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BMC Microbiology Dec 2016Environmental chlamydiae belonging to the Parachlamydiaceae are obligate intracellular bacteria that infect Acanthamoeba, a free-living amoeba, and are a risk for...
BACKGROUND
Environmental chlamydiae belonging to the Parachlamydiaceae are obligate intracellular bacteria that infect Acanthamoeba, a free-living amoeba, and are a risk for hospital-acquired pneumonia. However, whether amoebae harboring environmental chlamydiae actually survive in hospital environments is unknown. We therefore isolated living amoebae with symbiotic chlamydiae from hospital environments.
RESULTS
One hundred smear samples were collected from Hokkaido University Hospital, Sapporo, Japan; 50 in winter (February to March, 2012) and 50 in summer (August, 2012), and used for the study. Acanthamoebae were isolated from the smear samples, and endosymbiotic chlamydial traits were assessed by infectivity, cytokine induction, and draft genomic analysis. From these, 23 amoebae were enriched on agar plates spread with heat-killed Escherichia coli. Amoeba prevalence was greater in the summer-collected samples (15/30, 50%) than those of the winter season (8/30, 26.7%), possibly indicating a seasonal variation (p = 0.096). Morphological assessment of cysts revealed 21 amoebae (21/23, 91%) to be Acanthamoeba, and cultures in PYG medium were established for 11 of these amoebae. Three amoebae contained environmental chlamydiae; however, only one amoeba (Acanthamoeba T4) with an environmental chlamydia (Protochlamydia W-9) was shown the infectious ability to Acanthamoeba C3 (reference amoebae). While Protochlamydia W-9 could infect C3 amoeba, it failed to replicate in immortal human epithelial, although exposure of HEp-2 cells to living bacteria induced the proinflammatory cytokine, IL-8. Comparative genome analysis with KEGG revealed similar genomic features compared with other Protochlamydia genomes (UWE25 and R18), except for a lack of genes encoding the type IV secretion system. Interestingly, resistance genes associated with several antibiotics and toxic compounds were identified.
CONCLUSION
These findings are the first demonstration of the distribution in a hospital of a living Acanthamoeba carrying an endosymbiotic chlamydial pathogen.
Topics: Acanthamoeba; Anti-Bacterial Agents; Base Sequence; Chlamydia; Cytokines; DNA, Bacterial; Environmental Microbiology; Genes, Bacterial; Hospitals; Humans; Phylogeny; RNA, Ribosomal, 16S; Seasons; Symbiosis
PubMed: 27978822
DOI: 10.1186/s12866-016-0906-1 -
Acta Parasitologica Sep 2013The present study investigated the susceptibility of Acanthamoeba spp. trophozoites to two multipurpose systems for cleaning and maintenance of contact lenses. Three...
The present study investigated the susceptibility of Acanthamoeba spp. trophozoites to two multipurpose systems for cleaning and maintenance of contact lenses. Three strains of trophozoites from the ATCC (A. castellani T4, A. castellani Neff, and A. polyphaga) and two Acanthamoeba isolates obtained from swimming pools (PT5 and PO1) were placed in monoxenic culture. To test their survival in cleaning solutions for contact lenses, the trophozoites were exposed for 4 and 24 h to two multipurpose solutions (A and B), and were then inoculated into a new monoxenic culture. Amoebic growth on the plates was observed after 72 h of incubation. Trophozoites from all three ATCC strains and one isolate from a swimming pool (PO1) grew in all plates after 4 h of exposure to solutions A and B. After 24 h, the ATCC strains and the PO1 isolate showed growth in most of the plates treated. Only the PT5 isolate showed susceptibility to both solutions over the time intervals tested. The two solutions were not completely effective against most strains and isolates over the time intervals tested. These results are important, since species of Acanthamoeba are widely distributed in the environment and are potential agents of eye pathologies.
Topics: Acanthamoeba; Antiprotozoal Agents; Cell Survival; Contact Lens Solutions; Humans
PubMed: 23990426
DOI: 10.2478/s11686-013-0143-9 -
Acta Microbiologica Et Immunologica... Mar 2018Acanthamoeba has a worldwide distribution in the environment and it is capable of causing a painful sight-threatening disease of the cornea designated as Acanthamoeba...
Acanthamoeba has a worldwide distribution in the environment and it is capable of causing a painful sight-threatening disease of the cornea designated as Acanthamoeba keratitis (AK). Nowadays, the cases of AK have surged all over the world along with its disease burden due to increasing use of contact lenses used not only for optical correction but also for cosmetic purposes. In our present work, epithelial abrasion of a 27-year-old female soft contact lens wearer with keratitis was examined. Genotype identification was carried out with a real-time fluorescence resonance energy transfer polymerase chain reaction (PCR) assay based on sequence analysis of the 18S rRNA gene. Genotyping allowed the identification of a T8 group isolate. The analysis confirmed the importance of a complete diagnostic protocol, including a PCR assay, for the clinical diagnosis of AK from human samples. Acanthamoeba T8 should be considered as potential causative organism in keratitis in human.
Topics: Acanthamoeba; Acanthamoeba Keratitis; Adult; Amebiasis; Cornea; Female; Genotype; Humans; Phylogeny
PubMed: 29471697
DOI: 10.1556/030.65.2018.007 -
The Journal of Eukaryotic Microbiology 1995Seabottom sediments from a discontinued Philadelphia-Camden 40-Mile ocean sewage disposal site were cultured for cyst-forming free-living amoebae. Barge delivered wastes... (Comparative Study)
Comparative Study
Seabottom sediments from a discontinued Philadelphia-Camden 40-Mile ocean sewage disposal site were cultured for cyst-forming free-living amoebae. Barge delivered wastes were discharged at the site from 1973 until 1980 when the site was closed. One station at the southeast margin of the site was sampled at a depth of approximately 50 m, twice in 1978 and once in 1982, 1983 and 1984. Sediment from the 1978 collection yielded Acanthamoeba polyphaga, Vahlkampfia sp., and an unknown amoeba with stellate endocysts similar to those of A. astronyxis. Trophozoites and cysts of the isolate were typical of those described for the genus Acanthamoeba. Biochemical tests employing enzyme electrophoresis and morphological studies on live and stained specimens showed that the isolate was distinct from other well-described species within the family Acanthamoebidae Sawyer & Griffin, 1975.
Topics: Acanthamoeba; Animals; New Jersey; Pennsylvania; Seawater; Sewage; Species Specificity; Water Pollution
PubMed: 8520585
DOI: 10.1111/j.1550-7408.1995.tb01619.x -
Optometry and Vision Science : Official... Jun 2011To compare the effects of drying the lens case with tissue on the presence of Acanthamoeba with cases left wet and to determine adherence to the lens case of varying... (Comparative Study)
Comparative Study
PURPOSE
To compare the effects of drying the lens case with tissue on the presence of Acanthamoeba with cases left wet and to determine adherence to the lens case of varying concentrations of Acanthamoeba suspensions. The effect of drying on viability of Acanthamoeba in new, used, and soiled lens cases was compared over a 24 h period.
METHODS
New (16) and scratched (16) lens cases were rinsed with a range of Acanthamoeba suspensions. Eight of each group were dried with tissue and the presence of Acanthamoeba was determined in all cases using polymerase chain reaction. To examine effects of drying, forty-two lens case wells were scratched to simulate use and 21 of these were artificially soiled with serum Bovine albumin. These cases and a further 21 unused wells were contaminated with Acanthamoeba (×10/ml) and then left to dry in a cool, dry environment. Three wells of each group were sampled at time 0, 2, 4, 6, 8, 12, and 24 h, and the number of viable Acanthamoeba were determined.
RESULTS
Acanthamoeba were more likely to adhere to used than unused lens cases (p < 0.05). Detection of Acanthamoeba in wiped lens cases was at 2-log dilutions less than in cases left wet for both new and used lens cases. Adherence were significantly different between rinse and rinse/dried cases (p = 0.015). Air drying significantly reduced the numbers of viable amoebic cysts and trophozoites and the effect was time dependent. Survival was significantly higher in used and soiled wells.
CONCLUSIONS
Drying with tissue after rinsing significantly reduces numbers of adhering Acanthamoeba. Acanthamoeba were found to be able to adhere even to new unused cases, so the importance of proper cleaning and disinfection of lens cases cannot be underestimated. Air drying reduces viability but some viable cells were present at 24 h in soiled cases, confirming the role of biofilm in protecting organisms from desiccation.
Topics: Acanthamoeba; Biofilms; Cell Adhesion; Cell Survival; Cells, Cultured; Contact Lenses; Desiccation; Equipment Contamination; Humans; Serum Albumin, Bovine; Time Factors; Water
PubMed: 21460755
DOI: 10.1097/OPX.0b013e318215c316 -
Parasitology Research Apr 2017Free-living amoebae of the genus Acanthamoeba are worldwide present in natural and artificial environments, and are also clinically important, as causative agents of...
Free-living amoebae of the genus Acanthamoeba are worldwide present in natural and artificial environments, and are also clinically important, as causative agents of diseases in humans and other animals. Acanthamoeba comprises several species, historically assigned to one of the three groups based on their cyst morphology, but presently recognized as at least 20 genotypes (T1-T20) on the basis of their nuclear 18S ribosomal RNA (rRNA) gene (18S rDNA) sequences. While strain identification may usually be achieved targeting short (<500 bp) 18S ribosomal DNA (rDNA) fragments, the use of full-length gene sequences (>2200 bp) is necessary for correct genotype description and reliable molecular phylogenetic inference. The genotype T15, corresponding to Acanthamoeba jacobsi, is the only genotype described on the basis of partial sequences (~1500 bp). While this feature does not prevent the correct identification of the strains, having only partial sequences renders the genotype T15 not completely defined and may furthermore affect its position in the Acanthamoeba molecular tree. Here, we complete this gap, by obtaining full-length 18S rDNA sequences from eight A. jacobsi strains, genotype T15. Morphologies and physiological features of isolated strains are reported. Molecular phylogeny based on full 18S rDNA confirms some previous suggestions for a genetic link between T15 and T13, T16, and T19, with T19 as sister-group to T15.
Topics: Acanthamoeba; Animals; DNA, Protozoan; DNA, Ribosomal; Genotype; Humans; Phylogeny; RNA, Ribosomal, 18S
PubMed: 28190156
DOI: 10.1007/s00436-017-5406-1 -
The Journal of Eukaryotic Microbiology 2006
Topics: Acanthamoeba; Amebiasis; Animals; Disease Models, Animal; Mexico; Mice; Soil Microbiology; Water Microbiology
PubMed: 17169014
DOI: 10.1111/j.1550-7408.2006.00156.x -
Journal of Water and Health Dec 2012This study was conducted to address the distribution of Acanthamoeba genotypes in therapeutic hot springs in Iran. Sixty water and sediment samples were collected from...
This study was conducted to address the distribution of Acanthamoeba genotypes in therapeutic hot springs in Iran. Sixty water and sediment samples were collected from bicarbonate, sulphur, and sodium chloride thermal springs in the northwest. All hot springs examined are used mainly for health purposes in Iran. Acanthamoeba were identified by both morphology and PCR (polymerase chain reaction). Genotype identification was based on the sequencing of a highly variable and informative region of Diagnostic Fragment 3 (stem 29-1 of 18S rRNA gene) within Acanthamoeba-specific amplimer (ASA.S1). Twenty percent of hot springs were contaminated with thermotolerant Acanthamoeba belonging to the potentially pathogenic T4 and T3 genotypes. A high number (91.7%) of strains showed growth at 37 °C, and eight isolates showed growth at 42 °C. A single isolate (HSNW2) was detected in waters at 70 °C. The presence of thermotolerant Acanthamoeba highlights a risk factor for susceptible individuals, as Acanthamoeba-related keratitis continues to rise in Iran. Periodic surveillance of thermal waters as well as improved filtration and disinfection is recommended to prevent disease related to pathogenic Acanthamoeba. This is the first comprehensive molecular study of Acanthamoeba genotypes in hot springs in Iran and the first to report the occurrence of the T3 genotype (corresponding to Acanthamoeba griffini) in thermal water sources in this country.
Topics: Acanthamoeba; Base Sequence; Genotype; Hot Springs; Iran; Molecular Sequence Data; Polymerase Chain Reaction; RNA, Protozoan; RNA, Ribosomal, 18S; Recreation; Sequence Alignment
PubMed: 23165720
DOI: 10.2166/wh.2012.032 -
Experimental Parasitology Sep 2010Acanthamoeba are free-living amoebae found in most environments that can cause brain and corneal infections. To infect humans, these pathogens must interact with host...
Acanthamoeba are free-living amoebae found in most environments that can cause brain and corneal infections. To infect humans, these pathogens must interact with host cells and the extracellular matrix (ECM). In order to define the mode by which amoebae recognize ECM components and process this recognition, we analyzed Acanthamoeba culbertsoni attachment and invasion, respectively, on collagen I and laminin-1 and on tridimensional collagen I and matrigel matrices. We determined that amoebae surface proteins are involved in adhesion, that exogenous sugars can decrease adhesion and invasion, and that adhesion and invasion are dependent on microfilament reorganization. In addition, we determined the role of serine- and metallo-proteases on invasion and found that adhesion was blocked when amoebae were treated with a metallo-protease inhibitor. Collectively, these results suggest that adhesion and invasion are protease- and microfilament-dependent events in which amoebic surface proteins play a pivotal role.
Topics: Acanthamoeba; Bridged Bicyclo Compounds, Heterocyclic; Carbohydrates; Cell Adhesion; Collagen; Colorimetry; Extracellular Matrix; Laminin; Peptide Hydrolases; Periodic Acid; Thiazolidines; Trypsin
PubMed: 19698710
DOI: 10.1016/j.exppara.2009.08.004 -
Experimental Parasitology Nov 2006In this study we report observations on the structural mechanisms of the cytopathic effect of Acanthamoeba castellanii trophozoites on cultured MDCK cell monolayers....
In this study we report observations on the structural mechanisms of the cytopathic effect of Acanthamoeba castellanii trophozoites on cultured MDCK cell monolayers. Co-incubations were carried out for a maximum of 24h. The first evidence of damage to the cell monolayer was detected by measuring the transepithelial resistance of cell monolayers that interacted with the amoebae. At 6h, transepithelial resistance diminished to 51% and amoebae required 5-6h to produce evidence of structural injury at the light microscopy level. Following 12h of incubation, the cell monolayer was severely damaged. After making intimate contact with the surface of target cells, trophozoites detached cells from the substrate, lysed and by means of food-cups ingested the damaged cells. There was no morphological evidence of modifications in MDCK cell membranes, membrane fusion or junction formation between the amoeba and host plasma membrane. The lytic capacity of the amoebas appears to be the result of cytotoxic factors secreted by the amoebae since, when monolayers were incubated with conditioned medium, there was also a decrease in the transepithelial resistance. Besides, mechanical injury produced by the attachment and movement of the trophozoites may contribute to the disruption of the cell monolayer. As in other pathogenic amoebae, the cytopathic action of A. castellanii on the cell monolayers can subjectively be separated into four stages: adhesion, cytolysis, phagocytosis, and intracellular degradation.
Topics: Acanthamoeba; Animals; Cell Adhesion; Cell Line; Coculture Techniques; Culture Media, Conditioned; Dogs; Electric Impedance; Electrophysiology; Epithelial Cells; Host-Parasite Interactions; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; Microscopy, Phase-Contrast; Phagocytosis
PubMed: 16631747
DOI: 10.1016/j.exppara.2006.02.023