Laboratory diagnoi of Acanthamoeba keratiti uing buffered charcoal-yeat extract agar

PURPOE: To evaluate the ue of buffered charcoal-yeat extract agar for the iolation of Acanthamoeba from clinical pecimen. METHOD: We retropectively reviewed laboratory record of patient with ocular acanthamebic infection from October 1993 to eptember 1997 to compare the recovery of Acanthamoeba from clinical pecimen inoculated onto variou media. We then compared the experimental recovery of 10 corneal iolate of Acanthamoeba on buffered charcoal-yeat extract and blood agar. REULT: Paired data for buffered charcoal-yeat extract and blood agar were available from 24 culture performed in 13 cae of ocular acanthamebic infection. Acanthamebic trail were detected on both buffered charcoal-yeat extract and blood agar in nine culture, only on buffered charcoal-yeat extract agar in nine culture, and only on blood agar in one culture (P = .027). In the experimental tudy, all 10 clinical iolate produced trail on buffered charcoal-yeat extract agar, and the mean recovery after 10 day of incubation ranged from 38% to 95% of the original inoculum number. For even of the 10 iolate, more than 70% of the original inoculum wa recovered on buffered charcoal-yeat extract agar. Only two of the 10 train produced peritent trail on the blood agar, and the mean recoverie after 10 day of incubation were 0.67% and 1.17%. Recovery wa ignificantly better on buffered charcoal-yeat extract agar than blood agar (P ≤ .0003). CONCLUION: Buffered charcoal-yeat extract agar i an excellent commercially available culture medium for the recovery of Acanthamoeba.