Aspergillus Keratitis

Thomas, Philip A.

doi:10.1007/978-90-481-2408-4_57

Cited by 3 publications

(3 citation statements)

References 95 publications

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“…Trauma was a key predisposing factor for the infection, as it was expected based on previous reports (Kredics et al, 2007; Thomas, 2009; Manikandan et al, 2013). Additionally, Manikandan et al (2013) listed co-existing ocular conditions and systemic diseases, such as diabetes mellitus and hypertension, among the risk factors for Aspergillus keratitis (Manikandan et al, 2013).…”

Section: Discussionsupporting

confidence: 67%

“…Fungal keratitis typically affects middle-aged men having agriculture-related or other outdoor occupations in developing countries. While trauma has been the key predisposing factor, diabetes mellitus, contact lens wear, corticosteroid therapy, a prior eye surgery or eye disease are also among the frequently reported other risk factors for the infection (Bharathi et al, 2007; Thomas, 2009; Thomas and Kaliamurthy, 2013; Ranjini and Waddepally, 2016). Among filamentous fungal aetiologies, the genera Fusarium (31–52.5%) and Aspergillus (11–41%) are the main pathogens (Chowdhary and Singh, 2005; Ranjini and Waddepally, 2016; Manikandan et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

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Characterization of Aspergillus tamarii Strains From Human Keratomycoses: Molecular Identification, Antifungal Susceptibility Patterns and Cyclopiazonic Acid Producing Abilities

et al. 2019

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Aspergillus tamarii appears to be an emerging aetiological agent of human keratomycoses in South India. The investigated strains were isolated from six suspected fungal keratitis patients attending a tertiary care eye hospital in Coimbatore (Tamil Nadu, India), and were initially identified by the microscopic examinations of the scrapings and the cultures. Our data suggest that A. tamarii could be easily overlooked when identification is carried out based on morphological characteristics alone, while the sequence analysis of the calmodulin gene can be used successfully to recognize this species accurately. According to the collected clinical data, ocular trauma is a common risk factor for the infection that gradually developed from mild to severe ulcers and could be healed with an appropriate combined antifungal therapy. Antifungal susceptibility testing revealed that A. tamarii strains are susceptible to the most commonly used topical or systemic antifungal agents (i.e., econazole, itraconazole and ketoconazole) except for natamycin. Moreover, natamycin proved to be similarly less effective than the azoles against A. tamarii in our drug interaction tests, as the predominance of indifferent interactions was revealed between natamycin and econazole and between natamycin and itraconazole as well. Four and five isolates of A. tamarii were confirmed to produce cyclopiazonic acid (CPA) in RPMI-1640 – which is designed to mimic the composition of human extracellular fluids – and in yeast extract sucrose (YES) medium, respectively, which is a widely used culture medium for testing mycotoxin production. Although a ten times lower mycelial biomass was recorded in RPMI-1640 than in YES medium, the toxin contents of the samples were of the same order of magnitude in both types of media. There might be a relationship between the outcome of infections and the toxigenic properties of the infecting fungal strains. However, this remains to be investigated in the future.

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Section: Discussionsupporting

confidence: 67%

Section: Introductionmentioning

confidence: 99%

Characterization of Aspergillus tamarii Strains From Human Keratomycoses: Molecular Identification, Antifungal Susceptibility Patterns and Cyclopiazonic Acid Producing Abilities

et al. 2019

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“…Although in vitro antifungal susceptibility testing may not always accurately predict the clinical response of individual fungal keratitis patients, literature data about the minimum inhibitory concentrations (MICs) of antifungals against various isolates of filamentous fungi causing keratitis are highly valuable in guiding the clinicians to select the appropriate therapeutic agents . Due to the fact that the practice of subjecting fungal isolates to antifungal susceptibility tests remains uncommon across the diagnostic microbiology laboratories, and that the susceptibility pattern is depending from the involved species of Aspergillus / Fusarium as well as the nature and concentration of the drug, it is further emphasised that the isolates should compulsorily be examined for their susceptibility to increase the chances of an accurate therapy.…”

Section: Significance Of Susceptibility Testing In the Management Of mentioning

confidence: 99%

Filamentous fungal infections of the cornea: a global overview of epidemiology and drug sensitivity

Kredics

Narendran

Shobana³

et al. 2015

Mycoses

129

113

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Fungal keratitis is a serious suppurative, usually ulcerative corneal infection which may result in blindness or reduced vision. Epidemiological studies indicate that the occurrence of fungal keratitis is higher in warm, humid regions with agricultural economy. The most frequent filamentous fungal genera among the causal agents are Fusarium, Aspergillus and Curvularia. A more successful therapy of fungal keratitis relies on precise identification of the pathogen to the species level using molecular tools. As the sequence analysis of the internal transcribed spacer (ITS) region of the ribosomal RNA gene cluster (rDNA) is not discriminative enough to reveal a species-level diagnosis for several filamentous fungal species highly relevant in keratitis infections, analysis of other loci is also required for an exact diagnosis. Molecular identifications may also reveal the involvement of fungal species which were not previously reported from corneal infections. The routinely applied chemotherapy of fungal keratitis is based on the topical and systemic administration of polyenes and azole compounds. Antifungal susceptibility testing of the causal agents is of special importance due to the emergence and spread of resistance. Testing the applicability of further available antifungals and screening for new, potential compounds for the therapy of fungal keratitis are of highlighted interest.

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Efficacy of adjuvant intrastromal and combination of intrastromal and intracameral voriconazole in <em>Aspergillus fumigatus</em>-induced moderate fungal keratitis in rabbits

et al. 2021

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BACKGROUND There is no in vivo evidence for the effectiveness of adjuvant intrastromal and combination of intrastromal and intracameral voriconazole (VCZ) for treating Aspergillus fumigatus keratitis. This study aimed to compare the efficacy of both agents against it. METHODS A randomized, masked, controlled experimental study was conducted on 11 albino New Zealand white rabbits in which moderate fungal keratitis was induced by inoculating spores of A. fumigatus to the cornea. The rabbits were allocated into 3 groups: 50 μg/0.1 ml intrastromal VCZ injection, 50 μg/0.1 ml intrastromal VCZ and intracameral VCZ injections, and topical VCZ (control). The treatment was given 5 days after inoculation. Epithelial defect, infiltrate size, corneal ulcer depth, and hypopyon were evaluated clinically. Histopathological and mycological examinations were also done 14 days after treatment. RESULTS All rabbits in the adjuvant treatment groups demonstrated a tendency of a better clinical response with decreasing size of epithelial defect (p = 0.679) and infiltrate (p = 0.755) than in the control group. Direct microscopy, corneal culture, and chop corneal tissue culture were still positive in most of the rabbits from all groups. Histopathological examination showed an increase of inflammatory cells after treatment in all groups, especially in rabbits which were inoculated with A. fumigatus spores in both eyes. CONCLUSIONS An adjuvant combination of intrastromal and intracameral VCZ showed a tendency of better clinical response for A. fumigatus-induced moderate fungal keratitis in rabbits.

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Aspergillus Keratitis

Cited by 3 publications

References 95 publications

Characterization of Aspergillus tamarii Strains From Human Keratomycoses: Molecular Identification, Antifungal Susceptibility Patterns and Cyclopiazonic Acid Producing Abilities

Characterization of Aspergillus tamarii Strains From Human Keratomycoses: Molecular Identification, Antifungal Susceptibility Patterns and Cyclopiazonic Acid Producing Abilities

Filamentous fungal infections of the cornea: a global overview of epidemiology and drug sensitivity

Efficacy of adjuvant intrastromal and combination of intrastromal and intracameral voriconazole in <em>Aspergillus fumigatus</em>-induced moderate fungal keratitis in rabbits

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