title: Newer emerging pathogens of ocular non-sporulating molds (NSM) identified by polymerase chain reaction (PCR)-based DNA sequencing technique targeting internal transcribed spacer (ITS) region.
abstract: OBJECTIVE
  To apply Polymerase Chain Reaction (PCR)-based DNA sequencing targeting Internal Transcribed Spacer (ITS) region for identification of non-sporulating molds (NSM) to species level which formed 12% of ocular isolates of fungi in a tertiary eye hospital in South India.
  
  
  METHODS
  Fifty ocular filamentous fungal NSM isolates recovered from 45 patients were included in the study. PCR-based DNA sequencing technique targeting ITS region was applied to identify NSM.
  
  
  RESULTS
  PCR-based DNA sequencing revealed 23 established pathogens involving 8 genera (Aspergillus, Fusarium, Bipolaris, Pythium, Cochilobolus, Exserohilum, Pseudoallescheria, and Scedosporiumspecies) and 27 emerging pathogens involving 7 genera (Botryosphaeria Lasiodiplodia species, Thielavia tortuosa, Glomerulla singulata, Macrophomina phaseolina, Rhizoctonia bataticola, and Podosporaspecies) reported for the first time in literature related to ocular infections. Fifteen (30%) patients with fungal keratitis caused by NSM failed to respond to standard antifungal therapy.
  
  
  CONCLUSIONS
  PCR-based DNA sequencing technique is a rapid, reliable, and valuable tool to identify 54% of NSM as newer potential pathogens of fungi causing ocular mycoses.
authors.affiliation: L & T Microbiology Research Centre, Vision Research Foundation, Chennai, India.
authors.forename: R
authors.initials: R
authors.lastname: Bagyalakshmi
authors.forename: K L
authors.initials: KL
authors.lastname: Therese
authors.forename: S
authors.initials: S
authors.lastname: Prasanna
authors.forename: H N
authors.initials: HN
authors.lastname: Madhavan
mesh_terms: D001483:Base Sequence; D003320:Corneal Ulcer / Q000382:microbiology*; D004271:DNA, Fungal / Q000032:analysis; D021903:DNA, Ribosomal Spacer / Q000032:analysis*; D015821:Eye Infections, Fungal / Q000382:microbiology*; D005658:Fungi / Q000145:classification* / Q000235:genetics / Q000472:pathogenicity*; D006801:Humans; D008969:Molecular Sequence Data; D016533:Mycological Typing Techniques; D009181:Mycoses / Q000382:microbiology*; D016133:Polymerase Chain Reaction
chemical_list: D004271:DNA, Fungal; D021903:DNA, Ribosomal Spacer