Indian Journal of Pathology and Microbiology

CASE REPORT
Year
: 2016  |  Volume : 59  |  Issue : 1  |  Page : 117--118

Keratomycosis caused by Blastoschizomyces capitatus


Susanta Kumar Sahu1, Jayashree Dora2, Gopeswari Hota2,  
1 Department of Microbiology, VSS Institute of Medical Sciences and Research, Burla, Sambalpur, Odisha, India
2 Department of Ophthalmology, VSS Institute of Medical Sciences and Research, Burla, Sambalpur, Odisha, India

Correspondence Address:
Susanta Kumar Sahu
Department of Microbiology, VSS Institute of Medical Sciences and Research, Burla, Sambalpur - 768 017, Odisha
India

Abstract

Keratomycosis or fungal infections of cornea are common causes of ocular morbidity particularly in developing countries and in tropical climate. Traumatic inoculation is the predominant predisposing factor for this condition. Most of the cases are caused by filamentous fungi. Blastoschizomyces capitatus is one of the emerging fungal agents causing infection in different organ systems particularly in immunocompromised individuals. Barring one case of keratitis and melting of corneal graft there is no report of keratomycosis by B. capitatus. Here we present a case of keratomycosis caused by B. capitatus, which is the first such case reported from India.



How to cite this article:
Sahu SK, Dora J, Hota G. Keratomycosis caused by Blastoschizomyces capitatus.Indian J Pathol Microbiol 2016;59:117-118


How to cite this URL:
Sahu SK, Dora J, Hota G. Keratomycosis caused by Blastoschizomyces capitatus. Indian J Pathol Microbiol [serial online] 2016 [cited 2021 Nov 30 ];59:117-118
Available from: https://www.ijpmonline.org/text.asp?2016/59/1/117/178232


Full Text

 INTRODUCTION



Fungal infections of the cornea (mycotic keratitis, keratomycosis) are common causes of ocular morbidity, particularly in the agricultural areas of developing countries. [1] The filamentous fungi are the predominant cause of fungal keratitis following trauma. [2] Blastoschizomyces capitatus, previously known as Trichosporon capitatum or Geotrichum capitatum or Blastoschizomyces pseudotrichosporom is a yeast-like fungus widely distributed in nature and may form a minor part of the microflora of skin, gastrointestinal, and respiratory tract. [3],[4],[5] It is a rare cause of invasive fungal infection in immunocompromised individuals. However, there are reports of its isolation from immunocompetent hosts also. [6],[7] Reports of keratitis caused by this fungus are rare, and literature search showed no report of B. capitatus keratitis from the Indian subcontinent. We here present, probably for the first time from India, a case of keratitis caused by B. capitatus in a patient presenting with a history of corneal trauma.

 CASE REPORT



The patient, a 52-year-old agriculture worker from a rural area, was admitted in the ophthalmology ward with purulent corneal ulcer. He had a history of a foreign body in the eye 5 days back which was unsuccessfully treated at a local hospital. Routine investigations of blood showed normal hematological and biochemical values. He was HIV-seronegative and was not a known diabetic nor on any immunosuppressive therapy.

The patient was examined in the ophthalmology department, put under antibiotic therapy, both topical and systemic and taken for operation theater. Under the operating microscope, the foreign body was removed and corneal scrapings collected. The foreign body and part of the corneal scrapings were sent in sterile normal saline for microscopy. A part of the corneal scrapings are directly inoculated onto sheep blood agar (BA), Cystine-Lactose-Electrolyte Deficient (CLED) agar, Sabouraud Dextrose agar (SDA), and SDA with cycloheximide. The BA and CLED agar plates were incubated at 37±C; the inoculated SDA tubes were incubated at room temperature. A part of the scrapings was smeared on a clean slide for Gram stain.

In 10% KOH mount of the foreign body, a structure resembling an insect wing was observed under the microscope [[Figure 1]-inset]. Branching hyphal strands with oval and spherical yeast like cells were also seen in the corneal scrapings [Figure 1].{Figure 1}

Culture of the corneal scrapings on SDA, BA, and CLED agar revealed growth of whitish and wrinkled yeast-like colonies after 72 h of incubation [[Figure 2] on left]. The isolate was resistant to cycloheximide. Gram stain of the colonies showed the presence of budding yeast cells and pseudohyphae, branching hyphae, and the presence of anneloconidia and arthroconidia [[Figure 2] on right]. The fungus was found to assimilate glucose and galactose; other sugars such as lactose, sucrose, maltose, mannitol, trehalose, and raffinose are not assimilated; it was urease negative and able to grow at 45±C. The isolate was identified as B. capitatus by its morphology, ability to grow at 45±C, resistance to cycloheximide and biochemical reactions.{Figure 2}

The patient showed improvement after put under systemic liposomal amphotericin B and topical antifungal treatment.

 DISCUSSION



Fungal keratitis is one of the major causes of ocular morbidity in tropical countries. It may account for more than 50% of ocular mycosis. It is largely seen in young adults with trauma as a major predisposing factor. In a large series of case studies from South India, it is seen that the filamentous fungi are the major cause of keratomycosis. Depending upon geographic location 6-20% of all microbial keratitis cases are due to fungal infection. While tropical climates show a preponderance of filamentous fungi, temperate climates show higher percentages of yeast infections. [2],[6]

B. capitatus is one of the rare and emerging causes of invasive fungal disease in immunocompromised individuals such as neutropenia, leukemia, bone marrow transplant recipients, aplastic anemia, and endocarditis. It has been reported to cause fungemia, pneumonia, brain abscess, osteomyelitis, urinary tract infection, endocarditis, hepatosplenic infection, spondylosis, discitis and onychomycosis. [3],[4],[5] Rarely cases of invasive disease by B. capitatus in immunocompetent hosts have been reported. In our particular case, there is no evidence of any immunological suppression or neutropenia.

Though the exact source of infection is not known, it has been isolated from environmental sources as well as from the human skin and mucosal flora. Climatic factors seem to play some selective role in the epidemiology of infections caused by B. capitatus. Most cases (87%) are reported from Europe, particularly in the Mediterranean region during the hottest period of the year. [5] However, since the last few years cases of invasive infection have been reported from India both from immunocompromised as well as immunocompetent hosts. [7],[8]

Reports of keratitis caused by B. capitatus are scarce. Levy et al. had reported a case of B. capitatus keratitis and melting in a corneal graft in Canada. [9] Literature search showed no case of B. capitatus keratitis reported from the Indian subcontinent. In the present case, the individual has no predisposing factor except trauma by a foreign body. Though there was no other immunocompromised condition, corneal trauma may itself predispose the individual to that infection.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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