Search Results (128)

In Brazil, Plasmodium infections in non-human primates (NHPs) have been associated with P. simium and P. brasilianum, which are morphologically and genetically similar to the human-infecting species P. vivax and P. malariae, respectively. Surveillance and monitoring of wild NHPs are crucial for understanding the distribution of these parasites and assessing the risk of zoonotic transmission. This study aimed to detect the presence of Plasmodium spp. genetic material in Platyrrhini primates from 47 municipalities in the states of Bahia and Minas Gerais. The animals were captured using Tomahawk-type live traps baited with fruit or immobilized with tranquilizer darts. Free-ranging individuals were chemically restrained via inhalation anesthesia using VetBag^® or intramuscular anesthesia injection. Blood samples were collected from the femoral vein. A total of 298 blood and tissue samples were collected from 10 primate species across five genera: Alouatta caraya (25), Alouatta guariba clamitans (1), Callicebus melanochir (1), Callithrix geoffroyi (28), Callithrix jacchus (4), Callithrix kuhlii (31), Callithrix penicillata (175), Callithrix spp. hybrids (15), Leontopithecus chrysomelas (16), Sapajus robustus (1), and Sapajus xanthosthernos (1). Molecular diagnosis was performed using a nested PCR targeting the 18S small subunit ribosomal RNA (18S SSU rRNA) gene, followed by sequencing. Of the 298 samples analyzed, only one (0.3%) from Bahia tested positive for Plasmodium brasilianum/P. malariae. This represents the first detection of this parasite in a free-living C. geoffroyi in Brazil. These findings highlight the importance of continued surveillance of Plasmodium infections in NHPs to identify regions at risk for zoonotic transmission. Full article

Limited molecular data exist on zoonotic parasites Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi in Angus calves from Guizhou, China. This study constitutes the first molecular epidemiological survey of these pathogens in this region. 817 fecal samples from Angus calves across 7 intensive beef farms (Bijie City). Nested PCR methods targeting SSU rRNA (Cryptosporidium spp.), gp60 (Cryptosporidium bovis subtyping), bg/gdh/tpi (G. duodenalis), and ITS (E. bieneusi) coupled with DNA sequencing were employed. DNA sequences were analyzed against the NCBI. database. Statistical differences were assessed via a generalized linear mixed-effects model. Cryptosporidium spp. prevalence 23.5% (192/817; 95% CI 28.1–34.6%), with C. bovis predominating 89.6% (172/192; 95% CI 84.4–93.5%) and six subtypes (XXVIa-XXVIf). Highest infection in 4–8-week-olds 29.9% (143/479; 95% CI 25.8–34.1%) (p < 0.01). G. duodenalis: 31.3% (256/817; 95% CI 28.1–34.6%) positive, overwhelmingly assemblage E 97.6% (6/256; 95% CI 0.9–5.0%), zoonotic assemblage A was marginal 0.7% (6/817; 95% CI 0.3–1.6%). Farm-level variation exceeded 10-fold (e.g., Gantang: 55.0% (55/100; 95% CI 44.7–65.0%) vs. Tieshi: 4.9% (5/102; 95% CI 1.6–11.1%). E. bieneusi: prevalence 19.7% (161/817; 95% CI 17.0–22.6%), exclusively zoonotic genotypes BEB4: 49.7% (80/161; 95% CI 41.7–57.7%); I: 40.4% (65/161; 95% CI 32.7–48.4%). Strong diarrhea association (p < 0.01) and site-specific patterns (e.g., Guanyindong: 39.2%). While Giardia exhibited the highest prevalence (31.3%) with minimal zoonotic risk, Enterocytozoon—despite lower prevalence (19.7%)—posed the greatest public health threat due to exclusive circulation of human-pathogenic genotypes (BEB4/I) and significant diarrhea association, highlighting divergent control priorities for these enteric parasites in Guizhou calves. Management/Public health impact: Dominant zoonotic E. bieneusi genotypes (BEB4/I) necessitate: 1. Targeted treatment of 4–8-week-old Angus calves. 2. Manure biofermentation (≥55 °C, 3 days), and 3. UV-disinfection (≥1 mJ/cm²) for karst water to disrupt transmission in this high-humidity region. Full article

In order to investigate the infection status of Cryptosporidium in O. curzoniae and B. grunniens in Zoige County, Sichuan Province, fecal samples from B. grunniens and gastrointestinal contents from captured O. curzoniae were collected between March and December 2023 from five townships (Dazhasi, Axi, Hongxing, Tangke, and Maixi). Genomic DNA was extracted, and nested PCR targeting the small subunit (SSU) rRNA gene of Cryptosporidium was performed. PCR-positive products were sequenced, trimmed, aligned, and subjected to phylogenetic analysis to determine species and genotypes. A total of 242 samples were obtained, of which 20 were Cryptosporidium SSU rRNA-positive, yielding an overall detection rate of 8.3% (20/242). The detection rates of O. curzoniae and B. grunniens were 7.0% (8/114) and 9.4% (12/128), respectively. Among the five sampling sites, Maixi town exhibited the highest detection rate (32.4%, 11/44), followed by Hongxing town (15.2%, 7/46) and Tangke town (4.6%, 2/44). Phylogenetic analysis detected an unidentified Cryptosporidium sp. in O. curzoniae, while C. bovis (n = 10) and C. ryanae (n = 2) were detected in B. grunniens. These findings demonstrate that Cryptosporidium infections are present in both O. curzoniae and B. grunniens in Zoige County, with notable differences in infection rates and species composition. Continued surveillance of Cryptosporidium in local livestock and wildlife is warranted to provide critical data for regional public health management. Full article

Although Dientamoeba fragilis is a common protozoan in humans, its pathogenicity and clinical significance in human diseases remain poorly understood. This study aimed to determine the frequency of D. fragilis in adult ulcerative colitis patients and to assess its relationship with clinical findings, disease characteristics, and biochemical parameters. Patient data were analysed in a prospective, single-centre, cross-sectional design. Faecal samples were consecutively collected from June to December 2024 and screened for D. fragilis positivity using polymerase chain reaction. Of the 110 patients, 33 (30%) were in the active stage of the disease, while 77 (70%) were in remission. The overall frequency of D. fragilis was 10.9% (n = 12), with all isolates classified as genotype 1 according to SSU rRNA sequence analysis. Other protozoa identified were Blastocystis sp. (n = 5, 4.5%), Entamoeba coli (n = 1, 0.9%), and Iodamoeba bütschlii (n = 1, 0.9%). Two patients were co-infected with D. fragilis and Blastocystis. No significant associations were found between D. fragilis positivity and the disease stage, gastrointestinal symptoms, treatment response, or biochemical findings. In conclusion, despite the relatively small sample size, these findings highlight a limited clinical role of D. fragilis in adult ulcerative colitis patients. Full article

Several trichomonad species have already been reported from cattle, including Tetratrichomonas buttreyi and Pentatrichomonas hominis. However, there is currently a lack of information concerning the prevalence of trichomonad species in cattle in Shanxi Province, North China. In this study, 761 fecal samples from cattle across three counties in Shanxi Province, namely Qi, Jishan, and Shanyin, were examined for the presence of T. buttreyi and P. hominis DNA through a nested PCR assay targeting a specific segment of the small subunit ribosomal RNA (SSU rRNA) gene. The results showed that the total prevalence of T. buttreyi in cattle was found to be 74.5%, with region and sex identified as risk factors for infection. P. hominis exhibited an overall prevalence of 3.0%, with strong associations observed between infection and both region and age. Sequencing analysis indicated that some T. buttreyi isolates and all P. hominis isolates were identical to those reported previously based on the analysis of SSU rRNA sequences, while certain T. buttreyi isolates exhibited minor allelic variations. These results enhance our understanding of the geographical distribution and genetic characterization of T. buttreyi and P. hominis in cattle. Full article

Microsporidiosis is a zoonotic disease that derives from disparate sources. Most of the microsporidial agents are host-specific but some are capable of interspecies transmission, causing disease in various animals including humans. Human microsporidiosis may be caused by 17 species, with Encephalitozoon cuniculi, E. intestinalis and E. hellem mostly being responsible for human infections worldwide. Wildlife and migratory waterfowl can serve as reservoirs of these human-infectious agents and play a significant role in disseminating these pathogens into the environment. The aim of the study was to detect E. cuniculi, E. intestinalis and E. hellem in wild, migratory greater white-fronted geese (Anser albifrons) and other Anatidae members in feacal samples obtained in north-western Poland, using a molecular method. We collected 189 fecal droppings from Anatidae species (75 samples from greater white-fronted geese and 114 from other Anser spp.) during autumn migration. New species specific primers for PCR amplification were used to amplify a fragment of the small subunit ribosomal (SSU) rRNA of E. cuniculi, E. intestinalis and E. hellem. All fecal droppings were negative for E. intestinalis and E. hellem whereas E cuniculi was detected in 6 of 189 fecal samples (3.2%; 95% CI: 1.3–6.3%). In total, 1 of 75 tested fecal samples of greater white-fronted geese was positive (1.3%; 95% CI: 0.08–5.7%) while 5 of 114 (4.4%; 95% CI: 1.6–9.1%) tested fecal samples without exact species affiliation (only Anser sp.) were also positive. The phylogenetic analysis placed the sequences obtained from the birds’ droppings in the clade E. cuniculi from various rodents, wild carnivores and humans. Our results provide the first description of the occurrence and genotyping of the microsporidian E. cuniculi in greater white-fronted geese and in other members of the Anserinae Subfamily. Our findings support the results of other authors that E. cuniculi may originate from diverse sources, including common waterfowl. Our results are important in a One Health context, as wild migrating waterfowl may disseminate this zoonotic agent in remote regions through their migratory behaviour. These species should be considered significant sources of zoonotic pathogens, potentially hazardous to domestic and farmed animals as well as humans. Full article

Herbivorous protistan grazers are ubiquitous and abundant in marine and temperate freshwater environments. However, little is known about the algivorous ciliates and their feeding habits in outdoor mass algal cultures. In this study, we report on one hypotrich ciliate, identified as Sterkiella histriomuscorum, from the outdoor mass culture of Scenedesmus in Arizona, USA. A long-term field survey revealed that this species often occurs in Scenedesmus culture in spring and summer, and can graze very heavily on Scenedesmus cells. By isolating Sterkiella cells and then observing them via light microscopy and electron microscopy, detailed information about the morphology, ultrastructure, excystment process, and feeding characteristics of the ciliate was obtained. Specifically, it seems that S. histriomuscorum has a range of different strategies for excystment, and the sharp change in the ion concentration in the environment around the cyst results in osmotic shock, which likely facilitates the excystment. Feeding experiments revealed that S. histriomuscorum preferred to graze on chlorophytes as well as the diatom Phaeodactylum tricornutum and had no interaction with chrysophytes or cyanobacteria. Molecular phylogenetic analysis based on the SSU rRNA gene sequence indicated that both the genus Sterkiella and the species S. histriomuscorum are non-monophyletic. The information obtained from this study will help advance our understanding of the biodiversity and ecological function of S. histriomuscorum, and will also be very useful in the development of early warning systems and control measures for preventing or treating this contaminant in microalgal mass cultures. Full article

This study reports two novel species, Gogorevia contracta sp. nov. and G. recticentralis sp. nov., which were isolated from freshwater environments in South Korea. Using an integrative taxonomic approach, we conducted morphological analyses using light microscopy and scanning electron microscopy, along with molecular phylogenetic investigations using SSU rRNA and rbcL gene sequences. Phylogenetic reconstructions highlighted the distinct characteristics of both species, confirming their classification within the genus Gogorevia and elucidating their evolutionary relationships. Morphologically, G. contracta was characterized by a bow-tie-shaped central area and circular depressions in the rapheless valve, whereas G. recticentralis exhibited a rectangular-to-wedge-shaped central area with parallel striae near the center of the raphe valve. Our findings highlighted the ecological significance of Gogorevia species and suggested their potential role as bioindicators of water quality in relatively unpolluted freshwater systems. Over the past decade, our research has focused on the taxonomic and ecological study of diatoms in the Han River system and identified 136 species, including nine newly described taxa. The findings of the present study contribute to a growing understanding of Gogorevia diversity, underscore the importance of region-specific diatom indices, and support the integration of morphological and molecular methods into diatom systematics. Full article

Parasitic protozoa such as Lankesterella and Isospora are common in avian hosts, particularly in passerines. Despite their high prevalence, the diversity of these parasites within avian populations remains poorly understood. This study aimed to assess the diversity of Lankesterella and Isospora in passerine birds, using the SSU rRNA gene to characterize and compare the genetic variation in both parasites across multiple avian host species. For Isospora, the extraintestinal blood stages and oocysts from feces were compared. Minimum spanning networks were constructed to visualize haplogroups in relation to host specificity and to reveal the identity of various developmental stages. A total of 122 sequences from eight passerine species were used to generate a haplotype network for Lankesterella, and a total of 103 sequences (64 from blood and 39 from feces) was used for Isospora. We detected a total of 36 haplotypes for Lankesterella and 33 haplotypes for Isospora. In Lankesterella, we confirmed that the sedge warbler has its own specific lineages, whereas other warbler species share lineages belonging to three haplogroups; blue, great, marsh and willow tits have their own unique groups of lineages. Isospora is less host-specific than Lankesterella in avian hosts; nevertheless, Isospora sequences from blood and feces were identical in their respective hosts. Our findings provide insights into the diversity and host specificity of blood coccidians; moreover, we molecularly characterized the developmental stages of Isospora. Full article

Ciliates of the genus Frontonia have been extensively studied to resolve their phylogenetic and evolutionary history, but challenges remain. This study used molecular analyses of SSU rRNA genes, phylogenetic tree reconstruction, molecular dating, and diversification analysis, together with ancestral state reconstruction of morphological traits and habitat preferences. Data included newly sequenced Korean species, GenBank records and published morphological information. Phylogenetic trees revealed paraphyly within Frontonia, identifying four groups that emerged in the Mesozoic era: Group I (~172 mya), Group II (~83 mya), Group III (~115 mya), and Group IV (~190 mya), with a common ancestor dating to ~420 mya in the Palaeozoic era. Diversification analysis revealed higher extinction rates (0.826 and 0.613 species/year) than speciation rates (0.011 and 0.016 species/year). Morphological evolution showed habitat adaptation and plasticity, with habitat transitions unrelated to contractile vacuolar traits. The SSU rRNA gene polymorphism likely contributed to the paraphyletic state of Frontonia. These results highlight the complex evolutionary patterns of the genus, shaped by genetic diversity, morphology, and environmental constraints. Full article

The aim of this study was to analyse and characterise Cryptosporidium spp. in sheep and goats in Gran Canaria (Spain) and to identify the risks and economic factors related to the disease. During sampling, a semi-structured survey was conducted with farmers, and faecal samples were collected from lambs, goat kids, sheep, and adult goats from a total of 30 farms. Adult samples were examined microscopically for the presence of Cryptosporidium spp. oocysts, with only three positive samples being found in sheep and one in goats. The PCR of the SSU rRNA gene was performed on all juvenile and adult samples, and positive samples from lambs (8.3%), sheep (6.9%), goat kids (23.3%), and goats (2.5%) were subjected to sequencing, detecting three of the most important species in small ruminants: C. parvum, C. xiaoi, and C. ubiquitum. By sequencing the GP60 PCR products, two subtypes of C. parvum belonging to the IId family were identified, IIdA16G1 and IIdA23G1, with the latter being the most frequent. Although the prevalence of the disease was not very high, the zoonotic potential of C. parvum and the limited awareness of the parasite among farmers make surveillance and health education focused on the control of this member of Apicomplexa necessary. Full article

Between March and August 2024, three species of Fundulus topminnows, including two northern studfish, Fundulus catenatus, six blackspotted topminnows, Fundulus olivaceus, and eleven blackstriped topminnows, Fundulus notatus, were collected from various Ouachita River drainage watersheds in Arkansas, USA. They were examined for myxozoans by having their gill, gallbladder, fins, integument, mesenteries, musculature, and other major organs examined. The mesenteries of two (33%) F. olivaceus from Town Creek (Fulton County, Arkansas, USA) were infected with a new myxozoan, Myxobolus storeri sp. n. Molecular data consisted of a 1726 base pair sequence of the partial small subunit ribosomal RNA gene for M. storeri sp. n. Histologically, plasmodia were limited to mesenteric adipose and hepatic parenchyma, causing slight compression of neighboring tissue but producing no associated inflammatory response in the examined histosections. This is the first time a myxozoan has been described from F. olivaceus and is the seventh species recorded from any member of the fish family Fundulidae. Full article

Myxozoans represent a significant group of parasitic pathogens affecting both wild and farmed fish. For accurate and comprehensive early detection, the composition of myxozoan pathogens in fish has consistently been a primary focus for parasitologists. In China, we undertook an investigation into myxozoan infection in fish from Shandong Province, China, successfully isolating a myxozoan species from gibel carp Carassius auratus gibelio Bloch, 1782 and goldfish C. auratus Linnaeus, 1758. In the present study, this myxozoan species was identified by detailed morphological and molecular analysis. This parasite is characterized by the presence of visible plasmodia in various organs (intestine, liver, gallbladder, and abdominal cavity) of gibel carp as well as the abdominal cavities of goldfish. In comparison to all documented myxozoan species, this myxozoan species exhibits morphological identity with Myxobolus pronini Liu, Batueva, Zhao, Zhang, Zhang, Li, Li, 2016, in terms of spore morphology. Molecular sequence analysis, including sequence similarity, variable site, and the secondary structure of SSU rRNA, indicates that the present myxozoan species closely resembles M. pronini. Furthermore, phylogenetic analyses revealed that all isolates collected from different organs and hosts in this study clustered with M. pronini, forming a distinct branch within the Carassius-infecting clade. Consequently, the present myxozoan species can be confidently identified as M. pronini. Compared with the previous reports on M. pronini, this study documents, for the first time, goldfish as a host, intestines and gallbladders as the sites of infection, and Shandong Province as the geographic distribution of this myxozoan species. Full article

The diversity of anaerobic ciliates is greatly underestimated owing to the limitation in sampling and cultivation when compared with their aerobic counterparts. In this study, four anaerobic ciliates, viz. Brachonella abnormalis sp. nov., Brachonella contorta (Levander, 1894) Jankowski, 1964, Metopus contortus (Quennerstedt, 1867) Kahl, 1932, and Metopus major Kahl, 1932, were investigated by live observation, protargol staining and 18S rRNA gene sequencing. B. abnormalis sp. nov. can be separated from its congeners by a combination of the following features: bullet-shaped cell with a life size of about 130–190 × 90–120 μm, dikinetids distributed along dorsal dome kineties, highly developed adoral zone comprised of 87–107 polykinetids, making about 450° spiralization around the long axis. The present work demonstrates that two known species, M. contortus and M. major, have a special trait never previously reported, viz. short, regularly arranged preoral dome dikinetids. Species with short, regularly arranged dome dikinetids appear in divergent clades in SSU rRNA gene trees, which may infer that this trait evolved several times. Phylogenetic analyses based on SSU rRNA gene sequence data also support the monophyly of the genus Brachonella and the paraphyly of the order Metopida, respectively. Full article

Giardia duodenalis is a zoonotic parasite that causes gastrointestinal diseases in both humans and animals. To evaluate the prevalence and genetic diversity of G. duodenalis in black goats, we collected 539 fecal samples from nine districts in Fujian Province, China. The presence of G. duodenalis was confirmed through nested PCR targeting the SSU rRNA gene, and genotyping was performed at the beta-giardin, glutamate dehydrogenase, and triosephosphate isomerase loci. Among the samples, 115 tested positive, yielding an overall infection rate of 21.34%. Assemblages A and E were identified, with assemblage E being predominant. Statistical analysis revealed significant regional differences in infection rates (p < 0.01), with Zhangzhou exhibiting the highest infection rate (39%) and Fuzhou the lowest (3.13%). No significant differences in infection rates were observed based on age: 24.56% (56/228) for goats <1 year, 14.92% (27/181) for goats 1–2 years, 26.8% (26/97) for goats 2–3 years, and 18.18% (6/33) for goats ≥ 3 years. Similarly, no significant differences were found between sexes: 24.84% (40/161) for males and 19.84% (75/378) for females. Notably, assemblage A, a zoonotic genotype, was detected, indicating a potential risk of cross-species transmission. This study contributes to a deeper understanding of G. duodenalis in black goats and provides critical data for the development of targeted control strategies in Fujian Province. Full article