Pulmonary infection by Lophomonas spp. and Aspergillus spp. in a B-cell acute lymphocytic leukemia patient from Chile.

The flagellated protozoan Lophomonas spp. is a commensal microorganism found in the intestinal tracts of cockroaches, termites, mites, and certain birds. It is the causative agent of a rare infection in humans called lophomoniasis, primarily affecting the lungs and mainly immunocompromised individuals. This parasitosis is transmitted to humans by air or through ingestion of the cystic forms of the parasite. We describe the case of a 50-year-old patient treated at a tertiary hospital in southern Chile with a history of B-cell acute lymphocytic leukemia. Radiological findings, along with increased levels of inflammatory parameters and galactomannan antigen in serum and Bronchoaveolar Lavage (BAL) raised the suspicion of a pulmonary infection. Microscopic study of BAL revealed oval to pyriform cells with mobile flagella at the anterior end, which were identified as Lophomonas spp. trophozoites, which based on EORTC/MSG criteria were associated with diagnosis of a probable pulmonary aspergillosis. Lophomoniasis was treated with metronidazole (500 mg IV every 8 h) for 14 days and pulmonary aspergillosis required a combination of fluconazole, voriconazole, anidulafungin, liposomal amphotericin B and isavuconazole. The patient responded favorably and was discharged after 95 days of hospitalization. This case highlights the importance of recognizing lophomoniasis as a parasitic infection in respiratory samples from immunocompromised patients who present pulmonary symptoms, especially those who do not respond satisfactorily to conventional antimicrobial treatments. Further research is needed to understand the various sources of Lophomonas spp. infection and develop infection prevention strategies particularly for high-risk patients.

Molecular evidence of hepatozoonosis in tigers of Vidarbha region of Maharashtra State of India.

BACKGROUND: Hepatozoonosis has been reported in many species around the world. Few incidences have been reported in various species of wild felids. Tigers are endangered large cats and are protected under the Wildlife Protection Act, 1972 under Schedule I. The study was carried out to estimate the positivity rate of hepatozoonosis in tigers of the Vidarbha region of Maharashtra, India. METHODS: Blood (n = 21) or tissue samples (n = 5) were collected from 26 wild captured / zoo-born or dead tigers during the quarantine period/post-mortem examination. Blood smear examination along with Polymerase Chain Reaction (PCR) studies were conducted for the detection of hepatozoonosis. All the amplicons from the positive samples were purified and sequenced, and the sequences were subjected to nBLAST analysis to detect the species of Hepatozoon. The sequences were deposited into public domain database of National Center for Biotechnology Information (NCBI) and accession numbers were allotted. A phylogenetic study was undertaken to understand the evolutionary lineage of the pathogen. Tissue distribution studies were carried out on tissue samples received during post mortem. A clinical case in a tiger cub was managed and sub-clinical cases were monitored for relapse. Age-wise, sex-wise, region-wise and captive time-wise positivity rate was estimated. The data was analyzed using statistical tools. RESULTS: A total of 12 tigers were found positive for H. felis during the screening. A clinical case was diagnosed and successfully treated. The age group of 0-3 years reported a positivity rate of 66.66%, and all the cases found positive were reported between the age group of 0-7 years. Males reported a positivity rate of 58.33 per cent, while females reported 35.71%. Taboba and Andhari Tiger Reserve of the state had a positivity rate of 52.94 per cent. However, the statistical analysis for blood parameters and positivity rate by 't' test and Chi-squared test were found to be non-significant. CONCLUSIONS: An overall positivity rate of 46.15% indicates the wide distribution of hepatozoonosis among wild tigers of the Vidarbha region of Maharashtra, India, which is strategically important considering the gene flow and migration of tigers. Hepatozoonosis can progress to clinical outcomes in young animals and require veterinary intervention. Molecular tools and phylogenetic studies can supplement important data on circulating species of Hepatozoon in the field. Further studies on the clinical management and epidemiology of the infection in wild felids will comprehend the cause of wildlife conservation.

Identification and characterization of archaeal-type FAD synthase as a novel tractable drug target from the parasitic protozoa Entamoeba histolytica.

Flavin adenine dinucleotide (FAD) is an essential cofactor for numerous flavoenzymes present in all living organisms. The biosynthesis of FAD from riboflavin involves two sequential reactions catalyzed by riboflavin kinase and flavin adenine dinucleotide synthase (FADS). Entamoeba histolytica, the protozoan parasite responsible for amebiasis, apparently lacks a gene encoding FADS that share similarity with bacterial and eukaryotic canonical FADS, yet it can synthesize FAD. In this study, we have identified the gene responsible for FADS and thoroughly characterized physiological and biochemical properties of FADS from E. histolytica. Phylogenetic analysis revealed that the gene was likely laterally transferred from archaea. The kinetic properties of recombinant EhFADS were consistent with the notion that EhFADS is of archaeal origin, exhibiting KM and kcat values similar to those of the arachaeal enzyme while significantly differing from the human counterpart. Repression of gene expression of EhFADS by epigenetic gene silencing caused substantial reduction in FAD levels and parasite growth, underscoring the importance of EhFADS for the parasite. Furthermore, we demonstrated that EhFADS gene silencing reduced thioredoxin reductase activity, which requires FAD as a cofactor and makes the ameba more susceptible to metronidazole. In summary, this study unveils unique evolutionary and biochemical features of EhFADS and underscores its significance as a promising drug target in combating human amebiasis.IMPORTANCEFAD is important for all forms of life, yet its role and metabolism are still poorly studied in E. histolytica, the protozoan parasite causing human amebiasis. Our study uncovers the evolutionary unique key enzyme, archaeal-type FADS for FAD biosynthesis from E. histolytica for the first time. Additionally, we showed the essentiality of this enzyme for parasite survival, highlighting its potential as target for drug development against E. histolytica infections.

Insights into Peptidyl-Prolyl cis-trans Isomerases from Clinically Important Protozoans: From Structure to Potential Biotechnological Applications.

Peptidyl-prolyl cis/trans isomerases (PPIases) are present in a wide variety of microorganisms, including protozoan parasites such as Trypanosoma cruzi, Trypanosoma brucei, Trichomonas vaginalis, Leishmania major, Leishmania donovani, Plasmodium falciparum, Plasmodium vivax, Entamoeba histolytica, Giardia intestinalis, Cryptosporidium parvum, and Cryptosporidium hominis, all of which cause important neglected diseases. PPIases are classified as cyclophilins, FKBPs, or parvulins and play crucial roles in catalyzing the cis-trans isomerization of the peptide bond preceding a proline residue. This activity assists in correct protein folding. However, experimentally, the biological structure-function characterization of PPIases from these protozoan parasites has been poorly addressed. The recombinant production of these enzymes is highly relevant for this ongoing research. Thus, this review explores the structural diversity, functions, recombinant production, activity, and inhibition of protozoan PPIases. We also highlight their potential as biotechnological tools for the in vitro refolding of other recombinant proteins from these parasites. These applications are invaluable for the development of diagnostic and therapeutic tools.

Heme metabolism in Strigomonas culicis: Implications of H2O2 resistance induction and symbiont elimination.

Monoxenous trypanosomatid Strigomonas culicis harbors an endosymbiotic bacterium, which enables the protozoa to survive without heme supplementation. The impact of H2O2 resistance and symbiont elimination on intracellular heme and Fe2+ availability was analyzed through a comparison of WT strain with both WT H2O2-resistant (WTR) and aposymbiotic (Apo) protozoa. The relative quantification of the heme biosynthetic pathway through label-free parallel reaction monitoring targeted mass spectrometry revealed that H2O2 resistance does not influence the abundance of tryptic peptides. However, the Apo strain showed increased coproporphyrinogen III oxidase and ferrochelatase levels. A putative ferrous iron transporter, homologous to LIT1 and TcIT from Leishmania major and Trypanosoma cruzi, was identified for the first time. Label-free parallel reaction monitoring targeted mass spectrometry also showed that S. culicis Iron Transporter (ScIT) increased 1.6- and 16.4-fold in WTR and Apo strains compared to WT. Accordingly, antibody-mediated blockage of ScIT decreased by 28.0% and 40.0% intracellular Fe2+concentration in both WTR and Apo strains, whereas no effect was detected in WT. In a heme-depleted medium, adding 10 µM hemin decreased ScIT transcript levels in Apo, whereas 10 µM PPIX, the substrate of ferrochelatase, increased intracellular Fe2+ concentration and ferric iron reduction. Overall, the data suggest mechanisms dependent on de novo heme synthesis (and its substrates) in the Apo strain to overcome reduced heme availability. Given the importance of heme and Fe2+ as cofactors in metabolic pathways, including oxidative phosphorylation and antioxidant systems, this study provides novel mechanistic insights associated with H2O2 resistance in S. culicis.

miRNA, New Perspective to World of Intestinal Protozoa and Toxoplasma.

BACKGROUND: miRNAs are known as non-coding RNAs that can regulate gene expression. They are reported in many microorganisms and their host cells. Parasite infection can change or shift host miRNAs expression, which can aim at both parasite eradication and infection. PURPOSE: This study dealt with examination of miRNA expressed in intestinal protozoan, coccidia , as well as profile changes in host cell miRNA after parasitic infection and their role in protozoan clearance/ survival. METHODS: The authors searched ISI Web of Sciences, Pubmed, Scholar, Scopus, another databases and articles published up to 2024 were included. The keywords of miRNA, intestinal protozoa, toxoplasma and some words associated with topics were used in this search. RESULTS: Transfection of miRNA mimics or inhibitors can control parasitic diseases, and be introduced as a new therapeutic option in parasitology. CONCLUSION: This review can be used to provide up-to date knowledge for future research on these issues.

A review of Hepatozoonosis caused by Hepatozoon canis in dogs.

Hepatozoon canis is a type of single-celled organism is spread by ticks and commonly affects dogs. It is responsible for causing one of the most significant parasitic diseases in dogs, called Hepatozoonosis. It is considered one of the most common causes of canine vector-borne diseases because it is closely linked to Rhipicephalus sanguineus (the brown dog tick), a species found worldwide. Hepatozoonosis caused by H. canis is prevalent in regions such as South Europe, South America, Asia, and Africa. H. canis often causes emaciation, anemia, and intermittent fever in infected dogs. The drugs used to treat H. canis infection in dogs include the combination of imidocarb dipropionate with doxycycline, toltrazoril, tetracycline hydrochloride, and the combination of trimethoprim-sulfamethoxazole.The primary solution to prevent the spread of infections caused by H. canis is to control the population of R. sanguineus ticks because H. canis is spread through ticks. This review aims to provide a brief overview of various studies conducted on the morphology, life cycle, hosts, epidemiology, clinical symptoms, laboratory diagnosis, autopsy findings, differential diagnosis, treatment, and prevention methods of H. canis.

THE 72-KDA PROTEIN OF NAEGLERIA FOWLERI PLAYS AN IMPORTANT ROLE IN THE ADHESION OF TROPHOZOITES TO BALB/C MICE NASAL EPITHELIUM.

Naegleria fowleri is a protozoan that causes primary amebic meningoencephalitis (PAM). The infection occurs when the trophozoites enter the nasal cavity, adhere to the nasal mucosa, invade the epithelium, and migrate until they reach the olfactory bulb. Like other pathogens, there is evidence that the adhesion of N. fowleri to host cells is an important factor in the process of cytopathogenicity and disease progression. However, the factors involved in the adhesion of the pathogen to the cells of the nasal epithelium have not been characterized. The objective of this study was to identify a protein on the surface of N. fowleri, which could act as adhesin to the mouse nasal epithelium in the PAM model. The interaction between proteins of extracts of N. fowleri and cells of the nasal epithelium of BALB/c mice was analyzed using overlay and Western blot assays. A 72-kDa band of N. fowleri interacted directly with epithelial cell proteins, this polypeptide band was purified and analyzed by mass spectrometry. Analysis revealed that polypeptide bands of 72 kDa contained peptides that matched the membrane protein, actin 1 and 2, and Hsp70. Moreover, the N. fowleri extracts resolved in 2D-SDS-PAGE showed that 72-kDa spot interacted with proteins of mouse epithelial cells, which include characteristics of the theoretical data of molecular weight and pH obtained in the analysis by mass spectrometry. Immunofluorescence tests showed that this protein is located on the surface of trophozoites and plays an important role in the adhesion of amoeba either in vitro or in vivo assays, suggesting that this protein contributes during the N. fowleri invasion and migration to the brain, causing primary amoebic meningoencephalitis.

Analyzing the Interaction between Tetrahymena pyriformis and Bacteria under Different Physicochemical Conditions When Infecting Guppy Using the eDNA Method.

In the aquaculture system of ornamental fish, the interaction between bacterial microbiota and ciliate protozoa can prevent or promote disease outbreaks, and different physicochemical conditions will affect the relationships between them. We investigated the interaction between bacterial microbiota and the parasite Tetrahymena pyriformis when infecting Poecilia reticulata (guppy) under different physicochemical conditions. The abundance of T. pyriformis in water, the relative abundance of bacterial species, and histopathological observation were studied or monitored using environmental DNA (eDNA) extraction technology, the qPCR method, and 16s rRNA sequencing, respectively. The morphological identification and phylogenetic analysis of T. pyriformis were carried out. The infected guppy tissue was also stained by the hematoxylin and eosin methods. The results showed: (1) the bacterial communities of water samples were mainly composed of species assigned to Proteobacteria and Bacteroidetes, and Tabrizicola and Puniceicoccaceae were positively correlated with fish mortality, T. pyriformis abundance, and temperature. (2) Arcicella and Methyloversatilis universalis with different correlations between ciliates appeared in different treatment groups, the result of which proved that environmental factors affected the interaction between bacteria and T. pyriformis. (3) Lower temperatures and a higher pH were more beneficial for preventing disease outbreaks.

Trypanosoma cruzi assembles host cytoplasmic processing bodies to evade the innate immune response.

Processing bodies (P-bodies, PBs) are cytoplasmic foci formed by condensation of translationally inactivated messenger ribonucleoprotein particles (mRNPs). Infection with the protozoan parasite Trypanosoma cruzi (T. cruzi) promotes PB accumulation in host cells, suggesting their involvement in host mRNA metabolism during parasite infection. To identify PB-regulated mRNA targets during T. cruzi infection, we established a PB-defective human fibrosarcoma cell line by knocking out the enhancer of mRNA decapping 4 (EDC4), an essential component of PB assembly. Next-generation sequencing was used to establish transcriptome profiles for wild-type (WT) and EDC4 knockout (KO) cells infected with T. cruzi for 0, 3, and 24 h. Ingenuity pathway analysis based on the differentially expressed genes revealed that PB depletion increased the activation of several signaling pathways involved in the innate immune response. The proinflammatory cytokine IL-1ß was significantly upregulated following infection of PB-deficient KO cells, but not in WT cells, at the mRNA and protein levels. Furthermore, the rescue of PB assembly in KO cells by GFP-tagged wild-type EDC4 (+WT) suppressed IL-1ß expression, whereas KO cells with the C-terminal-deleted mutant EDC4 (+Δ) failed to rescue PB assembly and downregulate IL-1ß production. Our results suggest that T. cruzi assembles host PBs to counteract antiparasitic innate immunity.

The 26 S proteasome in Entamoeba histolytica: divergence of the substrate binding pockets from host proteasomes.

OBJECTIVE: Proteasomes are conserved proteases crucial for proteostasis in eukaryotes and are promising drug targets for protozoan parasites. Yet, the proteasomes of Entamoeba histolytica remain understudied. The study's objective was to analyse the differences in the substrate binding pockets of amoeba proteasomes from those of host, and computational modelling of ß5 catalytic subunit, with the goal of finding selective inhibitors. RESULTS: Comparative sequence analysis revealed differences in substrate binding sites of E. histolytica proteasomes, especially in the S1 and S3 pockets of the catalytic beta subunits, implying differences in substrate preference and susceptibility to inhibitors from host proteasomes. This was strongly supported by significantly lower sensitivity to MG132 mediated inhibition of amoebic proteasome ß5 subunit's chymotryptic activity compared to human proteasomes, also reflected in lower sensitivity of E. histolytica to MG132 for inhibition of proliferation. Computational models of ß4 and ß5 subunits, and a docked ß4-ß5 model revealed a binding pocket between ß4-ß5, similar to that of Leishmania tarentolae. Selective inhibitors for visceral leishmaniasis, LXE408 and compound 8, docked well to this pocket. This functional and sequence-based analysis predicts differences between amoebic and host proteasomes that can be utilized to develop rationally designed, selective inhibitors against E. histolytica.

Unveiling risks in healthy food: Vegetables and fruits are linked to the distribution chain of protozoan parasites.

Vegetable and fruit contamination is recognized as a significant parasite transmission route. This review presents the current state of vegetables ad fruits contamination with food-borne parasitic protozoa worldwide. We consider the methodologies and strategies for detecting parasitic stages developed in the last decade and the contamination data. Asia had the highest number of reports (94 studies), followed by Africa (74 studies). At the country level, with 41 studies, Iran had the most reports among other countries, followed by Nigeria (28 studies). According to the studies included in the current review, 41.22% of vegetables and fruits were contaminated with different species of protozoan parasites. Among different continents, Asia accounted for the highest contamination rate of protozoan parasites (57.12%). Giardia spp. (10%) had the highest contamination rate in vegetables and fruits, followed by Entamoeba coli (8%), E. histolytica/dispar (7%), and Cryptosporidium spp. (6%). This study provides essential data for health authorities to develop food safety programs. The presence of protozoan parasites in fruits and vegetables highlights the critical need for maintaining rigorous food safety measures across the entire production and distribution process, particularly in countries that are major producers and distributors of these food items.

The Search for Drugs Derived from Natural Products for Toxoplasma gondii Infection Treatment in the Last 20 Years - A Systematic Review.

INTRODUCTION: Toxoplasmosis is a worldwide distributed zoonosis caused by Toxo-plasma gondii (T. gondii), an obligate intracellular protozoan. The infection in immunocompetent hosts usually progresses with mild or no symptoms. However, in immunocompromised individu-als, this disease can cause severe or fatal symptoms. METHOD: Sulfadiazine and pyrimethamine are two drugs used as standard therapies for human toxoplasmosis. Although they do not cause chronic infection, they may cause hematological tox-icity, hypersensitivity, intolerance, teratogenic effects, gastrointestinal disorders, and bone mar-row suppression. RESULT: The limited effect, significant toxicity, and emerging resistance to current drugs available to treat T. gondii infections require investigating other effective, nontoxic, and well-tolerated al-ternatives. Medicinal plants are, traditionally, the most promising sources used to treat infectious diseases. CONCLUSION: This review provides data on new therapeutic and prophylactic methods for T. gondii infection based on the use of extracts and/or compounds derived from natural products, which have been reported to be useful as alternative treatment options in the last 20 years.

Electrochemical biosensors for the detection of protozoan parasite: a scoping review.

The development of rapid, accurate, and efficient detection methods for protozoan parasites can substantially control the outbreak of protozoan parasites infection, which poses a threat to global public health. Idealistically, electrochemical biosensors would be able to overcome the limitations of current detection methods due to their simplified detection procedure, on-site quantitative analysis, rapid detection time, high sensitivity, and portability. The objective of this scoping review is to evaluate the current state of electrochemical biosensors for detecting protozoan parasites. This review followed the most recent Preferred Reporting Items for Systematic Review and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) recommendations. Using electrochemical biosensor and protozoan parasite keywords, a literature search was conducted in PubMed, Scopus, Web of Science, and ScienceDirect on journals published between January 2014 and January 2022. Of the 52 studies, 19 were evaluated for eligibility, and 11 met the review's inclusion criteria to evaluate the effectiveness and limitations of the developed electrochemical biosensor platforms for detecting protozoan parasite including information about the samples, biomarkers, bioreceptors, detection system platform, nanomaterials used in fabrication, and limit of detection (LoD). Most electrochemical biosensors were fabricated using conventional electrodes rather than screen-printed electrodes (SPE). The range of the linear calibration curves for the developed electrochemical biosensors was between 200 ng/ml and 0.77 pM. The encouraging detection performance of the electrochemical biosensors demonstrate their potential as a superior alternative to existing detection techniques. On the other hand, more study is needed to determine the sensitivity and specificity of the electrochemical sensing platform for protozoan parasite detection.

Evaluation of Three Different Selective Media for Enumeration of Clostridium perfringens in Untreated and Treated Wastewater.

Current and emerging legislation in North Carolina and other regions calls for the enumeration of Clostridium perfringens as a surrogate indicator for protozoan parasites in various types of waters. Past studies that have evaluated selective media for the detection of this bacterium have provided limited, conflicting, and inconclusive results. In this study, membrane filtration was used to enumerate C. perfringens as culturable spores or total culturable cells in 19 samples of untreated and 25 samples of partially treated wastewaters on 3 candidate media, Tryptose Sulfite Cycloserine Agar (TSC), CP ChromoSelect Agar (CPCS), and membrane Clostridium perfringens Agar (m-CP) in parallel, and the results were compared. Presumptive isolates from each agar were further subjected to phenotypic confirmation tests for acid phosphatase production and stormy fermentation to further determine the performance of each agar. The CPCS agar was determined to have the highest enumerative capacity of total C. perfringens cells when compared to both TSC agar and m-CP agar (p-value < 0.05), but there was no significant difference in its ability to detect spores when compared to TSC agar (p-value > 0.05). The overall specificity of CPCS agar as determined by agreement of results from both confirmation tests was 0.81, while the specificity of TSC agar was only 0.28. Based on its performance, ease of preparation and use and consistency of colony characteristics, CPCS agar is recommended as the preferred medium for C. perfringens enumeration in wastewater.

Entamoeba histolytica: EhADH, an Alix Protein, Participates in Several Virulence Events through Its Different Domains.

Entamoeba histolytica is the protozoan causative of human amoebiasis. The EhADH adhesin (687 aa) is a protein involved in tissue invasion, phagocytosis and host-cell lysis. EhADH adheres to the prey and follows its arrival to the multivesicular bodies. It is an accessory protein of the endosomal sorting complexes required for transport (ESCRT) machinery. Here, to study the role of different parts of EhADH during virulence events, we produced trophozoites overexpressing the three domains of EhADH, Bro1 (1-400 aa), Linker (246-446 aa) and Adh (444-687 aa) to evaluate their role in virulence. The TrophozBro11-400 slightly increased adherence and phagocytosis, but these trophozoites showed a higher ability to destroy cell monolayers, augment the permeability of cultured epithelial cells and mouse colon, and produce more damage to hamster livers. The TrophozLinker226-446 also increased the virulence properties, but with lower effect than the TrophozBro11-400. In addition, this fragment participates in cholesterol transport and GTPase binding. Interestingly, the TrophozAdh444-687 produced the highest effect on adherence and phagocytosis, but it poorly influenced the monolayers destruction; nevertheless, they augmented the colon and liver damage. To identify the protein partners of each domain, we used recombinant peptides. Pull-down assays and mass spectrometry showed that Bro1 domain interplays with EhADH, Gal/GalNAc lectin, EhCPs, ESCRT machinery components and cytoskeleton proteins. While EhADH, ubiquitin, EhRabB, EhNPC1 and EhHSP70 were associated to the Linker domain, and EhADH, EhHSP70, EhPrx and metabolic enzymes interacted to the Adh domain. The diverse protein association confirms that EhADH is a versatile molecule with multiple functions probably given by its capacity to form distinct molecular complexes.

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.

Detection of Toxoplasma gondii in wild bivalves from the Kerguelen and Galapagos archipelagos: influence of proximity to cat populations, exposure to marine currents and kelp density.

Oocysts of the protozoan Toxoplasma gondii are found in felid feces and can be washed into coastal waters, where they persist for months, attaching to algae and accumulating in invertebrates. We used wild bivalves to assess contamination of coastal waters of the Kerguelen and Galapagos archipelagos by this zoonotic parasite. Additionally, we leveraged the contrasting situations of these archipelagos to identify some potential drivers of contamination. In the Galapagos, with a cat density reaching 142 per km2, 15.38% of the sampled oysters (Saccostrea palmula) tested positive for T. gondii by quantitative real-time PCR (qPCR) (n = 260), and positive samples were found in all eight sampling sites. In Kerguelen, with 1-3 cats per km2, 40.83% of 120 tested mussels (Mytilus edulis platensis) were positive, and positive samples were found in four out of the five sampling sites. These findings provide evidence of T. gondii contamination in the coastal waters of these archipelagos. Furthermore, T. gondii-positive bivalves were found on islands located 20 km away (Galapagos) and 5 km away (Kerguelen) from the nearest cat population, indicating that T. gondii oocysts can disperse through waterborne mechanisms over several kilometers from their initial deposition site. In the Galapagos, where runoff is infrequent and all sites are exposed to currents, the prevalence of qPCR-positive bivalves did not show significant variations between sites (p = 0.107). In Kerguelen where runoff is frequent and site exposure variable, the prevalence varied significantly (p < 0.001). The detection of T. gondii in Kerguelen mussels was significantly correlated with the site exposure to currents (odds ratio (OR) 60.2, p < 0.001) and the on-site density of giant kelp forests (OR 2.624, p < 0.001). This suggests that bivalves can be contaminated not only by oocysts transported by currents but also by consuming marine aggregates containing oocysts that tend to form in kelp forests.

Meningoencephalitis with malacia caused by Sarcocystis calchasi in a rock pigeon in Japan.

Sarcocystis spp. cause pigeon protozoan encephalitis, a neuronal disease. A female pigeon exhibiting torticollis had a necrotic area in the cerebral hemisphere surrounded by lesions with perivascular cuffing, gliosis, granulomatous foci, and meningitis. Non-necrotic lesions were also observed in the brainstem. Intact and degenerative schizonts were observed within the neuropils and neurons in the lesions. Deoxyribonucleic acid (DNA) was extracted from paraffin-embedded brain tissues and genetically analyzed after gel electrophoresis to determine Sarcocystis spp. using specific primer sets for 28S ribosomal ribonucleic acid and internal transcribed spacer region-1. DNA sequencing confirmed a significant homology with S. calchasi. This is the first report of meningoencephalitis with malacia caused by S. calchasi in a rock pigeon in Japan.

Blowflies (Diptera: Calliphoridae) as potential mechanical vectors of the protozoan cyst and helminthic eggs in Kashmir Himalaya, India.

Blowflies (Diptera: Calliphoridae) are an important group of non-biting flies that are potential mechanical vectors of protozoan and helminthic pathogens. The present study was carried out to isolate and identify protozoan cysts and helminthic eggs transmitted by blowflies. Surveys were carried out at six different sites, viz., butcher shops, fish markets, garbage piles, water bodies, and open vegetation in the Kashmir Himalaya. The flies were collected with the help of a sweeping net and using day-old beef liver as bait from March 2021 to February 2023. A total of 968 blowflies were collected, out of which 83 were found carrying at least one protozoan cyst and helminthic egg with six identified species of parasites. Garbage piles were recorded with the highest number of positive cases (10.81%), while human habitation had the highest transmission rate (3.3%). Chrysomya megacephala (Fabricius) was reported to have the highest number of parasitic cysts and ova (one protozoan cyst and three helminthic eggs), while Ascaris lumbricoides and Entamoeba coli were found to be the most abundant parasites reported from the surface of these flies. The number of parasites isolated from the surface of the blowflies was statistically significant (F = 9.073, df = 1, and p = 0.014), indicating a positive association between the number of parasites isolated from blowflies and the collection sites. Supplementary Information: The online version contains supplementary material available at 10.1007/s12639-024-01663-5.