Non-traumatic keratitis due to Colletotrichum truncatum

Abstract

Introduction:The fungal genus Colletotrichum is an uncommon cause of human infections. It has been implicated in cutaneous phaeohyphomycosis, artritis and keratitis secondary to traumatic implantation.Case presentation:We report two cases of keratitis due Colletotrichum truncatum in middle-aged, immunocompetent persons without history of trauma. The aetiological agents were identified based on DNA sequencing. Azoles and echinocandins showed high minimal inhibitory concentrations while amphotericin B was ≤ 0.25 mg l−1. Both patients failed topical antifungal treatment and needed penetrating keratoplasty with a favourable outcome.Conclusion:C. truncatum caused keratomycosis which did not respond to topical antifungal agents. To the best of our knowledge these are the first reported cases of keratitis due to this fungus in Cuba and Latin-America and highlights the expanding spectrum of fungal agents causing eye infections.

Colletotrichum keratitis: A rare yet important fungal infection of human eyes

“…Among the known species of Colletotrichum , C. dematium is the most reported pathogen for keratitis, followed by C. gloeosporioides and C. truncatum. In our study, all seven isolates belonged to two species complexes: C. truncatum and C. gloeosporioides and no C. dematium . C. dematium has been synonymised with many species, especially C. truncatum , but now they are found phylogenetically distinct and belongs to their own clades .…”

“…It used to be an infrequent cause—accounting for 1.85%‐3.33%—of fungal keratitis diagnosed by smear and cultures . Current knowledge of Colletotrichum keratitis is based on sporadic case reports and a few small case series from various countries, including India, the United States, Japan, Spain, Canada, and Cuba . Previous studies reported that the ratio of Colletotrichum spp.…”

“…Species implicated in keratitis include C. dematium , C. coccodes, C. gloeosporioides , C. graminicola , C. crassipes, C. truncatum, and a Colletotrichum isolate without identification to species level . Only a few studies have diagnosed Colletotrichum keratitis based on nucleic acid sequence analyses, mainly sequencing the internal transcribed spacer (ITS) regions of ribosomal DNA . However, along with the application of molecular methods in fungal taxonomy, several new species of Colletotrichum are described based on not only their morphological characters, but also their molecular signatures.…”

“…3 Colletotrichum spp. has been recognised as a rare cause of human infections in recent years, 4 it can cause cutaneous mycosis, 5 arthritis, 6 endophthalmitis, 2,7 and keratitis. 2,8,9 Cases of Colletotrichum keratitis, an infrequent cause of fungal keratitis, are mostly documented in case reports and small series.…”

“…2,8,9 Cases of Colletotrichum keratitis, an infrequent cause of fungal keratitis, are mostly documented in case reports and small series. Species implicated in keratitis include C. dematium, [10][11][12][13][14] C. coccodes, 13,15,16 C. gloeosporioides, 9,[17][18][19][20] C. graminicola, 21,22 C. crassipes, 13 C. truncatum, 2,4,8 and a Colletotrichum isolate without identification to species level. [23][24][25] Only a few studies have diagnosed Colletotrichum keratitis based on nucleic acid sequence analyses, mainly sequencing the internal transcribed spacer (ITS) regions of ribosomal DNA.…”