Diagnostic Evaluation of Co-Occurrence of Acanthamoeba and Fungi in Keratitis: A Preliminary Report

Raghavan, Anita; Baidwal, Shaffie; Vijayaraghavan, Prabhu; Rajeswari, Sakthi; Rajaraman, Revathi; Narendran, Venkatapathy; Menon, Sunitha; Rammohan, Ram

doi:10.1097/ico.0000000000001441

Cited by 4 publications

(2 citation statements)

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“…Since IK can be caused by a variety of microorganisms and often reflects polymicrobial co-infection also including fungi and/or bacteria in addition to Acanthamoeba (10,11), a strategy to addressing this situation could be to apply Next Generation Sequencing (NGS) of ribosomal genes in corneal scrapings to screen for all non-viral causes of IK in the early phase of the disease.…”

Section: Introductionmentioning

confidence: 99%

Detection and Identification ofAcanthamoebaand Other Nonviral Causes of Infectious Keratitis in Corneal Scrapings by Real-Time PCR and Next-Generation Sequencing-Based 16S-18S Gene Analysis

et al. 2021

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Acanthamoeba is a free-living amoeba of extensive genetic diversity. It may cause infectious keratitis (IK), which can also be caused by bacteria, fungi, and viruses. High diagnostic sensitivity is essential to establish an early diagnosis of Acanthamoeba-associated keratitis. Here, we investigated the applicability of next-generation sequencing (NGS)-based ribosomal gene detection and differentiation (16S-18S) compared with specific real-time PCR for detection of Acanthamoeba. Two hundred DNAs extracted from corneal scrapings and screened by Acanthamoeba-specific real-time PCR were analyzed using an in-house 16S-18S NGS assay. Of these, 24 were positive using specific real-time PCR, 21 of which were positive using the NGS assay. Compared with real-time PCR; the specificity and sensitivity of the NGS assay were 100% and 88%, respectively. Genotypes identified by the NGS assay included T4 (n = 19) and T6 (n = 2). Fungal and bacterial species of potential clinical relevance were identified in 31 of the samples negative for Acanthamoeba, exemplified by Pseudomonas aeruginosa (n = 11), Moraxella spp. (n = 6), Staphylococcus aureus (n = 2), Fusarium spp. (n = 4), and Candida albicans (n = 1). Conclusively, the 16S-18S assay was slightly less sensitive than real-time PCR in detecting Acanthamoeba-specific DNA in corneal scrapings. Robust information on genotype was provided by the NGS assay, and other pathogens of potential clinical relevance were identified in 16% of the samples negative for Acanthamoeba. NGS-based detection of ribosomal genes in corneal scrapings could be an efficient screening method for detecting non-viral causes of IK, including Acanthamoeba.

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Section: Introductionmentioning

confidence: 99%

Detection and Identification ofAcanthamoebaand Other Nonviral Causes of Infectious Keratitis in Corneal Scrapings by Real-Time PCR and Next-Generation Sequencing-Based 16S-18S Gene Analysis

et al. 2021

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“…Aufgrund der möglichen Koinfektion sind wir der Meinung, dass alle diagnostischen Modalitäten – Polymerasekettenreaktion (PCR), In-vitro-Kultivierung, Histologie und in vivo konfokale Mikroskopie – parallel durchgeführt werden sollten [ 4 , 11 ]. Bei der therapierefraktären kontaktlinsenassoziierten mykotischen Keratitis muss man nicht selten auch auf Koinfektionen oder Superinfektionen gefasst sein [ 8 , 9 ]. Bei Koinfektionen ist es meistens problematisch, rechtzeitig die adäquate Therapie einzuleiten.…”

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Mischinfektionen bei kontaktlinsenassoziierter mykotischer Keratitis mit Pseudomonas oder Akanthamöben

et al. 2020

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ZusammenfassungKontaktlinsenassoziierte Keratitiden werden immer häufiger. Die mykotische Keratitis ist ein relativ seltenes, aber sehr ernst zu nehmendes Krankheitsbild. Meist wird im Frühstadium eine falsche Diagnose gestellt und dadurch die adäquate Therapie verzögert. Bei der therapierefraktären kontaktlinsenassoziierten mykotischen Keratitis können nicht selten auch Koinfektionen oder Superinfektionen bestehen. Wir stellen 2 Patienten mit initial unklarer Keratitis vor, bei denen eine Mischinfektion der mykotischen Keratitis mit Pseudomonas aeruginosa bzw. Akanthamöben nachgewiesen werden konnte. In beiden Fällen war die zeitnahe perforierende Excimerlaser-Keratoplastik mit Einzelknüpfnähten und adäquater Lokaltherapie über 8 Wochen therapeutisch erfolgreich.

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The Acanthamoeba–Fungal Keratitis Study

Raghavan

Baidwal

Narendran

et al. 2019

American Journal of Ophthalmology

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Diagnostic Evaluation of Co-Occurrence of Acanthamoeba and Fungi in Keratitis: A Preliminary Report

Cited by 4 publications

References 48 publications

Detection and Identification ofAcanthamoebaand Other Nonviral Causes of Infectious Keratitis in Corneal Scrapings by Real-Time PCR and Next-Generation Sequencing-Based 16S-18S Gene Analysis

Detection and Identification ofAcanthamoebaand Other Nonviral Causes of Infectious Keratitis in Corneal Scrapings by Real-Time PCR and Next-Generation Sequencing-Based 16S-18S Gene Analysis

Mischinfektionen bei kontaktlinsenassoziierter mykotischer Keratitis mit Pseudomonas oder Akanthamöben

The Acanthamoeba–Fungal Keratitis Study

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