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Mycologia 2023Based on a study of 255 collections from four continents and four floristic kingdoms, we describe 15 new species of the genus . The new species, all morphologically...
Based on a study of 255 collections from four continents and four floristic kingdoms, we describe 15 new species of the genus . The new species, all morphologically close to , and , differ from each other by the structure of the peridium and, in some cases, also by the color of the fresh spore mass and the ornamentation of the capillitium and spores. Species delimitation is confirmed by two independently inherited molecular markers, as well as previously performed tests of reproductive isolation and genetic distances. We studied authentic material of and and found fresh specimens of these species, which allowed us to obtain molecular barcodes and substantiate the separation of new species from these taxa. We propose to retain the name for the globally most abundant species, for which we provide a more precise description and a neotypification. Two formerly described species, and , we consider to be dubious. We do not recognize the species .
Topics: Microscopy, Electron, Scanning; Myxomycetes; Spores, Protozoan; Species Specificity; DNA, Protozoan; DNA Barcoding, Taxonomic
PubMed: 37224183
DOI: 10.1080/00275514.2023.2199109 -
Parasites & Vectors Jul 2023A close connection between a protozoan parasite and the balance of the other gut microbes of the host has been demonstrated. The calves may be naturally co-infected with...
BACKGROUND
A close connection between a protozoan parasite and the balance of the other gut microbes of the host has been demonstrated. The calves may be naturally co-infected with many parasites, and the co-effects of parasites on other intestinal microbes of calves remain unclear. This study aims to preliminarily reveal the relationship between intestinal parasites and other intestinal microbes in calves.
METHODS
Fecal samples were collected from four calves with bloody diarrhea, four calves with watery diarrhea, and seven normal calves, and the microbial flora of the samples were analyzed by whole-genome sequencing. Protozoal parasites were detected in the metagenome sequences and identified using polymerase chain reaction (PCR).
RESULTS
Cryptosporidium, Eimeria, Giardia, Blastocystis, and Entamoeba were detected by metagenomic analysis, and the identified species were Giardia duodenalis assemblage E, Cryptosporidium bovis, Cryptosporidium ryanae, Eimeria bovis, Eimeria subspherica, Entamoeba bovis, and Blastocystis ST2 and ST10. Metagenomic analysis showed that the intestinal microbes of calves with diarrhea were disordered, especially in calves with bloody diarrhea. Furthermore, different parasites show distinct relationships with the intestinal microecology. Cryptosporidium, Eimeria, and Giardia were negatively correlated with various intestinal bacteria but positively correlated with some fungi. However, Blastocystis and Entamoeba were positively associated with other gut microbes. Twenty-seven biomarkers not only were significantly enriched in bloody diarrhea, watery diarrhea, and normal calves but were also associated with Eimeria, Cryptosporidium, and Giardia. Only Eimeria showed a distinct relationship with seven genera of bacteria, which were significantly enriched in the healthy calves. All 18 genera of fungi were positively correlated with Cryptosporidium, Eimeria, and Giardia, which were also significantly enriched in calves with bloody diarrhea. Functional genes related to parasites and diseases were found mainly in fungi.
CONCLUSIONS
This study revealed the relationship between intestinal protozoan parasites and the other calf gut microbiome. Different intestinal protozoan parasites have diametrically opposite effects on other gut microecology, which not only affects bacteria in the gut, but also is significantly related to fungi and archaea.
Topics: Animals; Cattle; Parasites; Cryptosporidiosis; Cryptosporidium; Metagenome; Intestinal Diseases, Parasitic; Giardiasis; Giardia; Giardia lamblia; Blastocystis; Eimeria; Entamoeba; Feces; Diarrhea
PubMed: 37525231
DOI: 10.1186/s13071-023-05877-z -
Parasitology Research Jan 2024Primary amebic meningoencephalitis (PAM) is a necrotizing and hemorrhagic inflammation of the brain and meninges caused by Naegleria fowleri, a free-living thermophilic... (Review)
Review
Primary amebic meningoencephalitis (PAM) is a necrotizing and hemorrhagic inflammation of the brain and meninges caused by Naegleria fowleri, a free-living thermophilic ameba of freshwater systems. PAM remains a neglected disease that disproportionately affects children in tropical and subtropical climates, with an estimated mortality rate of 95-98%. Due to anthropogenic climate change, the average temperature in the USA has increased by 0.72 to 1.06 °C in the last century, promoting the poleward spread of N. fowleri. PAM is often misdiagnosed as bacterial meningitis or viral encephalitis, which shortens the window for potentially life-saving treatment. Diagnosis relies on the patient's history of freshwater exposure and the physician's high index of suspicion, supported by cerebrospinal fluid studies. While no experimental trials have been conducted to assess the relative efficacy of treatment regimens, anti-amebic therapy with adjunctive neuroprotection is standard treatment in the USA. We performed a literature review and identified five patients from North America between 1962 and 2022 who survived PAM with various degrees of sequelae.
Topics: Child; Humans; Naegleria fowleri; Central Nervous System Protozoal Infections; Brain; Climate Change; Disease Progression
PubMed: 38182931
DOI: 10.1007/s00436-023-08094-w -
International Journal of Molecular... Sep 2023Extracellular vesicles (EVs) of protozoan parasites have diverse biological functions that are essential for parasite survival and host-parasite interactions. In this...
Extracellular vesicles (EVs) of protozoan parasites have diverse biological functions that are essential for parasite survival and host-parasite interactions. In this study, we characterized the functional properties of EVs from , a pathogenic amoeba that causes a fatal brain infection called primary amoebic meningoencephalitis (PAM). EVs (NfEVs) have been shown to be internalized by host cells such as C6 glial cells and BV-2 microglial cells without causing direct cell death, indicating their potential roles in modulating host cell functions. NfEVs induced increased expression of proinflammatory cytokines and chemokines such as TNF-α, IL-1α, IL-1β, IL-6, IL-17, IFN-γ, MIP-1α, and MIP-2 in BV-2 microglial cells; these increases were initiated via MyD88-dependent TLR-2/TLR-4. The production levels of proinflammatory cytokines and chemokines in NfEVs-stimulated BV-2 microglial cells were effectively downregulated by inhibitors of MAPK, NF-κB, or JAK-STAT. Phosphorylation levels of JNK, p38, ERK, p65, JAK-1, and STAT3 were increased in NfEVs-stimulated BV-2 microglial cells but were effectively suppressed by each corresponding inhibitor. These results suggest that NfEVs could induce proinflammatory immune responses in BV-2 microglial cells via the NF-κB-dependent MAPK and JAK-STAT signaling pathways. Taken together, these findings suggest that NfEVs are pathogenic factors involved in the contact-independent pathogenic mechanisms of by inducing proinflammatory immune responses in BV-2 microglial cells, further contributing to deleterious inflammation in infected foci by activating subsequent inflammation cascades in other brain cells.
Topics: Microglia; NF-kappa B; Naegleria fowleri; Extracellular Vesicles; Cytokines; Blood Group Antigens; Immunity
PubMed: 37686429
DOI: 10.3390/ijms241713623 -
Physical Biology Nov 2023The tubular network-forming slime moldis able to maintain long-scale contraction patterns driven by an actomyosin cortex. The resulting shuttle streaming in the network...
The tubular network-forming slime moldis able to maintain long-scale contraction patterns driven by an actomyosin cortex. The resulting shuttle streaming in the network is crucial for the organism to respond to external stimuli and reorganize its body mass giving rise to complex behaviors. However, the chemical basis of the self-organized flow pattern is not fully understood. Here, we present ratiometric measurements of free intracellular calcium in simple morphologies ofnetworks. The spatiotemporal patterns of the free calcium concentration reveal a nearly anti-correlated relation to the tube radius, suggesting that calcium is indeed a key regulator of the actomyosin activity. We compare the experimentally observed phase relation between the radius and the calcium concentration to the predictions of a theoretical model including calcium as an inhibitor. Numerical simulations of the model suggest that calcium indeed inhibits the contractions in, although a quantitative difference to the experimentally measured phase relation remains. Unraveling the mechanism underlying the contraction patterns is a key step in gaining further insight into the principles of's complex behavior.
Topics: Calcium; Actomyosin; Models, Theoretical; Actin Cytoskeleton; Physarum polycephalum
PubMed: 37975194
DOI: 10.1088/1478-3975/ad0a9a -
JPMA. the Journal of the Pakistan... Oct 2023
Topics: Humans; Naegleria fowleri; Central Nervous System Protozoal Infections
PubMed: 37876108
DOI: 10.47391/JPMA.9657 -
PeerJ 2023Microbial communities associated with macroorganisms might affect host physiology and homeostasis. Bacteria are well studied in this context, but the diversity of...
BACKGROUND
Microbial communities associated with macroorganisms might affect host physiology and homeostasis. Bacteria are well studied in this context, but the diversity of microeukaryotes, as well as covariations with bacterial communities, remains almost unknown.
METHODS
To study microeukaryotic communities associated with Planorbidae snails, we developed a blocking primer to reduce amplification of host DNA during metabarcoding analyses. Analyses of alpha and beta diversities were computed to describe microeukaryotes and bacteria using metabarcoding of 18S and 16S rRNA genes, respectively.
RESULTS
Only three phyla (Amoebozoa, Opisthokonta and Alveolata) were dominant for microeukaryotes. Bacteria were more diverse with five dominant phyla (Proteobacteria, Bacteroidetes, Tenericutes, Planctomycetes and Actinobacteria). The composition of microeukaryotes and bacteria were correlated for the species, but not for . Network analysis highlighted clusters of covarying taxa. Among them, several links might reflect top-down control of bacterial populations by microeukaryotes, but also possible competition between microeukaryotes having opposite distributions (Lobosa and Ichthyosporea). The role of these taxa remains unknown, but we believe that the blocking primer developed herein offers new possibilities to study the hidden diversity of microeukaryotes within snail microbiota, and to shed light on their underestimated interactions with bacteria and hosts.
Topics: Animals; RNA, Ribosomal, 16S; Bacteria; Eukaryota; Microbiota; Snails
PubMed: 38144201
DOI: 10.7717/peerj.16639 -
Experimental Parasitology Aug 2023Blastocystis is an enteric protozoan parasite with extensive genetic variation and unclear pathogenicity. It is commonly associated with gastrointestinal symptoms such...
Blastocystis is an enteric protozoan parasite with extensive genetic variation and unclear pathogenicity. It is commonly associated with gastrointestinal symptoms such as nausea, diarrhea, vomiting and abdominal pain in immunocompromised individuals. In this study, we explored the in vitro and in vivo effects of Blastocystis on the activity of a commonly used CRC chemotherapeutic agent, 5-FU. The cellular and molecular effects of solubilized antigen of Blastocystis in the presence of 5-FU were investigated using HCT116, human CRC cell line and CCD 18-Co, normal human colon fibroblast cells. For the in vivo study, 30 male Wistar rats were divided into six groups, as follows; Control Group: oral administration of 0.3 ml Jones' medium, Group A: rats injected with azoxymethane (AOM), Group A-30FU: Rats injected with AOM and administered 30 mg/kg 5-FU, Group B-A-30FU: rats inoculated with Blastocystis cysts, injected with AOM and administered 30 mg/kg 5-FU, Group A-60FU: rats injected with AOM and administered 60 mg/kg 5-FU and Group B-A-60FU: rats inoculated with Blastocystis cysts, injected with AOM and administered 60 mg/kg 5-FU. The in vitro study revealed that the inhibitory potency of 5-FU at 8 μM and 10 μM was reduced from 57.7% to 31.6% (p < 0.001) and 69.0% to 36.7% (p < 0.001) respectively when co-incubated with Blastocystis antigen for 24 h. However, the inhibitory potency of 5-FU in CCD-18Co cells was not significantly affected in the presence of Blastocystis antigen. The reduced inhibitory potency of 5-FU against cancer cell proliferation due to the presence of Blastocystis is consistent with the upregulation of expression of type 2 cytokines, transforming growth factor (TGF-β) and nuclear factor E2-related factor 2 (Nrf2) gene expression. Increased inflammation and abnormal histopathological findings along with a significant cancer multiplicity and adenoma incidence were evident in the intestine of the B-A-30FU and B-A-60FU groups when compared with the A-30FU and A-60FU groups respectively. Our in vitro and in vivo findings indicate that Blastocystis infection could potentially interfere with chemotherapy regimens such as 5-FU in CRC patients undergoing chemotherapy.
Topics: Humans; Rats; Male; Animals; Fluorouracil; Blastocystis; Rats, Wistar; Colorectal Neoplasms; Cysts
PubMed: 37308003
DOI: 10.1016/j.exppara.2023.108564 -
Biochemical and Biophysical Research... Jun 2023DydA plays an important role in chemotaxis, development, and cell growth as an adaptor protein that connects Ras signaling and cytoskeletal rearrangement. DydA is a...
DydA plays an important role in chemotaxis, development, and cell growth as an adaptor protein that connects Ras signaling and cytoskeletal rearrangement. DydA is a downstream effector of RasG and is involved in controlling cell polarity and pseudopodia formation during chemoattractant-directed cell migration. To understand the mechanism by which DydA functions on the cell migration, we investigated the dynamic subcellular localization of DydA in response to chemoattractant stimulation and found that DydA rapidly and transiently translocated to the cell cortex through the RA domain and the PRM region in DydA in response to chemoattractant stimulation. The PRM region appears to play a primary role in the translocation of DydA to the cell cortex and in its localization to the actin foci at the bottom of cells. Colocalization experiments of GFP-PRM with RFP-coronin indicated that GFP-PRM preceded GFP-coronin by 2-3 s in response to chemoattractant stimulation. These results suggest that the PRM region plays an indispensable role in relaying upstream regulators, such as RasG, to downstream effectors by mediating the localization of DydA to the cell cortex upon chemoattractant stimulation.
Topics: Dictyostelium; Chemotaxis; Actins; Chemotactic Factors; Protozoan Proteins
PubMed: 37121129
DOI: 10.1016/j.bbrc.2023.04.086 -
Parasitology Research Dec 2023To investigate the prevalence of Blastocystis and Dientamoeba fragilis in diarrhea patients and healthy individuals in Corum, Türkiye, fecal samples from 92 diarrhea...
To investigate the prevalence of Blastocystis and Dientamoeba fragilis in diarrhea patients and healthy individuals in Corum, Türkiye, fecal samples from 92 diarrhea patients and 50 healthy individuals were collected and evaluated using direct microscopy and molecular methods to screen for bacteria, protozoa, and viruses. The prevalence of Blastocystis was 24.6% in total and more frequent in the healthy group (30.0%). The commonly detected STs (subtypes) were ST3 (40.0%) and ST2 (34.2%). The distribution of Blastocystis STs in the healthy and diarrheal groups did not show any difference in sex and age, but ST3 was detected more frequently in patients aged from 40 to 59 years (p < 0.05). Alleles 4 (8/12) and 2 (4/12) were present in ST1; 9 (3/5) and 12 (2/5) in ST2; 34 (9/14), 36 (3/14), and 38 (2/14) in ST3; and only allele 42 (2/2) in ST4. D. fragilis was present in 8.4% of the population. However, there was no statistically significant difference between the healthy and diarrheic groups (12.0% and 6.5%, respectively), neither with respect to age nor sex. Co-infection was 58.3% and was more frequent in healthy individuals (33.3%) than in diarrhea patients (25.0%). Blastocystis ST3 was the most common subtype detected, with D. fragilis at 33.3%. Salmonella, Shigella, or helminth eggs were not observed in all groups, but Entamoeba histolytica, Giardia intestinalis, Cryptosporidium, Rotavirus, Adenovirus, and Clostridium difficile toxin were found only in diarrhea patients. These findings support the hypothesis that Blastocystis and D. fragilis may be part of the healthy human gut microbiome.
Topics: Humans; Adult; Middle Aged; Blastocystis; Dientamoeba; Blastocystis Infections; Cryptosporidiosis; Prevalence; Interleukin-1 Receptor-Like 1 Protein; Cryptosporidium; Diarrhea; Feces
PubMed: 37779160
DOI: 10.1007/s00436-023-07987-0