[Development of a loop-mediated isothermal amplification assay for rapid detection of Enterobacter sakazakii in powdered infant formula].
OBJECTIVE
A loop-mediated isothermal amplification (LAMP) technology with two loop primers was developed for rapidly detecting Enterobacter sakazakii in powdered infant formula.


METHODS
Sequences of 16S-23S rRNA of Enterobacter sakazakii (ATCC29544) were used as target sequences, to design outer primers, inner primers and loop primers. We judged the results of detection, through visible to the naked eye of the white precipitate.


RESULTS
The sensitivity of the LAMP assay was 0.101 CFU/mL; the detection limit of artificial contamination was 1.1 CFU/g. The detection could be finished about an hour from dealing with the sample to report the results with DNA kit. Compared with LAMP, the sensitivity of the PCR assay was 101 CFU/mL and the detection limit of artificial contamination was 1100 CFU/g in three hours. To apply the same method of extracting DNA, from dealing with the sample to report the results, it took about three hours.


CONCLUSIONS
Therefore, this LAMP-based assay is sensitive and fast. These results indicate that LAMP can provide a rapid yet simple test for the detection of Enterobacter sakazakii in powdered infant formula.
Hu
Lianxia
L
Institute of Food Science and Technology, Agricultural University of Hebei, Baoding 071001, China. hulianxia168@tom.com
Zhang
Wei
W
Zhang
Xianzhou
X
Yuan
Yaowu
Y
Zhang
Yunzhe
Y
Zhang
Huiyan
H
Ma
Xiaoyan
X
Su
Xudong
X
D044083:Cronobacter sakazakii / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D006801:Humans; D007223:Infant; D041943:Infant Formula; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D016133:Polymerase Chain Reaction; D015203:Reproducibility of Results