Detection and characterization of broad-host-range plasmids in environmental bacteria by PCR

The application of PCR primers specific for the plasmid DNA sequences of incompatibility (Inc) groups shows that IncQ and IncP DNA sequences are present in soil and manure slurry while IncN and IncW sequences are present mainly in manure samples. The method offers a good technique for identifying Inc-containing plasmids in nonculturable and culturable bacteria. However, the primers identify only those sequences that are highly similar to their reference sequences. The DNA of plasmids classified on the basis on conventional methods may differ from that of the reference sequences.