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Global prevalence of free-living amoebae in solid matrices - A systematic review with meta-analysis.Acta Tropica Nov 2023The ubiquitous free-living amoebae (FLA) are microorganisms of significant medical, sanitary, and ecological importance. However, their characterization within solid... (Meta-Analysis)
Meta-Analysis Review
The ubiquitous free-living amoebae (FLA) are microorganisms of significant medical, sanitary, and ecological importance. However, their characterization within solid matrices such as soil, dust, sediment, mud, sludge, and compost remain to be systematized. In this study, we conducted a systematic review with meta-analysis to explore the global distribution of FLA in solid matrices. From the analysis of 104 out of 4,414 scientific articles retrieved from different databases, it was found that the general global prevalence of FLA in solid matrices was of 55.13% (95% confidence interval (CI) 49.32-60.94). Specifically, FLA prevalence was high in soil (72.40%, 95% CI 69.08-75.73), sediment (57.91%, 95% CI 50.01-65.81), mud (52.90%, 95% CI 24.01-81.78), dust (48.60%, 95% CI 43.00-54.19), and sewage sludge (40.19%, 95% CI 30.68-49.70). In aerosols it was comparatively lower (17.21%, 95% CI 12.76-21.66). Acanthamoeba spp. (52.23%) and Hartmanella/Vermamoeba spp. (36.06%) were found to be more prevalent, whereas Naegleria spp. (34.98%) and Balamuthia spp. (27.32%) were less prevalent. The distribution of the highest global prevalence values for species of Acanthamoeba spp., considering different publication periods of the studies, is as follows: A. hatchetti (51.46%), A. rhysodes (47.49%), A. polyphaga (36.37%), A. culbertsoni (34.31%), A. castellanii (34.21%), and A. lenticulata (32.82%). For other FLA species, the distribution is: Hartmannella/Vermamoeba vermiformis (91.57%), Naegleria fowleri (42.32%), Naegleria gruberi (32.39%), and Balamuthia mandrillaris (25%). The most prevalent Acanthamoeba genotypes were T4 (33.38%) and T3 (23.94%). Overall, the global prevalence of FLA in solid matrices is as high as or greater than that reported in water by previous systematic reviews. Thus, actions aimed at reducing exposure to FLA or exploring their ecological dynamics should consider not only water but also the various solid matrices. The finding outlined here can provide valuable insights for such actions, e.g., informing on the level of exposure to FLA, or on the microbial biodiversity of specific environmental compartments.
Topics: Animals; Amoeba; Prevalence; Sewage; Acanthamoeba; Coleoptera; Dust; Soil; Water
PubMed: 37633571
DOI: 10.1016/j.actatropica.2023.107006 -
Scientific Reports Jul 2020Multinuclearity is a widespread phenomenon across the living world, yet how it is achieved, and the potential related advantages, are not systematically understood. In...
Multinuclearity is a widespread phenomenon across the living world, yet how it is achieved, and the potential related advantages, are not systematically understood. In this study, we investigate multinuclearity in amoebae. We observe that non-adherent amoebae are giant multinucleate cells compared to adherent ones. The cells solve their multinuclearity by a stretchy cytokinesis process with cytosolic bridge formation when adherence resumes. After initial adhesion to a new substrate, the progeny of the multinucleate cells is more numerous than the sibling cells generated from uninucleate amoebae. Hence, multinucleate amoebae show an advantage for population growth when the number of cells is quantified over time. Multiple nuclei per cell are observed in different amoeba species, and the lack of adhesion induces multinuclearity in diverse protists such as Acanthamoeba castellanii, Vermamoeba vermiformis, Naegleria gruberi and Hartmannella rhysodes. In this study, we observe that agitation induces a cytokinesis delay, which promotes multinuclearity. Hence, we propose the hypothesis that multinuclearity represents a physiological adaptation under non-adherent conditions that can lead to biologically relevant advantages.
Topics: Acanthamoeba castellanii; Cell Culture Techniques; Cell Nucleus; Cytokinesis; Microscopy, Electron, Scanning
PubMed: 32694508
DOI: 10.1038/s41598-020-68694-9 -
Iranian Journal of Parasitology 2017is an opportunistic amphizoic protozoan found in different fresh water sources. The aim of this study was to identify and characterize isolates from surface resting...
BACKGROUND
is an opportunistic amphizoic protozoan found in different fresh water sources. The aim of this study was to identify and characterize isolates from surface resting waters, in Northwest Iran.
METHODS
Samples were collected from twenty-two different areas, between May and Sep 2014. After filtration, samples were cultivated on non-nutrient agar. The extracted DNAs were amplified and sequenced using partial 18S rRNA in order to genotype and phylogenetic analyses.
RESULTS
Thirty-four (68%) out of 50 collected samples were positive for free-living amoebae based on both culture and morphological characterizations but 28 samples were identified as spp. by PCR. Sequentially, one isolate was identified as , (T5) (AN: KP940443, identity 99.7%-100%, and divergence 0.3%) whilst other sequenced isolates identified spp. (AN: KP940444-45) as very similar to and with identity 100% and divergence 0%.
CONCLUSION
Surface resting waters in Northwest Iran, were potentially contaminated with pathogenic amphizoic protozoan. Further studies will be required to determine other species and genotypes in the region.
PubMed: 28979345
DOI: No ID Found -
Zhongguo Ji Sheng Chong Xue Yu Ji Sheng... Apr 2016To identify the species of a morphologically Acanthamoeba-like pathogen in sputum from a patient with repeated cough.
OBJECTIVE
To identify the species of a morphologically Acanthamoeba-like pathogen in sputum from a patient with repeated cough.
METHODS
Protozoa were isolated from the sputum and cultured for morphological observation of the trophozoites and cysts. DNA was extracted from the cultivated sample, and PCR was performed using primers as follows: 18S universal primers for amoeba family(Ami6F1 and Ami9R) and for amoeba genus(JDP1 and JDP2), and primers for 18S full-length sequence of S-7 ATCC reference strain of Acanthamoeba griffini (AacGF and AscGR). The 18S rRNA was sequenced, followed by homology analysis. The maximum likelihood method was used to construct phylogenetic tree.
RESULTS
Microscopic examination showed that the trophozites had spine and irregular-shape pseudopodia bulge. The cysts were encapsulated by double membrane layer with the inner membrane having star-like processes. As expected, PCR amplification resulted in bands of 830, 479 and 1 957 bp, respectively, which were blasted to be 99%, 99% and 100% homologous to those of A. griffini(U07412.1). Phylogenetic tree indicated that this acanthamobe in the patient’s sample was 91.4%, 99.6%, 94.5% and 91.8% homologous to keratitis-associated A. castellanii, A. polyphage, A. cullbertsoni and A. rhysodes.
CONCLUSION
The parasite in sputum of the patient with respiratory tract infection is Acanthamoeba griffini.
Topics: Acanthamoeba; Animals; Base Sequence; DNA Primers; DNA, Protozoan; Humans; Phylogeny; Polymerase Chain Reaction; RNA, Ribosomal, 18S; Respiratory Tract Infections
PubMed: 30124240
DOI: No ID Found -
Iranian Journal of Parasitology 2014The free-living amoebae Acanthamoeba spp. have been recognized as etiologic agents of amoebic encephalitis, keratitis, otitis, lung lesions and other skin infections...
BACKGROUND
The free-living amoebae Acanthamoeba spp. have been recognized as etiologic agents of amoebic encephalitis, keratitis, otitis, lung lesions and other skin infections mainly in immuno-compromised individuals. The purpose of this study is to detect the presence of Acanthamoeba in swimming pools in Egypt using a polymerase chain reaction (PCR) method.
METHODS
Water samples were collected from 10 different swimming pools in Cairo, Egypt. Samples were cultured on non-nutrient agar for the detection of Acanthamoeba isolates that were confirmed by PCR amplification using genus specific primers. The molecularly confirmed Acanthamoeba isolates were morphologically identified to the species level.
RESULTS
Members of genus Acanthamoeba were detected in 49.2% of the examined swimming-pool water samples. Morphologically, six Acanthamoeba species were isolated from the examined swimming pool water namely A. polyphaga, A.castellanii, A. rhysodes, A. mauritaniensis, A. royreba and A. triangularis. All the identified species of Acanthamoeba were molecularly confirmed to be related to the genus Acanthamoeba.
CONCLUSION
The isolated species of Acanthamoeba could provoke variable degrees of infections to the swimmers. The culture method is cheaper and easier than PCR techniques that are faster for the detection of free-living amoebae.
PubMed: 25848385
DOI: No ID Found -
Lipids Apr 2014Ether lipids were identified among components liberated with HF and nitrous acid deamination from Acanthamoeba rhysodes whole cells and its membrane...
Ether lipids were identified among components liberated with HF and nitrous acid deamination from Acanthamoeba rhysodes whole cells and its membrane glycoinositolphospholipids (GIPL). Liberated ether glycerols were converted to various derivatives that served characterization thereof. These included TMS and isopropylidene derivatives, oxidation with sodium periodate to aldehyde followed by reduction with NaBH4 to alcohol, and reaction of the alcohol with acetic anhydrite to form acetate derivatives. Periodate sensitivity demonstrated that the alkyl side chains were linked to the sn-1 position of glycerol. Combined information from TLC, GC-MS analysis, MALDI-TOF spectrometry, and chemical degradation experiments indicated the presence of ether-linked saturated normal and branched hydrocarbons with a length of C20-23 in the phospholipid fraction, C20-24 in free GPI, and C21-23 in the LPG polymer. The distribution of particular classes of alkylglycerols was similar for phospholipid and GPI fractions, and amounted to 2.62% (±0.04-0.28) 1-O-eicosanyl-sn-glycerol, 16.66% (±0.32-1.1) 1-O-uncosanyl-sn-glycerol, 9.18% (±0.33-1.37) anteiso-1-O-docosanyl-sn-glycerol, 47.56% (±0.32-2.14) 1-O-docosanyl-sn-glycerol, 20.56% (±0.58-1.67) anteiso-1-O-tricosanyl-sn-glycerol, and 2.34% (±0.12-0.63) 1-O-tricosanyl-sn-glycerol. For LPG preparation, the most abundant were anteiso-1-O-tricosanyl-sn-glycerol (57.26%) and 1-O-docosanyl-sn-glycerol (30.12%). The data from TLC and GC-MS analysis showed that ether lipids from phospholipids probably represent the lyso-alkylglycerol type, while those derived from GIPL are alkylacylglycerol moieties.
Topics: Acanthamoeba; Ethers; Gas Chromatography-Mass Spectrometry; Glycerol; Glycolipids; Membrane Lipids; Phospholipids
PubMed: 24535098
DOI: 10.1007/s11745-014-3884-9 -
Experimental Parasitology Sep 2010Several species of free-living amoebae can cause disease in humans. However, in addition to the direct pathogenicity of e.g. Acanthamoebae and Naegleria species, they...
Several species of free-living amoebae can cause disease in humans. However, in addition to the direct pathogenicity of e.g. Acanthamoebae and Naegleria species, they are recognized as environmental hosts, indirectly involved in the epidemiology of many pathogenic bacteria. Although several studies have demonstrated intracellular survival of many different bacteria in these species, the extent of such interactions as well as the implications for the epidemiology of the bacterial species involved, are largely unknown and probably underestimated. In this study, we evaluated eight different unicellular eukaryotic organisms, for their potential to serve as environmental hosts for Campylobacter species. These organisms include four amoebozoas (Acanthamoeba polyphaga, Acanthamoeba castellanii, Acanthamoeba rhysodes and Hartmanella vermiformis), one alveolate (Tetrahymena pyriformis), one stramenopile (Dinobryon sertularia), one eugoenozoa (Euglena gracilis) and one heterolobosea (Naegleria americana). Campylobacter spp. including Campylobacter jejuni, Campylobacter coli and Campylobacter lari are the most common cause of gastroenteritis in the western world. Survival and replication of these three species as well as Campylobacter hyointestinalis were assessed in co-cultures with the eukaryotic organisms. Campylobacter spp. generally survived longer in co-cultures, compared to when incubated in the corresponding growth media. The eukaryotic species that best promoted bacterial survival was the golden algae D. sertularia. Three species of amoebozoas, of the genus Acanthamoeba promoted both prolonged survival and replication of Campylobacter spp. The high abundance in lakes, ponds and water distribution networks of these organisms indicate that they might have a role in the epidemiology of campylobacteriosis, possibly contributing to survival and dissemination of these intestinal pathogens to humans and other animals. The results suggest that not only C. jejuni, but a variety of Campylobacter spp. can interact with different eukaryotic unicellular organisms.
Topics: Acanthamoeba; Campylobacter; Coculture Techniques; Eukaryota; Humans
PubMed: 20056117
DOI: 10.1016/j.exppara.2009.12.016 -
Genomics Aug 2009Free-living amoebae act as environmental hosts of several intracellular pathogens. We examined the interaction between Acanthamoeba rhysodes and Salmonella, a human...
Free-living amoebae act as environmental hosts of several intracellular pathogens. We examined the interaction between Acanthamoeba rhysodes and Salmonella, a human intracellular pathogen. There was no difference among three different serovars of Salmonella in terms of their growth within A. rhysodes over time. The number of intracellular bacteria increased at 6 h post-infection, and the viability of A. rhysodes was significantly reduced at 24 h post-infection. Amoebic cell death was characterized by TUNEL and Annexin V assay, without DNA ladder identified, indicating an apoptosis-like cell death in Salmonella-infected A. rhysodes. Global gene expression screening between intracellular and extracellular Salmonella by microarray and quantitative PCR showed that genes from Salmonella pathogenicity islands and virulence plasmid were up-regulated within A. rhysodes. The phase-dependent expression pattern suggests their distinct roles in the pathogenesis. A. rhysodes and Salmonella provide a model to study transient symbiosis between bacterial pathogens and protozoa in an aquatic ecosystem.
Topics: Acanthamoeba; Animals; Apoptosis; Gene Expression Regulation, Bacterial; Microbial Viability; Salmonella typhimurium
PubMed: 19446019
DOI: 10.1016/j.ygeno.2009.05.004 -
Eye & Contact Lens Jan 2009Effective pharmacotherapy for Acanthamoeba keratitis has been hampered because of the marked resistance of various stains to a variety of antimicrobial agents. In view...
OBJECTIVES
Effective pharmacotherapy for Acanthamoeba keratitis has been hampered because of the marked resistance of various stains to a variety of antimicrobial agents. In view of the fact that topical Brolene (propamidine isethionate) and neosporin are currently considered to be the first-line medical treatment of choice in Europe, we sought to determine whether Alexidine is equally effective, because the latter drug is more readily available in the United States.
METHODS
Trophozoites and cysts from 3 pathogenic corneal isolates (A. castellanii, A. polyphaga, and A. rhysodes) were incubated in peptone-yeast extract-glucose medium containing different concentrations of Alexidine for 24 hr. The number of trophozoites was counted by hemocytometer. The cysts were plated in to nonnutrient agar plates precoated with Escherichia coli and observed for viability or excystment over a period of 2 weeks. The capacity of different concentrations of Alexidine to induce cytolysis of corneal epithelial cells was tested in vitro. Chinese hamster corneas were treated with 5 microL of Alexidine topically, every hour; 6 times a day and the corneas were stained with fluorescein to asses the epithelial defects in vivo.
RESULTS
Alexidine was effective in killing the trophozoites at a concentration of 10 microg/mL. However, a higher concentration of Alexidine (100 microg/mL) is required to kill Acanthamoeba cysts and the cytotoxic activities of Alexidine are comparable with chlorhexidine. We have also demonstrated that both Alexidine and chlorhexidine at 100 microg/mL induced significant cytopathic effect on the corneal epithelial cells in vitro. In vivo results indicate that Alexidine at a concentration of 100 microg/mL is less toxic than chlorhexidine when applied topically to the Chinese hamster cornea.
CONCLUSIONS
Our study has identified Alexidine as a novel anti-Acanthamoeba drug and suggests that Alexidine may be an effective therapeutic option because of its potency and low toxicity to the corneal tissues when applied topically in vivo.
Topics: Acanthamoeba; Administration, Topical; Amebiasis; Amebicides; Animals; Biguanides; Chlorhexidine; Cornea; Cricetinae; Cricetulus; Dose-Response Relationship, Drug; Epithelium, Corneal; Parasitic Sensitivity Tests; Trophozoites
PubMed: 19125040
DOI: 10.1097/ICL.0b013e3181909ae6 -
Parasitology Research Mar 2009We present a novel and simple technique for storing live Acanthamoeba for long periods of time. The amoebae are maintained at refrigerator temperatures in a...
We present a novel and simple technique for storing live Acanthamoeba for long periods of time. The amoebae are maintained at refrigerator temperatures in a peptone-yeast extract-glucose (PYG) medium normally used for cultivation. Using this method, we obtained survival rates of at least 4 years for Acanthamoeba polyphaga and 3 years for Acanthamoeba castellanii and Acanthamoeba rhysodes. Advantages of this storage method are: (1) it is quick and simple, (2) inexpensive, (3) does not require encystment before storage, (4) resuscitation of cysts can be achieved within a week of culture in PYG medium at 27 degrees C, and does not require co-culture with bacteria or any special equipment.
Topics: Acanthamoeba; Acanthamoeba castellanii; Animals; Culture Media; Parasitology; Preservation, Biological; Refrigeration; Time Factors
PubMed: 19089450
DOI: 10.1007/s00436-008-1304-x