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Sáenz V, Lizcano Salas AF, Gené J, Celis Ramírez AM. Fusarium and Neocosmospora: fungal priority pathogens in laboratory diagnosis. Crit Rev Microbiol 2024:1-14. [PMID: 38949272 DOI: 10.1080/1040841x.2024.2369693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 06/11/2024] [Indexed: 07/02/2024]
Abstract
Fusarium and Neocosmospora are two fungal genera recently recognized in the list of fungal priority pathogens. They cause a wide range of diseases that affect humans, animals, and plants. In clinical laboratories, there is increasing concern about diagnosis due to limitations in sample collection and morphological identification. Despite the advances in molecular diagnosis, due to the cost, some countries cannot implement these methodologies. However, recent changes in taxonomy and intrinsic resistance to antifungals reveal the necessity of accurate species-level identification. In this review, we discuss the current phenotypic and molecular tools available for diagnosis in clinical laboratory settings and their advantages and disadvantages.
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Affiliation(s)
- Valeri Sáenz
- Grupo de Investigación Celular y Molecular de Microorganismos Patógenos (CeMoP), Departamento de Ciencias Biológicas, Universidad de Los Andes, Bogotá, Colombia
| | - Andrés Felipe Lizcano Salas
- Grupo de Investigación Celular y Molecular de Microorganismos Patógenos (CeMoP), Departamento de Ciencias Biológicas, Universidad de Los Andes, Bogotá, Colombia
| | - Josepa Gené
- Unitat de Micologia i Microbiologia Ambiental (MicroAmb), Facultat de Medicina i Ciències de la Salut i Institut d'Investigació Sanitària Pere Virgili (IISPV), Universitat Rovira i Virgili, Reus, Spain
| | - Adriana Marcela Celis Ramírez
- Grupo de Investigación Celular y Molecular de Microorganismos Patógenos (CeMoP), Departamento de Ciencias Biológicas, Universidad de Los Andes, Bogotá, Colombia
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Warnnissorn P, Sawatdiwithayayong J, Surit P. Efficacy and Rapidity of Potassium Hydroxide Mount and Modified Chicago Sky Blue 6B Stain with Potassium Hydroxide in Fungal Keratitis Detection. KOREAN JOURNAL OF OPHTHALMOLOGY 2024; 38:98-104. [PMID: 38351488 PMCID: PMC11016681 DOI: 10.3341/kjo.2023.0106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 12/22/2023] [Accepted: 01/20/2024] [Indexed: 04/16/2024] Open
Abstract
PURPOSE To compare the efficacy and rapidity of direct microscopic detection of fungal elements from corneal ulcers between 10% potassium hydroxide (KOH) and 1% Chicago Sky Blue 6B (CSB) in 10% KOH (CSB-KOH). METHODS Thirty patients with clinically suspected fungal keratitis were recruited. Participants with impending corneal perforation were excluded. Two slides were smeared with corneal ulcer scrapings from the ulcer's edge and base for comparison of fungal staining solutions. One slide was infused with KOH, and the other slide was filled with CSB-KOH. Additional scraping was collected for inoculation on Sabouraud dextrose agar for fungal culture. The sensitivity, specificity and rapidity of both stainings were analyzed. RESULTS The sensitivity of fungal culture, KOH, and CSB-KOH were 43.75% (95% confidence interval [CI], 19.75%-70.12%), 62.50% (95% CI, 35.43%-84.80%), and 87.50% (95% CI, 61.65%-98.45%), respectively. The specificity were 100% (95% CI, 69.15%-100%) of both stainings and fungal culture which analyzed from 16 fungal keratitis cases by laboratory and clinical diagnosis. Mean CSB-KOH examination time was quicker than KOH with the mean time difference of 5.6 minutes (95% CI, 3.22-7.98 minutes) and p-value < 0.001. CONCLUSIONS CSB-KOH was more effective and faster than KOH in detecting fungal elements from corneal ulcers. Therefore, CSB-KOH may be beneficial in diagnosing fungal keratitis and preventing blindness. Moreover, to the best of our knowledge, this is the first use of CSB stain in fungal keratitis detection.
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Affiliation(s)
- Prateep Warnnissorn
- Department of Medicine, Faculty of Medicine, Naresuan University, Phitsanulok,
Thailand
| | | | - Phrutthinun Surit
- Department of Biochemistry, Faculty of Medical Science, Naresuan University, Phitsanulok,
Thailand
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Tuft S, Stone NRH, Burton MJ, Johnson EM, Borman AM. Antifungal susceptibility profiles for fungal isolates from corneas and contact lenses in the United Kingdom. Eye (Lond) 2024; 38:529-536. [PMID: 37684376 PMCID: PMC10858215 DOI: 10.1038/s41433-023-02719-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 08/09/2023] [Accepted: 08/25/2023] [Indexed: 09/10/2023] Open
Abstract
OBJECTIVE To report the identification and results of susceptibility testing for fungal isolates from the cornea or contact lens care systems. MATERIALS AND METHODS In this retrospective epidemiological study, we searched the results of fungal cultures from cornea or contact lens systems referred for identification and susceptibility testing to the United Kingdom National Mycology Reference Laboratory between October 2016 and March 2022. For each fungal isolate, we recorded the genus and species of the fungus and the minimum inhibitory concentration (MIC) to six antifungal agents available to treat corneal infection (amphotericin, econazole, itraconazole, natamycin, posaconazole, and voriconazole). RESULTS There were 600 isolates from 585 patients, comprising 374 (62%) from corneal samples and 226 from contact lenses and care systems, of which 414 (69%) isolates were moulds (filamentous fungi) and 186 (31%) were yeasts. The most frequent moulds isolated were Fusarium spp (234 isolates, 39%) and Aspergillus spp (62, 10%). The most frequent yeasts isolated were Candida spp (112, 19%), predominantly Candida parapsilosis (65, 11%) and Candida albicans (33, 6%), with 35 isolates (6%) of Meyerozyma guilliermondii. In vitro susceptibility was greatest for natamycin (347 moulds tested, mode 4 mg/L, range 0.25-64 mg/L; 98 yeasts tested, mode 4 mg/L, range 0.5-32 mg/L), with susceptibility for 94% for moulds and 99% yeasts. Of the 16 isolates interpreted as highly resistant to natamycin (MIC ≥16 mg/L), 13 were Aspergillus flavus complex. CONCLUSIONS In vitro susceptibility supports the use of natamycin for the empiric treatment of fungal keratitis in the UK.
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Affiliation(s)
- Stephen Tuft
- Moorfields Eye Hospital, 162 City Road, London, EC1V 2PD, UK.
- UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK.
| | - Neil R H Stone
- Department of Clinical Microbiology, University College London Hospitals NHS Foundation Trust, 250 Euston Road, London, NW1 2PG, UK
| | - Matthew J Burton
- Moorfields Eye Hospital, 162 City Road, London, EC1V 2PD, UK
- International Centre for Eye Health, London School of Hygiene & Tropical Medicine, Keppel St, London, WC1E 7HT, UK
| | - Elizabeth M Johnson
- UK National Mycology Reference Laboratory, UK Health Security Agency South-West, Bristol, and MRC Centre for Medical Mycology, University of Exeter, Exeter, UK
| | - Andrew M Borman
- UK National Mycology Reference Laboratory, UK Health Security Agency South-West, Bristol, and MRC Centre for Medical Mycology, University of Exeter, Exeter, UK
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Toumasis P, Tsantes AG, Tsiogka A, Samonis G, Vrioni G. From Clinical Suspicion to Diagnosis: A Review of Diagnostic Approaches and Challenges in Fungal Keratitis. J Clin Med 2024; 13:286. [PMID: 38202293 PMCID: PMC10779560 DOI: 10.3390/jcm13010286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 12/25/2023] [Accepted: 01/02/2024] [Indexed: 01/12/2024] Open
Abstract
Fungal keratitis is a relatively rare yet severe ocular infection that can lead to profound vision impairment and even permanent vision loss. Rapid and accurate diagnosis plays a crucial role in the effective management of the disease. A patient's history establishes the initial clinical suspicion since it can provide valuable clues to potential predisposing factors and sources of fungal exposure. Regarding the evaluation of the observed symptoms, they are not exclusive to fungal keratitis, but their timeline can aid in distinguishing fungal keratitis from other conditions. Thorough clinical examination of the affected eye with a slit-lamp microscope guides diagnosis because some clinical features are valuable predictors of fungal keratitis. Definitive diagnosis is established through appropriate microbiological investigations. Direct microscopic examination of corneal scrapings or biopsy specimens can assist in the presumptive diagnosis of fungal keratitis, but culture remains the gold standard for diagnosing fungal keratitis. Advanced molecular techniques such as PCR and MALDI-ToF MS are explored for their rapid and sensitive diagnostic capabilities. Non-invasive techniques like in vivo confocal microscopy (IVCM) and optical coherence tomography (OCT) are useful for real-time imaging. Every diagnostic technique has both advantages and drawbacks. Also, the selection of a diagnostic approach can depend on various factors, including the specific clinical context, the availability of resources, and the proficiency of healthcare personnel.
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Affiliation(s)
- Panagiotis Toumasis
- Department of Ophthalmology, 212 Military Hospital of Xanthi, 67100 Xanthi, Greece
| | - Andreas G. Tsantes
- Department of Microbiology, Saint Savvas Oncology Hospital, 11522 Athens, Greece
- Laboratory of Haematology and Blood Bank Unit, Attikon Hospital, School of Medicine, National and Kapodistrian University of Athens, 12462 Athens, Greece
| | - Anastasia Tsiogka
- First Department of Ophthalmology, National and Kapodistrian University of Athens, “G. Gennimatas” General Hospital, 11527 Athens, Greece
| | - George Samonis
- Department of Medicine, University of Crete, 71500 Heraklion, Greece
| | - Georgia Vrioni
- Department of Microbiology, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
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Gunasekaran R, Chandrasekaran A, Rajarathinam K, Duncan S, Dhaliwal K, Lalitha P, Prajna NV, Mills B. Rapid Point-of-Care Identification of Aspergillus Species in Microbial Keratitis. JAMA Ophthalmol 2023; 141:966-973. [PMID: 37768674 PMCID: PMC10540059 DOI: 10.1001/jamaophthalmol.2023.4214] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 07/30/2023] [Indexed: 09/29/2023]
Abstract
Importance Microbial keratitis (MK) is a common cause of unilateral visual impairment, blindness, and eye loss in low-income and middle-income countries. There is an urgent need to develop and implement rapid and simple point-of-care diagnostics for MK to increase the likelihood of good outcomes. Objective To evaluate the diagnostic performance of the Aspergillus-specific lateral-flow device (AspLFD) to identify Aspergillus species causing MK in corneal scrape and corneal swab samples of patients presenting with microbial keratitis. Design, Setting, and Participants This diagnostic study was conducted between May 2022 and January 2023 at the corneal clinic of Aravind Eye Hospital in Madurai, Tamil Nadu, India. All study participants were recruited during their first presentation to the clinic. Patients aged 15 years or older met the eligibility criteria if they were attending their first appointment, had a corneal ulcer that was suggestive of a bacterial or fungal infection, and were about to undergo diagnostic scrape and culture. Main Outcomes and Measures Sensitivity and specificity of the AspLFD with corneal samples collected from patients with MK. During routine diagnostic scraping, a minimally invasive corneal swab and an additional corneal scrape were collected and transferred to aliquots of sample buffer and analyzed by lateral-flow device (LFD) if the patient met the inclusion criteria. Photographs of devices were taken with a smartphone and analyzed using a ratiometric approach, which was developed for this study. The AspLFD results were compared with culture reports. Results The 198 participants who met the inclusion criteria had a mean (range) age of 51 (15-85) years and included 126 males (63.6%). Overall, 35 of 198 participants with corneal scrape (17.7%) and 17 of 40 participants with swab samples (42.5%) had positive culture results for Aspergillus species. Ratiometric analysis results for the scrape samples found that the AspLFD achieved high sensitivity (0.89; 95% CI, 0.74-0.95), high negative predictive value (0.97; 95% CI, 0.94-0.99), low negative likelihood ratio (0.12; 95% CI, 0.05-0.30), and an accuracy of 0.94 (95% CI, 0.90-0.97). Ratiometric analysis results for the swab samples showed that the AspLFD had high sensitivity (0.94; 95% CI, 0.73-1.00), high negative predictive value (0.95; 95% CI, 0.76-1.00), low negative likelihood ratio (0.07; 95% CI, 0.01-0.48), and an accuracy of 0.88 (95% CI, 0.73-0.96). Conclusions and Relevance Results of this diagnostic study suggest that AspLFD along with the ratiometric analysis of LFDs developed for this study has high diagnostic accuracy in identifying Aspergillus species from corneal scrapes and swabs. This technology is an important step toward the provision of point-of-care diagnostics for MK and could inform the clinical management strategy.
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Affiliation(s)
- Rameshkumar Gunasekaran
- Department of Ocular Microbiology, Aravind Eye Hospital and Postgraduate Institute of Ophthalmology, Madurai, Tamil Nadu, India
| | - Abinaya Chandrasekaran
- Department of Cornea and Refractive Surgery Services, Aravind Eye Hospital and Postgraduate Institute of Ophthalmology, Madurai, Tamil Nadu, India
| | - Karpagam Rajarathinam
- Department of Ocular Microbiology, Aravind Eye Hospital and Postgraduate Institute of Ophthalmology, Madurai, Tamil Nadu, India
| | - Sheelagh Duncan
- Translational Healthcare Technologies Group, Centre for Inflammation Research, University of Edinburgh, United Kingdom
| | - Kevin Dhaliwal
- Translational Healthcare Technologies Group, Centre for Inflammation Research, University of Edinburgh, United Kingdom
| | - Prajna Lalitha
- Department of Ocular Microbiology, Aravind Eye Hospital and Postgraduate Institute of Ophthalmology, Madurai, Tamil Nadu, India
| | - N. Venkatesh Prajna
- Department of Cornea and Refractive Surgery Services, Aravind Eye Hospital and Postgraduate Institute of Ophthalmology, Madurai, Tamil Nadu, India
| | - Bethany Mills
- Translational Healthcare Technologies Group, Centre for Inflammation Research, University of Edinburgh, United Kingdom
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Chiang JCB, Roy M, Kim J, Markoulli M, Krishnan AV. In-vivo corneal confocal microscopy: Imaging analysis, biological insights and future directions. Commun Biol 2023; 6:652. [PMID: 37336941 DOI: 10.1038/s42003-023-05005-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 05/31/2023] [Indexed: 06/21/2023] Open
Abstract
In-vivo corneal confocal microscopy is a powerful imaging technique which provides clinicians and researcher with the capabilities to observe microstructures at the ocular surfaces in significant detail. In this Mini Review, the optics and image analysis methods with the use of corneal confocal microscopy are discussed. While novel insights of neuroanatomy and biology of the eyes, particularly the ocular surface, have been provided by corneal confocal microscopy, some debatable elements observed using this technique remain and these are explored in this Mini Review. Potential improvements in imaging methodology and instrumentation are also suggested.
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Affiliation(s)
- Jeremy Chung Bo Chiang
- School of Optometry and Vision Science, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, Australia
- School of Optometry, College of Health and Life Sciences, Aston University, Birmingham, NSW, UK
| | - Maitreyee Roy
- School of Optometry and Vision Science, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, Australia
| | - Juno Kim
- School of Optometry and Vision Science, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, Australia
| | - Maria Markoulli
- School of Optometry and Vision Science, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, Australia
| | - Arun V Krishnan
- School of Clinical Medicine, University of New South Wales, Sydney, NSW, Australia.
- Department of Neurology, Prince of Wales Hospital, Sydney, NSW, Australia.
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