Alternaria chartarum sclerokeratouveitis: A new fungus cause.

We report a case of Alternaria chartarum sclerokeratouveitis with an unfavorable response to treatment. To the best of our knowledge, there are no previous reports of this fungus invading the sclera. A 68-year-old diabetic farmer male patient presented with a 3-week history of pain and redness and a decrease in visual acuity occurring 5 days before admittance in the right eye. Examination revealed severe mixed hyperemia and a scleral calcified plaque with a surrounding area of ischemia and lysis. The cornea showed diffuse infiltrates, stromal edema, and hypopyon. Initial scrapings were negative, and empiric antibiotics were started. After a fungus was reported, topical and systemic antifungals were initiated, but there was no clinical response. The eye was enucleated. A slow-growing fungus A. chartarum, resistant to voriconazole, was isolated. Fungal etiology must be kept in mind when dealing with infectious scleritis. Despite treatment, the outcome of this case was unfavorable due to the slow-growing nature of the fungus and this strain's resistance to voriconazole.

First Demonstration of Clinical Fusarium Strains Causing Cross-Kingdom Infections from Humans to Plants.

Mycotoxins from the Fusarium genus are widely known to cause economic losses in crops, as well as high mortalities rates among immunocompromised humans. However, to date, no correlation has been established for the ability of Fusarium to cause cross-kingdom infection between plants and humans. The present investigation aims to fill this gap in the literature by examining cross-kingdom infection caused by Furasium strains isolated from non-immunocompromised or non-immunosuppressed humans, which were subsequently reinfected in plants and on human tissue. The findings document for the first time cross-kingdom infective events in Fusarium species, thus enhancing our existing knowledge of how mycopathogens continue to thrive in different hosts.

Evaluation of the sensitivity to chlorhexidine, voriconazole and itraconazole of T4 genotype Acanthamoeba isolated from Mexico.

Free-living amoebae of the genus Acanthamoeba are the etiological agents of cutaneous lesions, granulomatous amoebic encephalitis (GAE) and amoebic keratitis (AK), which are chronic infections with poor prognosis if not diagnosed promptly. Currently, there is no optimal therapeutic scheme to eradicate the pathologies these protozoa cause. In this study we report the morphological and molecular identification of three species of the genus Acanthamoeba, belonging to T4 group; A. polyphaga isolated from the corneal ulcer of a patient sample of AK case; A. castellanii isolated from the contact lens of an AK patient and A. palestinensis obtained from a soil sample. The in vitro activity of chlorhexidine, itraconazole and voriconazole drugs against trophic stage was also evaluated through a colorimetric assay based on the oxidation-reduction of alamar blue. The strains in the study were sensitive to the evaluated drugs; although when determining the 50% inhibitory concentration (IC50) statistically significant differences were observed. A. castellanii showed to be highly sensitive to voriconazole (0.66 ±â€¯0.13 µM) but the least sensitive to chlorhexidine and itraconazole (8.61 ±â€¯1.63 and 20.14 ±â€¯4.93 µM, respectively), A. palestinensis showed the highest sensitivity to itraconazole (0.502 ±â€¯0.11 µM) and A. polyphaga expressed moderate sensitivity to chlorhexidine and itraconazole and lower sensitivity to voriconazole (10.10 ±â€¯2.21 µM). These results showed that species of the genus Acanthamoeba express different sensitivity to the tested drugs, which could explain the problems surrounding the establishment of a treatment of choice in the infections caused by these amoebae. We consider that although chlorhexidine and itraconazole show good activity on these amoebae and have been used in cases of AK in Mexico with acceptable results, voriconazole should be considered as the first therapeutic option of future Acanthamoeba infections that will be diagnosed in our country.

Acanthamoeba keratitis in Mexico: Report of a clinical case and importance of sensitivity assays for a better outcome.

Acanthamoeba keratitis (AK) is a sight-threatening corneal infection. The early symptoms include redness, pain, photophobia and intense tearing. Chronic infection usually progresses to stromal inflammation, ring ulcers, corneal opacification and hypopyon. Here we document an AK case in a high myopic 38-year-old woman from Mexico City, with a history of wearing contact lenses while swimming. Corneal scrapes cultures were positive only for amoebae, consequently a treatment including netilmicin 0.3% and oral itraconazole 100 mg/12 h was prescribed. The infection was resolved after 8 months, leaving a slight leucoma outside the visual axis, with a visual acuity of 20/150. In the laboratory, the amoebic isolate was axenized in PYG medium, with an optimal growth at 30 °C, and was identified morphologically as Acanthamoeba polyphaga according to the taxonomic criteria of Page (1988) and placed in the T4 group by genotyping. The virulence of this strain (40%) was determined by intranasal inoculation of 1 × 106/20 µl trophozoites in BALB/c mice recovering from brain, proving their invasion ability and by the interaction with monolayers of epithelial cells of the established MDCK line of canine kidney origin (1:2 ratio of interaction), at 1, 3, 6, 8 and 24 h; trophozoites migrated to cell junctions inducing few lytic zones. In addition to the biological characterization, in vitro drug sensitivity tests were performed using chlorhexidine, itraconazole, netilmicin and voriconazole. Results revealed that voriconazole was the most effective compound. A. polyphaga remains as one of the most frequently isolated species producing AK. The treatment of AK case using netilmicin and oral itraconazole solved the disease, but the healing process was wide-ranging (8 months). The use of voriconazole and chlorhexidine may be an alternative treatment of future AK cases in Mexico.

Acanthamoeba genotypes T3 and T4 as causative agents of amoebic keratitis in Mexico.

Free-living amoebae (FLA) are widely distributed worldwide. Some genera included in this group act as opportunistic pathogens causing fatal encephalitis and Acanthamoeba keratitis (AK), a sight-threatening infection of the cornea associated with the use of soft contact lenses that could even end in blindness if an early diagnosis and treatment are not achieved. Furthermore, the numbers of AK cases keep rising worldwide mainly due to an increase of contact lens wearers and lack of hygiene in the maintenance of lenses and their cases. In Mexico, no cases of AK have been described so far although the isolation of other pathogenic FLA such as Naegleria fowleri and Balamuthia mandrillaris from both clinical and environmental sources has been reported. The present study reports two cases of Acanthamoeba keratitis diagnosed in two patients admitted to the Hospital "Luis Sánchez Bulnes" for Blindness Prevention in Mexico City, Mexico. Corneal scrapes and contact lenses were checked for the presence of Acanthamoeba strains in both patients. Strains were axenized after initial isolation to classify at the genotype level. After sequencing the diagnostic fragment 3 (DF3) region located on the 18S ribosomal DNA (rDNA) gene of Acanthamoeba, genotype T3 and genotype T4 were identified in clinical case 1 and 2, respectively. To our knowledge, these are the first reported cases of AK in Mexico in the literature and the first description of Acanthamoeba genotypes T3 and T4 as causative agents of amoebic infection.

Support of the laboratory in the diagnosis of fungal ocular infections.

This is a retrospective, and descriptive study about the support that the laboratory of microbiology aids can provide in the diagnosis of ocular infections in patients whom were attended a tertiary-care hospital in México City in a 10-year-time period. We describe the microbiological diagnosis in palpebral mycose; in keratitis caused by Fusarium, Aspergillus, Candida, and melanized fungi; endophthalmitis; one Histoplasma scleritis and one mucormycosis. Nowadays, ocular fungal infections are more often diagnosed, because there is more clinical suspicion and there are easy laboratory confirmations. Correct diagnosis is important because an early medical treatment gives a better prognosis for visual acuity. In some cases, fungal infections are misdiagnosed and the antifungal treatment is delayed.

[Mycotic keratitis in an eye care hospital in Mexico City]. / Queratomicosis en un centro de atención oftalmológica en la Ciudad de México.

BACKGROUND: Some of the most common precipitating events for keratomycoses (fungal keratitis), include surgical trauma (after cornea transplantation), the use of contaminated contact lenses or alterations in lacrimal secretions. Diagnosis and treatment (to avoid loss of vision) for these type of infections are challenging. OBJECTIVE: Retrospective review of the diagnosis, epidemiology, etiology and response to treatment in 219 patients with fungal keratitis in Mexico. METHODS: We have studied the diagnosis, epidemiology, etiology and response to treatment in 219 patients from different states in the Mexican Republic in the Cornea Department at an Ophthalmology Hospital in Mexico D.F. RESULTS: Trauma was the precipitating event in 77 patients (36%), of which 12 (5.4%) were due to surgical trauma; 152 patients (64.8%) did not report any prior trauma. There were 165 male (75.3%) and 54 female (24.6%) patients, with an average age of 46 years old. For clinical and visual treatment patients were treated with topical and oral antifungals and surgery. One or more surgeries were performed on a total of 81 patients (36.9%). A total of 62 patients (28.3%) received a corneal transplant, and 19 patients (8.7%) were subjected to conjunctival flap or scleral-conjunctival surgery. CONCLUSIONS: In Mexico, keratomycoses affect mostly male patients in a 4:1 ratio over females. Fusarium solani was the most frequent agent of fungal keratitis in our study (37.2%), and the highest number of corneal ulcers and eviscerations (26%) was present in patients infected by Aspergillus. The best therapeutic responses were with combination of topical antifungals against dematiaceous fungi.

Atypical mycobacterium keratitis associated with penetrating keratoplasty: case report of successful therapy with topical gatifloxacin 0.3%.

PURPOSE: To report successful therapy with gatifloxacin 0.3% ophthalmic solution (Zymar) in a patient with atypical mycobacterium keratitis after penetrating keratoplasty. METHODS: A 58-year-old patient was referred for evaluation of microbial keratitis after penetrating keratoplasty. RESULTS: Clinical examination of the patient revealed an infiltrate at the inferior graft-host junction with a satellite lesion with a mild inflammatory reaction in the anterior chamber. Microbiologic evaluation confirmed the diagnosis of atypical mycobacteria keratitis. The corneal abscess was completely eradicated with a topical course of gatifloxacin 0.3% with preservation of graft clarity and good visual acuity. Topical treatment with gatifloxacin 0.3% was continued for an additional period of 5 months. CONCLUSION: Topical gatifloxacin 0.3% may be successfully used to treat microbial keratitis resulting from atypical mycobacteria.

Chlamydia trachomatis in the conjunctiva of children living in three rural areas in Mexico.

OBJECTIVES: Chlamydia trachomatis infections, in the context of extreme poverty, may trigger trachoma. Because the levels of C. trachomatis eye infections in Mexico are unknown, this study sought to determine if C. trachomatis was present in the conjunctiva of children living in three poor, rural areas of the country. METHODS: Clinical diagnosis of conjunctival follicles in children was conducted during the 2004 visual acuity assessment campaigns in rural areas of the states of Chiapas, Oaxaca, and Zacatecas. C. trachomatis detection was carried out by sampling the children with follicles and examining the specimens after Giemsa or microimmunofluorescence (MIF) staining. RESULTS: A total of 941 children from 6 to 12 years of age were examined in 2004. Of the 484 in Chiapas, 30% were found to have follicles; of the 181 in Zacatecas, 22%; and of the 276 in Oaxaca, 42%. C. trachomatis was detected at levels ranging between 2% and 5%; positive by Giemsa in 4.5% of the children with follicles, and by MIF in 15.5%. CONCLUSIONS: Considering that the chlamydiae sampling procedures and detection methods used in this study were not the most sensitive, the results underestimate the chlamydial eye infections and represent a conservative assessment of a potential risk for preventable visual impairment. Because C. trachomatis was detected here at levels similar to those reported for low-endemic trachoma areas, health authorities should be prepared to implement appropriate measures should it be confirmed that the visual health of Mexico's children is at risk.