Search Results (98)

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

Leishmaniasis is a zoonotic disease caused by protozoa of the genus Leishmania, transmitted by phlebotomine sand flies. Understanding the feeding behavior and infection rates of these vectors is crucial for disease surveillance and control. We aimed to investigate the natural infection rate of Leishmania spp. in phlebotomines and analyze their blood-feeding patterns in one of the priority areas of the state of São Paulo for the implementation of insecticide-impregnated dog collars. Sand flies were collected from urban and peri-urban areas between 2022 and 2024 using CDC light traps, manual aspiration, and Shannon traps. PCR was used to detect Leishmania DNA (SSU rDNA gene), and blood meal sources (COI gene). A total of 414 sand flies were collected, with 222 engorged females analyzed for blood meals and 192 specimens tested for Leishmania spp. infection. The predominant blood source was humans (67%), followed by chickens (64.1%), and dogs (18.9%), considering that 45.1% of the samples presented mixed blood meals. Leishmania infantum was found in 1% of the samples. These findings highlight the feeding plasticity of sand flies and their potential role in disease transmission, reinforcing the need for continuous epidemiological surveillance and vector control strategies, particularly the implementation of insecticide-impregnated dog collars. Full article

The cosmopolitan nematode Spirinia parasitifera has long been considered a single, morphologically variable species; however, mounting molecular evidence suggests that it represents a complex of cryptic taxa. In this study, we describe Spirinia koreana sp. nov., a new species collected from intertidal sediments of the Republic of Korea. The new species exhibits a high degree of morphological resemblance to both S. antipodea and S. parasitifera, with overlapping ranges in most morphological traits. While certain measurements, such as relatively shorter body length, more slender form (higher a ratio), moderately long tail length, and shorter spicule length differ from those in some described populations, no single morphological character alone reliably separates S. koreana from all previously reported specimens of S. parasitifera or S. antipodea. Nevertheless, molecular evidence from multiple genetic markers clearly supports its distinction as a separate species. Molecular data from mitochondrial COI, 18S rRNA, and 28S rRNA genes confirm the genetic distinctness of the Korean specimens from S. parasitifera and S. antipodea. Notably, S. koreana sp. nov. differs from other Spirinia species by 2.1–3.4% in 18S and up to 34.4% in 28S sequences, surpassing thresholds previously used to delimit marine nematode species. Our results emphasize the value of integrative taxonomy combining fine-scale morphology and multi-marker molecular data to uncover hidden diversity in meiofaunal nematodes. 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

The fungal family Mortierellaceae represents ubiquitous and ecologically significant components of soil ecosystems across terrestrial habitats. Through an integrative taxonomic approach combining multi-locus phylogenetic analyses (ITS, LSU, SSU rDNA, RPB1, and Act) with detailed morphological examinations of rhizosphere soil isolates, four novel species within this family were proposed. This study elucidates the morphological distinctions of novel species from allied species and the phylogenetic relationships among the novel and existing species within the family. Linnemannia rotunda sp. nov. (closely related to L. longigemmata) is distinguished by its globose sporangia and sporangiospores. Mortierella acuta sp. nov. (clustering with M. yunnanensis) is characterized by spiky collarettes. Mortierella oedema sp. nov. (a sister to M. macrocystis) exhibits distinctive ampulliform swellings. Mortierella tibetensis sp. nov. (clustering with M. parvispora) is named for its geographic origin in Tibet. As the eighth installment in a systematic investigation of early diverging fungal groups in China, this work expands the global taxonomic inventory of Mortierellaceae to 148 species, underscoring the ongoing discovery of cryptic biodiversity within this ecologically pivotal group. Full article

In recent decades, ships’ ballast water and associated sediments have been recognized globally as significant vectors for the dissemination of non-indigenous species, which has attracted extensive attention due to its ecological and economic impacts. The characteristics of production of resting cysts in the dinoflagellate life cycle further increases the risk of biological invasions through ballast tank sediments. Despite extensive research which has characterized the species diversity of dinoflagellate cysts within ballast tank sediments, the possibility and importance of invasions caused by different ribosomal types of the same species have been paid little attention. In this study, two cultures of dinoflagellates were established through cyst germination from the ballast tank sediments collected from two ships (“THETIS” and “WARIYANAREE”) arriving at the Jiangyin Port (China) and identified as Wangodinium sinense Z. Luo, Zhangxi Hu, Yingzhong Tang and H.F. Gu by comprehensive phylogenetic analysis of rDNA sequences (including LSU, SSU, and ITS1-5.8S-ITS2). Despite the rDNA sequences of the isolates showing a generally high similarity to reference sequences, the LSU D1-D6 sequences contained up to 11 stable single nucleotide polymorphisms (SNPs), while SSU and ITS1-5.8S-ITS2 sequences exhibited up to five and two divergence sites, respectively. Moreover, phylogenetic analyses based on partial LSU and SSU rDNA sequences further indicated that strains germinated from ships’ ballast tank sediments formed a strongly supported sister clade to the strains previously isolated from Chinese and Korean waters, representing a novel ribo-type distinct from Chinese and Korean strains. Detailed morphological observations using light microscopy (LM) and scanning electron microscopy (SEM) did not find differences between our isolates and the holotype of the species in key diagnostic characteristics including the position and shape of the nucleus and chloroplasts, as well as the ASC structure, which suggested that no significant morphological divergence has occurred among these ribo-types. Acute toxicity exposure assays indicated that this ribo-type of W. sinense posed no lethal effect on rotifers at concentrations ≤ 10⁴ cells/mL, yet it remains necessary to maintain vigilance regarding the potential risk of algal blooms resulting from higher cell density or environmental changes in the invaded ecosystems. This study reports the first successful germination of W. sinense cysts from ballast tank sediments, indicating that its cysts may be widely transferred through ballast tank sediments, and presents a potential risk of bio-invasions of new genotypes of species to a region where other genotypes of the same species have been present as indigenous species. Full article

Fine nematodes of the family Capillariidae parasitize various organs and tissues in fish, amphibians, reptiles, avians, and mammals. Currently classified into more than 20 genera, these nematodes are primarily distinguished based on the caudal structures of male worms. Morphological and molecular analyses were conducted on 15 mammal-parasitic species belonging to the genera Aonchotheca (A. putorii, A. suzukii n. sp., A. suis n. comb. (syn. Capillaria suis), A. riukiuensis, and A. bilobata), Pearsonema (P. neoplica n. sp., P. feliscati, P. iharai n. sp., and P. toriii n. sp.), Liniscus (L. himizu), Calodium (C. hepaticum), Echinocoleus (E. yokoyamae n. sp.), and Eucoleus (E. kaneshiroi n. sp., E. aerophilus, and Eucoleus sp.), using specimens from various wild and domestic animals in Japan and brown rats in Indonesia. As demonstrated in this study, nearly complete SSU rDNA sequencing is a powerful tool for differentiating closely related species and clarifying the phylogenetic relationships among morphologically similar capillariid worms. Additionally, most capillariid worms detected in dogs and cats are suspected to be shared with their respective wildlife reservoir mammals. Therefore, molecular characterization, combined with the microscopic observation of these parasites in wildlife mammals, provides a robust framework for accurate species identification, reliable classification, and epidemiological assessment. 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

Entamoeba spp. are common zoonotic intestinal protozoa, which can lead to serious intestinal diseases in both humans and animals through fecal–oral transmission, leading to significant economic losses and public health challenges. To reveal the prevalence of Entamoeba in sheep and cattle in Shanxi Province, North China, fecal samples were collected from 311 sheep, 392 dairy cattle, and 393 beef cattle from three representative counties in the northern, central, and southern regions of Shanxi Province. DNA was extracted from the fecal samples and amplified by PCR with primers targeting the nuclear small subunit ribosomal RNA (SSU rRNA) gene of Entamoeba spp., followed by the sequencing of the positive products. The overall infection rates of Entamoeba were 51.5% (160/311), 82.9% (325/392), and 79.1% (311/393) in sheep, dairy cattle, and beef cattle, respectively. Statistical analysis showed a significant correlation between the infection rate of Entamoeba and the location factor in sheep, dairy cattle, and beef cattle (p < 0.001). According to the obtained SSU rRNA sequences, several Entamoeba species, namely Entamoeba bovis, Entamoeba Ribosomal Lineage (RL) 2, Entamoeba RL4, and Entamoeba RL8, were identified. This study represents the first molecular survey of Entamoeba prevalence in sheep, beef cattle, and dairy cattle in Shanxi Province. The findings extend the geographical distribution of Entamoeba spp. and provide valuable scientific data for the prevention and control of amoebiasis in Shanxi Province. Full article

Several species of amoebae in the genus Entamoeba forming four-nucleated mature cysts are pathogenic, but their identification is challenging due to a lack of distinctive morphological traits. Furthermore, host species cannot reliably be used as a criterion for identification. In this study, several isolates of four-nucleated cyst-forming Entamoeba species from animals at the Zoo Aquarium of Madrid are genetically identified. Entamoeba cysts were identified through microscopic analysis of faecal samples; none of the animals exhibited symptoms. DNA was extracted, and a fragment of the SSU-rRNA gene was PCR-amplified and sequenced to identify the species. Entamoeba dispar was identified in mantled guerezas (Colobus guereza), lar gibbons (Hylobates lar), greater rheas (Rhea americana) and giant anteaters (Myrmecophaga tridactyla). Entamoeba hartmnanni was detected in mandrills (Mandrillus sphinx) and chimpanzees (Pan troglodytes). Entamoeba nuttalli was detected in mandrills; the analysis of sequences available in GenBank revealed that this species has also been detected in human samples. The identification of the Entamoeba species across diverse host species underscores the need for genetic confirmation to prevent misidentifications. These findings expand the known host range of these species and emphasize the importance of regular monitoring to minimize transmission risks, including potential cross-species transmission to/from humans. Full article

Dunaliella salina, a halophilic unicellular chlorophyte, produces bioactive compounds and biofuels applicable to various industries. Despite its industrial significance, comprehensive studies on the morphological, physiological, and biochemical characteristics of the genus Dunaliella remain challenging. In this study, we characterized an axenically isolated green alga from a salt pond in Taean, Republic of Korea, and assessed its industrially relevant traits. The morphological characteristics were typical of D. salina, and molecular phylogenetic analysis of the SSU, ITS1-5.8S-ITS, LSU regions of rDNA, and rbcL gene confirmed the isolate as D. salina strain DSTA20. The optimal temperature, salinity, and photon flux density required for its growth were determined to be 21 °C, 0.5 M NaCl, and 88 µmol m⁻² s⁻¹, respectively. Dried biomass analysis revealed 42.87% total lipids, with major fatty acids, including α-linolenic acid (31.55%) and palmitic acid (21.06%). The alga produced high-value carotenoids, including β-carotene (2.47 mg g⁻¹ dry weight (DW)) and lutein (1.39 mg g⁻¹ DW), with peak levels at 0.25 M salinity. Glucose (195.5 mg g⁻¹ DW) was the predominant monosaccharide. These findings highlight the potential of D. salina DSTA20 for biodiesel production and as a source of ω-3 fatty acids, carotenoids, and glucose. Morphological traits provide insights relevant to the industrial potential of the species. Full article

Two new species of free-living marine nematodes, Metachromadora parobscura sp. nov. and Molgolaimus longicaudatus sp. nov., from mangrove wetlands of Beihai, Guangxi province in China, are described. Metachromadora parobscura sp. nov. is characterized by eight longitudinal rows of somatic setae arranged from the posterior part of the body, loop-shaped amphidial foveae with an open top and double contours, pharynx with bipartite cuticularized internal cavity, spicules with well-developed capitulum, gubernaculum canoe-shaped, without apophysis, 6–8 precloacal tubular supplements, and a short, conical tail with two ventral protuberances. It could be easily distinguished from the known species by spicule length and numbers of precloacal supplements. Molgolaimus longicaudatus sp. nov. is characterized by short cephalic setae, relatively small amphidial fovea, slender spicules ventrally bent with pronounced hooked capitulum and tapered distal end, two poriform precloacal supplements, and a relatively long conico-cylindrical tail. It differs from other species by the shape of spicules and long tail. Nearly full-length SSU sequences (1542–1592 bp) of the two species were provided, and phylogenetic trees based on maximum likelihood analyses supported the taxonomic position of the two new species. The combined use of traditional morphology-based taxonomy and molecular approaches has been proven to be a good choice for identification of free-living nematodes. Full article

The monotypic genus Prasiolopsis has been known for a long time, but is often overlooked because of difficulties in identification and the morphological variability between uniseriate filaments and cell packages forming pseudoparenchymatic thalli depending on age. We investigated a strain (SAG 84.81) originally denoted as Trichophilus welckeri, which was isolated from the hairs of the sloth Bradypus tridactylus, and compared it with other available strains of Prasiolopsis and of the sister genus Pseudomarvania. Our investigations clearly showed that this strain differed in morphology, especially of the chloroplast, from those originally described for Trichophilus. Phylogenetic analyses of the SSU and ITS rDNA sequences revealed that the strain SAG 84.81 is sister to several strains of P. ramosa within the Prasiola clade (Trebouxiophyceae). Using the ITS-2/CBC approach, we clearly demonstrated that this strain represented a new species of Prasiolopsis, which we proposed here as P. wulf-kochii. In addition, we evaluated the ITS-2/CBC approach by comparing it with the two species of Pseudomarvania. All investigated strains showed CBCs and HCBCs, which support their species delimitation. The sequencing data of Trichophilus welckeri available in GenBank were phylogenetically re-evaluated by including all representatives of the Ulotrichales (Ulvophyceae). Our analyses showed that these sequences formed their own lineage within this order. Full article

To tease apart differences between conventional cage (CC) and cage-free (CF) housing systems, this study focuses on the effects of excreta exposure and age by comparing microbial communities, intestinal permeability, and corticosterone in hens in enriched colonies (EC) and CF housing systems during early- and late-lay. Hens were randomly selected from two rooms of CF (n = 20) and EC (n = 20) at 35 and 76 weeks of age. One hour following an oral gavage of fluorescein isothiocyanate dextran (FITC-D), hens were euthanized, and ileal contents and blood were collected. Serum FITC-D using a fluorescent spectrophotometer and corticosterone using a commercial competitive ELISA kit were analyzed. Following DNA isolation from the ileum contents, the V4 region of the 16S rRNA gene was sequenced. Sequence data were filtered in Mothur v1.43.0, followed by de novo operational taxonomic unit (OTU) clustering and classifying with the SILVA SSU v138 reference database. Serum FITC-D was altered by housing type, age of hens, and the interaction between housing type and age of hens (p < 0.001), with 76-week-old hens housed in EC having the highest FITC-D. Corticosterone increased with age (p = 0.023). Microbial community diversity measurements favored hens housed in the CF housing system as ileal contents tended to have increased species evenness (p = 0.008) and greater alpha diversity (p = 0.006). The majority of the over-representation of OTUs were associated with peak lay. Full article