background: acanthamoeba keratitis (ak) is potentially a sight-threatening infection and its treatment is challenging. this is mainly due to presence of resistant cyst form. indeed, cysts are highly resistant to current available drugs. chemical drugs are toxic to human keratocytes. it should also be mentioned that most available anti- acanthamoeba drugs are poorly cysticidal, in iran and world...

Free-living amoebae of the Acanthamoeba species are the causative agent of Acanthamoeba keratitis (AK), a sight-threatening corneal infection that causes severe pain and a characteristic ring-shaped corneal infiltrate. Innate immune responses play an important role in resistance against AK. The aim of this study is to determine if Toll-like receptors (TLRs) on corneal epithelial cells are activ...

The nuclear small subunit ribosomal RNA (Rns) gene has been used in the last decade to establish genotypes of the genus Acanthamoeba based upon these sequences. In some cases direct sequencing of the Rns gene has resulted in mixed sequences, suggesting either a mixed culture of more than one Acanthamoeba strain or the presence of multiple alleles of this gene in a single Acanthamoeba strain. A ...

The first genus- and subgenus-specific fluorescent oligonucleotide probes for in situ staining of Acanthamoeba are described. Sequences of these phylogeny-based probes complement the 18S rRNA and the gene encoding it (18S rDNA). The genus-specific probe (GSP) is a fluorescein-labeled 22-mer specific for Acanthamoeba as shown here by its hybridization to growing trophozoites of all 12 known Acan...

To the Editor: Free-living amebae are ubiquitous protists able to endure extreme temperature and pH in diverse environments (1). In past decades, interest in them increased as causes of infections, such as keratitis (2) and granulomatous encephalitis (3). Acanthamoeba spp. can harbor pathogenic microorganisms as endosymbionts, such as bacteria (e.g., Legionella spp., Pseudomonas aeruginosa, and...

Acanthamoeba keratitis (AK) is a rare but sight-threatening disease caused by pathogenic species of Acanthamoeba. Despite its ubiquitous nature, the incidence of AK is relatively low compared to other forms of infectious keratitis. Although contact lens wear is a major risk factor, exposure to contaminated water and ocular trauma are also associated with AK. Once a patient develops AK the progn...

BACKGROUND Acanthamoeba is a rare cause of encephalitis yet is associated with high mortality. Treatment protocols vary greatly and generally include combination therapy across a wide spectrum of antiinfective classes. CASE DESCRIPTION A 63-year-old male who underwent renal transplantation presented 6 months after transplantation with depressed level of consciousness. Imaging of the head with...

Prolonged culturing of many microorganisms leads to the loss of virulence and a reduction of their infective capacity. However, little is known about the changes in the pathogenic strains of Acanthamoeba after long culture periods. Our study evaluated the effect of prolonged culturing on the invasiveness of different isolates of Acanthamoeba in an in vivo rat model. ATCC strains of Acanthamoeba...

Acanthamoeba species are known to cause 2 well-described entities: (1) granulomatous amoebic encephalitis (GAE), which usually affects immunocompromised hosts, and (2) keratitis, which typically follows trauma associated with contamination of water or contact lenses. Less common manifestations include pneumonitis and a subacute granulomatous dermatitis. We describe a case of granulomatous derma...

Background: Acanthamoeba is a free living ubiquitous protozoa, capable of causing Acanthamoeba keratitis (AK) of eyes and Acanthamoeba meningitis/ meningoencephalitis (AME) of central nervous system in human. Identification of amoeba is possible by a light microscope but, due to its poor resolution power, it is insufficient to distinguish the intimate sub cellular structures. As the resolution ...