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The Science of the Total Environment Sep 2022Cryptosporidium is the leading agent of waterborne parasitic protozoan outbreaks and is the second leading cause of infant mortality due to diarrhoea worldwide....
Cryptosporidium is the leading agent of waterborne parasitic protozoan outbreaks and is the second leading cause of infant mortality due to diarrhoea worldwide. Acanthamoeba spp. causes Acanthamoeba keratitis (AK) and a life-threatening condition known as granulomatous amoebic encephalitis (GAE). The present study aimed to assess the water quality of an indigenous and a rural community for waterborne parasitic protozoan contamination. Aquatic samples (n = 22) were processed by filtration of 500 mL portion through a 1.2 μm pore size glass microfiber filter and eluted for light microscopy, culture in non-nutrient agar, and PCR analysis. Overall, 36% (8/22) of the investigated aquatic samples were positive for either Cryptosporidium spp. oocysts (13%; 3/22) or Acanthamoeba spp., (36%; 8/22) or both (13%; 3/22). Cryptosporidium spp. oocysts were detected in 27% (3/11) of wet season samples only while Acanthamoeba spp. were detected in 18% (2/11) and 55% (6/11) of wet and dry season samples, respectively. Subsequently, molecular detection for Acanthamoeba species identified A. lenticulata and A. hatchetti with 98-99% BLAST similarity. This is the first report on the simultaneous contamination of Cryptosporidium and Acanthamoeba in well water sources in East-Southeast Asia, the first detection of Acanthamoeba spp. in biofilms in the Philippines, and the longest viability demonstrated for A. lenticulata in two-year-old water samples stored at room temperature.
Topics: Acanthamoeba; Animals; Biofilms; Child, Preschool; Cryptosporidiosis; Cryptosporidium; Humans; Oocysts; Philippines
PubMed: 35533862
DOI: 10.1016/j.scitotenv.2022.155752 -
Journal of Medical Microbiology Jan 2020keratitis is a sight-threatening corneal infection that is commonly reported among contact lens users and those suffering from corneal trauma. The prevalence of...
keratitis is a sight-threatening corneal infection that is commonly reported among contact lens users and those suffering from corneal trauma. The prevalence of species or genotypes in causing keratitis infection is not well known. This study was conducted to identify and genotype isolates from keratitis patients, targeting the ribosomal nuclear subunit () region, and describe the associated clinical presentation and treatment outcome. Thirty culture-confirmed patients with keratitis, identified in a tertiary eye care centre in South India during the period from December 2016 to December 2018, were included in this study. The data collected from patient records include demographic details, history of illness, mode of trauma, treatment history and follow-up status. The genotype and species were identified based on the sequence and phylogenetic tree analysis. was the most predominant keratitis-causing species, followed by and . Three major genotypes were identified (T4, T11 and T12), with the T4 genotype being the most predominant, with four subclusters, i.e. T4A, T4B, T4D and T4E. This is the first report on corneal infection by the T11 genotype and the T12 genotype. No significant correlation was observed between the clinical outcomes of corneal disease and the genotypes or species. genotyping is very effective in identifying the species and genotype in keratitis. Genotyping of spp. will help to advance our understanding of genotype-specific pathogenesis and geographical distribution.
Topics: Acanthamoeba Keratitis; Acanthamoeba castellanii; Genes, rRNA; Genotype; Genotyping Techniques; Humans; India; Phylogeny; Tertiary Care Centers
PubMed: 31846414
DOI: 10.1099/jmm.0.001121 -
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 -
Journal of Water and Health Sep 2015Free living amoebae (FLA) are amphizoic protozoa that are ubiquitous in nature. Infection with FLA may result in neurological, ocular and skin infections. Exposure to...
Free living amoebae (FLA) are amphizoic protozoa that are ubiquitous in nature. Infection with FLA may result in neurological, ocular and skin infections. Exposure to Acanthamoeba occurs frequently through water contact and knowledge of the presence of the organisms in water sources is important in understanding transmission dynamics. The distribution of Acanthamoeba was studied in recreational and domestic water samples collected from across Jamaica. Morphological assessment and polymerase chain reaction revealed Acanthamoeba spp. isolates in 50.6% (42/83) and 17.3% (14/81) of recreational and domestic water, respectively. Sequencing of the DF3 region of the 18S rDNA resulted in the identification of genotypes T3, T4, T5, T10 and T11 corresponding to Acanthamoeba spp: A. griffini, A. triangularis, A. lenticulata, A. culbertsoni and A. hatchetti. Moreover, T4 was the most frequently isolated genotype in both recreational and domestic water. Thermotolerance and osmotolerance assays indicated that most isolates were potentially pathogenic. This is the first report of T3 and T10 genotypes in the Caribbean and the first report of these Acanthamoeba spp. in Jamaican waters. The study shows that there is potential risk of infection to contact wearers who practise poor lens care. Further, Acanthamoeba should be considered as a cause of neurological infections in Jamaica.
Topics: Acanthamoeba; Bathing Beaches; Contact Lenses; Fresh Water; Genotype; Humans; Jamaica; Natural Springs; Risk Assessment; Seawater
PubMed: 26322776
DOI: 10.2166/wh.2015.232 -
Folia Parasitologica Dec 2022Species of Acanthamoeba Volkonsky, 1931 are the commonest among free-living amoebae that are widespread in different water resources but with lacking phylogenetic data....
Species of Acanthamoeba Volkonsky, 1931 are the commonest among free-living amoebae that are widespread in different water resources but with lacking phylogenetic data. This study aims at detecting molecular prevalence and genetic diversity of Acanthamoeba isolates in Kafrelsheikh Governorate, Egypt. Forty-eight water samples were collected from 12 swimming pools; four samples during each season over one year. Samples were filtered, cultivated on non-nutrient agar plates and examined microscopically. Polymerase chain reaction (PCR) and sequence analysis of positive samples targeting diagnostic fragment 3 (DF3) of the small subunit rRNA gene were done. Cultivation succeeded to detect 14 (29%) positive samples while PCR missed three positive samples. The obtained sequences were phylogenetically analysed. The phylogenetic tree was constructed for them with sequences of reference species from the NCBI database. The identified species were Acanthamoeba castellanii Douglas, 1930 (T4), A. astronyxis (Ray et Hayes, 1954) (T9) and A. hatchetti Sawyer, Visvesvara et Harke, 1977 (T11). The prevalence of species of Acanthamoeba was higher during summer and fall. Therefore, the control of the presence of Acanthmoeba spp. in swimming pools needs immediate, effective and practical measures to prevent and control infection with species of Acanthamoeba.
Topics: Acanthamoeba; Phylogeny; Egypt; Swimming Pools; Genotype
PubMed: 36534004
DOI: 10.14411/fp.2022.029 -
Investigative Ophthalmology & Visual... Sep 2018To assess the amoebicidal effect of titanium dioxide (TiO2)/UV-A combination against Acanthamoeba sp trophozoites and cysts.
PURPOSE
To assess the amoebicidal effect of titanium dioxide (TiO2)/UV-A combination against Acanthamoeba sp trophozoites and cysts.
METHODS
The amoebicidal effect of the TiO2/UV-A combination was tested on trophozoites and cysts of clinical isolates of Acanthamoeba hatchetti and Acanthamoeba sp genotype T4, obtained from two severe cases of ulcerative keratitis. Samples of cultured Acanthamoeba were transferred to a 96-well plate. We tested the effect of sterile water (blank control), TiO2 alone, UV-A alone, TiO2 and additional UV-A exposure, chlorhexidine 0.02% alone, chlorhexidine 0.02% and TiO2, chlorhexidine and UV-A, chlorhexidine 0.02% and TiO2, and additional UV-A exposure. Cell viability assessment was done using the trypan blue dye exclusion method.
RESULTS
The combination of TiO2 with UV-A demonstrated antitrophozoite and anticyst activity (P < 0.05). This in vitro study showed a synergistic effect of the association of chlorhexidine with TiO2 and UV-A on cysts (P < 0.001).
CONCLUSIONS
Given the in vitro synergistic effectiveness of the association of chlorhexidine with TiO2 and UV-A against cysts, the treatment of Acanthamoeba keratitis could be improved by this new therapeutic approach.
Topics: Acanthamoeba; Acanthamoeba Keratitis; Amebicides; Animals; Humans; Photochemotherapy; Photosensitizing Agents; Time Factors; Titanium; Ultraviolet Rays
PubMed: 30242357
DOI: 10.1167/iovs.18-25003 -
Parasites & Vectors Mar 2016Acanthamoeba is an emerging potentially pathogenic amoeba that has been receiving increasing attention worldwide as a reservoir and potential vector for the transmission...
BACKGROUND
Acanthamoeba is an emerging potentially pathogenic amoeba that has been receiving increasing attention worldwide as a reservoir and potential vector for the transmission of pathogenic bacteria. It is also associated with brain cell damage, keratitis and skin irritation in humans. Its effects are more severe in immunocompromised individuals. This study provides for the first time in Uganda, information on the prevalence and genotypes of Acanthamoeba in environmental and domestic (tap) water.
METHODS
A total of 324 environmental and 84 tap water samples were collected between November 2013 and September 2014. The samples were centrifuged, cultured (Non-Nutrient agar seeded with gram-negative bacteria) and observed under a microscope. After confirmation of Acanthamoeba, genomic DNA was extracted for PCR assays by chemical lysis and purification with phenol/chloroform/isoamyl alcohol. Samples that showed the strongest positive bands (400-600 bp) were subjected to cycle sequencing.
RESULTS
Among environmental and tap water samples, 107 (33 %) and 36 (42.9 %) tested positive for Acanthamoeba spp., respectively. Prevalence of Acanthamoeba from specific environmental locations was as follows; Kazinga channel banks (60.7 %), Fish landing sites (50 %), River Kyambura (39.6 %) and Kazinga mid channel (5.3 %). There was a significant difference (p = 0.001) in the prevalence of Acanthamoeba between sampling sites. The mean (Mean ± SE) occurrence of the organism was higher in Kazinga channel banks (3.44 ± 0.49) and Fish landing sites (3.08 ± 0.53). Correlation between in situ parameters and Acanthamoeba was insignificant except for the Dissolved Oxygen (mg/ML) which was negatively correlated (r = -0.231, p = 0.001) to Acanthamoeba. Six distinct partial Acanthamoeba T-genotype groups T1, T2, T4, T5, T6 and T11 were obtained. Ultimately, Acanthamoeba spp., Acanthamoeba hatchetti and Acanthamoeba polyphaga were isolated in the current study.
CONCLUSIONS
There was a high prevalence of Acanthamoeba in communal piped tap and environmental water used by communities, indicating poor environmental and domestic water quality.
Topics: Acanthamoeba; DNA, Protozoan; Genetic Variation; Genotype; Microscopy; Polymerase Chain Reaction; Prevalence; Sequence Analysis, DNA; Uganda; Water
PubMed: 26935431
DOI: 10.1186/s13071-016-1411-y -
The Korean Journal of Parasitology Apr 2022Acanthamoeba keratitis (AK) is a rare ocular disease, but it is a painful and sight-threatening infectious disease. Early diagnosis and adequate treatment are necessary...
Acanthamoeba keratitis (AK) is a rare ocular disease, but it is a painful and sight-threatening infectious disease. Early diagnosis and adequate treatment are necessary to prevent serious complications. While AK is frequently diagnosis via several PCR assays or Acanthamoeba-specific antibodies, a more specific and effective diagnostic method is required. This study described the production of a polyclonal peptide antibody against the periplasmic binding protein (PBP) of A. castellanii and investigated its diagnostic potential. Western blot analysis showed that the PBP antibody specifically reacted with the cell lysates of A. castellanii. However, the PBP antibody did not interact with human corneal epithelial (HCE) cells and the other 3 major causative agents of keratitis. Immunocytochemistry (ICC) results revealed the specific detection of A. castellanii trophozoites and cysts by PBP antibodies when A. castellanii were co-cultured with HCE cells. PBP antibody specificity was further confirmed by co-culture of A. castellanii trophozoites with F. solani, S. aureus, and P. aeruginosa via ICC. The PBP antibody specifically reacted with the trophozoites and cysts of A. polyphaga, A. hatchetti, A. culbertsoni, A. royreba, and A. healyi, thus demonstrated its genus-specific nature. These results showed that the PBP polyclonal peptide antibody of A. castellanii could specifically detect several species of Acanthamoeba, contributing to the development of an effective antibody-based AK diagnostics.
Topics: Acanthamoeba; Acanthamoeba Keratitis; Animals; Antibodies; Humans; Peptides; Periplasmic Binding Proteins; Staphylococcus aureus; Trophozoites
PubMed: 35500897
DOI: 10.3347/kjp.2022.60.2.143 -
Journal Francais D'ophtalmologie Apr 2020Acanthamoeba keratitis due to a genus of free-living amoebae is a severe corneal infection. Treatment of this disease is based on the combined use of antiseptics and...
Acanthamoeba keratitis due to a genus of free-living amoebae is a severe corneal infection. Treatment of this disease is based on the combined use of antiseptics and other drugs, including azoles. We tested isavuconazole, the latest marketed azole, in vitro, against A. castellanii, A. lenticulata and A. hatchetti. Our results show that isavuconazole presents slight amoebistatic activity against A. castellanii trophozoites but no cysticidal activity. Isavuconazole could be used only in association for management of AK due to A. castellanii.
Topics: Acanthamoeba; Acanthamoeba Keratitis; Acanthamoeba castellanii; Animals; Dose-Response Relationship, Drug; Humans; Nitriles; Parasite Encystment; Parasitic Sensitivity Tests; Pyridines; Triazoles; Trophozoites
PubMed: 32151474
DOI: 10.1016/j.jfo.2019.06.014 -
Microorganisms Aug 2022keratitis (AK) is a dangerous infectious disease, which is associated with a high risk of blindness for the infected patient, and for which no standard therapy exists...
keratitis (AK) is a dangerous infectious disease, which is associated with a high risk of blindness for the infected patient, and for which no standard therapy exists thus far. Patients suffering from AK are thus treated, out of necessity, with an off-label therapy, using drugs designed and indicated for other diseases/purposes. Here, we tested the capability of the off-label anti-amoebic drugs chlorhexidine (CH; 0.1%), dibromopropamidine diisethionate (DD; 0.1%), hexamidine diisethionate (HD; 0.1%), miltefosine (MF; 0.0065%), natamycin (NM; 5%), polyhexamethylene biguanide (PHMB; 0.02%), povidone iodine (PVPI; 1%), and propamidine isethionate (PD; 0.1%) to suppress trophozoite formation of and cysts on non-nutrient agar plates. Of the eight off-label anti-amoebic drugs tested, only PVPI allowed for a complete suppression of trophozoite formation by drug-challenged cysts for all four isolates in all five biological replicates. Drugs such as NM, PD, and PHMB repeatedly suppressed trophozoite formation with some, but not all, tested isolates, while other drugs such as CH, DD, and MF failed to exert a relevant effect on the excystation capacities of the tested isolates in most, if not all, of our repetitions. Our findings suggest that pre-testing of the AK isolate with the non-nutrient agar plate assay against the anti-amoebic drug intended for treatment should be performed to confirm that the selected drug is cysticidal for the isolate.
PubMed: 36014060
DOI: 10.3390/microorganisms10081642