Enhanced attachment of acanthamoeba to extended-wear silicone hydrogel contact lenses

Beattie, Tara K.; Tomlinson, Alan; McFadyen, Angus; Seal, D.V.; Grimason, Anthony

doi:10.1016/s0161-6420(02)01971-1

Cited by 63 publications

(63 citation statements)

References 25 publications

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“…36 The greater affinity of Acanthamoeba trophozoites for silicone hydrogel lenses, as compared with conventional hydrogel lenses (P<0.001) was attributed to the attachment characteristics of the polymer of silicon type. 37,38 The attachment of Acanthamoeba trophozoites to different soft contact lens materials, such as polymacon, etafilcon A, lidofilcon A, and bufilcon A varied significantly, with the greatest adherence being observed for lidofilcon A and the least for the etafilcon A lenses. 29 Adherence of cysts and trophozoites was found to be higher for the non-ionic than for the ionic disposable lenses.…”

Section: Attachment Of Acanthamoeba To Contact Lensesmentioning

confidence: 99%

“…P. aeruginosa could significantly enhance Acanthamoeba trophozoite attachment to hydrogel contact lenses, 60 but not to silicone ones. 37 The combination of P. aeruginosa and Acanthamoeba was assumed to be selectively exclusive, causing potentially devastating ocular infections in contact lens wearers. 33,61 Sodium salicylate reduced trophozoite attachment to hydrogel lenses when inoculated with P. aeruginosa.…”

Section: Mechanical Ways Used In Contact Lensmentioning

confidence: 99%

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How Could Contact Lens Wearers Be at Risk of Acanthamoeba Infection? A Review

Ibrahim

Boase

Cree

2009

Journal of Optometry

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Contact lens wear is highly influential on the incidence of ulcerative keratitis worldwide, particularly in developed countries. The association between Acanthamoeba keratitis and contact lens wear is firmly established; it may account for up to 95% of the reported cases. Before the popularisation of soft contact lens wear, Acanthamoeba keratitis was extremely rare. In 2000 it was estimated that the number of contact lens wearers worldwide was about 80 million, out of whom 33 million were in the United States and 90% of them wore hydrogel soft lenses. Contact lens-related problems depend on many factors, such as lens material, wearing modality, lens hygiene, type of lens-caring solution, the degree of compliance of the lens user with lens wear and care procedures, lens overwear, sleeping in lenses, rate of changing lenses, and lens case hygiene. This paper is a thorough review of the literature aiming to highlight the role of one of the main risk factors of infectious keratitis, contact lens wear, and also to show the responsibility of lens users in aggravating this risk. RESUMENLa utilización de lentes de contacto es un factor que influye sumamente en la incidencia de la queratitis ulcerosa, en particular en los países desarrollados. La asociación entre queratitis por Acanthamoeba y el uso de lentes de contacto está firmemente establecida; podría representar aproximadamente hasta un 95% de los casos registrados. Antes de la popularización del uso de lentes de contacto, la queratitis por Acanthamoeba era muy poco frecuente. En el año 2000 se estimó que, a nivel mundial, había unos 80 millones de usuarios de lentes de contacto, de los cuales 33 millones residían en los Estados Unidos y, de ellos, el 90% utilizaban lentes de contacto blandas de hidrogel. Los problemas derivados del uso de lentes de contacto dependen de otros muchos factores, como el material del que está hecha la lente, la modalidad de uso, las medidas de higiene empleadas, el tipo de solución utilizada para la limpieza y el mantenimiento de la lente, el grado de cumplimiento terapéutico del usuario de las lentes respecto a su utilización y a su limpieza/mantenimiento, el uso de las lentes durante periodos excesivamente prolongados, el dormir con las lentes de contacto puestas, la frecuencia con la que el usuario se cambia de lentes y la limpieza de la funda de las lentes de contacto. Este artículo presenta una revisión minuciosa de la literatura, con el objetivo de resaltar el papel de uno de los principales factores de riesgo de desarrollo de queratitis infeccionsa, como es el uso de lentes de contacto, y con el fin de poner de relieve que el propio usuario de las lentes es, en ocasiones, el responsable de agravar este riesgo. (J Optom 2009;2:60-66 ©2009 Consejo General de Colegios de Ópticos-Optometristas de España) PALABRAS CLAVE: Acanthamoeba; queratitis; lentes de contacto; usuario de lentes de contacto; uso excesivo de las lentes de contacto.

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Section: Attachment Of Acanthamoeba To Contact Lensesmentioning

confidence: 99%

Section: Mechanical Ways Used In Contact Lensmentioning

confidence: 99%

How Could Contact Lens Wearers Be at Risk of Acanthamoeba Infection? A Review

Ibrahim

Boase

Cree

2009

Journal of Optometry

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“…42 Acanthamoeba has been isolated before from seawater, ocean sediment, chlorinated swimming pools (which can contain up to 10 4 amoebae per litre as they are resistant to chlorine) and a variety of other types of water 43 as well as from sewage outfalls. 30 In addition, a relationship between the presence of Acanthamoeba and faecal indicator bacteria has been found in samples of ocean sediment.…”

Section: Molecular Epidemiologymentioning

confidence: 99%

Acanthamoeba keratitis update—incidence, molecular epidemiology and new drugs for treatment

Seal

2003

Eye

175

135

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“…In developed countries, AK infections are usually associated with contact lens wear. Improper sterilization procedures have been identified as the cause of a large percentage of such AK infections (2,22,25). In developing nations, AK infections are not generally associated with contact lens wear; by contrast, most cases are the result of ocular trauma (6,23).…”

mentioning

confidence: 99%

Identification and Distribution of Acanthamoeba Species Genotypes Associated with Nonkeratitis Infections

Booton¹,

et al. 2005

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Acanthamoeba is a free-living protozoan genus found in a wide variety of natural habitats, including water, soil, and air. Pathogenic isolates of Acanthamoeba are medically relevant as the causative agent of sight-threatening Acanthamoeba keratitis (AK), serious infections of other organs, and fatal granulomatous amebic encephalitis. Previous work employing DNA sequences of nuclear and mitochondrial small-subunit rRNA genes (SSU rRNA genes) determined the genotypic diversity of Acanthamoeba and found that many named species of Acanthamoeba are associated with particular genotypes. These studies also concluded that nearly all AK infections result from a single molecular genotype: T4. Here, we asked whether Acanthamoeba clinical isolates from non-AK infections are also associated with particular genotypes. DNA sequence determination of nuclear SSU rRNA genes was employed for genotypic identification of 29 isolates of Acanthamoeba from non-AK infections. Sequence analysis demonstrates that T4 is the predominant genotype in non-AK infections, including those in brain, cerebrospinal fluid, nasal passages, skin, and lung. Rare genotypes (T1, T10, and T12) have been isolated from brain infections. We conclude that genotype T4 is the primary genotype in non-AK Acanthamoeba infections, as was the case in AK infections. However, the genotypes that were isolated from brains have not been observed in environmental isolates of Acanthamoeba, and their natural ecological niche is unknown.The genus Acanthamoeba is a group of nearly 25 named species that has a worldwide distribution. Members of Acanthamoeba are naked (i.e., lacking tests, walls, or tecta with openings), free-living amebae that inhabit a wide range of natural ecological niches, including fresh and brackish water, beach sand, soil, air, etc. (4, 13, 16, 17). Acanthamoeba also has been isolated from humans and animals (16,18). In addition to its natural distribution, Acanthamoeba can be opportunistically pathogenic, being identified as the causative agent of a painful and sight-threatening infection of the cornea, Acanthamoeba keratitis (AK) (22). These infections can occur in otherwise healthy, nonimmunocompromised individuals. In developed countries, AK infections are usually associated with contact lens wear. Improper sterilization procedures have been identified as the cause of a large percentage of such AK infections (2, 22, 25). In developing nations, AK infections are not generally associated with contact lens wear; by contrast, most cases are the result of ocular trauma (6, 23).Acanthamoeba is also responsible for life threatening infections in patients with immunodeficiency disease. These include documented infections of the skin, nasal passages, lung, and brain (16,17,18,19). In the brain, Acanthamoeba causes a severe encephalitis termed granulomatous amebic encephalitis, which is nearly always fatal (18). Variations in the pathogenicity of different Acanthamoeba strains have been recognized in laboratory studies, but the relevance of these results to hum...

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Enhanced attachment of acanthamoeba to extended-wear silicone hydrogel contact lenses

Cited by 63 publications

References 25 publications

How Could Contact Lens Wearers Be at Risk of Acanthamoeba Infection? A Review

How Could Contact Lens Wearers Be at Risk of Acanthamoeba Infection? A Review

Acanthamoeba keratitis update—incidence, molecular epidemiology and new drugs for treatment

Identification and Distribution of Acanthamoeba Species Genotypes Associated with Nonkeratitis Infections

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