in physiological immunity. Importantly, while environmental stressors can lead to elevated hormones in vertebrates, such as glucocorticoids, that can reduce physiological immunity in certain contexts, behavioural defences may also be compromised. Here, we investigate anti-parasite behaviour and immune responses against a trematode (flatworm) parasite by larval amphibians (tadpoles) exposed or not to a simulated general stressor in the form of exogenous corticosterone. Tadpoles that were highly active in the presence of the trematode infectious stage (cercariae) had lower infection loads, and parasite loads from tadpoles treated only with dechlorinated water were significantly lower than those exposed to corticosterone or the solvent control. However, treatment did not affect immunity as measured through white blood-cell profiles, and there was no relationship between the latter and anti-parasite behaviour. Our results suggest that a broad range of stressors could increase host susceptibility to infection through altered anti-parasite behaviours if they elevate endogenous glucocorticoids, irrespective of physiological immunity effects. How hosts defend themselves against parasitism in the context of multiple challenges represents an important topic for future research, particularly as the risk posed by infectious diseases is predicted to increase in response to ongoing environmental change. [ABSTRACT FROM AUTHOR]

Aims: To determine the role of the kynurenine (KYN) pathway in rhodoquinone (RQ) and de novo NAD+ biosynthesis and whether NAD+ rescue pathways are essential in parasitic worms (helminths). Results: We demonstrate that RQ, the key electron transporter used by helminths under hypoxia, derives from the tryptophan (Trp) catabolism even in the presence of a minimal KYN pathway. We show that of the KYN pathway genes only the kynureninase and tryptophan/indoleamine dioxygenases are essential for RQ biosynthesis. Metabolic labeling with Trp revealed that the lack of the formamidase and kynurenine monooxygenase genes did not preclude RQ biosynthesis in the flatworm Mesocestoides corti. In contrast, a minimal KYN pathway prevented de novo NAD+ biosynthesis, as revealed by metabolic labeling in M. corti, which also lacks the 3-hydroxyanthranilate 3,4-dioxygenase gene. Our results indicate that most helminths depend solely on NAD+ rescue pathways, and some lineages rely exclusively on the nicotinamide salvage pathway. Importantly, the inhibition of the NAD+ recycling enzyme nicotinamide phosphoribosyltransferase with FK866 led cultured M. corti to death. Innovation: We use comparative genomics of more than 100 hundred helminth genomes, metabolic labeling, HPLC-mass spectrometry targeted metabolomics, and enzyme inhibitors to define pathways that lead to RQ and NAD+ biosynthesis in helminths. We identified the essential enzymes of these pathways in helminth lineages, revealing new potential pharmacological targets for helminthiasis. Conclusion: Our results demonstrate that a minimal KYN pathway was evolutionary maintained for RQ and not for de novo NAD+ biosynthesis in helminths and shed light on the essentiality of NAD+ rescue pathways in helminths. [ABSTRACT FROM AUTHOR]

A high-caloric diet is associated with metabolic syndrome (MetS) and type 2 diabetes (T2D). Obesity-associated adipose tissues suffer from sustained chronic low-grade inflammation mediated by proinflammatory innate and adaptive immune cells. Helminth parasites maintain an immune homeostasis by inducing anti-inflammatory type 2 and regulatory immune responses to benefit the host. Specific proteins or molecules secreted by helminths that induce a sustained immune balance in different MetS conditions should be explored as next-generation therapeutics to treat metabolic diseases. Obesity is a worldwide pandemic and major risk factor for the development of metabolic syndrome (MetS) and type 2 diabetes (T2D). T2D requires lifelong medical support to limit complications and is defined by impaired glucose tolerance, insulin resistance (IR), and chronic low-level systemic inflammation initiating from adipose tissue. The current preventative strategies include a healthy diet, controlled physical activity, and medication targeting hyperglycemia, with underexplored underlying inflammation. Studies suggest a protective role for helminth infection in the prevention of T2D. The mechanisms may involve induction of modified type 2 and regulatory immune responses that suppress inflammation and promote insulin sensitivity. In this review, the roles of helminths in counteracting MetS, and prospects for harnessing these protective mechanisms for the development of novel anti-diabetes drugs are discussed. [ABSTRACT FROM AUTHOR]

In the formation of helminth fauna, the formation of a high diversity of species, in the circulation of helminths between humans and ruminant domestic animals in nature and in their infection, in the completion of the development stages of biohelminths and their invasion and in the transfer of dangerous helminths from one area to another, their intermediate hosts have a great role. When determining the role of intermediate hosts in the spread of helminths of domestic carnivores, it was found that the intermediate hosts of 12 species of helminths are insects, 7 species are ruminants, 16 species are rodents, 5 species are reptiles and 3 species are earthworms. During the study, it was found that rodents were infected with cysticercoids of the mentioned helminths in 49.3%, reptiles with cysticercoids, procercoids and plerocercoids in 34.7%, snails in 24.7% and insects in 37.3%. Among the intermediate hosts, rodents prevail over other intermediate hosts with 16 species and infection rate of 49.3%. It comes from the ethology of rodents. The scientific-research work carried out in this direction has important theoretical and practical importance. The main direction in the fight against intermediate hosts is to break the chain between transmissible diseases and the agent that transmits them. [ABSTRACT FROM AUTHOR]

Deer are susceptible to infection with parasitic helminths, including species which are of increasing economic concern to the livestock industry due to anthelmintic drug resistance. This paper systematically collates helminth prevalence data from deer across Europe and explores patterns in relation to host and parasite species, as well as landscape factors. A livestock pasture contact index (LPCI) is developed to predict epidemiological overlap between deer and livestock, and hence to examine deer helminth fauna in the context of their surrounding environment. Fifty-eight studies comprising fallow (Dama dama), red (Cervus elaphus), roe (Capreolus capreolus) and sika (Cervus nippon) deer were identified. Deer populations in "likely" contact with livestock pasture had a higher mean prevalence of the abomasal nematodes Haemonchus contortus, Ostertagia ostertagi, Teladorsagia circumcincta and Trichostrongylus axei (p = 0.01), which are common in livestock and not primarily associated with deer. Roe deer populations had a higher prevalence of T. circumcincta (p = 0.02) and T. axei (p = 0.01) than fallow deer and a higher prevalence of H. contortus than both red (p = 0.01) and fallow deer (p = 0.02). Liver fluke and lungworm species were present sporadically at low prevalence, while the abomasal nematode Ashworthius sidemi occurred locally at high prevalence. Insights from this research suggest that deer helminth fauna is reflective of their surrounding environment, including the livestock species which inhabit areas of shared grazing. This is explored from an epidemiological perspective, and the prospect of helminth transmission between wild and domestic hosts is discussed, including drug-resistant strains, alongside the role of helminths as indicators relevant to the transmission of other pathogens at the wildlife–livestock interface. [ABSTRACT FROM AUTHOR]

Introduction: All organs of any organism can be affected by helminths. They can be seen in a broad spectrum, from simple infestations to extensive, life-threatening involvement. Symptomatology is usually of chronic latent course. However, sometimes the presentation is acute and requires urgent surgical intervention. Material and Methods: We conducted a retrospective observational prospective recruitment study of patients undergoing emergency surgery for helminth infection from January 2000 to December 2019 at a university hospital. Sociodemographic and analytical variables, variables related to the clinical process, and the diagnostic test were analysed. Variables related to the surgical procedure and postoperative complications were also analysed. Results: A total of 36 patients required emergency surgery for their helminth infection, which represented 0.26% of emergency abdominal surgeries. The mean age was 34.91 ± 21.5 years, with a predominance of men (69.4%). Most patients presented with pain in the right iliac fossa (69.4%), followed by symptoms compatible with intestinal obstruction (19.4%). The most frequent surgical interventions were appendectomy (38.9%) followed bowel resection (33.3%) and ileocecal resection (11.1%). Enterobious vermicularis and Anisakis simplex both together accounted for 75% of the sample. Statistically significant differences were identified in age (p < 0.001), diagnostic test performed (p = 0.032), intraoperative clinical diagnosis (p = 0.005) and surgical treatment received (p < 0.001). Conclusion: The frequency of emergency surgeries for intestinal helminth parasitism is decreasing. However, the majority of these are E. vermicularis and Anisakis simplex, which have distinctly different clinical presentations. Identification and recognition by physicians continue to be necessary for further postoperative management and possible complications. [ABSTRACT FROM AUTHOR]

We report a case of infection with the zoonotic nematode Gongylonema sp. in a 24-year-old woman from Varna, Bulgaria. Two days before seeking medical attention, the patient had noticed a filamentous mass in her buccal mucosa that migrated when touched with the tongue. She manually removed a thread-like worm from the mucosa near her lower lip. Albendazole was prescribed for three days. The patient had no history of travelling abroad or contact with animals. To our knowledge, this is the sixth case that has been reported in the country.