In article <3270199D.430 at VBI.unibe.ch>, Andre Burnens <BURNENS at VBI.unibe.ch> says:
>>Please note that Brilliant Green agar does _not_ support growth of
>Salmonella typhi (whereas Hektoen does). A few % of salmonellae do no
>produce H2S; they readily grow on Hektoen but fail to produce black
>centers. The most important difference between BG and Hektoen is that BG
>usually is more selective, i.e. better suppresses competing flora. Thus
>BG is usually recommended for specimens with a heavy flora. It may,
>however, sometimes be too selective and suppress growth of salmonellae
>too. Therefore it is advisable to use both a strongly selective as well
>as a less selective (like Hektoen) medium in parallel.
As I understand it, and keep in mind I am not in clinical micro, the
clinical lab should always use bismuth sulfite if there is a possibility
that typhi is an issue. With regard to the other non-typhi
serovars, all bugs can give atypical reactions and that is why it
is best to use several different media. About 1% of
salmonella isolates are atypical.
The last I checked, typhi was still a relatively rare beast here in the U.S.
I seem to recall about 200 cases per year, but I may have a faulty memory.