[Rapid detection of salmonella in food by using fluorescently labeled phage O-I].
OBJECTIVE
To develop a rapid detection method for Salmonella in food by using specific Salmonella-phage O-I.


METHODS
One hundred bacteria strains and 120 food sample isolates were infected using fluorescently labeled O-I phage genome with SYBR gold stain (a nucleic acid dye, 1 x working solution), then were observed under epi-fluorescence microscopy. The sensitivity of the method was tested.


RESULTS
Among the 100 strains infected with O-I/SYBR gold stain, 40 Salmonella strains exhibited rod fluorescence. Other bacteria including 10 Proteus, 20 Shigella, 20 E. coli and 10 Staphylococcus did not exhibit this feature The sensitivity of detecting Salmonella was 10 CFU/100 microL. The detection for 120 food samples by using the O-I/SYBR gold stain had similar results to those by using the biochemical method.


CONCLUSIONS
Fluorescent-labeled O-I phage could rapidly, sensitively and specifically detect Salmonella species in food samples.
Jiang
Luyan
L
Jiangsu Entry/Exit Inspection and Quarantine Bureau, Nanjing 210001, China. jiangqin2006ok@163.com
Jiang
Qin
Q
Huang
Kehe
K
Zhang
Changyin
C
Tang
Taishan
T
D005456:Fluorescent Dyes / Q000737:chemistry*; D005516:Food Microbiology; D008856:Microscopy, Fluorescence; D015203:Reproducibility of Results; D012475:Salmonella / Q000302:isolation & purification* / Q000821:virology*; D012483:Salmonella Phages / Q000737:chemistry / Q000254:growth & development*
D005456:Fluorescent Dyes