Bacteriophage Therapy: Isolation and Identification of Lysogenic Bacteria of Propionibacterium acnes

Stacy Azeredo and Michael Davis, Department of Biomolecular Sciences, Central Connecticut State University

Acne is a common skin disease that plagues many cohorts of society. There are many medications and topical solutions that are marketed for the treatment and prevention of the pimples associated with this disease. The approach that we use to target this skin disease is called bacteriophage therapy. A potential problem that arises with bacteriophage therapy is the potential for the integration of the phage DNA with the bacterial DNA, creating what is called a latently infected bacterial cell termed a lysogen. There are three main reasons why finding a lysogen is important. We are testing our bank of Propionibacterium acnes bacteria to separate the lysogens from non-lysogens so we have two distinct populations of P. acnes. These separate populations will be important to future experiments of extracting the phage from these sources to test the different types of phage on the different populations of bacteria. Reducing the unintentional generation of recombinant phage is also important.  However, having these separate populations will prove useful when intentional recombinants are desired to create the best cocktail for treatment.

To detect if there are any lysogens P acnes DNA is used to perform DNA spot blots which are probed with the corresponding phage DNA. Any hybridization that occurs with the phage DNA (probe) to the chromosomal DNA may suggest integration of that phage DNA into the bacterial chromosome, yielding a lysogen. Once a lysogen is detected, these cells will be grown up and see if they act as lysogens in culture.  Our preliminary data suggests that the frequency in which we are detecting lysogens is consistent with the pre-established frequency measured for P. acnes.

 

Presented April 21, 2007 at the 61st Annual Eastern Colleges Science Conference, College of Mount Saint Vincent, Riverdale NY