Identification of Aspergillus species in oral tissue samples of patients with hematologic malignancies by in situ hybridization: a preliminary report.
OBJECTIVE
A definitive diagnosis of invasive oral aspergillosis can be difficult because the culturing of tissue samples frequently fails to isolate Aspergillus species. In addition, the mycelial elements of Aspergillus species seen in tissue sections are histopathologically indistinguishable from those of non-Aspergillus species. We analyzed the usefulness of a DNA probe directed against the alkaline proteinase (ALP) gene of Aspergillus fumigatus for the identification of Aspergillus species by the in situ hybridization (ISH) technique in patients with oral mycosis.


METHODS
The ALP probe was tested on tissue specimens from 16 patients with hematologic malignancies who had invasive, orofacial fungal infections and a positive culture for one of the following organisms: Aspergillus species in 13 patients (A. flavus in 10, A. terreus in 2, and A. fumigatus in 1), and Exophiala dermatitis, Trichoderma longibrachiatum, and Candida albicans in 1 patient each. In situ hybridization with the ALP probe was performed using formalin-fixed, paraffin-embedded tissue samples.


RESULTS
The ALP probe showed a strong reaction with specimens from all 13 patients who had culture-proven aspergillosis specimens attributable to A. flavus, A. terreus, and A. fumigatus. On the other hand, the ALP probe showed no cross-reactivity with other fungi (Exophiala dermatitis, Trichoderma longibrachiatum, and Candida albicans).


CONCLUSIONS
These findings indicate that ISH using an ALP probe may increase the accuracy of diagnosing invasive oral aspergillosis in immunocompromised patients, and facilitate the provision of adequate antifungal treatment.
Myoken
Yoshinari
Y
Department of Oral Surgery, Hiroshima Red Cross and Atomic Bomb Survivors Hospital, Hiroshima, Japan. myoken@do5.enjoy.ne.jp
Sugata
Tatsumi
T
Mikami
Yuzuru
Y
Murayama
Somay Yamagata
SY
Fujita
Yoshinori
Y
D000328:Adult; D000368:Aged; D000469:Alkaline Phosphatase / Q000235:genetics; D001228:Aspergillosis / Q000150:complications / Q000175:diagnosis*; D001230:Aspergillus / Q000235:genetics / Q000302:isolation & purification*; D004271:DNA, Fungal / Q000032:analysis; D005260:Female; D005656:Fungal Proteins / Q000235:genetics; D006801:Humans; D016867:Immunocompromised Host; D017403:In Situ Hybridization / Q000379:methods*; D007938:Leukemia / Q000150:complications* / Q000188:drug therapy / Q000382:microbiology; D008297:Male; D008875:Middle Aged; D009503:Neutropenia / Q000139:chemically induced / Q000150:complications; D015345:Oligonucleotide Probes; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013280:Stomatitis / Q000150:complications / Q000382:microbiology*
D004271:DNA, Fungal; D005656:Fungal Proteins; D015345:Oligonucleotide Probes; D000469:Alkaline Phosphatase