Two cases of acanthamoeba keratitis diagnosed only by real-time polymerase chain reaction.
OBJECTIVE
To report 2 cases of Acanthamoeba keratitis whose causative pathogen was detected only by real-time polymerase chain reaction (PCR).


METHODS
Histological examinations of corneal scrapings were stained with Fungiflora Y. Corneal scrapings were also cultured on nonnutrient agar. Real-time PCR analyses of corneal scrapings were also performed.


RESULTS
Both cases had clinical signs and risk factors of Acanthamoeba infection. Histological examinations of corneal scrapings with Fungiflora Y staining were negative, and the cultures did not grow any pathogens. Real-time PCR analysis was positive for Acanthamoeba DNA from 2 corneal scrapings. Antiamoebic treatments led to excellent clinical improvements.


CONCLUSIONS
These results indicate that PCR analyses can detect the DNA of Acanthamoeba in corneal scrapings and may be a valuable supplemental examination. This method is especially helpful when clinical signs and risk factors of Acanthamoeba infection are present but histological examinations with Fungiflora Y staining and cultures are negative.
Kandori
Michiko
M
Department of Ophthalmology, Osaka University Medical School, Suita, Japan.
Inoue
Tomoyuki
T
Takamatsu
Fumihiko
F
Kojima
Yoshinao
Y
Hori
Yuichi
Y
Maeda
Naoyuki
N
Tano
Yasuo
Y
D000048:Acanthamoeba / Q000235:genetics / Q000302:isolation & purification*; D015823:Acanthamoeba Keratitis / Q000175:diagnosis* / Q000469:parasitology*; D000328:Adult; D000818:Animals; D003315:Cornea / Q000469:parasitology*; D016054:DNA, Protozoan / Q000032:analysis; D005260:Female; D006801:Humans; D008297:Male; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012307:Risk Factors; D014792:Visual Acuity
D016054:DNA, Protozoan