[Development of effective detection method for Coxiella burnetii in mayonnaise by real-time PCR and investigation of C. burnetii contamination in commercial mayonnaise in Tokyo].
A PCR method for the effective detection of Coxiella burnetii in commercially available mayonnaise was developed. Sample preparations were isolated from 50 g portions of each mayonnaise product by four successive extraction steps in phosphate buffer with 2.0 M NaCl. These extracts were then centrifuged at 20,000 x g for 60 min. DNA was isolated from the solution containing the precipitate with a commercial kit, and amplified quantitatively using real-time PCR that targeted the com1 region of C. burnetii. The recoveries of C. burnetii from 2 kinds of commercial mayonnaise specimens, with a baseline control of 1 x 10(7) particles of the Nine Mile phase II strain, were 85.0 +/- 6.0% and 72.0 +/- 0.4%, respectively. The determination limit of this method was 500 C. burnetii particles per 50 g of mayonnaise. The DNA specimens isolated from 50 different commercial mayonnaise samples sold in Tokyo using this method were amplified using both nested PCR and real-time PCR. No contamination by C. burnetii was detected in any of the mayonnaise samples.
Sadamasu
Kenji
K
Department of Microbiology, Tokyo Metropolitan Institute of Public Health, 3-24-1, Shinjuku-ku, Tokyo 169-0073, Japan.
Tabei
Yukiko
Y
Shinkai
Takayuki
T
Hasegawa
Michiya
M
Kaneko
Seiji
S
Hirai
Akihiko
A
Nakama
Akiko
A
Ishizaki
Naoto
N
Odagiri
Megumi
M
Kamata
Shin-ichi
S
Yano
Kazuyoshi
K
Kai
Akemi
A
Morozumi
Satoshi
S
D016997:Coxiella burnetii / Q000235:genetics / Q000302:isolation & purification*; D004269:DNA, Bacterial / Q000302:isolation & purification; D004531:Eggs / Q000382:microbiology; D005506:Food Contamination; D005516:Food Microbiology; D016133:Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D014041:Tokyo
D004269:DNA, Bacterial