The aim of this study is to develop for the high sensitive isolation methods for
Vibrio cholerae from frozen food samples. After being frozen at -20℃ for one week, the bacterial numbers of
V. cholerae in physiological saline were reduced by a factor of 1/100-1/10,000. However, this bacterium was able to be isolated from the frozen food samples by using the immunomagnetic beads technique. In order to achieve a higher level of detection, enrichment procedures were repeated several times. A shrimp sample stored at -80℃ for one year after inoculation with 0.5m
l (10
3 cfu/m
l) of
V. cholerae serotype O139 required the enrichment procedures to be repeated three times for isolation. In addition, an original selective agar plate supplemented with 0.1 % volume of sodium pyruvic acid and 2,000 U/plate of catalase was useful for the isolation of
V. cholerae. In this study, the application of the immunomagnetic beads separation technique and use of the improved selective agar plate after the enrichment procedure of the samples (occasionally, repeated several times) should facilitate a comprehensive approach to the detection of small numbers of
V. cholerae in frozen foods.
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