Morphomolecular identification of heavy parasitic typhlitis in layer flocks: tissue response and cell-mediated reaction.

BACKGROUND: Heterakis gallinarum (H. gallinarum) is a common poultry parasite that can be found in the ceca of many gallinaceous bird species, causing minor pathology and reduced weight gain. Most infections go unnoticed in commercial flocks due to the dependence on fecal egg counts, which are prone to false-negative diagnoses. Furthermore, there is a lack of research on gastrointestinal nematodes that use molecular identification methods, which could be essential for rapid diagnosis and developing efficient control approaches. As a result, the study aimed to look at the cause of mortality in layer chickens induced by H. gallinarum in Egyptian poultry farms using morphological, ultrastructural, and molecular characterization. Histopathological, immunohistochemical, and cell-mediated immune responses from damaged cecal tissues were also examined. RESULTS: Seventy bird samples from ten-layer flocks of different breeds (Native, white, and brown layers) suffering from diarrhea, decreased egg output, and emaciation were collected. Cecal samples were collected from affected and non-affected birds and were examined for parasitic diseases using light and a scanning electron microscope. The mitochondrial cytochrome oxidase 1 (COX1) gene was used to characterize H. gallinarum. Our results showed that the collected nematodal worms were identified as H. gallinarum (male and female), further confirmed by COX1 gene amplification and sequence alignment. Gene expression analysis of the inflammatory markers in infected tissues showed a significant up-regulation of IL-2, IFN-γ, TLR-4, and IL-1ß and a significant down-regulation of the anti-inflammatory IL-10. The mRNA level of the apoptotic cas-3 revealed apoptotic activity among the H. gallinarum samples compared to the control group. CONCLUSIONS: Our results implemented the use of molecular methods for the diagnosis of Heterakis, and this is the first report showing the tissue immune response following infection in layers: upregulation of IL-1ß, IFN-γ, Il-2, and TLR-4, while down-regulation of anti-inflammatory IL-10 in cecal tissue, Cas-3 apoptotic activity and Nuclear factor-κB (NF-κB)activity with immunophenotyping of T-cells in Heterakis infected tissue.

Prevalence, socio-economic, and associated risk factors of oral cavity parasites in children with intellectual disability from Lorestan province, Iran.

Introduction: Children with intellectual disability (ID) often face challenges in maintaining proper oral hygiene due to their motor, sensory, and intellectual impairments, which can lead to compromised oral health; therefore, there is a need to enhance the oral health status of these populations and establish an effective system for administering preventive interventions. Here, we aimed to evaluate the prevalence of Entamoeba gingivalis and Trichomonas tenax among children with ID in Lorestan province, in Western Iran through parasitological and molecular methods. Methods: The current descriptive investigation involved 215 in children with ID and 215 healthy children (non-ID) who were referred to health facilities in Lorestan province, Iran between October 2022 and March 2024. The prevalence of protozoa in the oral cavity was found through the utilization of both microscopic analysis and conventional polymerase chain reaction (PCR) techniques. Results: The total prevalence of the E. gingivalis and T. tenax in children with ID was found to be 87 (40.5%) and 92 (42.8%) through microscopic and PCR methods, respectively. Among the positive samples, 57 (61.9%) and 35 (38.1%) children tested positive for E. gingivalis and T. tenax, respectively. In contrast, among the 215 non-ID children in the control group, 39 (18.1%) and 42 (19.5%) tested positive by microscopic and PCR methods, respectively. Among positive samples in non-ID children, 23 (54.7%) and 19 (45.3%) children were positive for E. gingivalis and T. tenax, respectively. Multiple logistic regression analysis indicated that residing in urban areas, parental education, monthly family income, and tooth brushing p<0.001) were identified as independent risk factors for oral cavity parasites. Conclusion: This study identified a notable prevalence of oral cavity parasites in children with ID in Lorestan province, Western Iran. It is imperative to recognize the primary risk factors associated with these parasites, particularly inadequate teeth brushing, in order to enhance public and oral health strategies for children with ID. Therefore, pediatric dental professionals should remain vigilant regarding these risk factors to effectively recognize and address oral health issues in this population, thereby mitigating the occurrence of oral diseases and infections.

Trematode Diplostomum pseudospathaceum inducing differential immune gene expression in sexual and gynogenetic gibel carp (Carassius gibelio): parasites facilitating the coexistence of two reproductive forms of the invasive species.

Introduction: Parasite-mediated selection is considered one of the potential mechanisms contributing to the coexistence of asexual-sexual complexes. Gibel carp (Carassius gibelio), an invasive fish species in Europe, often forms populations composed of gynogenetic and sexual specimens. Methods: The experimental infection was induced in gynogenetic and sexual gibel carp using eye-fluke Diplostomum pseudospathaceum (Trematoda), and the transcriptome profile of the spleen as a major immune organ in fish was analyzed to reveal the differentially expressed immunity-associated genes related to D. pseudospathaceum infection differing between gynogenetic and sexual gibel carp. Results: High parasite infection was found in gynogenetic fish when compared to genetically diverse sexuals. Although metacercariae of D. pseudospathaceum are situated in an immune-privileged organ, our results show that eye trematodes may induce a host immune response. We found differential gene expression induced by eye-fluke infection, with various impacts on gynogenetic and sexual hosts, documenting for the majority of DEGs upregulation in sexuals, and downregulation in asexuals. Differences in gene regulation between gynogenetic and sexual gibel carp were evidenced in many immunity-associated genes. GO analyses revealed the importance of genes assigned to the GO terms: immune function, the Notch signaling pathway, MAP kinase tyrosine/threonine/phosphatase activity, and chemokine receptor activity. KEGG analyses revealed the importance of the genes involved in 12 immunity-associated pathways - specifically, FoxO signaling, adipocytokine signaling, TGF-beta signaling, apoptosis, Notch signaling, C-type lectin receptor signaling, efferocytosis, intestinal immune network for IgA production, insulin signaling, virion - human immunodeficiency virus, Toll-like receptor signaling, and phosphatidylinositol signaling system. Discussion: Our study indicates the limited potential of asexual fish to cope with higher parasite infection (likely a loss of capacity to induce an effective immune response) and highlights the important role of molecular mechanisms associated with immunity for the coexistence of gynogenetic and sexual gibel carp, potentially contributing to its invasiveness.

Prevalence and Predictors of Intestinal Parasitic Infections at King Abdulaziz University Hospital, Jeddah, Saudi Arabia, from 2019 to 2023: A Retrospective Study.

Purpose: Parasitic infections are a primary cause of illness worldwide and a public health problem. This study highlighted the prevalence of intestinal parasitic (IP) infections and their updated epidemiologic status from 2019 to 2023 at King Abdulaziz University Hospital, Jeddah, Saudi Arabia. Patients and Methods: A retrospective study was conducted from 2019 to 2023 at King Abdulaziz University Hospital. The laboratory results, socio-demographic information, and the year of data collection were collected from the hospital's parasitology laboratory. The data were analyzed using SPSS version 26. Ethical approval was obtained from the National Committee of Bioethics (NCBE) - King Abdul Aziz City for Science and Technology, with an approval number of 258-22. Results: During the study period, 7673 stool samples were requested for intestinal parasite examination. The prevalence of IP infection from 2019 to 2023 was 212/7673, with a percentage of 2.8%. Infected patients had a mean (SD) age of 37.68 (17.27) years. Most infected patients were females (61%) and from Saudi Arabia (37.1%). Most stool samples were brown (79.1%), and about half were soft (51.7%). 2019 had the highest number of infected cases (28.3%), while the number of cases decreased in 2023 (8.8%), the lowest during five years. The most predominant parasite among study subjects was Blastocystis hominis (48.11%). Conclusion: The prevalence of IP infection is lower than in previous comparable surveys. Maintaining personal hygiene, conducting epidemiological surveillance, and enhancing environmental sanitation can prevent and control infections.

Rodent-adapted Cryptosporidium infection in humans: Seven new cases and review of the literature.

Cases of cryptosporidiosis in humans have been reported with strong indication of transmission from rodents. Here, we report seven new human cases of cryptosporidiosis involving rodent-adapted species (Cryptosporidium ditrichi [n = 1], Cryptosporidium mortiferum [n = 4; previously known as Cryptosporidium chipmunk genotype I], Cryptosporidium tyzzeri [n = 1], and Cryptosporidium viatorum [n = 1]) and review cases of human infection caused by these four species published to date. The seven new cases were detected in Denmark within a period of twelve months from 2022 to 2023. Only the C. tyzzeri and C. viatorum cases were associated with travel outside Denmark. The total number of human cases of cryptosporidiosis due to C. ditrichi and C. tyzzeri documented to date globally are still limited (4 and 7, respectively), whereas cases involving C. viatorum and C. mortiferum have been detected to a larger extent (43 and 63 cases, respectively). The four new cases of C. mortiferum were all of the XIVaA20G2T1 subtype, which is the only subtype identified so far in Scandinavia, and which is a subtype not yet found outside of Scandinavia. The new C. viatorum case was identified as the XVaA3g subtype. The C. tyzzeri case was subtyped as IXbA6. No subtype data were produced for C. ditrichi due to lack of a subtype assay. Review of existing data suggests the presence of C. ditrichi and C. mortiferum primarily in northern countries and C. tyzzeri and C. viatorum primarily in warmer climates. While our data may further support the role of Cryptosporidium as a cause of zoonotic disease, case descriptions should be obtained where possible to determine if Cryptosporidium species primarily adapted to rodents are the likely cause of symptoms or just an incidental finding.

Control of companion animal parasites and impact on One Health.

The last decades have witnessed an increase in the global population and movements of companion animals, contributing to changes in density and distribution of pet parasites. Control of companion animal parasites (CAPs) becomes increasingly relevant because of the intensifying human-animal bond. Parasites impact on the health of humans and their pets, but also of wildlife and the environment. We conducted a qualitative review on the current advancements, gaps and priorities for the monitoring and treatment of CAPs with a focus on securing public health. There is a need to raise awareness, coordinate global surveillance schemes and better quantify the impact of companion animal parasites on One Health.

Mass mortality event of round sardinella Sardinella aurita Valenciennes associated with Glugea Thélohan, 1891 microsporidian infection off the southern Italian coast.

Intracellular parasites of the genus Glugea Thélohan, 1891 (Microsporidia) comprise about 34 putative species capable of causing high morbidity and mortality in freshwater and marine teleost fishes. In this study, we report on the first mass mortality event associated with Glugea sp. infecting free-ranging round sardinella Sardinella aurita in the southern Tyrrhenian Sea (Italy). Here, we describe the ultrastructure of mature spores of this microsporidian and characterize it molecularly, as well as report its phylogenetic position. Most of the affected fish showed an irregular swelling of its abdomen. At necropsy, a variable number of xenomas, spherical to ellipsoidal in shape, were found in the peritoneal cavity strongly attached to the viscera of all fish. Histological analysis revealed varying severity of chronic inflammation along with occasional necrosis in visceral organs associated with multiple xenoma proliferation. These pathological findings were considered the main cause of this mass mortality event. Morphologically, the present material was closely related to G. sardinellesis and G. thunni. The phylogenetically closest taxa to the newly SSU rDNA sequence were G. thunni and an erroneusly identified  G. plecoglossi, which were very closely related to each other, also suggesting that all these sequences might belong to the same species.

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

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

Current status of intestinal parasitic infections and associated risk factors in rural population of Guilan province, northern Iran: trichostrongyliasis is the most prevalent helminthic infection.

Aim: This study aimed to determine the distribution of enteric parasitic infections and related risk factors among rural communities of Guilan province, Northern Iran, and to compare the results with the situation in the past. Background: Intestinal parasitic infections are still considered as a major public health concern, particularly in human communities with poor economy and sanitation. Methods: This cross-sectional study was performed in rural areas of Masal and Shanderman district from February to December 2020. A total of 917 stool samples were collected and examined for presence of intestinal helminthes and protozoa using direct, formalin-ether and Kato-Katz techniques. Results: A total of 156 (17%) out of 917 examined individuals were infected with intestinal parasites. The overall prevalence of protozoa, helminths and mixed infections were 11.8% (108/917), 4.5% (41/917) and 0.8% (7/917), respectively. Blastocystis was the most prevalent intestinal protozoa (9.6%) followed by Giardia lamblia (1.9%), Endolimax nana (1.1%), E. coli (0.8%) and Entamoeba hartmani (0.1%). The highest prevalence of intestinal helminths belonged to Trichostongylus spp. (3.5%) and Strongyloides stercoralis (1.3%). Statistical analysis showed significant association between giardiasis and sex (P<0.03). On the other hand, prevalence of enteric helminths was influenced by close contact with livestock, keeping herbivorous animals at home, job, education, and consumption of uncooked vegetables (P<0.05). Conclusion: The findings indicate a decreasing trend in the prevalence of intestinal parasitic infections in Guilan province in comparison to the past few decades. Hookworm infections, which was very prevalent in the area, are now rare, while trichostrongylosis showed a high prevalence in rural residents of the study area.

Can Parasites be Useful?

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

Are Rattus rattus fleas invasive? Evaluation of flea communities in invasive and native rodents in Chile.

Co-invasion, characterized by the simultaneous introduction of hosts and parasites with the latter establishing themselves in native hosts, is a phenomenon of ecological concern. Rattus rattus, a notorious invasive species, has driven the extinction and displacement of numerous avian and mammalian species and serves as a key vector for diseases affecting both humans and wildlife. Among the parasites hosted by R. rattus are fleas, which exhibit obligate parasitic behaviour, a generalist nature and high prevalence, increasing the likelihood of flea invasion. Simultaneously, invasive species can serve as hosts for native parasites, leading to potential amplification or dilution of parasite populations in the environment. In Chile, R. rattus has been present since the 17th century because of the arrival of the Spanish colonizers through the ports and has spread throughout urban, rural and wild Chilean territories. This study aims to evaluate whether co-invasion of native fleas of invasive rats occurs on native rodents in Chile and to determine whether black rats have acquired flea native to Chile during their invasion. For this, we captured 1132 rodents from 26 localities (20° S-53° S). Rattus rattus was found coexisting with 11 native rodent species and two species of introduced rodents. Among the native rodents, Abrothrix olivacea and Oligoryzomys longicaudatus exhibited more extensive sympatry with R. rattus. We identified 14 flea species associated with R. rattus, of which only three were native to rats: Xenopsylla cheopis, Leptopsylla segnis and Nosopsyllus fasciatus. These three species presented a higher parasite load in black rats compared to native fleas. Leptopsylla segnis and N. fasciatus were also found associated with native rodent species that cohabit with R. rattus. The remaining species associated with R. rattus were fleas of native rodents, although they were less abundant compared to those associated with native rodents, except for Neotyphloceras pardinasi and Sphinctopsylla ares. Although there has been evidence of flea transmission from rats to native species, the prevalence and abundance were relatively low. Therefore, it cannot be definitively concluded that these fleas have established themselves in native rodent populations, and hence, they cannot be classified as invasive fleas. This study underscores R. rattus' adaptability to diverse environmental and geographical conditions in Chile, including its capacity to acquire fleas from native rodents. This aspect has critical implications for public health, potentially facilitating the spread of pathogens across various habitats where these rats are found.

Prevalence of intestinal protozoan parasites among Asian schoolchildren: a systematic review and meta-analysis.

PURPOSE: Intestinal protozoan parasites among Asian schoolchildren are a subject of concern due to their prevalence and potential health impact. Understanding and addressing this issue is crucial for public health in the region. METHODS: We conducted a comprehensive search for articles published up to December 2023 across four databases, including Scopus, PubMed, ProQuest, and Web of Science. To estimate the combined prevalence, a random-effects model with a 95% confidence interval (CI) was applied, and the statistical analysis was performed using meta-analysis packages in R version (3.6.1). This study is registered with PROSPERO (CRD42023481146). RESULTS: Among 131 eligible articles, the prevalence of intestinal protozoan parasites was 0.208 (95% CI = 0.180-0.238). Lebanon and Tajikistan had the highest country-level prevalence at 0.851 and 0.836, respectively, with Giardia duodenalis being the most prevalent species at 0.082. CONCLUSION: In summary, our study highlights the urgent public health issue of protozoan parasites among Asian schoolchildren due to poor sanitation and water quality. Immediate interventions are essential, considering climate and socioeconomic factors, to combat these infections and improve overall health.

SUPPLEMENTAL DESCRIPTION OF CABALLEROTREMA ANNULATUM (DIESING, 1850) OSTROWSKI DE NÚÑEZ AND SATTMANN, 2002 (DIGENEA: CABALLEROTREMATIDAE) FROM A NEW HOST (ELECTROPHORUS CF. VARII) AND LOCALITY (AMAZON RIVER, COLOMBIA) WITH PHYLOGENETIC ANALYSIS AND EMENDED GENERIC DIAGNOSIS.

Herein, we provide a supplemental description of Caballerotrema annulatum (Diesing, 1850) Ostrowski de Núñez and Sattmann, 2002 (Digenea: Caballerotrematidae Tkach, Kudlai, and Kostadinova, 2016) based on specimens collected from the intestine of an electric eel, Electrophorus cf. varii (Gymnotiformes: Gymnotidae) captured in the Amazon River (Colombia). This caballerotrematid can be differentiated from its congeners by the following combination of morphological features: body surface spines forming contiguous transverse rows, concentric (wrapping dorso-ventrally around body), distributing into posterior body half (vs. restricted to anterior body half in Caballerotrema brasiliensePrudhoe, 1960; indeterminate for Caballerotrema aruanenseThatcher, 1980 and Caballerotrema piscicola [Stunkard, 1960] Kostadinova and Gibson, 2001); head collar lacking projections (vs. having them in C. brasiliense, C. aruanense, and C. piscicola), narrow (head collar more narrow than maximum body width vs. the head collar being obviously wider than the body in C. brasiliense, C. aruanense, and C. piscicola); corner spines clustered (vs. corner spines distributing as 2 separated pairs in C. brasiliense, C. aruanense, and C. piscicola); pharynx approximately at level of the corner spines (vs. pharynx far anterior to corner spines in C. brasiliense, C. aruanense, and C. piscicola); and testes ovoid and nonoverlapping (C. aruanense; vs. sinuous and overlapping in C. brasiliense and C. piscicola). Based on our results, we revise the diagnosis of CaballerotremaPrudhoe, 1960 to include features associated with the shape and distribution of body surface spines, orientation and position of head collar spines, cirrus sac, seminal vesicle, oviduct, Laurer's canal, oötype, vitellarium, and transverse vitelline ducts. We performed Bayesian inference analyses using the partial large subunit ribosomal (28S) DNA gene. Our 28S sequence of C. annulatum was recovered sister to that of Caballerotrema sp. (which is the only other caballerotrematid sequence available in GenBank) from an arapaima, Arapaima gigas (Schinz, 1822) (Osteoglossiformes: Arapaimidae) in the Peruvian Amazon. Our sequence of C. annulatum comprises the only caballerotrematid sequenced tethered to a morphological description and a voucher specimen in a lending museum. The present study is a new host record and new locality record for C. annulatum. The phylogeny comprises the most resolved and taxon-rich evolutionary hypothesis for Echinostomatoidea published to date.

Urban house finches are more resistant to the effects of artificial light at night.

Rapid urbanization of habitats alters the physical, chemical, auditory, and photic environments of human and wild animal inhabitants. One of the most widespread transformations is caused by artificial light at night (ALAN), but it is not clear the extent to which individuals acclimate to such rapid environmental change. Here, we tested the hypothesis that urban birds show increased resistance to harmful behavioral, parasitological, and physiological effects of ALAN. We captured house finches (Haemorhous mexicanus), a bird that commonly inhabits cities and their natural surroundings, from two urban and two rural sites in Phoenix, Arizona, USA, which differ by both degree of urbanization and by multiple orders of magnitude in ALAN intensity, and placed them in a common garden laboratory setting. We exposed half of the birds from each habitat type to ecologically relevant levels of night lighting during the subjective night and found that, while ALAN exposure reduced sleep in both urban and rural birds, ALAN-exposed urban birds were able to sleep longer than ALAN-exposed rural birds. We also found that ALAN exposure increased the proliferation rate of an intestinal coccidian parasite (Isospora spp.) in both urban and rural birds, but that the rate of proliferation was lower in urban relative to rural birds. We found that night lighting suppressed titers of feather corticosterone in rural but not urban birds, suggesting that light impairs HPA function through chronic stress or suppression of its circadian rhythmicity, and that urban birds were again resistant to this effect. Mediation analyses show that the effect of ALAN exposure in rural birds was significantly sleep-mediated for feather corticosterone but not coccidiosis, suggesting a diversity of mechanisms by which ALAN alters physiology. We contribute further evidence that animals from night-lit habitats can develop resistance to ALAN and its detrimental effects.

PREVALENCE OF THE BOPYRID ISOPOD PROBOPYRUS PANDALICOLA IN DAGGERBLADE GRASS SHRIMP FROM SALT MARSH CREEKS AND PANNES OF CAPE COD, MASSACHUSETTS.

In salt marsh ecosystems, daggerblade grass shrimp, Palaemon (Palaemonetes) pugio, play a crucial role in food webs and serve as the definitive host for the bopyrid isopod Probopyrus pandalicola. These ectoparasites infest the branchial chambers of grass shrimp, which can lead to decreased energy availability and sterilization of infected hosts. Although bopyrid isopod infestation of daggerblade grass shrimp has been frequently reported in literature from coastal marshes of the southeastern United States, the prevalence of this parasite has not been recently documented in daggerblade grass shrimp from marshes of the northeastern United States. The goal of this project was to quantify the prevalence of Pr. pandalicola infestations in Pa. pugio across Cape Cod, Massachusetts. We evaluated bopyrid isopod prevalence from shrimp collected from 5 different salt marsh habitats along Cape Cod in August 2021. Bopyrid isopod infestations were found in shrimp at 4 of 5 salt marshes, with prevalence ranging from 0.04 to 14.1%. Seasonal resampling of one of the salt marshes revealed the highest average infestation prevalence in spring (<17.1%) and an isolated high of 30.3% prevalence in a single salt panne. A series of linear and multivariate models showed that panne area, shrimp abundance, and distance to shoreline were related to Pr. pandalicola shrimp infestations in salt pannes in summer. This study describes the prevalence of the bopyrid isopod infesting daggerblade grass shrimp in salt marshes in New England, with implications for how parasitized shrimp influence salt marsh food webs in which they are found.

METAZOAN PARASITE COMMUNITY OF THE YELLOW SNAPPER LUTJANUS ARGENTIVENTRIS: FACTORS THAT INFLUENCING SPECIES COMPOSITION AND RICHNESS.

A total of 366 individuals of Lutjanus argentiventris (Peters, 1869) were collected over a 5-yr period (October 2018 to June 2022) from Acapulco Bay, Mexico. Parasite communities in Lutjanus argentiventris were quantified and analyzed to determine the main factors that generate changes in species richness and/or species composition over time. The digeneans and copepods were the best-represented parasite groups. The parasite communities were characterized by a high numerical dominance of ectoparasites, mainly isopod larvae. Species richness at the component community level (9-23 species) was similar to the reported richness in other Lutjanus spp. The parasite communities of Lutjanus argentiventris exhibited high variability in species composition, suggesting that each parasite species may respond differently to environmental changes. However, the species richness and diversity were fairly stable over time; therefore, a clear pattern of interannual variation was not observed. Variations in the community structure probably were due to factors such as host traits (e.g., feeding behavior and body size), and possible interannual differences in environmental factors amplified by the occurrence of the anomalous event of La Niña.

Seeing the unseen: illuminating Toxoplasma gondii's metabolic manipulation.

Intracellular infection by a pathogen induces significant rewiring of host cell signaling and biological processes. Understanding how an intracellular pathogen such as Toxoplasma gondii modulates host cell metabolism with single-cell resolution has been challenged by the variability of infection within cultures and difficulties in separating host and parasite metabolic processes. A new study from Gallego-Lopez and colleagues (G. M. Gallego-López, E. C. Guzman, D. E. Desa, L. J. Knoll, M. C. Skala, mBio e00727-24, 2024, https://doi.org/10.1128/mbio.00727-24) applies a quantitative imaging approach to evaluate the host cell metabolism during intracellular infection with Toxoplasma. This study provides important insights into host metabolic responses to Toxoplasma infection and offers a valuable tool to dissect the mechanisms underlying parasite infection and pathophysiology.

Cryptosporidium impacts epithelial turnover and is resistant to induced death of the host cell.

Infection with the apicomplexan parasite Cryptosporidium is a leading cause of diarrheal disease. Cryptosporidiosis is of particular importance in infants and shows a strong association with malnutrition, both as a risk factor and as a consequence. Cryptosporidium invades and replicates within the small intestine epithelial cells. This is a highly dynamic tissue that is developmentally stratified along the villus axis. New cells emerge from a stem cell niche in the crypt and differentiate into mature epithelial cells while moving toward the villus tip, where they are ultimately shed. Here, we studied the impact of Cryptosporidium infection on this dynamic architecture. Tracing DNA synthesis in pulse-chase experiments in vivo, we quantified the genesis and migration of epithelial cells along the villus. We found proliferation and epithelial migration to be elevated in response to Cryptosporidium infection. Infection also resulted in significant cell loss documented by imaging and molecular assays. Consistent with these observations, single-cell RNA sequencing of infected intestines showed a gain of young and a loss of mature cells. Interestingly, enhanced epithelial cell loss was not a function of enhanced apoptosis of infected cells. To the contrary, Cryptosporidium-infected cells were less likely to be apoptotic than bystanders, and experiments in tissue culture demonstrated that infection provided enhanced resistance to chemically induced apoptosis to the host but not bystander cells. Overall, this study suggests that Cryptosporidium may modulate cell apoptosis and documents pronounced changes in tissue homeostasis due to parasite infection, which may contribute to its long-term impact on the developmental and nutritional state of children. IMPORTANCE: The intestine must balance its roles in digestion and nutrient absorption with the maintenance of an effective barrier to colonization and breach by numerous potential pathogens. An important component of this balance is its constant turnover, which is modulated by a gain of cells due to proliferation and loss due to death or extrusion. Here, we report that Cryptosporidium infection changes the dynamics of this process increasing both gain and loss of enterocytes speeding up the villus elevator. This leads to a much more immature epithelium and a reduction of the number of those cells typically found toward the villus apex best equipped to take up key nutrients including carbohydrates and lipids. These changes in the cellular architecture and physiology of the small intestine may be linked to the profound association between cryptosporidiosis and malnutrition.

Zoonotic pathogens in wild Asian primates: a systematic review highlighting research gaps.

Introduction: Ongoing global changes, including natural land conversion for agriculture and urbanization, modify the dynamics of human-primate contacts, resulting in increased zoonotic risks. Although Asia shelters high primate diversity and experiences rapid expansion of human-primate contact zones, there remains little documentation regarding zoonotic surveillance in the primates of this region. Methods: Using the PRISMA guidelines, we conducted a systematic review to compile an inventory of zoonotic pathogens detected in wild Asian primates, while highlighting the coverage of primate species, countries, and pathogen groups surveyed, as well as the diagnostic methods used across the studies. Moreover, we compared the species richness of pathogens harbored by primates across diverse types of habitats classified according to their degree of anthropization (i.e., urban vs. rural vs. forest habitats). Results and discussion: Searches of Scopus, PubMed, and the Global Mammal Parasite Database yielded 152 articles on 39 primate species. We inventoried 183 pathogens, including 63 helminthic gastrointestinal parasites, two blood-borne parasites, 42 protozoa, 45 viruses, 30 bacteria, and one fungus. Considering each study as a sample, species accumulation curves revealed no significant differences in specific richness between habitat types for any of the pathogen groups analyzed. This is likely due to the insufficient sampling effort (i.e., a limited number of studies), which prevents drawing conclusive findings. This systematic review identified several publication biases, particularly the uneven representation of host species and pathogen groups studied, as well as a lack of use of generic diagnostic methods. Addressing these gaps necessitates a multidisciplinary strategy framed in a One Health approach, which may facilitate a broader inventory of pathogens and ultimately limit the risk of cross-species transmission at the human-primate interface. Strengthening the zoonotic surveillance in primates of this region could be realized notably through the application of more comprehensive diagnostic techniques such as broad-spectrum analyses without a priori selection.