|INFECTIOUS DISEASE GRAND ROUND
|Year : 2020 | Volume
| Issue : 3 | Page : 472-474
Mycotic keratitis due to Cylindrocarpon lichenicola: Successful salvage of the eye
M Suchitra Shenoy1, Rajesh R Nayak2, Vijay Pai3, K Archana Bhat1
1 Department of Microbiology, Kasturba Medical College, Mangalore, Manipal Academy of Higher Education, Manipal, Karnataka, India
2 Department of Ophthalmology, Kasturba Medical College, Mangalore, Manipal Academy of Higher Education, Manipal, Karnataka, India
3 Department of Ophthalmology, K.S. Hegde Medical Academy, Mangalore, Karnataka, India
|Date of Submission||29-Aug-2020|
|Date of Decision||13-Sep-2020|
|Date of Acceptance||10-Oct-2020|
|Date of Web Publication||4-Nov-2020|
Dr. K Archana Bhat
Department of Microbiology, Kasturba Medical College, Mangalore, Manipal Academy of Higher Education, Manipal, Karnataka - 575 001
Source of Support: None, Conflict of Interest: None
We hereby report a successfully salvaged eye due to mycotic keratitis by Cylindrocarpon lichenicola in a 60-year-old female from Kasaragod (Kerala). The patient came with a history of pain, photophobia and decreased vision of the right eye. The microbiological investigations of the corneal scraping revealed C. lichenicola. C. lichenicola is a soil saprophyte. Since the ulcer worsened paracentesis followed by therapeutic keratoplasty and adjunct therapy with natamycin drops, voriconazole drops and oral ketoconazole was given. We stress that evidence-based timely medical and surgical intervention helped in the restoration of the vision in an infected eye.
Keywords: Cylindrocarpon lichenicola, keratoplasty, ketoconazole, mycotic keratitis, paracentesisCylindrocarpon lichenicola, keratoplasty, ketoconazole, mycotic keratitis, paracentesis
|How to cite this article:|
Shenoy M S, Nayak RR, Pai V, Bhat K A. Mycotic keratitis due to Cylindrocarpon lichenicola: Successful salvage of the eye. Indian J Med Microbiol 2020;38:472-4
|How to cite this URL:|
Shenoy M S, Nayak RR, Pai V, Bhat K A. Mycotic keratitis due to Cylindrocarpon lichenicola: Successful salvage of the eye. Indian J Med Microbiol [serial online] 2020 [cited 2020 Nov 28];38:472-4. Available from: https://www.ijmm.org/text.asp?2020/38/3/472/299844
| ~ Introduction|| |
Mycotic keratitis is common in the tropics and developing countries. People working outdoors and those involved in agriculture are at increased risk. The soil particles or plant materials with the fungal spores maybe a predominant source. Mycotic keratitis maybe a diagnostic challenge to the laboratory physician as well as the clinician. Reports of mycotic keratitis due to Cylindrocarpon lichenicola from published literature are very few. We hereby present a case of mycotic keratitis secondary to a rare, emerging hyaline fungus Cylindrocarpon lichenicola, in an immunocompetent patient.
| ~ Case Report|| |
The patient was a female aged about 60 years from a village in Kasaragod (Kerala) presented with watering, irritation, pain, photophobia and redness of the right eye for 1 week. History of any trauma or foreign body in the eyes was not mentioned. She was neither using a contact lens nor gave any history of previous ocular infection or disease.
The right eye was examined which showed a visual acuity restricted to perception of light only and a slit-lamp examination revealed circumcorneal congestion and a corneal ulcer which had irregular margins, striate keratopathy and an epithelial defect with corneal infiltration. The examination of the anterior chamber revealed the presence of hypopyon. Examination of the left eye revealed senile immature cataract. Differential diagnosis of bacterial and fungal keratitis was considered.
Corneal scrapings were taken from the edges and base of the corneal ulcer and sent for Gram's stain, Potassium hydroxide (KOH) mount, bacteriological and fungal culture.
Gram stain and bacteriological culture of corneal scrapings showed no organisms and no growth. KOH mount showed no fungal elements. Topical natamycin (5%), topical moxifloxacin and topical mydriatics were started empirically. Initially, the ulcer was quiescent, but after 5 days of treatment, the ulcer worsened which obviated the need for surgical intervention. Hence, lateral tarsorrhaphy was done impending perforation. The hypopyon regressed initially with topical ceftazidime and intravenous cefotaxime. However, after 2 days the ulcer worsened resulting in a stromal abscess despite antibiotic treatment. Hence, paracentesis with lateral tarsorrhaphy was done. The paracentesis sample was sent for bacteriological and fungal culture. Gram's stain of the paracentesis sample revealed that no organisms, bacteriological culture revealed no growth. KOH mount of the paracentesis sample showed septate fungal hyphae. Culture on Sabouraud's dextrose agar at 25°C [Figure 1], after 5 days showed initial white floccose growth of a fungus, later with age it was pale brown. Reverse of the fungal colony was light reddish-brown. Slide culture [Figure 2] showed thin, hyaline, septate hyphae. The conidiophore was simple, long and sparsely branched. The conidiophore was slender and tapering towards the end bearing conidiogenous cells (phialides). Macroconidia were arranged in singles and clusters at the apices of phialides. The macroconidia were cylindrical and smooth walled. The apex of macroconidia was blunt and rounded, had a truncate base with 3–6 septa. Terminal, hyalineand globose chlamydospores were seen. Microconidia were absent. Lactophenol cotton blue mount was consistent with the morphology of Cylindrocarpon lichenicola.
|Figure 2: Slide culture mount showing abundant cylindrical macroconidia and a single terminal, hyaline and globose chlamydospore|
Click here to view
Fusarium species resembles Cylindrocarpon species both in morphology and taxonomy. Hence, C. lichenicola may wrongly be identified as Fusarium solani.
The patient was started on oral ketoconazole. However, in spite of intervention and antifungal therapy the ulcer worsened necessitating therapeutic keratoplasty. On table, intracameral voriconazole injection was given. The corneal button was removed and sent for fungal culture. C. lichenicola was isolated from the corneal button as well.
The patient was continued on oral ketoconazole 200 mg BD for 4 weeks. The patient was continued on natamycin and voriconazole eye drops four times for 4 weeks. The eye is stabilised, but the graft has become opaque. A future re-keratoplasty is planned.
Cylindrocarpon infections are similar to that of F. solani. Cylindrocarpon spp. may cause mycotic keratitis. However, microscopically unlike F. solani, Cylindrocarpon differs in the shape of macroconidia (straight not curved/sickle shaped) and the apical cells are rounded (Cylindrocarpon spp.) and not tapering (Fusarium spp.). When the cost of therapy is not a concern, voriconazole is the antifungal of choice, especially in the treatment of atypical forms, or rarely reported fungus. Medical treatment failure is the prime indication for therapeutic keratoplasty.
Cylindrocarpon belongs to Family Nectriaceae, Order Hypocreales, Class Sardariomycetes, Phylum Ascomycetes. It has >35 species, six varieties and four groups. Each group differs from the presence or absence of microconidia and chlamydoconidia. Cylindrocarpon cyanescens, Cylindrocarpon vaginae, C. lichenicola and Cylindrocarpon destructans are the species that infect humans, of which C. lichenicola is associated with invasive disease.C. vaginae show small clumps or clusters of chlamydospores at the apex of the branches of hyphae, a feature that differentiates it from C. lichenicola.C. cyanescens possesses abundant microconidia but lacks macroconidia.C. lichenicola lacks microconidia and this differentiates it from the other two species, i.e., C. cyanescens and C. destructans which may produce microconidia.,
Massalongo was the one who originally reported C. lichenicola as Fusarium lichenicola.
Cylindrocarpon species is a soil saprophyte commonly inhabiting the roots of plants and trees in India and other countries with a tropical climate. Cylindrocarpon survives well in the hot and humid atmosphere of South India. Hence, it is commonly seen in agriculturists and people who work outdoors in whom accidental trauma may predispose to infection with this fungus. Our patient was an elderly female from a rural part of Kasaragod, Kerala (South India) which has hot and humid weather. She was immunocompetent and nondiabetic presented with keratitis. There was no history of any trauma. Probably due to the constant outdoor activities of the patient, there was accidental inoculation of the fungus into the eye by the strong winds associated with monsoon rains. Apart from mycotic keratitis, Cylindrocarpon may cause nonocular infections (athlete's foot, mycetoma following injury, disseminated infection in neutropenic patientsand peritonitis) in humans.
Keratomycosis due to C. lichenicola has been reported earlier from various geographic locations around the world, but this is the first report of keratomycosis from this part of South India. C. lichenicola causing cutaneous lesions has been reported from Sullia (south India).C. lichenicola causing keratomycosis has been reported from Tamil Nadu (South India).
The spectrum of infections caused by Cylindrocarpon spp. in humans is similar to F. solani infections. Compared to Fusarium species, reports of mycotic keratitis caused by Cylindrocarpon species are rare. Furthermore, the species of Cylindrocarpon appear similar in tissue, but they differ in their invasive ability. However, limited data are available with this regard. Data suggest poor prognosis and poor outcome of antifungal therapy in the treatment of either of these fungi. The response to topical voriconazole may vary by etiological agent. Although topical natamycin 5% has been reported to be successful in the treatment of Cylindrocarpon keratitis there are few reports with poor outcomes. Several studies have reported that systemic ketoconazole, itraconazole, miconazole, fluconazole, voriconazole and posaconazole have favorable outcomes. Ketoconazole due to its broad spectrum of activity is the preferred empirical antifungal of choice. Voriconazole may be used due to lesser side effects. In cases with advanced keratitis, impending perforations, keratitis threatening to involve limbus, severe corneal thinning, the decision to perform keratoplasty must be taken early. In our case, topical natamycin 5%, oral ketoconazole and topical voriconazole were used for treatment along with timely surgical intervention.
Our present experience supports the view that Cylindrocarpon spp. causes severe keratitis, however, early diagnosis and timely medical and surgical intervention helped in salvaging the eye stressing the need for evidence-based treatment.
The authors are grateful to Manipal Academy of Higher Education, Manipal and K.S Hegde Medical Academy, Mangalore for all the support.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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