Antifungal Susceptibility, Morphological and Molecular Characterization of Lasiodiplodia theobromae Isolated from a Patient with Keratitis

Mycopathologia. 2018 Jun;183(3):565-571. doi: 10.1007/s11046-017-0234-5. Epub 2018 Jan 30.

Abstract

Lasiodiplodia theobromae is a rare ocular pathogen. We report a patient with fungal keratitis caused by L. theobromae. The patient was a 75-year-old male, a farmer with diabetes type II, and no previous history of ocular trauma. Histopathology analysis revealed the presence fungi invading Descemet's membrane of the cornea. The fungus was characterized by septate, highly bulged fungal filaments involving full corneal thickness in the corresponding histopathology specimens. A dematiaceous mold was isolated and initally identified as L. theobromae by microscopic and macroscopic morphology, and further confirmed by PCR-based determination of internal transcribed spacer (ITS) regions of ribosomal DNA. Antifungal susceptibility tests showed sensitivity to amphotericin B (AMB) and voriconazole ( VRC), and resistance to other azoles, including itraconazole (ITC) and fluconazole (FLC). Corneal transplant was performed. Despite in vitro itraconazole resistance, the patient was successfully treated with oral itraconazole, topical voriconazole and natamycin, combined with ocular injections of amphotericin B and voriconazole.

Keywords: Amphotericin B; Antifungal treatment; Corneal ulcer; Fungal keratitis; Lasiodiplodia theobromae; Voriconazole.

Publication types

  • Case Reports

MeSH terms

  • Aged
  • Antifungal Agents / administration & dosage
  • Antifungal Agents / pharmacology
  • Ascomycota / cytology*
  • Ascomycota / drug effects
  • Ascomycota / genetics
  • Ascomycota / isolation & purification*
  • Cornea / pathology
  • Corneal Transplantation
  • DNA, Fungal / chemistry
  • DNA, Fungal / genetics
  • DNA, Ribosomal Spacer / chemistry
  • DNA, Ribosomal Spacer / genetics
  • Diabetes Mellitus, Type 2 / complications
  • Drug Resistance, Fungal
  • Eye Infections, Fungal / drug therapy
  • Eye Infections, Fungal / microbiology*
  • Eye Infections, Fungal / surgery
  • Histocytochemistry
  • Humans
  • Keratitis / drug therapy
  • Keratitis / microbiology*
  • Keratitis / surgery
  • Male
  • Microbial Sensitivity Tests
  • Microbiological Techniques
  • Polymerase Chain Reaction
  • Sequence Analysis, DNA
  • Treatment Outcome

Substances

  • Antifungal Agents
  • DNA, Fungal
  • DNA, Ribosomal Spacer