Detection of fungal organisms in eosinophilic mucin using a fluorescein-labeled chitin-specific binding protein.
BACKGROUND
The ability to identify fungal hyphae in patients with chronic rhinosinusitis (CRS) has been inconsistent. A new fluorescein-labeled staining method targets chitin found in fungal cell walls.


OBJECTIVE
We hypothesize that this method would be able to more consistently detect fungi within the mucin of CRS patients.


METHODS
Fifty-four consecutive CRS surgical patients were evaluated. After ensuring sensitivity and specificity of this new method, all specimens were stained with either fluorescein-labeled chitinase or Grocott methanamine silver stain for comparison.


RESULTS
All 54 specimens contained eosinophilic mucin on hematoxylin and eosin staining. One or more fungal hyphae could be visualized within the mucin of 54 (100%) of 54 specimens stained using the fluorescein-labeled chitinase. Only 41 (76%) of 54 of the specimens stained with the Grocott methanamine silver stain technique demonstrated fungi.


CONCLUSIONS
The fluorescein-labeled chitinase-staining technique has greater sensitivity in detecting fungal organisms within eosinophilic mucin. Fungal organisms are present in the mucin of CRS patients.
Taylor
Matthew J
MJ
Division of Allergy and Infection Diseases, Mayo Clinic, Rochester, MN 55905, USA.
Ponikau
Jens U
JU
Sherris
David A
DA
Kern
Eugene B
EB
Gaffey
Thomas A
TA
Kephart
Gail
G
Kita
Hirohito
H
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002352:Carrier Proteins; D002686:Chitin / Q000302:isolation & purification*; D002688:Chitinases; D002908:Chronic Disease; D004802:Eosinophilia / Q000382:microbiology* / Q000473:pathology; D005260:Female; D005452:Fluoresceins; D005456:Fluorescent Dyes; D006801:Humans; D025301:Hyphae / Q000302:isolation & purification; D008297:Male; D008875:Middle Aged; D009077:Mucins / Q000302:isolation & purification*; D012220:Rhinitis / Q000382:microbiology* / Q000473:pathology; D012852:Sinusitis / Q000382:microbiology* / Q000473:pathology; D013194:Staining and Labeling / Q000379:methods*
D002352:Carrier Proteins; D005452:Fluoresceins; D005456:Fluorescent Dyes; D009077:Mucins; D002686:Chitin; D002688:Chitinases