Contact lenses contamination by Acanthamoeba spp. in Upper Egypt (original) (raw)
Related papers
Acanthamoeba keratitis due to Acanthamoeba genotype T4 in a non-contact-lens wearer in Turkey
Parasitology Research, 2007
An otherwise healthy 22-year-old man presented with Acanthamoeba keratitis (AK) in the right eye. He was not a contact lens wearer and had no history of corneal trauma. The Acanthamoeba strain isolated from a corneal scraping was identified as morphological group II and genotype T4. Three more Acanthamoeba strains isolated from sites of possible human contact with acanthamoebae in the same geographical region, including a lens storage case, tap water and soil, were subjected to morphological and molecular biological identification. Whereas the strain from tap water also exhibited genotype T4, the two other isolates were identified as morphological group I and genotype T9. To the best of our knowledge, this is the first study identifying an AK-causing Acanthamoeba strain in Turkey and the first isolation of genotype T9 in this country.
Journal of clinical microbiology, 2000
Eighteen cases of Acanthamoeba-associated keratitis among contact lens wearers seen at the Department of Ophthalmology, Karl-Franzens-University, Graz, Austria, between 1996 and 1999 are reviewed. The amoebae were proven to be the causative agents in three patients. The aim of our study was to discriminate between clinically relevant and nonrelevant isolates and to assess the relatedness of the isolates to published strains. Altogether, 20 strains of free-living amoebae, including 15 Acanthamoeba strains, 3 Vahlkampfia strains, and 2 Hartmannella strains, were isolated from clinical specimens. The virulent Acanthamoeba strains were identified as A. polyphaga and two strains of A. hatchetti. To our knowledge this is the first determination of keratitis-causing Acanthamoeba strains in Austria. Clinically relevant isolates differed markedly from nonrelevant isolates with respect to their physiological properties. 18S ribosomal DNA sequence types were determined for the three physiologi...
Isolation and genotyping of Acanthamoeba strains from corneal infections in Italy
2010
Acanthamoeba keratitis (AK) is a corneal disease caused by members of a genus of free-living amoebae and is associated predominantly with contact lens (CL) use. This study reports 16 cases of culture-proven AK diagnosed in northern Italy. Genotype identification was carried out with a PCR assay based on sequence analysis of the 18S rRNA gene, and sensitivity and specificity were evaluated in comparison with traditional parasitological techniques. A 405 bp region of the 18S rRNA gene (ASA.S1) including diagnostic fragment 3 (DF3) was amplified using the genusspecific primers JDP1 and JDP2. Genotype assignment was based on phenetic analysis of the ASA.S1 subset of the nuclear small-subunit rRNA gene sequence excluding the highly variable DF3 region. Phylogenetic analysis was also performed on the sequences obtained. All patients complained of monolateral infection; 11 (68.75%) admitted improper CL disinfection. In 14/16 (87.5 %) subjects, corneal scrapings were stained with calcofluor white and haematoxylin and eosin and, in ten cases (62.5 %), microscopy was positive for Acanthamoeba cysts. In vitro culture on 3 % non-nutrient agar plates was obtained in all cases (100 %), whereas cloning and axenic growth were positive for 14 amoebic stocks (87.5 %). PCR analysis had 100 % sensitivity and specificity compared with in vitro axenic culture, showing positive amplification from 15 isolates. All Acanthamoeba strains belonged to the T4 genotype, the main AK-related genotype worldwide. These results confirmed the importance of a complete diagnostic protocol, including a PCR assay, for the clinical diagnosis of AK on biological samples. Genotyping allowed inclusion of all isolates in the T4 group, thus demonstrating the prevalence of this genotype in northern Italy.
Isolation and Genotyping of Acanthamoeba Strains from Corneal Scraps
2014
Purpose: To determine the prevalence and genotype of Acanthamoeba keratitis (AK) in patients referred to Farabi referral eye center Methods: In this study, corneal scraping specimens that obtained from keratitis patients examined for Acanthamoeba and its genotype identifications. Direct smears, cultivation in non-nutrient agar (NNA) followed by PCR were chosen as the basic diagnostic methods. The positive patients checked by confocal microscopy. For genotypic identifications of isolates from keratitis patients, DF3 region of rRNA gene amplified in PCR. Results: Five clinical specimens (5.6%) out of 89 collected samples showed positive by culture and PCR analysis. Then the results compared with confocal microscopy and all five patients confirmed as AK. The statistical analysis showed significant relation between infection with Acanthamoeba and wearing contact lenses (p=0.001). A logistic regression analysis showed, there is an inverse weak statistical relation between age and infecti...
Isolation of Acanthamoeba genotype T4 from a non-contact lens wearer from the Philippines
Tropical Medicine and Health, 2014
We report the case of a 76-year old Filipino male who presented with pain, redness, and blurring of vision of the right eye. Corneal scraping was done and sent to the St. Luke's Research and Biotechnology Group for detection and identification of the infectious agent. Morphological detection was performed by allowing the organism from the scraping to grow in 1.5% non-nutrient agar plate with heat-killed E. coli. Trophozoites with acanthopodia and double-walled cysts characteristic of Acanthamoeba were observed within the first and second week of observations, respectively. Molecular identification of the amoebae at the genus level based on the presence of Acanthamoeba-specific amplimer S1, ASA.S1 confirmed the morphological identification. Genotyping through sequence revealed that the organism belonged to T4, which is the genotype commonly present in the eye of keratitis patients.
Contact Lens-Associated Acanthamoeba Keratitis in Iran
Acanthamoeba keratitis is a vision-threatening infection caused by pathogenic species of the genus Acanthamoeba. In this study, 13 Acanthamoeba keratitis cases were diagnosed among 52 keratitis patients. To confirm the identity of Acanthamoeba at the genus level, a PCR-based method was used, and their pathogenic potential was determined using in vitro cytotoxicity assays on human corneal epithelial cells. Twelve (92.3%) of Acanthamoeba keratitis patients were contact lens wearers; among them eleven (91.7%) wore soft contact lenses. 11/13 (84.6%) isolates were axenised in liquid culture medium, of which 10 (90.9%) isolates disrupted corneal cells. Nine (69.2%) isolates showed Acanthamoeba sp. group II, and four (30.8%) showed group III morphology. To our knowledge this is the first report of determination of Acanthamoeba pathogenicity in Iran. This study confirms the importance of determination of pathogenic potential of Acanthamoeba isolates for clinical purposes.
Scandinavian Journal of Infectious Diseases, 2010
The genus Acanthamoeba represents free-living amoebae typically widespread in soil and water. It consists of more than 20 known species representing 15 genotypes of different pathogenicity and virulence. The aim of the study was the genotypic characterization of Acanthamoeba spp. isolated from human keratitis cases in Sweden. Thirteen amoeba isolates obtained from contact lens users with suspected Acanthamoeba keratitis (AK) were subjected to polymerase chain reaction amplification and subsequent sequencing of the SSU rRNA gene fragment. Sequence analysis identified 4 different genotypes in the studied material. The majority of samples (92%) represented sequences of T3, T4 and T11, all belonging to a cluster of related genotypes frequently described in AK cases. Similar to other reports, genotype T4 was the most common finding in our material (77% of samples). Interestingly, an uncommon genotype, T15, mostly reported from environmental sources, was found in a sample from a patient suffering from a protracted keratitis.
Acanthamoeba T4 genotype associeted with keratitis infection in Tunisia 2012
Acanthamoeba keratitis (AK) is a sight-threatening infection. We report five cases of AK diagnosed from 2005 to 2009 in the Laboratory of Parasitology-Mycology at Habib Bourguiba Sfax Hospital, Tunisia. All were associated with improper care of contact lenses (rinsing of contact lenses with tap water and inappropriate cleaning) and lens storage. The patients displayed different clinical presentations: corneal inflammation, corneal ulceration, and corneal abscess. The diagnosis was made after direct examination, culture, and polymerase chain reaction amplification with specific primers. The genotype classification was based on the highly variable DF3 region in the 18S rRNA gene. This is the first study characterizing Acanthamoeba genotype in Tunisia and North Africa. All Acanthamoeba isolates were associated to the T4 genotype. Three different DF3 sequence types were related to AK infections T4/10, T4/15, and T4/16.
Journal of the Egyptian Society of Parasitology, 2019
Acanthamoeba genus is a medically important free living amoeba causing serious humans infections. Amoebic keratitis (AK) is a sight threatening infection of cornea caused by Acanthamoeba pathogenic genotypes, which prevalence remarkably increased in developed countries. The study compared different methods for diagnosing AK and identified Acanthamoeba genotypes by molecular examination in contact lens wearers (CLWs). Patients were 79 clinical corneal swaps (CS) and 15 samples from contact lens storage cases (CLSC). Clinical CSs were divided into four groups; GI: 20 patients suffering from chronic corneal ulcers, GII: 15 patients with traumatic ulcers, GIII: 24symptomatic CLWs and GIV: 20asymptomatic control individuals. CLSC were provided from apparently healthy asymptomatic CLWs (15). Swabs and solution samples were underwent microscopic and staining examination, cultivation on non-nutrient agar (NNA) plates and PCR molecular analysis. Sequencing and genotyping of PCR-positive samples were performed. The results showed that Acanthamoeba parasites were detected in 3.8% of CS and 6.7% of CLSC samples. The highest significantly positive results were by culture (3.8%) followed by Giemsa and trichrome stains (2.5%) and lastly direct microscopy (1.3%) of CS samples. Only one positive sample (6.7%) was detected in CLSC by all methods, but without statistical significance. Sensitivity of PCR compared to culture was 25%. Acanthamoeba parasites in CS were from subgroup II with 12.5% detection rate in CLWs, but the positive case from CLSC was from subgroup I with 6.7% detection rate. This study confirmed different risk factors in association with AK in CLWs. Genotype determination for Acanthamoeba positive case by PCR revealed homology with Acanthamoeba genotype T9 isolate ICS20.
Acanthamoeba T4 genotype associated with keratitis infection in Tunisia
Acanthamoeba keratitis (AK) is a sight-threatening infection. We report five cases of AK diagnosed from 2005 to 2009 in the Laboratory of Parasitology-Mycology at Habib Bourguiba Sfax Hospital, Tunisia. All were associated with improper care of contact lenses (rinsing of contact lenses with tap water and inappropriate cleaning) and lens storage. The patients displayed different clinical presentations: corneal inflammation, corneal ulceration, and corneal abscess. The diagnosis was made after direct examination, culture, and polymerase chain reaction amplification with specific primers. The genotype classification was based on the highly variable DF3 region in the 18S rRNA gene. This is the first study characterizing Acanthamoeba genotype in Tunisia and North Africa. All Acanthamoeba isolates were associated to the T4 genotype. Three different DF3 sequence types were related to AK infections T4/10, T4/15, and T4/16.