Molecular identification of Podospora bulbillosa keratitis with progressive stromal thinning: a case report

Articles in Press

Document Type : Original Article

Authors

1 Farabi Eye Hospital, Tehran University of Medical Sciences; Department of Ophthalmology, School of Medicine, Islamic Azad University Tehran Medical Sciences, Tehran, Iran

2 Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran

3 Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran

4 Microbiology Unit, Department of Pathology, Farabi Eye Hospital, Tehran University of Medical Sciences, Tehran, Iran

5 Department of Medical Parasitology and Mycology, Faculty of Medical Sciences, Shahed University, Tehran, Iran

Abstract

Fungal keratitis (FK) is a sight-threatening corneal infection that is particularly prevalent in developing countries. This report describes a case of Podospora bulbillosa keratitis, a rare organism confirmed by polymerase chain reaction (PCR) following negative culture results. A 63-year-old male presented with a well-demarcated yellow-brown stromal infiltration. Microbiological evaluation revealed pigmented septate hyphae; however, culture remained negative, and molecular identification was performed using ITS1-5.8S-ITS2 rDNA sequences, which identified the isolate as Podospora bulbillosa (formerly Cladorrhinum bulbillosum). The patient received intensive topical voriconazole 1% and chlorhexidine 0.2% combined with oral voriconazole. Progressive thinning required cyanoacrylate glue. The infection resolved over three months, leaving a central scar. While infections by this organism have been rarely reported, additional cases are crucial to consolidate knowledge of clinical presentation and potential aggressiveness. This case emphasizes the value of molecular diagnostic tools in detecting unusual pathogens and guiding therapy.
 

Keywords

Main Subjects

References

Atighehchian M, Ghassemi H, Latifi G, Ouano D, Abedinifar Z, Zarei-Ghanavati M. 2025a. Topical caspofungin 0.5% monotherapy for filamentous fungal keratitis. Cornea. 45 (1): 13-20. https://doi.org/ 10.1097/ICO.0000000000003790.
Atighehchian M, Khodavaisy S, Abedinifar Z, Izadi A, Mosavand A, Zarei-Ghanavati M. 2025b. Unveiling rare fungal pathogens: clinical insights and molecular identification in fungal keratitis cases. International Ophthalmology. 46(1): 52. https://doi.org/10.1007/s10792-025-03908-5.
 Atighehchian M, Latifi G, Bardan AS, Ouano D, Zarei-Ghanavati S, Abedinifar Z, Zarei-Ghanavati M. 2025c. Comparative efficacy and safety of topical caspofungin 0.5% and voriconazole 1% for fungal keratitis: a pilot clinical trial. Scientific Reports. 15(1): 38879. https://doi.org/10.1038/s41598-025-22615-w.
Buchta V, Nekolová J, Jirásková N, Bolehovská R, Wipler J, Hubka V. 2019. Fungal keratitis caused by Colletotrichum dematium: case study and review. Mycopathologia. 184(3): 441-453. https://doi.org/10.1007/s11046-019-00335-w.
Gajjar D, Pal A, Santos J, Ghodadra B, Vasavada A. 2011. Severe pigmented keratitis caused by Cladorrhinum bulbillosum. Indian Journal of Medical Microbiology. 29(4): 434. https://doi.org/10.4103/0255-0857.90191.
Ghenciu LA, Faur AC, Bolintineanu SL, Salavat MC, Maghiari AL. 2024. Recent advances in diagnosis and treatment approaches in fungal keratitis: a narrative review. Microorganisms. 12(1): 161. https://doi.org/10.3390/microorganisms12010161.
Ghosh A, Kaur H, Gupta A, Singh S, Rudramurthy SM, Gupta S, Chakrabarti A. 2020. Emerging dematiaceous and hyaline fungi causing keratitis in a tertiary care centre from North India. Cornea. 39(7): 868-876. https://doi.org/10.1097/ICO.0000000000002295.
Khalili MR, Abtahi SMB, Atighehchian M, Hosseini S, Shirvani M, ... et al. 2020. Invasive fungal keratitis as an uncommon form of mucormycosis leading to endophthalmitis: report of two cases and literature review. Current Fungal Infection Reports. 14(4): 384-390. https://doi.org/10.1007/s12281-020-00403-5.
Madrid H, Cano J, Gené J, Guarro J. 2011. Two new species of Cladorrhinum. Mycologia. 103(4): 795-805.  https://doi.org/10.3852/10-150. 
Mitra S, Garg P, Murthy S, Jakati S, Dave VP, Seba E. 2024. Antifungal resistance, clinical outcome and clinico-microbiological correlation in ocular infections due to common melanized fungi Curvularia lunata and Lasiodiplodia theobromae in South India. Journal of Medical Microbiology. 73(11). 001924. https://doi.org/10.1099/jmm.0.001924.
Narayanan N, Bandodkar N, Anand AR. 2023. First report of a ring corneal ulcer caused by Cladorrhinum bulbillosum posing a diagnostic debacle: a case report. Indian Journal of Ophthalmology - Case Reports. 3(3): 663-667. https://doi.org/10.4103/IJO.IJO_868_23.
Natarajan R, Mehta S. 2020. Cladorrhinum bulbillosum keratitis: unraveling an unusual infection. Current Fungal Infection Reports. 14: 373-377. https://doi.org/10.1007/s12281-020-00405-3.
Sharma N, Bagga B, Singhal D, Nagpal R, Kate A, Saluja G, … et al. 2022. Fungal keratitis: A review of clinical presentations, treatment strategies and outcomes. The Ocular Surface.  24: 22-3. https://doi.org/10.1016/j.jtos.2021.12.001.
Tawde Y, Das S, Gupta A, Sharma S, Basak S, Shrimali T, … et al. 2023. Development of single-tube real-time PCR assay for the rapid detection of Aspergillus and Fusarium—the two most common causative agents in fungal keratitis. Mycoses. 66(9): 801-809. https://doi.org/10.1111/myc.13618.
 Wang XW, Bai FY, Bensch K, Meijer M, Sun BD, Han YF, Crous PW, Samson RA, Yang FY, Houbraken J. 2019. Phylogenetic re-evaluation of Thielavia with the introduction of a new family Podosporaceae. Studies in Mycology. 93: 155-252. https://doi.org/10.1016/j.simyco.2019.08.002.
Zapater RT, Scattini F. 1979. Mycotic keratitis by Cladorrhinum. Sabouraudia: Journal of Medical and Veterinary Mycology. 17(1): 65-69. https://doi.org/10.1080/00362177985380081.
Mycologia Iranica

Articles in Press, Accepted Manuscript
Available Online from 30 June 2026

Files

History

  • Receive Date: 28 May 2026
  • Revise Date: 21 June 2026
  • Accept Date: 25 June 2026
  • Publish Date: 30 June 2026

Share

How to cite

Statistics