The life cycles of the temperate lactococcal bacteriophage phi LC3 monitored by a quantitative PCR method

We present here a new and general approach for monitoring the life cycles o f temperate bacteriophages which establish lysogeny by inserting their geno mes site-specifically into the bacterial host chromosome. The method is bas ed on quantitative amplification of specific DNA sites involved in various cut-and-join events during the life cycles of the phages (i.e. the cos, att P, attB, attL and attR sites) with the use of sequence-specific primers. By comparing the amounts of these specific DNA sites at different intervals, we were able to follow the development of the lytic and lysogenic life cycl es of the temperate lactococcal bacteriophage phi LC3 after infection of it s bacterial host Lactococcus lactis ssp. cremoris IMN-C18. (C) 2000 Federat ion of European Microbiological Societies. Published by Elsevier Science B. V. All rights reserved.