Umnarj Paeratakul umnarj at mozart.inet.co.th
Wed Oct 30 07:08:20 EST 1996

stutjamalgeo at SPOCK.COLSF.EDU wrote:
>   For whoever is qualified to answer me: 
>   I would like to know what specific Bacteriophages will attack 
>Salmonella enteriditis.  I am working on the potential antibacterial 
>affects of phages against human pathogens.  
>   Any responses will be greately appreciated
>Thank you
>George T.

Dear George,

I do not have an answer to your question. BUT I can tell you that
you can isolate these phages from the environment quite easily.
I teach this method to my students, and they have a lot of fun
isolating coliphage from the sewer.

The trick is the enrichment technique.
First grow up your "victim"(Salmonella) in normal 
medium such as nutrient broth to high density.  
Mix about 10 ml of Salmonella + 10 ml of sewage or canal
water + 20 ml of double strength nutrient broth.  Incubate the 
culture overnight. 

If there is any phage that can infect Salmonella, it will
infect and the number will increase.  Don't worry about
other "contaminating" bacteria.

Next morning, use membrane filter (0.45 uM) filter out
the bacteria.  What you get is the low titer phage lysate.

Repeat the enrichment step again, but this time 
use the filtrate.  By the end of second round
you probably get the phage at 10>7 pfu/ml.
You can do the plaque assay to measure the titer.

In our hands, 80% of the student can get the phage. 

I just want to pitch in my 2 cents.  
Sorry if it does not help you.

Umnarj Paeratakul

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