We evaluated the most effective media for isolating hydrogen sulfide (H
2S) non-producing
Salmonella. Hydrogen sulfide non-producing
Salmonella is a common cause of of food poisoning and the incidence seems to be increasing. At present, it is popular to use medium for isolating
Salmonella that is based on
Salmonella spp. producing H
2S.
However, it is difficult to detect H
2S non-producing
Salmonella and it is very easy to miss them. We evaluated several popular media in food testing using 27 strains of H
2S nonproducing
Salmonella that were isolated from feces samples.
Many H
2S non-prpducing
Salmonella were not detectable by traditional media nor Rambach Agar or Brilliant Green Agar. The latter two media do not depend on H
2S production.
A new chromogenic medium CHROMagar Salmonella (CHROMagar Ltd; France) uses a specific enzymatic reaction of
Salmonella, and was able to distinguish all
Salmonella colonies clearly irrespective of H
2S production, therefore, the CHROMagar Salmonella is very valuable in screening for
Salmonella in food and environmental specimens. However, the media did not support the growth of
Shigella and
Salmonella Typhi and thus is not suitable for clinical specimens.
We believe that this chromogenic media should be widely used as isolating medium for the screening of
Salmonella to increase the reliability of food sanitary control.
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