Free-living amoebae of the genus Acanthamoeba are causal agents of a severe sight-threatening infection of the cornea known as Acanthamoeba keratitis. Moreover, the number of reported cases worldwide is increasing year after year, mostly in contact lens wearers, although cases have also been reported in non-contact lens wearers. Interestingly, Acanthamoeba keratitis has remained significant, de...

The majority of the keratitis-causing Acanthamoeba isolates are genotype T4. In an attempt to determine whether predominance of T4 isolates in Acanthamoeba keratitis is due to greater virulence or greater prevalence of this genotype, Acanthamoeba genotypes were determined for 13 keratitis isolates and 12 environmental isolates from Iran. Among 13 clinical isolates, eight (61.5%) belonged to T4,...

PURPOSE To produce animal models of Acanthamoeba keratitis and to evaluate the advantages and adaptation range of each of the three methods employed. MATERIALS AND METHODS Mice and Wistar rats in three groups of 15 rats and 15 mice each were used to establish the models. Right corneas in group A were scratched and challenged with Acanthamoeba. Those in group B were scratched and covered with ...

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 acr...

Members of the free-living amebic genera Acanthamoeba, Balamuthia, and Naegleria are known to cause infections of the central nervous system (CNS) of humans and other animals. Several species of Acanthamoeba cause an insidious and chronic disease, granulomatous amebic encephalitis (GAE), principally in immunocompromised hosts including persons infected with HIV/AIDS. Additionally, Acanthamoeba ...

Acanthamoeba are typically identified in the laboratory using culture and microscopic observation. In this paper we describe the isolation and specificity of antibody fragments that can be used for the identification of Acanthamoeba. A phage library expressing a large repertoire (approx. 5 x 10(9)) of antibody fragments was used to generate two libraries one enriched for bacteriophage that exhi...

A comprehensive survey assessing the presence of Acanthamoeba was conducted on 50 samples from water sources in parks and public squares from 22 municipal districts of Tehran, Iran. The prevalence and genotypes of Acanthamoeba were determined by PCR and the PCR fragments of ribosomal RNA genes sequenced. Sixteen (32%) samples were positive for Acanthamoeba spp. Sequence analysis revealed that t...

Acanthamoeba castellanii is a free-living protozoan pathogen capable of causing a blinding keratitis and fatal granulomatous encephalitis. Current treatment generally involves an hourly application of polyhexamethylene biguanide (PHMB) over a period of several days but this is not entirely effective against all strains/isolates. The tolerance mechanisms of PHMB in Acanthamoeba cells remain uncl...

Species of Acanthamoeba have been traditionally described using morphology (primarily cyst structure), or cytology of nuclear division (used by Pussard and Pons, 1977). Twenty-plus putative species were proposed based on such criteria. Morphology, however, is often plastic, dependent upon culture conditions. DNA sequences of the nuclear small subunit (18S) rRNA that can be used for the study of...

Six pathogenic strains of Naegleria fowleri, two of Acanthamoeba castellanii, and three of Acanthamoeba polyphaga were tested in vitro for susceptibility to a variety of potentially useful therapeutic agents. Minimal motility inhibitory concentrations and minimal inhibitory concentrations were determined by a technique of subculturing pure clones of amoebae in plastic tissue culture chamber sli...