Case of Keratitis Caused by Aspergillus tamarii

Abstract

We report a case of Aspergillus tamarii keratitis. Ocular injury was known to be a predisposing factor. Topical natamycin and econazole treatment and subsequent systemic ketoconazole treatment proved effective. The isolate was identified by morphological characteristics and sequence analysis as A. tamarii, a member of Aspergillus section Flavi not hitherto reported from keratomycosis. CASE REPORTA 32-year-old female from Coimbatore was presented to the Aravind Eye Hospital, Coimbatore, South India, on December 27, 2005, with complaints of pain, redness, and defective vision of a 4-day duration in the left eye. She indicated that she had suffered an ocular injury caused by an iron piece while hammering 4 days earlier. On examination, her uncorrected visual acuities in the right and left eyes were 6/9 (partial) and 1/2/60, respectively. An anterior segment examination of the left eye showed lid edema and conjunctival congestion. The cornea showed a central 3-by-3-mm ulcer with an anterior midstromal infiltrate with feathery edges and surrounding edema. The anterior chamber showed a moderate number of cells (2ϩ grade). The lens was clear. The anterior segment of the right eye and the posterior segments of both eyes were within normal limits.With due aseptic precautions, the ulcer was scraped and two smears were made on glass slides for a 10% KOH wet mount and Gram staining. The microscopic examination of the KOH wet mount and Gram staining showed fungal filaments. Material from scraping was also directly inoculated onto potato dextrose agar and incubated at 25°C. Based on the colony appearance, the fungus was identified as an Aspergillus sp. Topical antifungal therapy was started with 5% natamycin suspension and 2% econazole drops every half hour, along with 1% homatropine three times a day.When reviewed after 3 days, the patient's uncorrected visual acuity in the left eye had improved to 6/36, but the corneal midstromal infiltrate was still active. The anterior chamber showed a hypopyon of 0.5 mm. The patient was admitted as an inpatient and advised to continue the same medications along with 200 mg oral ketoconazole and 0.2% subconjunctival fluconazole based on the results of our previous study (6). The patient showed improvement during the next 3 weeks; the infiltrate reduced gradually, and the anterior segment inflammations subsided. On the last review, the anterior segment of the left eye showed a central nebular scar, with the best corrected visual acuity having improved to 6/12. The patient was advised to use glasses and to report for review after 6 months.The clinical isolate was further examined at the CBS Fungal Biodiversity Centre and at the University of Szeged for species assignment and antifungal susceptibility tests.Mycological study and diagnosis. The fungus was subcultured on malt extract agar plates and identified as Aspergillus tamarii Kita based on the colony morphology and microscopic features of the isolate ( Fig. 1 and 2). Colonies on malt extract agar at room temperature attained diameters o...

Misidentification of Aspergillus nomius and Aspergillus tamarii as Aspergillus flavus: Characterization by Internal Transcribed Spacer, β-Tubulin, and Calmodulin Gene Sequencing, Metabolic Fingerprinting, and Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry

“…It was difficult for clinical microbiology laboratories to identify rarely found molds as causes of various infections. The more widespread use of ITS and other gene sequencing has enabled clinical microbiology laboratories to con- fidently identify molds that are rarely found in patients after preliminary morphological examination (13)(14)(15)(16)(17)(18)29). In addition, novel fungal species associated with clinical infections have been discovered (9)(10)(11).…”

“…These results were also in line with those of metabolic fingerprinting, in which the A. flavus, A. nomius, and A. tamarii strains were separated into three clusters based on UHPLC MS analysis. Although A. flavus, A. nomius, and A. tamarii may (Table 2) (13)(14)(15)(16)(17)(18)29). Among the 15 strains with methods of laboratory diagnosis described in detail, all of them required molecular technologies (sequencing in 14 and high-performance liquid chromatography analysis of metabolites in 1) for identification.…”

“…In addition, it has led to the discovery of novel pathogenic fungal species (11,12). In the last decade, a number of case reports, with the help of ITS, ␤-tubulin, and calmodulin gene sequencing, have identified Aspergillus nomius and Aspergillus tamarii as causes of human infections (13)(14)(15)(16)(17)(18). Since A. nomius and A. tamarii are yellow and are also under the same Aspergillus section Flavi as A. flavus, we hypothesize that they can be easily misidentified as A. flavus and that a proportion of fungus isolates reported as A. flavus might be A. nomius or A. tamarii.…”

Uncommon Neosartorya udagawae Fungus as a Causative Agent of Severe Corneal Infection

“…Although less common than bacterial keratitis, fungal keratitis is more devastating, with deep infection often difficult to cure by antifungal medication (1,27). Aspergillus flavus, A. fumigatus, Aspergillus terreus, and Aspergillus niger (14) and, less frequently, Aspergillus tamari (12), Aspergillus nomius (16), Aspergillus tubingensis (13), and Aspergillus brasiliensis (15) have been isolated from keratomycosis cases. In contrast, N. udagawae, an ascomycete with an A. fumigatus-like anamorph (21), originally identified from Brazilian soil (11) and only recently implicated in cases of invasive aspergillosis (25), has not yet been reported from mycotic keratitis.…”

Mycotic Keratitis Due to Aspergillus nomius

“…A recent paper reported a corneal ulcer due to Aspergillus tamarii (15), suggesting that members of Aspergillus section Flavi other than A. flavus may also be potential causative agents of mycotic keratitis.…”