title: Pretreatment of sinus aspirates with dithiothreitol improves yield of fungal cultures in patients with chronic sinusitis.
abstract: BACKGROUND
  Mold pathogens are a leading cause of chronic rhinosinusitis. Successful isolation of mold on culture is helpful in establishing a diagnosis and guiding therapy. Though mucolytic agents are commonly used in European countries, they are not part of everyday use in North America. In this case-control prospective study, we investigated the yield of fungal culture before and after treatment of sinus aspirates with the mucolytic agent dithiothreitol in a United States hospital.
  
  
  METHODS
  Over a 5-month period during 2011-2012, 359 sinus aspirates from 294 patients with symptoms suspicious for chronic sinusitis or allergic fungal sinusitis were collected. Aspirates were cultured on fungal medium before and after treatment with dithiothreitol.
  
  
  RESULTS
  Of the 359 pairs of cultures, 62 (17.3%) demonstrated mold growth on at least 1 of the plates, 9 (14.5%) of which grew more than 1 species of mold. A total of 75 molds were identified, 41 (54.7%) of which were successfully cultured only when the mucus was pretreated with dithiothreitol (p < 0.0001). Quantitatively, more colonies grew from dithiothreitol-treated mucus than from direct-inoculation (p < 0.0001).
  
  
  CONCLUSIONS
  This study confirms improved recovery of mold from sinus cultures after pretreatment of samples with dithiothreitol. Further studies are needed to correlate these findings with clinical outcome.
authors.affiliation: Department of Pathology, Stanford University School of Medicine, Stanford, CA.
authors.forename: Karen M
authors.initials: KM
authors.lastname: Chisholm
authors.forename: Diane
authors.initials: D
authors.lastname: Getsinger
authors.forename: Winston
authors.initials: W
authors.lastname: Vaughan
authors.forename: Peter H
authors.initials: PH
authors.lastname: Hwang
authors.forename: Niaz
authors.initials: N
authors.lastname: Banaei
mesh_terms: D016022:Case-Control Studies; D002908:Chronic Disease; D004229:Dithiothreitol; D005658:Fungi / Q000254:growth & development*; D006801:Humans; D009093:Mucus / Q000382:microbiology*; D009181:Mycoses / Q000175:diagnosis / Q000382:microbiology*; D009297:Nasal Mucosa / Q000382:microbiology*; D011446:Prospective Studies; D012852:Sinusitis / Q000175:diagnosis / Q000382:microbiology*; D014481:United States
chemical_list: D004229:Dithiothreitol
keywords: allergic fungal sinusitis; chronic sinusitis; culture; dithiothreitol; fungus; mold; mucolytic agent