Search Results (437)

The paper presents the results of a microfossil study of Holocene sediments in the Yana River flow zone in the southeastern part of the Laptev Sea. A rich diatom flora (242 species and intraspecific taxa, of which 177 species are freshwater) was revealed; additionally, five species of marine tintinnids (planktonic ciliates) and 15 species of freshwater testate amoebae (testacean) were discovered for the first time in the sea sediments. Three assemblages of microfossils reflecting the phases of environmental changes during the Holocene transgression are distinguished in the studied sediments of core LV83-32. Assemblage 1 was formed under terrestrial conditions (assemblage of diatoms Eunotia-Pinnularia and testacean Difflugia-Cylindrifflugia-Centropyxis), assemblage 2 in the zone of mixing of sea and fresh waters (assemblages of diatoms Cyclotella striata-Aulacoseira, Thalassiosira hyperborea-Chaetoceros and T. hyperborea-Aulacoseira, testacean Cyclopyxis kahli, tintinnids Tintinnopsis fimbriata), and assemblage 3 reflects modern conditions in the inner shelf of the Laptev Sea under the strong influence of river runoff (assemblage of diatoms T. hyperborea-Aulacoseira-M. arctica and tintinnids Tintinnopsis ventricosoides). Changes in the natural environment in the coastal part of the Laptev Sea shelf during the Holocene, established by microfossil assemblages, are confirmed by geochemical data. Full article

Balantioides coli is the only ciliate currently described as an intestinal parasite of humans, although it can also infect other animals, particularly pigs. Its in vitro cultivation remains challenging, and no axenic culture system is currently available. Cultures are initiated by adding small amounts of feces containing cysts or trophozoites to the culture medium. Implantation success is lower when starting from cysts, and the mechanisms and early events of excystation remain poorly understood. In this study, we describe the sequence of events involved in excystation and identify factors potentially important for culture establishment. Cysts were obtained from orangutan feces and genetically confirmed as B. coli. Only viable cysts, determined by trypan blue or methylene blue exclusion, were used. After artificial digestion with pepsin and trypsin, cysts were incubated at 28 °C for up to 72 h in DMEM supplemented with L-glutamine, yeast extract, fetal bovine serum, and starch granules. Excystation began with a fissure in the cyst wall, allowing for bacterial entry. This appeared to stimulate the trophozoites, the increased motility of which progressively weakened and ruptured the wall, allowing for their emergence. Wall rupture and bacterial entry were critical for activation., whereas starch type had no apparent influence. Excystation occurred within the first hours; otherwise, cysts degenerated. Full article

We quantified the bioactive compounds of Ethiopian coffee (ETH), spent coffee grounds SCGs from ETH (SCG-ETH), and mixed SCGs (SCG-MIX) prepared by filtration methods and investigated the effect of SCG-ETH on ruminal fermentation as well as the anthelmintic activity of ETH. Three substrates, meadow hay (MH)-barley grain (MH-BG), MH-SCG-ETH, and BG-SCG-ETH (1:1 w/w), were fermented using an in vitro gas production technique. The bioactive compounds were quantitatively analyzed using ultra-high-resolution mass spectrometry. We performed an in vitro larval development test to determine the anthelmintic effect of an aqueous extract of ETH against the gastrointestinal nematode (GIN) Haemonchus contortus. The total content of bioactive compounds was highest in SCG-ETH, followed by SCG-MIX and ETH (35.2, 31.2, and 20.9 mg/g dry matter, respectively). Total gas and methane production (p < 0.001) were decreased by both MH-SCG-ETH and BG-SCG-ETH. The in vitro digestibility of dry matter was higher for MH-SCG-ETH and BG-SCG-ETH than for MH-BG. The aqueous ETH extract exhibited a strong larvicidal effect, with a mean lethal dose of 13.2 mg/mL for 50% mortality and 31.9 mg/L for 99% mortality. SCG substrates have the potential to modulate ruminal fermentation and serve as a source of anthelmintic bioactive compounds against GINs in ruminants. Full article

Background: The bone morphogenetic protein (BMP) signaling pathway is essential for lung development. BMP4, a key regulator, binds to type I (BMPR1) and type II (BMPR2) receptors to initiate downstream signaling. While the inactivation of Bmpr1a and Bmpr1b leads to tracheoesophageal fistulae, the role of BMPR2 mutations in lung epithelial development remains unclear. Methods: We generated induced pluripotent stem cells (iPSCs) from a patient carrying a BMPR2 mutation (c.631C>T), and gene-corrected isogenic controls were created using CRISPR/Cas9. These iPSCs were differentiated into lung progenitor cells and subsequently cultured to generate alveolar and airway organoids. The differentiation efficiency and epithelial lineage specification were assessed using immunofluorescence, flow cytometry, and qRT-PCR. Results: BMPR2-mutant iPSCs showed no impairment in forming a definitive or anterior foregut endoderm. However, a significant reduction in lung progenitor cell differentiation was observed. Further, while alveolar epithelial differentiation remained largely unaffected, airway organoids derived from BMPR2-mutant cells exhibited impaired goblet and ciliated cell development, with an increase in basal and club cell markers, indicating skewing toward undifferentiated airway cell populations. Conclusions: BMPR2 dysfunction selectively impairs late-stage lung progenitor specification and disrupts airway epithelial maturation, providing new insights into the developmental impacts of BMPR2 mutations. Full article

Cultures of primary human nasal epithelial cells (hNECs) differentiated at the air–liquid interface (ALI) represent a sophisticated and widely used model of the human upper respiratory epithelium. Despite the availability of various cell culture insert types and the well-established understanding that different culture media influence the cell culture characteristics, the possible impact of the insert brand remains rather underexplored. We cultured hNECs from nineteen healthy adult donors on three distinct brands of commercially available inserts—Corning^® Transwell^®, CELLTREAT^®, and ThinCert^®—and compared the ciliary activity and cellular composition of the cultures using high-speed video microscopy and flow cytometry, respectively. Additionally, we employed an alternative method of hNEC culture setup—the inverted condition—wherein the hNECs were seeded on the basal side of the insert with the idea to avoid mucus accumulation. Our results show that ciliary activity and cell type composition did not differ between insert types for both culture conditions. However, we found a higher ciliary beat frequency and a lower active (ciliated) area in the inverted setup compared to the conventional setup across all three insert brands. These findings indicate that all three mentioned insert types yield comparable cell cultures. Full article

Colpodella species are free-living predatory protists that prey on algae, ciliates and bodonids using myzocytosis. Colpodella species have been reported in human and animal infections. Polymerase chain reaction (PCR) using primers targeting 18S rRNA genes of Cryptosporidium and piroplasms have identified Colpodella species in arthropods, host blood and feces, demonstrating the phylogenetic closeness of Colpodella species to the apicomplexa. However, in human, animal and arthropod hosts, the life cycle stages of Colpodella are unknown. In this literature review, we provide an overview of the widespread occurrence of Colpodella species in ticks, and pathogenicity in humans and animals. We discuss methods for culture and microscopy that can aid diagnosis. Phylogenetic tree analysis of Colpodella species identified using 18S rRNA demonstrates that the Colpodella species identified in different geographic regions represent different species and strains that may impact virulence and zoonotic transmission. There is a pressing need to culture Colpodella species, and to stain cells for morphological identification. This will aid molecular investigations aimed at identifying molecular markers of Colpodella spp. facilitating transmission, survival and pathogenesis in hosts, and will determine which species and strains to prioritize for the risk of zoonotic infections to humans and for infections in animals. Full article

Kuibyshev Reservoir, the largest in the Volga basin, is poorly covered by modern molecular studies. The results of a metabarcoding study of pro- and eukaryotic microbial plankton in its lower section during the summer period are presented. Bacterioplankton composition was typical for most temperate freshwater bodies and characterized by the dominance of cyanobacteria, Pseudomonadota, Bacteroidota, Actinomycetota, and PVC superphylum (Verrucomicrobiota and Planctomycetota), with a somewhat increased proportion of the latter. The protist community was dominated by Cryptista, principally phototrophic, and various ciliates. Several picoeukaryotic groups were newly detected in the reservoir. A relationship between the composition of both bacterioplankton and protist communities and the stage of phytoplankton succession, including the cyanobacterial bloom, was observed. Some inconsistency between the cyanobacterial bloom phase and the structure of other parts of the microbial plankton is obviously due to some temporal delay, spatial station position, and inflow from tributaries. Heterotrophic bacterioplankton indicator species of the main bloom stage include OTUs representing both the phycosphere of colonial cyanobacteria and free-living species. Among the protists, sessile ciliates benefit most from plenty of substrates for colonization, while cyanobacterial grazers and parasites were minor. Overall, the cyanobacterial bloom creates new niches for the plankton community and significantly modifies its structure. Full article

Cilia are evolutionarily conserved, microtubule-based organelles characterized by their ultrastructures and diverse functional roles, including developmental signaling, mechanosensation, and fluid propulsion. They are widely distributed across cell surfaces and play crucial roles in cell cycle regulation and tissue homeostasis. Despite advances in studying their molecular regulation and functions, demonstrating the precise ultrastructure of cilia remains a challenge. Recent novel microscopy techniques, such as super-resolution microscopy and volume electron microscopy, are revolutionizing our understanding of their architecture and mechanochemical signaling. By integrating findings from different methodologies, this review highlights how these advances bridge basic research and clinical applications and provide a comprehensive understanding of the structural organization, functional mechanisms, and dynamic changes of cilia. Full article

This paper analyzes phytoplankton communities in the Eastern Tropical Pacific Ocean off Mexico (ETPOM) and the Southern Gulf of California (SGC) during the strong El Niño event of 2023/24. A multidisciplinary research cruise was conducted in the winter of 2024, during which high-resolution hydrographic data and water samples for phytoplankton cell determinations were collected at 33 sites. Additionally, satellite data were obtained to evaluate sea surface temperature and chlorophyll-a levels. A total of 269 phytoplankton species were identified, comprising one hundred and fifty diatoms, one hundred and twelve dinoflagellates, five silicoflagellates, one ciliate and one cyanobacteria. The dominant species included the diatom Pseudo-nitzschia pseudodelicatissima, the dinoflagellate Gyrodinium fusiforme, the silicoflagellate Octactis octonaria, and the ciliate Mesodinium rubrum. The cyanobacterium Trichodesmium hildebrandtii was also identified. In terms of total abundances, diatoms were the most prevalent, with 224,900 cells L⁻¹, followed by dinoflagellates at 104,520 cells L⁻¹, ciliates at 20,980 cells L⁻¹, cyanobacteria at 1760 cells L⁻¹, and silicoflagellates at 1500 cells L⁻¹. Notably, interesting differences emerged in species richness and abundance when comparing both regions. These results enhance our understanding of phytoplankton dynamics associated with strong El Niño events. The ETPOM remains a region that requires further monitoring through in situ observations. Full article

Background: Wastewater treatment plants (WWTPs) are hotspots for the emergence and spread of antibiotic resistance genes (ARGs). In activated sludge treatment systems, bacterivorous protozoa play a crucial role in biological processes, yet their impact on the horizontal gene transfer in Gram-positive enteric bacteria remains largely unexplored. This study investigated whether the ciliate Tetrahymena pyriformis facilitates the transfer of antibiotic resistance genes between Enterococcus faecalis strains. Methods: Conjugation assays were conducted under laboratory conditions using a vanA-carrying donor and a rifampicin-resistant recipient at an initial bacterial concentration of 10⁹ CFU/mL and ciliate density of 10⁵ N/mL. Results: Transconjugant numbers peaked at 2 h when experiments started with recipient bacteria harvested in the exponential growth phase, and at 24 h when bacteria were in the stationary phase. In both cases, vanA gene transfer frequency was highest at 24 h (10⁻⁴–10⁻⁵ CFU/mL), and the presence of energy sources increased gene transfer frequency by one order of magnitude. Conclusions: These findings suggest that ciliate grazing may contribute to vanA gene transfer in WWTP effluents, potentially facilitating its dissemination among permissive bacteria. Given the ecological and public health risks associated with vanA gene persistence in wastewater systems, understanding protozoan-mediated gene transfer is crucial for mitigating the spread of antibiotic resistance in aquatic environments. 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

A 78-year-old woman was referred to our hospital for close examination of an extramural submucosal tumor in the gastroesophageal region, suspected based on an imaging test performed for a chief complaint of epicardial pain while eating. Contrast-enhanced computed tomography revealed a 3 cm sized mass with well-defined margins and a homogeneous interior near the gastroesophageal junction. Endoscopic ultrasonography (EUS) revealed a large (28 mm) unilocular cystic lesion with a heterogeneous hypoechoic internal structure. The cyst wall was layered with a hypoechoic layer that appeared to be muscular and continuous with the external longitudinal muscle of the esophagus. Based on the EUS findings, an esophageal duplication cyst was diagnosed. Cystectomy was performed because the patient was symptomatic. Pathological examination revealed that the specimen was covered with columnar and pseudostratified ciliated epithelium without atypia and that the cyst wall comprised two layers of smooth muscle. No cartilaginous tissue was present, which is consistent with esophageal duplication cysts. Retrospectively, the EUS findings were consistent with the pathological findings. Full article

It is known that the ciliate Paramecium cell surface including cilia is completely covered by high-molecular-mass GPI-anchored proteins named surface antigens (SAgs). However, their functions are not well understood. It was found that ciliate Paramecium caudatum reversibly changes its SAgs depending on the absence or presence of the endonuclear symbiotic bacterium Holospora obtusa in the macronucleus. Immunofluorescence microscopy with a monoclonal antibody produced SAg of the H. obtusa-free P. caudatum strain RB-1-labeled cell surface of the H. obtusa-free P. caudatum RB-1 cell but not the H. obtusa-bearing RB-1 cell. When this antibody was added to the living P. caudatum RB-1 cells, only H. obtusa-free cells were immobilized. An immunoblot with SAgs extracted from Paramecium via cold salt/ethanol treatment showed approximately 266-kDa SAgs in the extract from H. obtusa-free cells and 188 and 149-kDa SAgs in the extract from H. obtusa-bearing cells. H. obtusa-free RB-1 cells produced from H. obtusa-bearing cells via treatment with penicillin-G-potassium re-expressed 266-kDa SAg, while the 188 and 149-kDa SAgs disappeared. This phenotypic change in the SAgs was not induced by degrees of starvation or temperature shifts. These results definitively show that Paramecium SAgs have functions related to bacterial infection. Full article

The ciliate parasite Ichthyophthirius multifiliis poses significant threats to grass carp (Ctenopharyngodon idellus) aquaculture. However, the limited understanding of host microbiota shifts and immune responses hinders effective control strategies. This study integrated analyses of host pathological indices, immune response and skin/gill/gut microbiota shifts after I. multifiliis infection. A histopathological examination identified gill and fin tissues embedded with I. multifiliis, accompanied by epithelial necrosis, and inflammatory cell infiltration. Biochemical profiling revealed marked elevations in aspartate aminotransferase (AST), alanine aminotransferase (ALT), urea (UREA), and creatinine (CREA) levels, indicating impaired hepatic and renal function. Quantitative RT-PCR analyses demonstrated the up-regulation of mucosal immune gene IgT and pro-inflammatory cytokine TNF-α while increasing the trend of systemic immune gene IgM. 16S rRNA sequencing revealed significant reductions in skin microbiota diversity. At the genus level, opportunistic pathogens Aeromonas and Vibrio proliferated in the intestine, whereas Flavobacterium and Candidatus Megaira increased in the skin and gills. Correlation analyses identified positive associations between Aeromonas/Vibrio abundance and host phenotype, contrasting with negative correlations observed for Sphingomonas, Acinetobacter, and Leifsonia. These findings demonstrate that I. multifiliis infection induces host microbiome dysbiosis and potentially opportunistic bacterial infections. This investigation advances our understanding of tripartite host–microbiota–parasite interactions and supports microbial community-based parasitosis control in fish culture. Full article

Background/Objectives: In vitro models play a crucial role in preclinical respiratory research, enabling the testing and screening of mucosal formulations, dosage forms, and inhaled drugs. Mucociliary clearance (MCC) is an essential defense mechanism in mucosal drug delivery but is often impaired in respiratory diseases. Despite its importance, standardized in vitro MCC assays are rarely reported. Furthermore, many published methods primarily measure cilia beat frequency (CBF), which requires high-speed cameras that are not accessible to all laboratories. Therefore, this study aimed to develop a physiologically relevant, differentiated in vitro model of the respiratory epithelium that incorporates both beating cilia and functional MCC. We chose porcine airway mucosa as an alternative to human tissue due to ethical considerations and limited availability. The established model is designed to provide a reproducible and accessible method for a broad range of research laboratories. Methods: The previously published tracheal mucosal primary cell (TMPC DS) model, derived from porcine tissue, lacked the presence of beating cilia, which are crucial for effective MCC analysis. For accurate MCC assessment, beating cilia are essential as they play a key role in mucus clearance. To address this limitation, the here-described ciliated tracheal mucosal primary cell (cTMPC) model was developed. cTMPCs were isolated from porcine tissue and cultured under air–liquid interface (ALI) conditions for 21 days to promote differentiation. This model was evaluated for cell morphology, tight junction formation, ciliated and mucus-producing cells, barrier function, gene expression, and tracer/IgG transport. MCC and the model’s suitability for standardized MCC assays were assessed using an inverted microscope. In contrast to the TMPC DS model, which lacked beating cilia and thus could not support MCC analysis, the cTMPC model allows for comprehensive MCC studies. Results: The developed differentiated in vitro model demonstrated key structural and functional features of the respiratory epithelium, including well-differentiated cell morphology, tight junction integrity, ciliated and mucus-producing cells, and effective barrier function. Functional MCC was observed, confirming the model’s potential for standardized clearance assays. Conclusions: This differentiated in vitro model closely replicates the structural and functional characteristics of in vivo airways. It provides a valuable platform for studying mucociliary clearance, toxicology, drug uptake, and evaluating mucosal formulations and dosage forms in respiratory research. Full article