Hektoen Enteric Agar vs Brilliant Green Agar (Salmonella De

richard richardz at cy-net.net
Thu Oct 24 14:08:06 EST 1996

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.
>Regards, Andre

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. 


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