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Pathogens (Basel, Switzerland) Aug 2023Free-living amoebas can impact the excretion of macroelements and microelements in urine. The aim of the present study was to examine the concentrations of...
Free-living amoebas can impact the excretion of macroelements and microelements in urine. The aim of the present study was to examine the concentrations of macroelements, including calcium (Ca), phosphorus (P), sodium (Na), potassium (K), and magnesium (Mg), as well as microelements such as manganese (Mn), zinc (Zn), copper (Cu), iron (Fe), and chromium (Cr), in the urine during acanthamoebiasis while considering the host's immunological status. This is the first study to show an increase in urinary excretion of Ca, Mn, Cu, Fe, Na, and Cr, along with a decreased excretion of K, in immunocompetent mice 16 days post sp. infection. In the final phase of infection (24 dpi), there was a further decrease in urinary K excretion and a lower level of P in sp. infected immunocompetent hosts. During acanthamoebiasis in immunosuppressed hosts, increased excretion of Zn, Fe, and Cr was observed at the beginning of the infection, and increased Na excretion only at 16 days post sp. infection. Additionally, host immunosuppression affected the concentration of Fe, Cr, Zn, Cu, Mn, and Ca in urine.
PubMed: 37623999
DOI: 10.3390/pathogens12081039 -
International Journal For Parasitology.... Aug 2023Naegleria fowleri is an opportunistic protozoan, belonging to the free-living amoeba group, that can be found in warm water bodies. It is causative agent the primary...
Naegleria fowleri is an opportunistic protozoan, belonging to the free-living amoeba group, that can be found in warm water bodies. It is causative agent the primary amoebic meningoencephalitis, a fulminant disease with a rapid progression that affects the central nervous system. However, no 100% effective treatments are available and those that are currently used involve the appearance of severe side effects, therefore, there is an urgent need to find novel antiamoebic compounds with low toxicity. In this study, the in vitro activity of six oxasqualenoids obtained from the red algae Laurencia viridis was evaluated against two different strains of N. fowleri (ATCC® 30808 and ATCC® 30215) as well as their cytotoxicity against murine macrophages. Yucatecone was the molecule with the highest selectivity index (>2.98 and 5.23 respectively) and it was selected to continue with the cell death type determination assays. Results showed that yucatone induced programmed cell death like responses in treated amoebae causing DNA condensation and cellular membrane damage among others. In this family of oxasqualenoids, it seems that the most significative structural feature to induce activity against N. fowleri is the presence of a ketone at C-18. This punctual oxidation transforms an inactive compound into a lead compound as the yucatecone and 18-ketodehydrotyrsiferol with IC values of 16.25 and 12.70 μM, respectively. The assessment of in silico ADME/Tox analysis revealed that the active compounds showed good Human Oral Absorption and demonstrate that are found to be within the limit of approved drug parameter range. Hence, the study highlights promising potential of yucatone to be tested for therapeutic use against primary amoebic meningoencephalitis.
Topics: Humans; Animals; Mice; Naegleria fowleri; Central Nervous System Protozoal Infections; Amoeba
PubMed: 37270868
DOI: 10.1016/j.ijpddr.2023.05.004 -
Parasite (Paris, France) 2024Parasites and free-living amoebae (FLA) are common pathogens that pose threats to wildlife and humans. The black-necked crane (Grus nigricollis) is a near-threatened...
Parasites and free-living amoebae (FLA) are common pathogens that pose threats to wildlife and humans. The black-necked crane (Grus nigricollis) is a near-threatened species and there is a shortage of research on its parasite diversity. Our study aimed to use noninvasive methods to detect intestinal parasites and pathogenic FLA in G. nigricollis using high-throughput sequencing (HTS) based on the 18S rDNA V9 region. A total of 38 fresh fecal samples were collected in Dashanbao, China, during the overwintering period (early-, middle I-, middle II-, and late-winter). Based on the 18S data, eight genera of parasites were identified, including three protozoan parasites: Eimeria sp. (92.1%) was the dominant parasite, followed by Tetratrichomonas sp. (36.8%) and Theileria sp. (2.6%). Five genera of helminths were found: Echinostoma sp. (100%), Posthodiplostomum sp. (50.0%), Euryhelmis sp. (26.3%), Eucoleus sp. (50.0%), and Halomonhystera sp. (2.6%). Additionally, eight genera of FLA were detected, including the known pathogens Acanthamoeba spp. (n = 13) and Allovahlkampfia spp. (n = 3). Specific PCRs were used to further identify the species of some parasites and FLA. Furthermore, the 18S data indicated significant changes in the relative abundance and genus diversity of the protozoan parasites and FLA among the four periods. These results underscore the importance of long-term monitoring of pathogens in black-necked cranes to protect this near-endangered species.
Topics: Animals; Feces; Helminths; RNA, Ribosomal, 18S; DNA Barcoding, Taxonomic; Birds; High-Throughput Nucleotide Sequencing; Prevalence; China; Bird Diseases; Helminthiasis, Animal; Eimeria; Theileria; Amoeba; DNA, Protozoan; Intestinal Diseases, Parasitic; Seasons; Phylogeny
PubMed: 38819296
DOI: 10.1051/parasite/2024028 -
Parasites, Hosts and Diseases May 2024Free-living amoebae (FLA) are found in diverse environments, such as soils, rivers, and seas. Hence, they can be used as bioindicators to assess the water quality based...
Free-living amoebae (FLA) are found in diverse environments, such as soils, rivers, and seas. Hence, they can be used as bioindicators to assess the water quality based solely on their presence. In this study, we determined the presence of FLA in river water by filtering water samples collected from various sites and culturing the resulting filtrates. FLA were detected in all the water samples with varying quality grades (Grades Ι-V). The significant increase in the size of the amoebae population with the deterioration in the water quality. Monoxenic cultures of the amoebae were performed, and genomic DNAs were isolated, among which 18S rDNAs were sequenced to identify the amoeba species. Of the 12 species identified, 10 belonged to the Acanthamoeba genus; of the remaining 2 species, one was identified as Vannella croatica and the other as a species of Vermamoeba. Acanthamoeba was detected in samples with Grades Ι to VI quality, whereas the Vermamoeba species was present only in Grade Ι water. V. croatica was found exclusively in water with Grade ΙΙ quality. Following morphological observations, genomic DNA was sequenced using 16S rDNA to determine whether the species of Acanthamoeba harbored endosymbionts. Most of the isolated Acanthamoeba contained endosymbionts, among which 4 species of endogenous bacteria were identified and examined using transmission electron microscopy. This study provides evidence that the distribution of amoebae other than Acanthamoeba may be associated with water quality. However, further confirmation will be required based on accurate water quality ratings and assessments using a more diverse range of FLA.
Topics: Amoeba; Water Quality; Phylogeny; Rivers; DNA, Protozoan; Acanthamoeba; RNA, Ribosomal, 18S; DNA, Ribosomal; Biodiversity; Sequence Analysis, DNA; RNA, Ribosomal, 16S
PubMed: 38835259
DOI: 10.3347/PHD.24020 -
Tropical Parasitology 2023. are free-living parasites increasingly implicated in causing keratitis (AK). AK is diagnosed by demonstration of parasites in corneal samples by direct microscopy,...
INTRODUCTION
. are free-living parasites increasingly implicated in causing keratitis (AK). AK is diagnosed by demonstration of parasites in corneal samples by direct microscopy, culture, and nucleic acid amplification. Most commonly, corneal scrapings are sent to the laboratory smeared between two glass slides. These scrapings are suitable for direct microscopy but less suitable for culture and polymerase chain reaction (PCR) which, in turn, are more sensitive for the diagnosis of AK.
AIM
The aim of the study was to explore better alternatives for transporting corneal scrapings from the point-of-care eye center to the concerned laboratories.
MATERIALS AND METHODS
The study used small Parafilm (Bemis Company Inc., USA) squares (PSs) of 1 cm each prepared by cutting Parafilm using a surgical blade under sterile conditions. Each of the four different dilutions of suspension (15, 30, 60, and 120 cells) was used in this study. Each dilution was added onto the surface of 36 PSs and kept at room temperature for 24-h, 48-h, and 72-h incubation. The PSs for one particular time point and dilution were used for calcofluor white staining, its inoculation onto the surface of nonnutrient agar having a lawn of , and -specific PCR amplification. In addition, two PSs inoculated with 30 cells and incubated for 24 h and 72 h were used for scanning electron microscopy (SEM).
RESULTS AND CONCLUSION
All three diagnostic techniques, i.e. microscopy, culture, and PCR, detected the presence of at all the tested concentrations and time points. However, the growth pattern on culture changed directly in proportion to increased incubation periods and increased concentration of inoculum. In addition, the adherence of to the Parafilm was confirmed by SEM; these results suggest the use of these PSs as a suitable matrix for the transport of corneal scrapings.
PubMed: 37860611
DOI: 10.4103/tp.tp_67_22 -
Microorganisms Apr 2024Neutrophils are the most abundant polymorphonuclear granular leukocytes in human blood and are an essential part of the innate immune system. Neutrophils are efficient... (Review)
Review
Neutrophils are the most abundant polymorphonuclear granular leukocytes in human blood and are an essential part of the innate immune system. Neutrophils are efficient cells that eliminate pathogenic bacteria and fungi, but their role in dealing with protozoan parasitic infections remains controversial. At sites of protozoan parasite infections, a large number of infiltrating neutrophils is observed, suggesting that neutrophils are important cells for controlling the infection. Yet, in most cases, there is also a strong inflammatory response that can provoke tissue damage. Diseases like malaria, trichomoniasis, leishmaniasis, Chagas disease, and amoebiasis affect millions of people globally. In this review, we summarize these protozoan diseases and describe the novel view on how neutrophils are involved in protection from these parasites. Also, we present recent evidence that neutrophils play a double role in these infections participating both in control of the parasite and in the pathogenesis of the disease.
PubMed: 38674770
DOI: 10.3390/microorganisms12040827 -
The ISME Journal Jan 2024Amoeba-bacteria interactions are prevalent in both natural ecosystems and engineered environments. Amoebae, as essential consumers, hold significant ecological...
Amoeba-bacteria interactions are prevalent in both natural ecosystems and engineered environments. Amoebae, as essential consumers, hold significant ecological importance within ecosystems. Besides, they can establish stable symbiotic associations with bacteria. Copper plays a critical role in amoeba predation by either killing or restricting the growth of ingested bacteria in phagosomes. However, certain symbiotic bacteria have evolved mechanisms to persist within the phagosomal vacuole, evading antimicrobial defenses. Despite these insights, the impact of copper on the symbiotic relationships between amoebae and bacteria remains poorly understood. In this study, we investigated the effects of copper stress on amoebae and their symbiotic relationships with bacteria. Our findings revealed that elevated copper concentration adversely affected amoeba growth and altered cellular fate. Symbiont type significantly influenced the responses of the symbiotic relationships to copper stress. Beneficial symbionts maintained stability under copper stress, but parasitic symbionts exhibited enhanced colonization of amoebae. Furthermore, copper stress favored the transition of symbiotic relationships between amoebae and beneficial symbionts toward the host's benefit. Conversely, the pathogenic effects of parasitic symbionts on hosts were exacerbated under copper stress. This study sheds light on the intricate response mechanisms of soil amoebae and amoeba-bacteria symbiotic systems to copper stress, providing new insights into symbiotic dynamics under abiotic factors. Additionally, the results underscore the potential risks of copper accumulation in the environment for pathogen transmission and biosafety.
Topics: Copper; Symbiosis; Amoeba; Bacteria; Stress, Physiological; Bacterial Physiological Phenomena
PubMed: 38848278
DOI: 10.1093/ismejo/wrae100 -
Scientific Reports Aug 2023Balamuthia mandrillaris is a pathogenic protozoan that causes a rare but almost always fatal infection of the central nervous system and, in some cases, cutaneous...
Balamuthia mandrillaris is a pathogenic protozoan that causes a rare but almost always fatal infection of the central nervous system and, in some cases, cutaneous lesions. Currently, the genomic data for this free-living amoeba include the description of several complete mitochondrial genomes. In contrast, two complete genomes with draft quality are available in GenBank, but none of these have a functional annotation. In the present study, the complete genome of B. mandrillaris isolated from a freshwater artificial lagoon was sequenced and assembled, obtaining an assembled genome with better assembly quality parameter values than the currently available genomes. Afterward, the genome mentioned earlier, along with strains V039 and 2046, were subjected to functional annotation. Finally, comparative genomics analysis was performed, and it was found that homologous genes in the core genome potentially involved in the virulence of Acanthamoeba spp. and Trypanosoma cruzi. Moreover, eleven of fifteen genes were identified in the three strains described as potential target genes to develop new treatment approaches for B. mandrillaris infections. These results describe proteins in this protozoan's complete genome and help prioritize which target genes could be used to develop new treatments.
Topics: Balamuthia mandrillaris; Virulence; Comparative Genomic Hybridization; Acanthamoeba; Genomics
PubMed: 37653073
DOI: 10.1038/s41598-023-41657-6 -
Microbiology Spectrum Aug 2023Cytoadherence and migration are crucial for pathogens to establish colonization in the host. In contrast to a nonadherent isolate of Trichomonas vaginalis, an adherent...
Cytoadherence and migration are crucial for pathogens to establish colonization in the host. In contrast to a nonadherent isolate of Trichomonas vaginalis, an adherent one expresses more actin-related machinery proteins with more active flagellate-amoeboid morphogenesis, amoeba migration, and cytoadherence, activities that were abrogated by an actin assembly blocker. By immunoprecipitation coupled with label-free quantitative proteomics, an F-actin capping protein (T. vaginalis F-actin capping protein subunit α [FACPα]) was identified from the actin-centric interactome. His-FACPα was detected at the barbed end of a growing F-actin filament, which inhibited elongation and possessed atypical activity in binding G-actin in assays. FACPα partially colocalized with F-actin at the parasite pseudopod protrusion and formed a protein complex with α-actin through its C-terminal domain. Meanwhile, FACPα overexpression suppressed F-actin polymerization, amoeboid morphogenesis, and cytoadherence in this parasite. Ser2 phosphorylation of FACPα enriched in the amoeboid stage of adhered trophozoites was reduced by a casein kinase II (CKII) inhibitor. Site-directed mutagenesis and CKII inhibitor treatment revealed that Ser2 phosphorylation acts as a switching signal to alter FACPα actin-binding activity and the consequent actin cytoskeleton behaviors. Through CKII signaling, FACPα also controls the conversion of adherent trophozoites from amoeboid migration to the flagellate form with axonemal motility. Together, CKII-dependent Ser2 phosphorylation regulates FACPα binding to actin to fine-tune cytoskeleton dynamics and drive crucial behaviors underlying host colonization by T. vaginalis. Trichomoniasis is one of the most prevalent nonviral sexually transmitted diseases. T. vaginalis cytoadherence to urogenital epithelium cells is the first step in the colonization of the host. However, studies on the mechanisms of cytoadherence have focused mainly on the role of adhesion molecules, and their effects are limited when analyzed by loss- or gain-of-function assays. This study proposes an extra pathway in which the actin cytoskeleton mediated by a capping protein α-subunit may play roles in parasite morphogenesis, cytoadherence, and motility, which are crucial for colonization. Once the origin of the cytoskeleton dynamics could be manipulated, the consequent activities would be controlled as well. This mechanism may provide new potential therapeutic targets to impair this parasite infection and relieve the increasing impact of drug resistance on clinical and public health.
Topics: Trichomonas vaginalis; Actins; Cytoskeleton; Actin Cytoskeleton; Actin Capping Proteins
PubMed: 37310229
DOI: 10.1128/spectrum.00596-23 -
Diagnostic Microbiology and Infectious... Oct 2023Acanthamoeba keratitis is a devastating infectious disease of the cornea caused by an opportunistic amoeba, Acanthamoeba castellanii. It is poorly recognized, and...
Acanthamoeba keratitis is a devastating infectious disease of the cornea caused by an opportunistic amoeba, Acanthamoeba castellanii. It is poorly recognized, and diagnostic delays can lead to irreversible damage to the vision. The gold standard for diagnosis has been a sample culture that lasts approximately 2 weeks. Nevertheless, the essence of time has led to the need for an accurate and fast technique to detect A. castellanii from a sample. We developed both traditional and quantitative real-time-PCR-based methods to detect A. castellanii in less than 3 hours and with the sensitivity of one amoeba. Diagnostic laboratories can select the best-suited method for their purposes from 2 comparable methods. The correct treatment can be initiated from the emergency room when the diagnosis has been made quickly within a few hours, hence saving the patient from long-term complications.
Topics: Humans; Acanthamoeba castellanii; Rapid Diagnostic Tests; Acanthamoeba Keratitis; Cornea; Real-Time Polymerase Chain Reaction
PubMed: 37506594
DOI: 10.1016/j.diagmicrobio.2023.116014