bacteriophages in E.coli

michelle kerr kerrmichel at HOTMAIL.COM
Tue Nov 2 13:25:46 EST 1999

     I am a college student studying microbiology. My peers and I just 
recently performed an experiment where we tested hamburger meat for 
bacteriophages using different strains of E.coli. The procedure we used was 
the hydrogen peroxide treatment with crystal violet agar plates for 
selective recovery of bacteriophages. For our lab report we would like to 
compare our results and procedures to ones that might have been possibly 
done in the past.  We have tried the internet, library, and the Journal of 
Applied and Environmental Microbiology. So far we have had next to no luck 
finding any articles that pertain to this test and food.  I was wondering if 
anyone might know of a source that we might not have tried or a experiment 
that was done that was similar to ours.
      Here is a detailed explanation of our procedure with a reference for 
anyone who might not be familiar with it. First we inoculated 10mL of TSB 
with five different E.coli host strains. We then let them incubate for 24 
hrs in a 37 degree celsius water bath. The next day we took 50g of a meat 
sample, and added water to bring the sample up to 100ml. We added 3.3mL of 
3% hydrogen peroxide per 100mL of sample. We then shook them for one hour at 
room temperature. After the hour period, we inactivated the peroxide by 
adding 5mg Catalase per 100mL. We took five different meat samples.  We 
added 100ml of water and then blended to liquid. We then added 0.1 mL of the 
E.coli host and 0.1 mL of the sample into 4mL top agar.  The top agar was 
then mixed and poured over crystal violet plates.  The plates were then 
incubated at 37 degrees Celsius for 24 hrs and were checked after 8 hours 
and at 24 hrs.
    Our results were inconclusive because no phages were found. A similar 
experiment was performed last year at St. Francis and phages were found.  We 
are trying to find a new procedure or similar ones to try to explain our 
lack of data.  Our professor would like to see us find as much information 
as possible so that we can put together a report for next year's students to 
research. Unfortunately, all we can find is the recovery of phages from 
water samples and sewage. Very little has been recovered so far an solid 
   The experiment was derived by my peers and I using an experiment that was 
in The Journal of Applied and Environmental Microbiology.  Issue is April 
1992 p 1159-1163 title is Use of Hydrogen Peroxide Treatment and Crystal 
Violet Agar Plates for Selective Recovery of Bacteriophages from Natural 
Environments. It was published by Abdolkarim Asghari.
                      Thank you,
                            Michelle Kerr
                   Sophomore at the University of St. Francis

Get Your Private, Free Email at

More information about the Microbio mailing list