Recent advances in diagnosis and management of Mycotic Keratitis

Maharana, Prafulla K.; Sharma, Namrata; Nagpal, Ritu; Jhanji, Vishal; Das, Sujata; Vajpayee, Rasik B

doi:10.4103/0301-4738.185592

Cited by 100 publications

(64 citation statements)

References 94 publications

(181 reference statements)

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“…Similar to CF cases, the use of polymyxin antibiotics can improve the poor prognosis of fungal keratitis, due to the emergence of MDR fungal pathogens, particularly Fusarium spp. [36], and to the limited ocular penetration of antifungals [37]. Notably, PMB can be formulated for ophthalmic use [16], which is described as a highly effective drug on bacterial corneal ulcerations [38].…”

Section: Discussionmentioning

confidence: 99%

In vitro polymyxin activity against clinical multidrug-resistant fungi

Yousfi

Ranque

Rolain

et al. 2019

Antimicrob Resist Infect Control

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Background Although antifungals are available and usually used against fungal infections, multidrug-resistant (MDR) fungal pathogens are a growing problem for public health. Moreover, fungal infections have become more prevalent nowadays due to the increasing number of people living with immunodeficiency. Thus, previously rarely-isolated and/or unidentified fungal species including MDR yeast and moulds have emerged around the world. Recent works indicate that polymyxin antibiotics (polymyxin B and colistin) have potential antifungal proprieties. Therefore, investigating the in vitro activity of these molecules against clinical multidrug-resistant yeast and moulds could be very useful. Methods In this study, a total of 11 MDR yeast and filamentous fungal strains commonly reported in clinical settings were tested against polymyxin antibiotics. These include strains belonging to the Candida , Cryptococcus and Rhodotorula yeast genera, along with others belonging to the Aspergillus , Fusarium , Scedosporium , Lichtheimia and Rhizopus mould genera. The fungicidal or fungistatic action of colistin against clinical yeast strains was determined by the time-kill study. Further, a checkerboard assay for its combination with antifungal agents, usually used in clinical practices (amphotericin B, itraconazole, voriconazole), was carried out against multi-drug resistant fungal strains. Results Polymyxin B and colistin exhibited an antifungal activity against all MDR fungal strains tested with MICs ranging from 16 to 128 μg/ml, except for the Aspergillus species. In addition, colistin has a fungicidal action against yeast species, with minimum fungicidal concentrations ranging from 2 to 4 times MICs. It induces damage to the MDR Candida albicans membrane. A synergistic activity of colistin-amphotericin B and colistin-itraconazole associations against Candida albicans and Lichtheimia corymbifera strains, respectively, and colistin-fluconazole association against Rhodotorula mucilaginosa, was demonstrated using a checkerboard microdilution assay. Conclusion colistin could be proposed, in clinical practice, in association with other antifungals, to treat life-threatening fungal infections caused by MDR yeasts or moulds.

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Section: Discussionmentioning

confidence: 99%

In vitro polymyxin activity against clinical multidrug-resistant fungi

Yousfi

Ranque

Rolain

et al. 2019

Antimicrob Resist Infect Control

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“…Our study also observed highly diverse pathogens. In addition to well-established infectious agents such as Alternaria, Bipolaris, Curvularia, and Penicillium , 25 , 26 rarely reported species included Corynespora, 27 Lasiodiplodia, 28 Scedosporium apiospermum, 29 Scedosporium, 26 Sarocladium, 30 and Scopulariopsis brevicaulis. 31 Moreover, Paracremonium and Phellinus , which have never been reported as pathogens of human keratitis, have been found.…”

Section: Discussionmentioning

confidence: 99%

Filamentous Fungal Keratitis in Taiwan: Based on Molecular Diagnosis

Hung

Yeh

Hui‐Kang

et al. 2020

Trans. Vis. Sci. Tech.

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Purpose To analyze the epidemiological pattern, demographics, risk factors, and treatment outcomes of filamentous fungal keratitis at a tertiary hospital in Taiwan. Methods We recruited 65 patients (65 eyes) with culture-proven filamentous fungal keratitis who received diagnosis and treatment at Chang Gung Memorial Hospital between 2015 and 2018. All isolates were examined through conventional morphological identification and subjected to molecular identification with internal transcribed spacer sequencing. Data on patient demographics, predisposing factors, and treatment outcomes were collected. Results In total, filamentous fungi belonged to 16 genera were identified. Fusarium spp. (29 cases [44.6%]) was the most commonly isolated organism overall, followed by Colletotrichum spp. and Purpureocillium linacinum (seven cases [10.8% for each]), and Aspergillus spp. (six cases [9.2%]). Some fungi that have not been regarded as human pathogens were also identified, such as Paracremonium and Phellinum . Among 52 (80%) patients with predisposing factors, 30 (46.2%) had trauma. The ulcers of 33 (50.8%) patients resolved with medical treatment only. Additionally, six patients (9.2%) had corneal perforation, and nine patients (13.9%) required therapeutic/destructive surgical interventions including therapeutic penetrating keratoplasty (seven patients) or evisceration (two patients). Only 16 patients (24.6%) had final visual acuity of 20/40 or better. Conclusions Through molecular diagnosis, a high diversity of fungal pathogens was revealed along with an increasing incidence of Colletotrichum spp. and Purpureocillium spp. in Taiwan. The most common risk factor for filamentous fungal keratitis was trauma. The visual outcomes were guarded. Translational Relevance The molecular diagnosis provides insight into accurate identification, which affects the epidemiology and diversity of pathogens of filamentous fungal keratitis.

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“…Во фрагментах всех 6 удаленных роговиц и в 2 исследованных соскобах с роговицы обнаружена ДНК Fungi и не обнаружена ДНК Candida albicans. Рост плесневых грибков (Аspergillius spp) на агаре Сабуро и отрицательные результаты ПЦР на Candida albicans согласуются с современными представлениями о ведущей роли нитчатых грибов, а не Сandida аlbicans, в этиологии кератомикозов у носителей контактных линз, в отличие от пациентов с предшествующими заболеваниями глазной поверхности, у которых кератиты обусловлены в основном Сandida аlbicans [4,6,7,12]. У 2 пациентов в удаленной при кератопластике роговице, помимо ДНК Fungi, обнаружена ДНК ВЭБ, а еще у одного -ДНК ВЭБ и ДНК ЦМВ.…”

Section: Discussionunclassified

“…Keywords: fungal corneal ulcers, laboratory diagnostics, PCR чувствительностью [6][7][8][11][12][13]. Однако многообразие видов патогенных грибов и отсутствие тест-систем для выявления многих из них ограничивают возможности ПЦР.…”

Section: Introductionunclassified

The Effectiveness of PCR in Diagnosis of Fungal Keratitis

et al. 2020

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Fungi implicated in mycotic keratitis include different species. Conventional methods for the diagnosis of fungal keratitis include staining of corneal scarpings, culture medium (Sabouraud agar) for isolating fungi.Purpose. To evaluate the effectiveness of polymerase chain reaction (PCR) for the detection of fungal etiology in comparison with the conventional diagnostic methods in cases with suspected fungal corneal ulcer.Patients and methods. Seven patients with severe corneal ulcers with more than 3 weeks duration. Corneal scarpings and corneal buttons from seven patients who had undergone therapeutic keratoplasty were used for microbiological and PCR analysis. PCR diagnostic kits for the differential detection of Candida albicans DNA and total fungi DNA (DNA Fungi), which allows to identify most pathogenic fungi without determining their species were used. Microbiological methods: microscopy of gramstained smears, culture techniques, including selective for fungi agar Saburo with chloramphenicol.Results. PCR: Fragments of all corneas removed from keratoplasty (6 patients) revealed fungal-common DNA (Fungi DNA) and did not detect Candida albicans DNA, which correlated with sowing results on Saburo medium (mold fungi found in 5 of 6 corneas). Fungi DNA was also detected in the corneal scraps taken prior to surgery; however, growth of fungi during sowing on various nutrient media was not found.Conclusion. Corneal fungal ulcers are a serious disease, often leading to visual disability. The rapid determination of etiology and the correct choice of therapy determines the outcomes of the disease. The advantage of PCR over the culture method: the speed of obtaining results (4 hours instead of 3–7 days); high sensitivity, which allows detecting fungi not only in the tissue of the removed cornea, but also in scrapes from the cornea ulcer of patients who previously received antifungal therapy. The presence of commercial kits for differential detection of fungal-common DNA and DNA of Candida albicans extends the possibilities of PCR in the screening diagnosis of fungal keratitis and the selection of drugs before determining the type of pathogen.

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Recent advances in diagnosis and management of Mycotic Keratitis

Cited by 100 publications

References 94 publications

In vitro polymyxin activity against clinical multidrug-resistant fungi

In vitro polymyxin activity against clinical multidrug-resistant fungi

Filamentous Fungal Keratitis in Taiwan: Based on Molecular Diagnosis

The Effectiveness of PCR in Diagnosis of Fungal Keratitis

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