Molecular mechanisms of emerging inflammasome complexes and their activation and signaling in inflammation and pyroptosis.

Inflammasomes are multi-protein complexes that assemble within the cytoplasm of mammalian cells in response to pathogen-associated molecular patterns (PAMPs) or damage-associated molecular patterns (DAMPs), driving the secretion of the pro-inflammatory cytokines IL-1ß and IL-18, and pyroptosis. The best-characterized inflammasome complexes are the NLRP3, NAIP-NLRC4, NLRP1, AIM2, and Pyrin canonical caspase-1-containing inflammasomes, and the caspase-11 non-canonical inflammasome. Newer inflammasome sensor proteins have been identified, including NLRP6, NLRP7, NLRP9, NLRP10, NLRP11, NLRP12, CARD8, and MxA. These inflammasome sensors can sense PAMPs from bacteria, viruses and protozoa, or DAMPs in the form of mitochondrial damage, ROS, stress and heme. The mechanisms of action, physiological relevance, consequences in human diseases, and avenues for therapeutic intervention for these novel inflammasomes are beginning to be realized. Here, we discuss these emerging inflammasome complexes and their putative activation mechanisms, molecular and signaling pathways, and physiological roles in health and disease.

Redescription of Raillietiella mottae (Raillietiellidae: Pentastomida) a generalist parasite of insectivorous lizards: phenotypic plasticity revealed by molecular data.

Pentastomida are lung parasites of a variety of hosts, mainly reptiles. Raillietiella is the genus with the largest number of species, whose taxonomic identification is still largely based on morphological data alone. In this classification, differences divide the genus into morphotypic groups. The Raillietiella parasites of insectivorous lizards, for example, are divided into "Group I" with species with hooks with sharp tips and "Group II" with posterior hooks with blunt tips. In the present work, we used molecular analysis to infer the morphological variation in hooks and size of specimens of Raillietiella mottae, parasites of several species of insectivorous lizards. Our results demonstrate that morphological differences comprise a phenotypic plasticity of a single species, whose variation is associated with host species, with females being larger and with hooks with blunt tips in nocturnal geckos and smaller ones with sharp tips in diurnal insectivorous lizards of different species, sizes, and habitats.

Two names, one species: redescription and phylogenetic position of Schrankiana formosula Freitas, 1959 provides new insights into the evolutionary history of the Cosmocercidae.

Schrankiana are gastrointestinal parasites of anurans, distributed throughout Central and South America. Schrankiana formosula and Schrankiana inconspicata are some of the most commonly reported species parasitising anurans from Brazil, and the morphological differences between them are unclear. In the present study, we redescribed S. formosula based on a re-examination of type series and newly collected material from the frog Leptodactylus pentadactylus in the state of Amapá, Brazil. Additionally, we re-examined the type series of S. inconspicata, and propose it as a junior synonym of S. formosula. We provide detailed morphological and morphometric data with intraspecific variation analyses and new molecular data for S. formosula. In the present phylogeny, S. formosula formed a well-supported clade with Raillietnema sp. and Labeonema synodontisi. Based on molecular phylogenetic analyses and some morphological similarities, our findings support the hypothesis that Schrankiana is a member of the family Cosmocercidae, not Atractidae. Additionally, we provide the first ultrastructural descriptions of S. formosula, and establish the species' phylogenetic position from the Cosmocercidae.

Mycoplasma bovis-associated verminous pneumonia in alpine chamois (Rupicapra rupicapra).

Pneumonia is a common disease affecting Alpine chamois. However, little is known concerning the etiological agents involved. We investigated whether Mycoplasma spp. infection occurs in Alpine chamois and describe the microscopic lesions associated with Mycoplasma-associated bronchopneumonia in this species. Lung tissues obtained from 45 chamois with gross evidence of pneumonia were analysed. The histological lesions and the presence of lungworms within the lungs were evaluated blindly. The presence of Mycoplasma spp. was assessed by immunohistochemistry (Mycoplasma bovis and Mycoplasma mycoides subsp. mycoides) and by end-point PCR. M. bovis was detected by immunohistochemistry and confirmed by PCR and sequencing in 6/45 (13%) cases, while all lungs were negative for M. mycoides subsp. mycoides. A significant association was found between the detection of M. bovis and the presence of severe lungworms infection in the examined lungs. We report for the first time M. bovis as a bacteria associated with verminous pneumonia in chamois.

Cats and dogs as hosts of Blastocystis - What is the evidence?

Blastocystis is one of the most common intestinal parasites observed in human and non-human hosts. Recent meta-analyses have indicated a potential role for pets such as dogs and cats as reservoir hosts of Blastocystis, but the data underpinning this hypothesis are of mixed quality. Reviewing data for 45,894 samples tested for Blastocystis by DNA-based methods and 11,908 subtype observations, a model was developed for calculating indices that could be used for evaluating individual species as natural hosts of Blastocystis, based on weighted products of positivity rates and subtype distributions. Data from cats and dogs were analysed, using other well-sampled hosts (pig, cattle, sheep, goat, and human) as references. Data from cats and dogs meeting the inclusion criteria were entered into the model. The overall positivity rates for pigs, cattle, sheep, goats, humans, dogs, and cats were 40 %, 40 %, 35 %, 28 %, 25 %, 6 %, and 5 %, respectively, with statistically significant lower positivity rates in cats and dogs (p < 0.0001). Indices indicating Blastocystis specificity to host ranged between 0.16 (humans) and 0.49 (cattle) for the reference hosts, whereas indices for cats and dogs were only 0.01 and 0.02, respectively. Finally, indices for ST specificity to host were higher for reference hosts (range, 0.66-0.93) than for cats (0.62) and dogs (0.56). Taken together, the analyses indicate that cats and dogs are not natural or reservoir hosts of Blastocystis and that the sporadic subtype pattern observed in these hosts might indicate exposure to Blastocystis through contaminated water/feed, including Blastocystis colonizing prey animals.

Extracellular vesicles release from protozoa parasite and animal model.

Diseases caused by protozoan parasites, such as leishmaniasis, trypanosomiasis, and malaria, are highly complex and together continue to cause high annual morbidity and mortality. The search for new compounds in environmental biodiversity, repositioning known drugs, and developing vaccines using old and innovative technologies have been employed to discover vaccines and new and alternative treatments. Extracellular vesicles (EVs) can carry parasite antigens, creating a new possibility to develop an effective and affordable platform for treatment, vaccines, and drug delivery. Thus, the evaluation of EVs in animal models can and should be explored among the countless biomedical applications. Herein, we will address the concept of EVs, their acquisition and characterization in protozoan parasite models, and the primary studies using these vesicles in therapeutic applications.

Retrospective Evaluation of Intestinal Protozoa Parasites in Patients Presenting to Kafkas University Health Research and Application Hospital Between 2019-2022.

OBJECTIVE: This study aimed to retrospectively evaluate the prevalence of protozoan parasites in stool samples collected from patients presenting with various gastrointestinal complaints to the Medical Parasitology Laboratory of Kafkas University Research and Application Hospital between 2019 and 2022. METHODS: Stool samples were initially examined using the native-Lugol method for the detection of protozoan parasites, followed by the formol-ethyl acetate sedimentation method, Giemsa, and carbol fuchsin staining methods. Specific immunochromatographic card tests were used for the diagnosis of Entamoeba histolytica, Cryptosporidium spp., and Giardia intestinalis. RESULTS: Of the 2.267 stool samples examined over the four-year period from January 2019 to December 2022, 7.63% were found to contain one or more protozoan parasites. Among these parasites, Entamoeba histolytica was detected at the highest rate of 4.06%. The other parasite species were identified as follows: Blastocystis spp. 1.15%, Entamoeba spp. and Entamoeba coli each 0.52%, Giardia intestinalis 0.48%, Endolimax nana 0.17%, and Entamoeba histolytica/dispar 0.08%. CONCLUSION: This study indicates that despite a decrease in the prevalence of intestinal protozoan infections in the Kars region, these infections remain a significant public health issue. Therefore, improvements in hygiene and sanitation conditions, increased public health education, and the widespread implementation of early diagnosis and treatment methods are necessary. Special measures should be taken to protect vulnerable groups, particularly children and the elderly.

Assessment of the Distribution of Intestinal Parasites Detected in the Parasitology Laboratory of Çukurova University Faculty of Medicine Between 2017 and 2021.

OBJECTIVE: It is known that protozoa and helminths that cause intestinal infections adversely affect human life. Changing climate and demographic and socio-economic factors worldwide necessitate the determination and updating of the incidence of these parasites. Our study aimed to retrospectively examine the distribution of intestinal parasites detected in the Parasitology Laboratory of Çukurova University Faculty of Medicine between 2017 and 2021. METHODS: Parasitological examinations were performed using the native-lugol and formol-ether condensation method. Staining method (Modified Ziehl-Neelsen) and cellophane tape method were then applied to evaluate the specimens considered necessary. RESULTS: One or more parasites were detected in 33 of 373 patients (8.8%) evaluated in the study. These were Giardia intestinalis at a rate of 30.5% (11/36), Enterobius vermicularis at a rate of 27.7% (10/36), Blastocystis sp. at a rate of 19.4% (7/36), Entamoeba coli at a rate of 11.1% (4/36), Cryptosporidium spp. at a rate of 8.3% (3/36) and Taenia saginata at a rate of 2.7% (1/36). It was determined that two patients were coinfected by Entamoeba coli and Blastocystis sp. while one patient was coinfected by Entamoeba coli and Giardia intestinalis. CONCLUSION: It is thought that determining the incidence of intestinal parasites, which are an important public health problem, may help guide studies for preventive health services. Although the five-year laboratory data obtained from the study do not reflect our region, it is thought that intestinal parasites maintain their importance.

Host-specific monogeneans parasitizing freshwater fish: The ecology and evolution of host-parasite associations.

Monogenea (Platyhelminthes), mainly gill and fin ectoparasites of fish, are often recognized as host specific and morphologically and ecologically diverse. These parasites exhibit high species diversity at the level of host species or individual fish specimens. Using case studies, especially those widely performed in Dactylogyrus parasitizing cyprinoid fish, this article presents current knowledge on the ecology and evolution of congeneric gill monogeneans. The important aspects of the ecology of congeneric monogeneans are highlighted, in particular: host specificity expressed at several host levels (from strict specificity to phylogenetic specificity), microhabitat specificity expressed by restricted positions on fish gills to facilitate intraspecific mating, and the link between microhabitat preference and morphological adaptation (i.e., sclerotized structures of the haptor) or reproductive isolation. From the evolutionary perspective, this study focused on the processes of the speciation and diversification of congeneric monogeneans, highlighting the role of host switch as the most prominent coevolutionary event, accompanied in some cases mostly by intrahost speciation or cospeciation, as revealed by cophylogenetic studies. Here, important knowledge on evolutionary patterns of host specificity, microhabitat specificity, and morphological adaptation is presented. Host-specific monogeneans may represent an important tool for studying the historical biogeography of their hosts. Specifically, in the case of freshwater fish hosts exhibiting disjunctive distribution, they reflect both historical and contemporary contacts. The role of host-specific congeneric monogeneans in revealing historical intercontinental and intracontinental contacts between freshwater fish is highlighted. Finally, the importance of the role of genetic coadaptation, limiting the presence of host-specific monogeneans in hybrid fish, is emphasized.

Title: Monogènes spécifiques à leur hôte parasitant les poissons d'eau douce : écologie et évolution des associations hôtes-parasites. Abstract: Les Monogènes (Plathelminthes), principalement ectoparasites des branchies et des nageoires des poissons, sont souvent reconnus comme spécifiques à leur hôte et diversifiés morphologiquement et écologiquement. Ces parasites présentent une grande diversité d'espèces au niveau des espèces hôtes ou des spécimens individuels de poissons. À l'aide d'études de cas (en particulier celles largement réalisées chez les Dactylogyrus parasitant les poissons cyprinoïdes), les connaissances actuelles sur l'écologie et l'évolution des monogènes branchiaux congénères sont présentées. Les aspects importants de l'écologie des monogènes congénères sont mis en évidence, en particulier la spécificité à l'hôte exprimée à plusieurs niveaux de l'hôte (de la spécificité stricte à la spécificité phylogénétique), la spécificité du microhabitat exprimée par des positions restreintes sur les branchies des poissons pour faciliter l'accouplement intraspécifique, et le lien entre la préférence du microhabitat et l'adaptation morphologique (c'est-à-dire les structures sclérifiées du hapteur) ou l'isolement reproductif. Du point de vue évolutif, l'étude a été concentrée sur les processus de spéciation et de diversification des monogènes congénères, soulignant le rôle du changement d'hôte comme l'événement coévolutif le plus important, accompagné surtout dans certains cas de spéciation ou de cospéciation intra-hôte, comme le révèlent les études cophylogénétiques. Des connaissances importantes sont présentées ici sur les modèles évolutifs de spécificité d'hôte, de spécificité de microhabitat et d'adaptation morphologique. Les monogènes spécifiques à l'hôte peuvent représenter un outil important pour étudier la biogéographie historique de leurs hôtes. Plus précisément, dans le cas des poissons d'eau douce hôtes présentant une distribution disjonctive, ils reflètent à la fois des contacts historiques et contemporains. Le rôle des monogènes congénères spécifiques à leur hôte dans la révélation des contacts intercontinentaux et intracontinentaux historiques entre poissons d'eau douce est mis en évidence. Enfin, l'importance du rôle de la coadaptation génétique limitant la présence de monogènes spécifiques à l'hôte chez les poissons hybrides est soulignée.

RAD51 recombinase and its paralogs: Orchestrating homologous recombination and unforeseen functions in protozoan parasites.

The DNA of protozoan parasites is highly susceptible to damage, either induced by environmental agents or spontaneously generated during cellular metabolism through reactive oxygen species (ROS). Certain phases of the cell cycle, such as meiotic recombination, and external factors like ionizing radiation (IR), ultraviolet light (UV), or chemical genotoxic agents further increase this susceptibility. Among the various types of DNA damage, double-stranded breaks (DSBs) are the most critical, as they are challenging to repair and can result in genetic instability or cell death. DSBs caused by environmental stressors are primarily repaired via one of two major pathways: non-homologous end joining (NHEJ) or homologous recombination (HR). In multicellular eukaryotes, NHEJ predominates, but in unicellular eukaryotes such as protozoan parasites, HR seems to be the principal mechanism for DSB repair. The HR pathway is orchestrated by proteins from the RAD52 epistasis group, including RAD51, RAD52, RAD54, RAD55, and the MRN complex. This review focuses on elucidating the diverse roles and significance of RAD51 recombinase and its paralogs in protozoan parasites, such as Acanthamoeba castellanii, Entamoeba histolytica (Amoebozoa), apicomplexan parasites (Chromalveolata), Naegleria fowleri, Giardia spp., Trichomonas vaginalis, and trypanosomatids (Excavata), where they primarily function in HR. Additionally, we analyze the diversity of proteins involved in HR, both upstream and downstream of RAD51, and discuss the implications of these processes in parasitic protozoa.

Parasites and Microbiota: Dual Interactions and Therapeutic Perspectives.

The human gut hosts a diverse and active community of bacteria that symbiotically support the physiology, metabolism, and immunity of the intestinal lining. Nevertheless, a dynamic community of parasites (helminths and protozoa) may share a habitat with gut-dwelling microbiota. Both microbiota and parasites can significantly change the physical and immunological environment of the gut, thus generating several mechanisms of interaction. Studying this field is crucial for understanding the pathogenesis of parasitic diseases. Additionally, intestinal microbiota and gut-dwelling parasites may interact with each other and with the host immunity to alleviate or exacerbate the disease. These interactions can alter the pathogenicity of both parasites and microbiota, thereby changing the infection outcomes and the overall disease profile. Parasites and microbiota interactions occur via several mechanisms, including physical alteration in both the gastrointestinal microenvironment and the adaptive and innate immune responses. By modulating the microbiota, treating parasitic infections and microbiota dysbiosis may be improved through knowing the mechanisms and consequences of the interactions between intestinal parasites and the microbiota. Thus, new biological tools of treatment including probiotics can be introduced, particularly with the emergence of drug resistance and adverse effects.

Coinfection of Toxoplasma gondii and Other Microorganisms: A Systematic Review and Meta-Analysis.

Toxoplasmosis is a disease caused by the intracellular protozoan Toxoplasma gondii, which has infected a third of the global population. Immunocompromised individuals and children with congenital disorders are most likely to be impacted by toxoplasmosis, and accurate diagnosis is essential. Toxoplasmosis is associated with HIV, schizophrenia, and diabetes. However, few studies have analyzed the association with other microorganisms. The purpose of this study was to determine the prevalence of coinfection of Toxoplasma gondii with other pathogens. From November 1997 to June 2024, PubMed, Science Direct, LAT index, Web of Science, Google Scholar, and Research Gate were searched. The keywords used were "Toxoplasma and microorganism coinfection", "Toxoplasma coinfection and parasites", "Toxoplasma coinfection and Protozoans or Bacteria or Helminths or Nematodes or Trematodes or Mycobacterium", "Toxoplasma gondii in coinfection with virus", and "Human Toxoplasmosis and coinfection". Next, OpenMeta Analyst Software version 12.11 was used for meta-analysis, creating forest plots, and determining heterogeneity I2. A total of 17,535 patients in 48 articles, of whom 5848 were seropositive to T. gondii, were included in this review. Population studies showed that the prevalence of virus infection was most frequent (32%), followed by parasites (18.4%), bacteria (29.7%), and fungi (5.8%). The pooled prevalence of coinfection was found to be 29.1%, with a lower bound of 0.232, an upper bound of 0.350, a standard error of 0.030, and p < 0.001. Heterogeneity (I2) was 99.12%, p < 0.001, with a global variance tau2 = 0.042. Toxoplasma gondii is an opportunist that mainly affects immunocompromised populations. The main coinfections were found to be viral infections, with HIV ranking first, followed by cytomegalovirus, hepatitis B and C, rubella, herpes simplex 1 and 2, SARS-CoV-2, and coxsackie virus.

Molecular Mechanisms of Drug Resistance in Leishmania spp.

The protozoan parasite Leishmania causes leishmaniasis, a neglected tropical disease, that disproportionately affects underdeveloped countries. This disease has major health, economic, and social implications, particularly because of the limited treatment options, high cost, the severe side effects associated with available therapeutics, and the high rate of treatment failure caused by the parasites' growing resistance to current medications. In this review, we describe first the common strategies used by pathogens to develop drug resistance and then focus on the arsenal of available drugs to treat leishmaniasis, their modes of action, and the molecular mechanisms contributing to drug resistance in Leishmania spp., including the role of genomic, transcriptional, and translational control. We focus more specifically on our recent discovery of translational reprogramming as a major driver of drug resistance leading to coordinated changes in the translation of transcripts and orchestrating changes in metabolome and lipidome to support drug resistance. A thorough understanding of these mechanisms is essential to identify the key elements needed to combat resistance and improve leishmaniasis treatment methods.

Molecular Survey of Parasitic Contamination of Frozen Berries.

Berries represent healthy dietary options and contain bioactive compounds associated with a decreased risk of diseases. Despite representing healthy food choices, these products can be contaminated by pathogenic microorganisms, including parasites. Among foodborne parasites, Giardia duodenalis, Cryptosporidium parvum, Cyclospora cayetanensis, Toxoplasma gondii, and Echinococcus multilocularis are of significant public health importance and have been recently detected in fresh berries in Europe, including Italy. Berries can be purchased fresh or frozen, and it is worrying that even frozen berries could represent a risk for the consumer. In fact, several parasites can resist freezing temperatures and have been responsible for outbreaks of infection. The aim of this study was to investigate the presence of G. duodenalis, C. parvum, C. cayetanensis, T. gondii, and E. multilocularis in frozen berries with simplex and multiplex real-time PCR protocols. A total of 108 packages of mixed frozen berries were bought from supermarkets located in a south-eastern region of Italy. The samples were tested using two simplex real-time PCR protocols targeting C. parvum and G. duodenalis, respectively, and a multiplex real-time PCR targeting C. cayetanensis, T. gondii, and E. multilocularis. None of the investigated parasites were detected in the frozen berry samples tested. This research topic is still unexplored and of great current interest. These results represent a first attempt to investigate parasitic contamination of frozen berries sold on the Italian market, but further large-scale surveys are required.

Molecular Testing of Environmental Samples as a Potential Source to Estimate Parasite Infection.

We discuss the potential usefulness of molecular testing of soil, dust, and water samples to detect medically important parasites, and where such testing could be used to supplement stool sampling in humans. A wide variety of parasites including protozoa and helminths, many of which are zoonotic, have an important infection reservoir in the environment. In some cases, this environmental period is essential for further parasite development. We describe the progress in implementing methods for the molecular detection of these parasites in soil across eight collaborating centers in Latin America and represent a variety of potential applications in improving our understanding of parasite epidemiology and mapping, surveillance, and control of these parasites. This methodology offers new opportunities for improving our understanding of a wide variety of parasites of public health importance and novel tools for their control.

Antioxidant and anti-glycation activities of Mandevilla velutina extract and effect on parasitemia levels in Trypanosoma cruzi experimental infection: in vivo, in vitro and in silico approaches.

ETHNOPHARMACOLOGICAL RELEVANCE: Mandevilla velutina (Mart. Ex Stadelm.) Woodson, known in Brazil as "infalível" and "jalapa", is a medicinal plant native from the Cerrado region (Brazilian Savannah). The underground organ (xylopodium) of this species is prepared as ethanolic extract or infusion and it is commonly used in traditional medicine to treat snake venom. Although, locals and indigenous populations from Cerrado have used M. velutina for the treatment of infection by Trypanosoma cruzi (Chagas' disease). AIM OF THE STUDY: This study aimed to evaluate the in vitro antioxidant and anti-glycation activities of the crude hydroethanolic extract of M. velutina xylopodium. Besides, it aimed to evaluate its effect on parasitemia levels in in vivo T. cruzi experimental infection. In addition, this study aimed to determine possible interactions between the main compound of the extract and molecular targets associated with survival and virulence of T. cruzi in in silico approaches. MATERIALS AND METHODS: Determination of total polyphenols, flavonoids and steroidal aglycones content were performed. In addition, high performance liquid chromatography (HPLC) was carried out to identify main compounds of the extract. Antioxidant activity was determined by DPPH radical scavenging, ferric ion reducing power (FRAP), Thiobarbituric acid reactive species (TBARS) and Oxygen Radical Absorbance Capacity (ORAC) methods. Anti-glycation activity was demonstrated through relative mobility in electrophoresis (RME), determination of free amino groups and inhibition of AGEs formation. Determination of the action of extract in parasitemia levels was performed by T. cruzi experimental infection of mice and nitrite levels were measured in the serum of animals evaluated in this study. Molecular docking analyses of the main compound (Velutinol A) with DNA and molecular targets associated with survival and virulence of T. cruzi. RESULTS: Phytoconstituents evaluation exhibited the presence polyphenols, flavonoids and steroidal aglycone, and HPLC identified the major presence of Velutinol A. Antioxidant and anti-glycation evaluations showed that the extract present significant activity in all methods evaluated. In addition, extract reduced the number of trypomastigotes and increased the survival of treated animals. The treatment using extract showed an interference in the synthesis of physiological nitric oxide as an immune response to infection. In silico assays demonstrated interaction between Velutinol A and DNA and molecular targets of T. cruzi. CONCLUSIONS: The results showed that the hydroethanolic extract of M. velutina xylopodium contains bioactive compounds including polyphenols, flavonoids and steroidal aglycones (mainly Velutinol A) of which may be responsible for the antioxidant, anti-glycation and anti-parasitic activity against T. cruzi. Trypanocidal activity of M. velutina compounds may be linked to their influence on NO synthesis during infection and/or their capacity to bind and inhibit molecules associated to virulence and survival of T. cruzi.

Divergent age-related changes in parasite infection occur independently of behaviour and demography in a wild ungulate.

As animals age, they exhibit a suite of phenotypic changes, often including reductions in movement and social behaviour ('behavioural ageing'). By altering an individual's exposure to parasites, behavioural ageing may influence infection status trajectories over the lifespan. However, these processes could be confounded by age-related changes in other phenotypic traits, or by selective disappearance of certain individuals owing to parasite-induced mortality. Here, we uncover contrasting age-related patterns of infection across three helminth parasites in wild adult female red deer (Cervus elaphus). Counts of strongyle nematodes (order: Strongylida) increased with age, while counts of liver fluke (Fasciola hepatica) and tissue worm (Elaphostrongylus cervi) decreased, and lungworm (Dictyocaulus) counts did not change. These relationships could not be explained by socio-spatial behaviours, spatial structuring, or selective disappearance, suggesting behavioural ageing is unlikely to be responsible for driving age trends. Instead, social connectedness and strongyle infection were positively correlated, such that direct age-infection trends were directly contrasted with the effects implied by previously documented behavioural ageing. This suggests that behavioural ageing may reduce parasite exposure, potentially countering other age-related changes. These findings demonstrate that different parasites can show contrasting age trajectories depending on diverse intrinsic and extrinsic factors, and that behaviour's role in these processes is likely to be complex and multidirectional.This article is part of the discussion meeting issue 'Understanding age and society using natural populations'.

Investigation of Enteric Parasites with a Focus on Zoonotic Parasites in the Feces of Galliformes.

Galliformes have a global distribution and are bred by humans as domestic animals or game birds. The world's poultry population is increasing due to high consumer demand for poultry products. Due to the increasing growth of Galliformes breeding, this study aimed to investigate gastrointestinal parasites in the feces of some species of Galliformes. In the present study, 100 distinct fecal samples were collected from seven different Galliformes species, including rural chickens, peacocks, partridges, pheasants, turkeys, quails, and guinea fowls. Sampling of each bird was performed separately, and these birds were kept in cages. In order to identify gastrointestinal parasites, the samples were evaluated using the Clayton-Lane method, the Modified Ziehl-Neelsen, and the Trichrome staining methods. Among 100 birds sampled, 53% were positive for gastrointestinal parasites. Moreover, 30%, 18%, and 5% of birds were infected with Eimeria spp., nematodes, and Giardia spp., respectively. The highest rate of parasitic infestation in Galliformes was related to protozoan infections, and the highest rate of protozoan infection was related to Eimeria (30%). In addition, complex infestation was not detected. Considering that most parasitic infections have been detected in apparently healthy birds, it is recommended to observe hygiene to regularly disinfect cages and reduce the density of birds in the nests. Due to the zoonotic potential of Giardia and the contamination of some birds with this parasite, this issue should be considered by public health officials, bird sellers' markets, owners, and breeders of these birds.

Effects of environmental factors on host-parasite interaction patterns in backyard-tethered goats of Kerala, India.

The environment is the most important stratum in the epidemiological triad of a parasitic disease and any variations in the environmental factors may decide the dynamic occurrence and existence of different lifecycle stages of these parasites. The present study investigated the correlations between key biometeorological and demographical parameters with the incidence of different gastrointestinal parasites and hemoparasites among goats. Four hundred and thirty-two goats were screened for parasitic infection in a yearlong survey conducted from July 2022 to June 2023 in the Teaching Veterinary Clinical Complex, Mannuthy, Kerala, India. The weather parameters (Tmax, Tmin, RH, THI, and bright sunshine hours), air quality parameters [AQI, PM2.5, and PM10], and demographic parameters (gender and age) were recorded along with the test positivity of different categories of gastrointestinal parasites and hemoparasites in goats by routine fecal sample examination and blood smear examination, respectively. The infection level was ranked based on the severity of the infection. The mean and daily variations in biometeorological parameters were calculated and the data were statistically analyzed to figure out the pertinent correlations in host-parasite-environment interaction patterns. High levels of parasitic infections with significant month-wise variations and climate-correlated peak infection patterns were noticed. The incidence of parasites was negatively correlated to all parameters except humidity, indicating more severe parasitism during monsoon months. The significant variations in the host-parasite interaction dynamics point towards the need for detailed explorations concerning the lifecycle of each specific parasite with a focus on the possible environment-favourable and resistant lifecycle stages. Future studies may be designed from a biometeorological perspective to develop a crucial understanding of host-parasite-environment interactions in goats ensuring sustainable goat farming.

Optimization of 18 S rRNA metabarcoding for the simultaneous diagnosis of intestinal parasites.

Recent advancements in next-generation sequencing (NGS) technologies have created new opportunities for comprehensive screening of multiple parasite species. In this study, we cloned the 18 S rDNA V9 region of 11 species of intestinal parasites into plasmids. Equal amounts and concentrations of these 11 plasmids were pooled, and amplicon NGS targeting the 18 S rDNA V9 region was performed using the Illumina iSeq 100 platform. A total of 434,849 reads were identified, and all 11 parasite species were detected, although the number of output reads for each parasite varied. The read count ratio, in descending order, was as follows: Clonorchis sinensis, 17.2%; Entamoeba histolytica, 16.7%; Dibothriocephalus latus, 14.4%; Trichuris trichiura, 10.8%; Fasciola hepatica, 8.7%; Necator americanus, 8.5%; Paragonimus westermani, 8.5%; Taenia saginata, 7.1%; Giardia intestinalis, 5.0%; Ascaris lumbricoides, 1.7%; and Enterobius vermicularis, 0.9%. We found that the DNA secondary structures showed a negative association with the number of output reads. Additionally, variations in the amplicon PCR annealing temperature affected the relative abundance of output reads for each parasite. These findings can be applied to improve parasite detection methodologies and ultimately enhance efforts to control and prevent intestinal parasitic infections.