-
Japanese Journal of Ophthalmology 1998Acanthamoeba keratitis is uncommon, but one of the most severe infectious diseases of the cornea. Delayed diagnosis or misdiagnosis as bacterial or herpes simplex...
Acanthamoeba keratitis is uncommon, but one of the most severe infectious diseases of the cornea. Delayed diagnosis or misdiagnosis as bacterial or herpes simplex keratitis leads to extensive corneal inflammation and profound visual loss. Therefore, accurate and rapid diagnosis of Acanthamoeba keratitis is essential for successful treatment and good prognosis. We evaluated the usefulness of acridine orange staining from corneal scrapings and contact lens solutions for the rapid diagnosis of four consecutive cases of Acanthamoeba keratitis. Gram stain and culture on nonnutrient agar plates with Escherichia coli overlay were also made. Corneal scrapings stained with acridine orange revealed yellow-to-orange polygonal, cystic structures consistent with the appearance of Acanthamoeba among inflammatory cells and the corneal epithelial cells. The contact lens case solutions of two patients also showed numerous cysts with double wall. Some organisms from the third patient were identified as Acanthamoeba castellani and others as Acanthamoeba lugdunensis. Based on the acridine orange staining results in four cases of Acanthamoeba keratitis, this stain is recommended as a simple and reliable method for the rapid diagnosis of this disease.
Topics: Acanthamoeba; Acanthamoeba Keratitis; Acridine Orange; Adolescent; Adult; Animals; Contact Lenses; Diagnosis, Differential; Epithelium, Corneal; Female; Fluorescent Dyes; Follow-Up Studies; Humans; Male; Microscopy, Fluorescence; Prospective Studies
PubMed: 9587842
DOI: 10.1016/s0021-5155(97)00127-5 -
The Korean Journal of Parasitology Mar 2007Recent in vitro studies have revealed that a certain Mycobacterium can survive and multiply within free-living amoebae. It is believed that protozoans function as host...
Recent in vitro studies have revealed that a certain Mycobacterium can survive and multiply within free-living amoebae. It is believed that protozoans function as host cells for the intracellular replication and evasion of Mycobacterium spp. under harmful conditions. In this study, we describe the isolation and characterization of a bacterium naturally observed within an amoeba isolate acquired from a contact lens storage case. The bacterium multiplied within Acanthamoeba, but exerted no cytopathic effects on the amoeba during a 6-year amoebic culture. Transmission electron microscopy showed that the bacteria were randomly distributed within the cytoplasm of trophozoites and cysts of Acanthamoeba. On the basis of the results of 18S rRNA gene analysis, the amoeba was identified as A. lugdunensis. A 16S rRNA gene analysis placed this bacterium within the genus Mycobacterium. The bacterium evidenced positive reactivity for acid-fast and fluorescent acid-fast stains. The bacterium was capable of growth on the Middlebrook 7H11-Mycobacterium-specific agar. The identification and characterization of bacterial endosymbionts of free-living protozoa bears significant implications for our understanding of the ecology and the identification of other atypical mycobacterial pathogens.
Topics: Acanthamoeba; Animals; Base Sequence; Contact Lens Solutions; Contact Lenses; DNA, Mitochondrial; Microscopy, Electron, Transmission; Mycobacterium; Phylogeny; Polymorphism, Restriction Fragment Length; RNA, Ribosomal, 16S; RNA, Ribosomal, 18S; Symbiosis
PubMed: 17374973
DOI: 10.3347/kjp.2007.45.1.11 -
International Journal of Molecular... Jan 2024Caffeic acid (CA) is one of the most abundant natural compounds present in plants and has a broad spectrum of beneficial pharmacological activities. However, in some...
Caffeic acid (CA) is one of the most abundant natural compounds present in plants and has a broad spectrum of beneficial pharmacological activities. However, in some cases, synthetic derivation of original molecules can expand their scope. This study focuses on the synthesis of caffeic acid phosphanium derivatives with the ambition of increasing their biological activities. Four caffeic acid phosphanium salts (CAPs) were synthesized and tested for their cytotoxic, antibacterial, antifungal, and amoebicidal activity in vitro, with the aim of identifying the best area for their medicinal use. CAPs exhibited significantly stronger cytotoxic activity against tested cell lines (HeLa, HCT116, MDA-MB-231 MCF-7, A2058, PANC-1, Jurkat) in comparison to caffeic acid. Focusing on Jurkat cells (human leukemic T cell lymphoma), the IC value of CAPs ranged from 0.9 to 8.5 μM while IC of CA was >300 μM. Antimicrobial testing also confirmed significantly higher activity of CAPs against selected microbes in comparison to CA, especially for Gram-positive bacteria (MIC 13-57 μM) and the yeast (MIC 13-57 μM). The anti- activity was studied against two pathogenic strains. In the case of , all CAPs revealed a stronger inhibitory effect (EC 74-3125 μM) than CA (>10 µM), while in strain, the higher inhibition was observed for three derivatives (EC 44-291 μM). The newly synthesized quaternary phosphanium salts of caffeic acid exhibited selective antitumor action and appeared to be promising antimicrobial agents for topical application, as well as potential molecules for further research.
Topics: Humans; Salts; Anti-Infective Agents; Antiprotozoal Agents; HeLa Cells; Caffeic Acids
PubMed: 38256271
DOI: 10.3390/ijms25021200 -
Journal of Clinical Microbiology Apr 2002We applied ribosomal DNA PCR-restriction fragment length polymorphism (RFLP) and mitochondrial DNA (mtDNA) RFLP analyses to 43 Acanthamoeba environmental isolates...
Mitochondrial DNA restriction fragment length polymorphism (RFLP) and 18S small-subunit ribosomal DNA PCR-RFLP analyses of Acanthamoeba isolated from contact lens storage cases of residents in southwestern Korea.
We applied ribosomal DNA PCR-restriction fragment length polymorphism (RFLP) and mitochondrial DNA (mtDNA) RFLP analyses to 43 Acanthamoeba environmental isolates (KA/LH1 to KA/LH43) from contact lens storage cases in southwestern Korea. These isolates were compared to American Type Culture Collection strains and clinical isolates (KA/E1 to KA/E12) from patients with keratitis. Seven riboprint patterns were seen. To identify the species of the isolates, a phylogenetic tree was constructed based on the comparison of riboprint patterns with reference strains. Four types accounted for 39 of the isolates belonging to the A. castellanii complex. The most predominant (48.8%) type was A. castellanii KA/LH2 type, which had identical riboprint and mtDNA RFLP patterns to those of A. castellanii Castellani, KA/E3 and KA/E8. The riboprint and mtDNA RFLP patterns of the KA/LH7 (20.9%) type were identical to those of A. castellanii Ma, a corneal isolate from the United States. The riboprint and mtDNA RFLP patterns of the KA/LH1 (18.6%) type were the same as those of A. lugdunensis L3a, KA/E2, and KA/E12. The prevalent pattern for each type of Acanthamoeba in southwestern Korea was very different from that from southeastern Korea and Seoul, Korea. It is noteworthy that 38 (88.4%) out of 43 isolates from contact lens storage cases of the residents in southwestern Korea revealed mtDNA RFLP and riboprint patterns identical to those found for clinical isolates in our area. This indicates that most isolates from contact lens storage cases in the surveyed area are potential keratopathogens. More attention should be paid to the disinfection of contact lens storage cases to prevent possible amoebic keratitis.
Topics: Acanthamoeba; Acanthamoeba Keratitis; Animals; Contact Lenses; DNA, Mitochondrial; DNA, Protozoan; DNA, Ribosomal; Equipment Contamination; Humans; Korea; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length; RNA, Ribosomal, 18S
PubMed: 11923331
DOI: 10.1128/JCM.40.4.1199-1206.2002 -
The Korean Journal of Parasitology Dec 2006The pathogenic mechanism of granulomatous amebic encephalitis (GAE) and amebic keratitis (AK) by Acanthamoeba has yet to be clarified. Protease has been recognized to... (Comparative Study)
Comparative Study
The pathogenic mechanism of granulomatous amebic encephalitis (GAE) and amebic keratitis (AK) by Acanthamoeba has yet to be clarified. Protease has been recognized to play an important role in the pathogenesis of GAE and AK. In the present study, we have compared specific activity and cytopathic effects (CPE) of purified 33 kDa serine proteinases from Acanthamoeba strains with different degree of virulence (A. healyi OC-3A, A. lugdunensis KA/E2, and A. castellanii Neff). Trophozoites of the 3 strains revealed different degrees of CPE on human corneal epithelial (HCE) cells. The effect was remarkably reduced by adding phenylmethylsulfonylfluoride (PMSF), a serine proteinase inhibitor. This result indicated that PMSF-susceptible proteinase is the main component causing cytopathy to HCE cells by Acanthamoeba. The purified 33 kDa serine proteinase showed strong activity toward HCE cells and extracellular matrix proteins. The purified proteinase from OC-3A, the most virulent strain, demonstrated the highest enzyme activity compared to KA/E2, an ocular isolate, and Neff, a soil isolate. Polyclonal antibodies against the purified 33 kDa serine proteinase inhibit almost completely the proteolytic activity of culture supernatant of Acanthamoeba. In line with these results, the 33 kDa serine proteinase is suggested to play an important role in pathogenesis and to be the main component of virulence factor of Acanthamoeba.
Topics: Acanthamoeba; Acanthamoeba Keratitis; Acanthamoeba castellanii; Animals; Cells, Cultured; Cornea; Encephalitis; Epithelial Cells; Humans; Serine Endopeptidases; Soil; Substrate Specificity; Trophozoites; Virulence; Virulence Factors
PubMed: 17170574
DOI: 10.3347/kjp.2006.44.4.321 -
The Korean Journal of Parasitology Jun 1997Transmission electron microscopy of an Acanthamoeba isolate (KA/L5) from a contact lens case revealed bacterial endosymbionts within cytoplasm of the amoebae. The...
Transmission electron microscopy of an Acanthamoeba isolate (KA/L5) from a contact lens case revealed bacterial endosymbionts within cytoplasm of the amoebae. The Acanthamoeba isolate belonged to the morphological group II. Based on the polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) of 18S ribosomal RNA coding DNA (rDNA), the isolate was identified as A. lugdunensis. Strain typing by isoenzyme analysis using isoelectric focusing (IEF) and mitochondrial (Mt) DNA RFLP revealed that the isolate was closely related with KA/L1, the most predominant type of isolates from contact lens storage cases, KA/E2, a clinical isolate, KA/W4, previously reported to host endosymbionts, and L3a strains of A. lugdunensis. The endosymbionts were similar to those of KA/W4 in aspects that they were randomly distributed in both trophozoites and cysts, and were rod-shaped bacteria measuring approximately 1.38 x 0.50 microns. But the number of endosymbionts per amoeba was significantly lower than that of KA/W4. They were neither limited by phagosomal membranes nor included in lacunaelike structure.
Topics: Acanthamoeba; Animals; Bacteria; Colony Count, Microbial; Contact Lenses; Cytoplasm; Symbiosis
PubMed: 9241987
DOI: 10.3347/kjp.1997.35.2.127