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Acanthamoeba keratitis

David T Truong, Minh-Thuy Bui, H Dwight Cavanagh
PURPOSE: To review the epidemiology, risk factors, microbiologic spectrum, and treatment of microbial keratitis during a 5-year period at an urban public hospital in comparison with an adjacent private university practice. METHODS: Retrospective chart review in the 5-year interval, 2009 through 2014. Primary outcome measures included patient age at presentation, best-corrected visual acuity (BCVA), risk factors, culture and sensitivities, treatment, and complication occurrence...
October 7, 2016: Eye & Contact Lens
Ali Kal, Mustafa Ilker Toker, Serpil Kaya
PURPOSE: The aim of this study was to compare the effects of widely used multipurpose contact lens solutions against Staphylococcus aureus and Pseudomonas aeruginosa, in addition to cystic and trophozoite forms of Acanthamoeba castellanii and A. polyphaga, that cause microbial keratitis. METHODS: Three multipurpose solutions were tested: SOLO-care, ReNu, and Opti-Free Express. The test solutions were challenged with P. aeruginosa (ATCC 27853) and S. aureus (ATCC 2913) based on the ISO stand-alone and regiment test procedure for disinfecting products, A...
October 13, 2016: International Ophthalmology
Federica Del Chierico, David Di Cave, Cristel Accardi, Maristella Santoro, Andrea Masotti, Rossella D'Alfonso, Federica Berrilli, Andrea Urbani, Lorenza Putignani
Over the years, the potential pathogenicity of Acanthamoeba for humans and animals has gained increasing attention from the scientific community. More than 24 species belong to this genus, however only some of them are causative agents of keratitis and encephalitis in humans. Due to technical difficulties in diagnosis, these infections are likely to be under-detected. The introduction of 18S rDNA amplification for the identification of Acanthamoeba has dramatically enhanced diagnosis performances, but the attestation of genotyping requires supplementary sequencing-based procedures...
September 20, 2016: Experimental Parasitology
Azar Shokri, Shahabeddin Sarvi, Ahmad Daryani, Mehdi Sharif
Acanthamoeba, a free-living amoeba, is widely distributed in the environment, water sources, soil, dust, and air. It can cause keratitis in contact lens wearers with poor hygiene and also fatal granulomatous amebic encephalitis (GAE) in immunocompromised hosts. The aim of this study was to gain some insights into the distribution and genotypes of the potentially pathogenic species of Acanthamoeba present in water sources in north of Iran. Total 43 Acanthamoeba species were isolated from 77 water samples taken from different water sources within the Mazandaran province in Northern Iran (Sari city and suburbs)...
August 2016: Korean Journal of Parasitology
Ruqaiyyah Siddiqui, Yousuf Aqeel, Naveed Ahmed Khan
For the past several decades, there has been little improvement in the morbidity and mortality associated with Acanthamoeba keratitis and Acanthamoeba encephalitis respectively. The discovery of a plethora of anti-Acanthamoebic compound(s) has not yielded effective marketed chemotherapeutics. The development of novel anti-Acanthamoebic chemotherapies of translational value and a lack of interest by the pharmaceutical industry has been disappointing. On the other hand, the market for contact lenses/contact lens disinfectants is a multibillion-dollar industry and has been successful and profitable...
September 6, 2016: Antimicrobial Agents and Chemotherapy
Andrew Purssell, Rachel Lau, Andrea K Boggild
BACKGROUND:  Amoebic keratitis is a potentially blinding eye infection caused by ubiquitous, free-living, environmental acanthamoebae, which are known to harbor bacterial endosymbionts. A Chlamydia-like endosymbiont has previously enhanced Acanthamoeba virulence in vitro. We investigated the potential effect of Acanthamoeba-endosymbiont coinfection in a human corneal tissue model representing clinical amoebic keratitis infection. METHODS:  Environmental and corneal Acanthamoeba isolates from the American Type Culture Collection were screened for endosymbionts by amplifying and sequencing bacterial 16S as well as Chlamydiales-specific DNA...
August 30, 2016: Journal of Infectious Diseases
Erika Orosz, Ágnes Farkas, István Kucsera
Acanthamoeba species are free-living amebae that can be found in almost every range of environments. Within this genus, numerous species are recognized as human pathogens, potentially causing Acanthamoeba keratitis (AK). AK is a corneal disease that is predominantly associated with contact lens use, the epidemiology of which is related to the specific genotype of Acanthamoeba. This study reports seven (7/16; 43.75%) positive cases. Detection of Acanthamoeba in corneal scrapings is based on cultivation and polymerase chain reaction (PCR) combined with the molecular taxonomic identification method...
September 2016: Acta Microbiologica et Immunologica Hungarica
S Reichart-Peter, K Manousaridis, H Dirschmid, S Mennel
A 31-year-old woman presented with mild keratitis of her left eye. The use of daily disposable contact lenses, regularly rinsed with tap water, and the development of perineural corneal infiltrates resulted in the clinical suspicion of infection with Acanthamoeba. Corneal epithelial scraping probe for polymerase chain reaction on Acanthamoeba confirmed the clinical diagnosis. Although the treatment was limited to low-dose propamidine monotherapy because of reduced tolerability, the keratitis healed with almost no scarring after 13 months of consequent medication...
August 24, 2016: Der Ophthalmologe: Zeitschrift der Deutschen Ophthalmologischen Gesellschaft
Mehmet Karakuş, Mehmet Aykur, Yusuf Özbel, Seray Töz, Hande Dağcı
Acanthamoeba is one of the most common free-living amoebas (FLA) that present in environment. In humans, Acanthamoeba can cause an infection of the eye termed Acanthamoeba keratitis, which mostly occurs in contact lens wearers. In the present study, we aimed to screen the presence of Acanthamoeba DNA in stray dogs using previously collected conjunctival swab samples in a hyper-endemic area for canine leishmaniasis. Totally, 184 dogs were included in the study and 27 of them (14.6%) were found positive for Acanthamoeba according to the 18s rRNA gene sequencing...
August 18, 2016: Acta Tropica
Jaya D Chidambaram, Namperumalsamy V Prajna, Natasha L Larke, Srikanthi Palepu, Shruti Lanjewar, Manisha Shah, Shanmugam Elakkiya, Prajna Lalitha, Nicole Carnt, Minna H Vesaluoma, Melanie Mason, Scott Hau, Matthew J Burton
PURPOSE: To determine the diagnostic accuracy of in vivo confocal microscopy (IVCM) for moderate to severe microbial keratitis (MK). DESIGN: Double-masked prospective cohort study. PARTICIPANTS: Consecutive patients presenting to Aravind Eye Hospital, Madurai, India, between February 2012 and February 2013 with MK (diameter ≥3 mm, excluding descemetocele, perforation, or herpetic keratitis). METHODS: Following examination, the corneal ulcer was scanned by IVCM (HRT3/RCM, Heidelberg Engineering, Heidelberg, Germany)...
August 15, 2016: Ophthalmology
Agnieszka Wojtkowiak-Giera, Monika Derda, Agnieszka Kolasa-Wołosiuk, Edward Hadaś, Danuta Kosik-Bogacka, Piotr Solarczyk, Paweł P Jagodziński, Elżbieta Wandurska-Nowak
The Toll-like receptors (TLRs) of the innate immune system play an important role in the recognition of pathogens such as bacteria, viruses, fungi, and parasites. In this study, we examined the changes in the level of expression of TLR2 and TLR4 mRNA and protein in the brains of mice infected with Acanthamoeba spp. The Acanthamoeba strains were isolated from a patient with Acanthamoeba keratitis (AK) (Ac55) and Malta Lake (Ac43). In the brain isolated from mice at 2 days post-infection (dpi) with Acanthamoeba strains Ac55 and Ac43, mRNAs for TLR2 and TLR4 were significantly more strongly expressed in comparison with the uninfected mice...
November 2016: Parasitology Research
E M Messmer
Histopathological evaluation of ocular tissues is important in differentiating between infectious and autoimmune disease. Inflammation, necrosis and keratolysis are common to most forms of keratitis. Histopathology can be of great help in identifying the causative organism, establishing a final diagnosis and/or managing the patient with herpes simplex virus keratitis, mycotic keratitis, acanthamoeba keratitis or microsporidia keratoconjunctivitis. Important pathogenetic knowledge with therapeutic relevance has been gained from histopathological studies in nummular keratitis after epidemic keratoconjunctivitis and atopic keratoconjunctivitis...
July 2016: Klinische Monatsblätter Für Augenheilkunde
Yukihiro Matsumoto, Osama M A Ibrahim, Takashi Kojima, Tais H Wakamatsu, Murat Dogru, Kazuo Tsubota
PURPOSE: To determine the killing effect of microwave irradiation on Acanthamoeba polyphaga. METHODS: The trophozoites and cysts of A. polyphaga both in water and on agar were exposed to microwave irradiation with a capacity of 750 W for 0, 1, 3, 5, and 10 minutes, respectively. Furthermore, the trophozoites and cysts of A. polyphaga in water were exposed to microwave irradiation with a capacity of 100, 300, and 500 W for 1 minute, respectively. RESULTS: The trophozoites and cysts of A...
November 2016: Cornea
Carolina Wagner, María Reyes-Batlle, Aurora Hernán, Elsy Rojas, Gladymar Pérez, Atteneri López-Arencibia, Ines Sifaoui, Enrique Martínez-Carretero, José E Piñero, Basilio Valladares, Jacob Lorenzo-Morales
Pathogenic strains of Acanthamoeba are causative agents of keratitis and encephalitis that often may end fatal in humans and other animals. In the present study, twenty-seven soil samples were collected in the Bolivar State in Venezuela and checked for the presence of Acanthamoeba. Samples were cultivated onto 2% non-nutrient agar plates seeded with a layer of heat killed E. coli. Amplification by PCR and sequencing of the DF3 region of the 18S rDNA of Acanthamoeba was carried out in order to confirm morphological identification of the amoebae...
September 1, 2016: Acta Parasitologica
Fatemeh Memari, Maryam Niyyati, Jacob Lorenzo-Morales, Zaynab Jonaydi
Acanthamoeba spp. is an opportunistic protozoan parasite which is the causative agent of granulomatous amoebic encephalitis (GAE) and Acanthamoeba keratitis (AK). GAE usually occurs in immunocompromised patients which in most cases is fatal. The present study was conducted to determine the genotypes of Acanthamoeba isolated from patients with compromised immunological status. For this purpose, 90 samples from the oral cavity of these individuals were collected in different hospitals of Tehran, Iran using sterile cotton swabs...
September 1, 2016: Acta Parasitologica
Alemao G Carpinteyro Sánchez, Veridiana Gomes Virginio, Vinicius José Maschio, Henrique Bunselmeyer Ferreira, Marilise Brittes Rott
Acanthamoeba spp. are free-living protists widely distributed in environment, able to cause keratitis, encephalitis and skin lesions in humans and animals. Acanthamoeba spp. exist in two forms: an infective trophozoite and a dormant cyst. Several factors contribute to the pathogenesis of Acanthamoeba spp. The parasite adhesion to the host cell is the primary step for infection and is mediated by a mannose binding-protein, expressed in the surface and considered the main pathogenicity factor in Acanthamoeba spp...
October 2016: Parasitology
Mohammed Essa Marghany Tolba, Enas Abdelhameed Mahmoud Huseein, Haiam Mohamed Mahmoud Farrag, Hanan El Deek Mohamed, Seiki Kobayashi, Jun Suzuki, Tarek Ahmed Mohamed Ali, Sumio Sugano
BACKGROUND: Free-living amoebae are present worldwide. They can survive in different environment causing human diseases in some instances. Acanthamoeba sp. is known for causing sight-threatening keratitis in humans. Free-living amoeba keratitis is more common in developing countries. Amoebae of family Vahlkampfiidae are rarely reported to cause such affections. A new genus, Allovahlkampfia spelaea was recently identified from caves with no data about pathogenicity in humans. We tried to identify the causative free-living amoeba in a case of keratitis in an Egyptian patient using morphological and molecular techniques...
July 2016: PLoS Neglected Tropical Diseases
Soundaram MeenakshiSundaram, Aalia Rasool Sufi, N Venkatesh Prajna, Jeremy D Keenan
IMPORTANCE: In vivo confocal microscopy could be useful in cases of fungal or acanthamoeba keratitis to determine the depth of infectious elements, but its accuracy in determining corneal thickness relative to more traditional techniques has not been well characterized. OBSERVATIONS: In this cross-sectional observational case series, central corneal thickness was determined by in vivo confocal microscopy, ultrasonic pachymetry, and Scheimpflug topography in 47 normal corneas and 23 keratoconic corneas from November 2014 to July 2015...
September 1, 2016: JAMA Ophthalmology
Tanitta Sampaotong, Usa Lek-Uthai, Jantima Roongruangchai, Kosol Roongruangchai
Acanthamoeba is a free-living opportunistic protozoan parasite that is found in diverse environments. It can cause keratitis, mostly related to inappropriate use of contact lenses, as well as life threatening diseases including encephalitis, disseminated sinusitis, and skin ulcers. This study investigated morphological changes and fine structures of the cyst form of Acanthamoeba spp. after treatment with effective microorganisms (EM™) using light and scanning electron microscopies. Acanthamoeba cysts treated with 1:2, 1:4, 1:6, and undiluted EM™ showed higher percentages of non-viable cysts than those treated with 1:8, 1:10, 1:100, 1:200, and 1:400 EM™ and at 5 days post-treatment developed from cystic stage to trophozoite stage...
June 2016: Journal of Parasitic Diseases: Official Organ of the Indian Society for Parasitology
Sangita P Patel, Jamie L Schaefer, Ryan Jaber, Joyce Paterson, Weiguo Liu, Federico Gonzalez-Fernandez
Purpose. Acanthamoeba keratitis remains a difficult diagnosis despite advances in genetic and imaging technologies. The purpose of this paper is to highlight the utility of cytology smears for diagnosis of Acanthamoeba keratitis. Methods. This is a case study of the diagnostic course for a patient with suspected Acanthamoeba keratitis. Results. A 40-year-old male with poor contact lens hygiene presented with severe left eye pain. Slit lamp examination showed two peripheral ring infiltrates without an epithelial defect...
2016: Case Reports in Ophthalmological Medicine
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