Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022568 (keratitis)
 5,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Microbial keratitis has been studied in Hong Kong as a representative sub-tropical climate of south China. An 18-month investigation in 1997/98 of 223 cases of ulcerative keratitis (presumed microbial) was conducted in the 2 million population of Shatin and Kowloon at the Prince of Wales and Hong Kong Eye Hospitals respectively with comprehensive microbiology. A case-control study was pursued at the same time between 45 contact-lens wearers (CLW) developing microbial keratitis and 135 lens-wearing volunteers matched for age, sex, educational status and visual acuity. Home water supplies were sampled for Acanthamoeba. Previous ocular surface disease and trauma (preventable by wearing goggles for grinding) were common predisposing causes while cosmetic wear of contact lenses was responsible for 26% of cases overall. Pseudomonas aeruginosa was the commonest bacterium isolated, from both CLW and non-CLW, with infection being acquired within the community. These 28 pseudomonads remained fully sensitive to the third-generation cephalosporins, aminoglycosides and quinolone antibiotics, which is very encouraging. Fungi were isolated, predominantly Fusarium sp., but less commonly than expected. A fungal/bacterial ratio was obtained of 1/17, while in comparison, the expected ratio for a tropical climate ranges from 1/5 (Singapore) to 1/2 (South India). Acanthamoeba was the second commonest microbe isolated from keratitis of CLW. The domestic water environment of 8% of homes of both patients and controls wearing contact lenses was colonized with Acanthamoeba. Lack of hygiene, use of tap water for storing lenses, failure to air-dry lens-storage cases or use of one-step hydrogen peroxide disinfectant were identified as risk factors for keratitis in CLW. The study results commend use of multipurpose solutions by CLW in Hong Kong to achieve the lowest expected rates of infection.
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PMID:Microbial keratitis in Hong Kong: relationship to climate, environment and contact-lens disinfection. 1157 73

Contact lens-related infectious keratitis is a potentially sight-threatening complication. Bacterial keratitis, mostly due to Gram-negative bacteria, is associated with poor lens hygiene, overnight wear, and contaminated lens care solutions. Contamination of the lens storage case may cause fungal keratitis. Acanthamoeba infection is related to the use of tap water or swimming while wearing soft lenses. Viruses are of less concern among contact lens wearers. Possible transmission of Creutzfeldt-Jakob disease by multi-patient trial lenses must be taken in account. To minimize these risk factors, regulations are applied at various levels: CE marking of contact lenses and care products as they are medical devices; contact lens fitting only by health care professionals; distribution of contact lenses by opticians and lens care solutions by opticians and pharmacists; hygienic management of trial lenses following official recommendations. Contact lens-related keratitis must be reported to health care Authorities.
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PMID:[Rules and regulations concerning contact lens-related infection]. 1517 56

We present the case report of the first identification of Acanthamoeba as a causative agent of keratitis in the Slovak Republic. For the first time, Acanthamoeba sp. Group III was isolated from a 53-year-old patient with keratitis, which was manifested after an injury of the right eye. A delayed visit to a physician as well as a late diagnosis of the illness led to the advanced stage of eye disease. As the treatment with itraconazol and cornea transplantation showed no result, enucleation of the eye was decided. Acanthamoeba ludgunensis was also the causative agent of keratitis in a 39-year-old patient wearing contact lenses. His complaints occurred a month after bathing in a thermal swimming pool. The symptoms presented in the left eye were those of herpetic keratitis, and led to a cloudy cornea with circular infliltrate and poor vision. A prompt clinical and laboratory diagnosis, along with treatment with propamidine-isetionate resulted in a significant improvement of the eye condition. Contact lenses were probably related to another case of Acanthamoeba keratitis. The patient, a 15-year-old girl, kept wearing contact lenses during bathing in various swimming pools and in the sea; her contact lenses were also regularly washed under tap water. Due to the fact that cysts of Acanthamoeba sp. group II were found in the contact lens solution, this is presumed to be the source of the eye infection.
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PMID:First cases of Acanthamoeba keratitis in Slovakia. 1562 46

In a previous study, we reported on the contamination rate of free living amoeba, including Acanthamoeba, isolated from contact lens storage cases (CLSC) and domestic tap water in Korea. In an effort to evaluate the potential kerato-pathogenicity of 5 isolates from CLSC and 17 isolates from domestic tap water, we have conducted an investigation into the morphological features, mitochondrial DNA (mtDNA) restriction fragment length polymorphism (RFLP) phenotypes, 18S rDNA sequences, and drug sensitivities of these isolates, and have compared the results with those of 20 amoebic keratitis (AK) isolates from Korea, as well as 14 reference strains. Cysts from 22 isolates obtained from CLSC and domestic tap water showed typical characteristics of morphological group 2. A total of three and five mtDNA RFLP patterns generated by EcoRI were found in 5 of the isolates from CLSC and 17 of the isolates from domestic tap water, respectively. The mtDNA RFLP patterns of four of the five isolates from the CLSC were found to be identical to those of the isolates from domestic tap water of students who had contaminated CLSC. The majority had mtDNA RFLP patterns identical to those of AK isolates in Korea. The results of 18S rDNA sequencing analysis were also shown to coincide with the results of mtDNA RFLP analysis. KA/WP12 was determined to be profoundly sensitive to chlorhexidine (MCC; 6.25microg/ml), and KAWP2 was the most sensitive strain to polyhexamethylene biguanide (PHMB) (MCC; 4.69microg/ml). Some difference in the cytopathic effects of isolates against human corneal epithelial cells was observed according to their mtDNA genotypes. In conclusion, domestic tap water may constitute a source of Acanthamoeba contamination of CLSC, and most isolates from CLSC and domestic tap water appear to be potentially keratopathogenic.
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PMID:Acanthamoeba: keratopathogenicity of isolates from domestic tap water in Korea. 1757 43

Acanthamoeba keratitis is a rare but serious complication of contact lens wear that may cause severe visual loss. The clinical picture is usually characterised by severe pain, sometimes disproportionate to the signs, with an early superficial keratitis that is often misdiagnosed as herpes simplex virus (HSV) keratitis. Advanced stages of the infection are usually characterised by central corneal epithelial loss and marked stromal opacification with subsequent loss of vision. In this paper, six cases of contact lens-related Acanthamoeba keratitis that occurred in Australia and New Zealand over a three-year period are described. Three of the patients were disposable soft lens wearers, two were hybrid lens wearers and one was a rigid gas permeable lens wearer. For all six cases, the risk factors for Acanthamoeba keratitis were contact lens wear with inappropriate or ineffective lens maintenance and exposure of the contact lenses to tap or other sources of water. All six patients responded well to medical therapy that involved topical use of appropriate therapeutic agents, most commonly polyhexamethylene biguanide and propamidine isethionate, although two of the patients also subsequently underwent deep lamellar keratoplasty due to residual corneal surface irregularity and stromal scarring. Despite the significant advances that have been made in the medical therapy of Acanthamoeba keratitis over the past 10 years, prevention remains the best treatment and patients who wear contact lenses must be thoroughly educated about the proper use and care of the lenses. In particular, exposure of the contact lenses to tap water or other sources of water should be avoided.
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PMID:Acanthamoeba keratitis and contact lens wear. 1769 81

We report a rare case of Acanthamoeba keratitis related to cosmetic contact lenses in both eyes. A 17-year-old girl with a history of wearing cosmetic contact lenses presented with keratitis. She purchased cosmetic contact lenses via the Internet, and followed a contact lens care system irregularly, occasionally using tap water. Cell culture was performed on samples collected from a corneal scraping, the contact lenses and the storage cases. The isolated organism was Acanthamoeba. The patient was treated with polyhexamethylene biguanide and chlorhexidine for 3 months, and recovered with normal visual acuity. Poor hygiene and insufficient disinfection may be major risk factors for Acanthameoba keratitis in cosmetic contact lens wearers. The cosmetic contact lens user should receive professional advice before accessing the lenses, and this must be communicated to the public.
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PMID:Acanthamoeba keratitis related to cosmetic contact lenses. 1799 88

The purpose was to identify the prevalence of naked amoebae in tap water in south Florida to ascertain the risk of amoebal infections of the cornea in contact lens wearers. Over the course of a 2-year period, water samples were collected from sites throughout Broward, Palm Beach, and Dade counties, Florida. The presence of amoebae in samples was based on an enrichment cultivation method appropriate for Acanthamoeba. Amoebae were identified using diagnostic features discernable by light microscopy. A total of 283 water samples were processed and amoebae were noted in 80 of these. Acanthamoeba were found on 8 occasions (2.8%). The genera Hartmannella and Vahlkampfia, rarely involved in keratitis cases, were found in 3.5% and 2.8% of samples, respectively. A total of 19 different naked amoebae were recorded and amoebae (regardless of genus) were present in 19.4% of all samples. Previous surveys in England and Korea have shown that acanthamoebae are found in 15 to 30% of tap water samples in the home and have been associated with corneal infection in contact lens wearers. The incidence of acanthamoebae infection in the USA (2.8%) has been found to be lower than that in the UK and it has been postulated that this is related to the lack of a storage water tank in the roof loft space. However, the level of treatment of municipal water is clearly not effective at killing amoebal cysts (or trophozoites) as evidenced by the high occurrence of amoebae (19.4%) in this study.
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PMID:Prevalence of Acanthamoeba and other naked amoebae in South Florida domestic water. 1799 10

Acanthamoeba spp., known to cause keratitis and granulomatous encephalitis in humans, are frequently isolated from a variety of water sources. Here we report for the first time the characterization of an Acanthamoeba sp. (ACC01) isolated from tap water in Brazil. This organism is currently being maintained in an axenic growth medium. Phylogenetic analysis based on SSU rRNA gene sequences positioned the new isolate in genotype T4, closest to the keratitis-causing isolate, A. polyphaga ATCC 30461 ( approximately 99% similarity). Acanthamoeba ACC01 and A. polyphaga 30461 both grew at 37 degrees C and were osmotically resistant, multiplying in hyperosmolar medium. Both isolates secreted comparable amounts of proteolytic enzymes, including serine peptidases that were optimally active at a near neutral/alkaline pH and resolved identically in gelatin gels. Incubation of gels at pH 4.0 with 2mM DTT also indicated the secretion of similar cysteine peptidases. Altogether, the results point to the pathogenic potential of Acanthamoeba ACC01.
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PMID:Genotyping, physiological features and proteolytic activities of a potentially pathogenic Acanthamoeba sp. isolated from tap water in Brazil. 1964 40

We describe a case of corneal chromoblastomycosis with Cladophialophora carrionii in a 69-year-old woman 4 weeks after clear corneal cataract surgery. The patient presented with right eye pain and decreased visual acuity of 20/100. Examination showed a deep posterior stromal keratitis accompanied by a dense fibrinous anterior chamber reaction. An aqueous tap was performed, and the patient was treated with topical, systemic, and intracameral antifungal and antibiotic agents. The infection was resistant to medical therapy and the course further complicated by secondary pupillary block glaucoma. After 10 days, a therapeutic penetrating keratoplasty was performed. The patient remained asymptomatic 20 months after the initial presentation, with corrected distance visual acuity restored to 20/40. To our knowledge, is the first reported case of corneal chromoblastomycosis with C carrionii. Early surgical treatment may be necessary to eradicate Cladophialophora species.
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PMID:Corneal chromoblastomycosis caused by Cladophialophora carrionii after cataract surgery. 2151 Nov 60

We report a case of a 21 year old male who presented with smear-proven fungal corneal ulcer in left eye, refractory to treatment with topical natamycin. Corneal smears and culture were taken along with anterior chamber tap for microbiological investigations and intracameral 1% voriconazole was injected followed by institution of oral as well as topical voriconazole drops. Corneal and aqueous smear as well as culture confirmed the presence of acanthamoeba. The keratitis responded favourably to voriconazole therapy which was instituted along with topical trophicidal drugs and anterior chamber became quiet by 7th day. The patient was slowly tapered from voriconazole and was off the drug by 6 months. At one year follow up, he continues to remain asymptomatic. The possibility exists that the fungal organisms had either partially or completely responded to natamycin eye drops and voriconazole therapy further inhibited their growth along with being highly efficacious in suppressing acanthamoeba trophozoites. Voriconazole may be specifically instrumental in corneal ulcers with coinfection of acanthamoeba and fungal organisms and preventing recrudescence of both. Normal saline wet mount and 10% KOH mount of paracentesis sample for suspicious cases of refractory corneal ulcers to specifically look for trophozoites in order to institute timely treatment are recommended.
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PMID:Role of voriconazole in combined acanthamoeba and fungal corneal ulcer. 2173 40


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