Hello everyone!

I've constructed a mutant strain of Salmonella using the lambda Red system (Datsenko & Wanner, 2000). After obtaining the resistant colonies and confirming insertion of the resistance cassette in the right place, I transferred the mutation to the wildtype strain using phage P22. But can I be sure that the only region transferred, to the resulting resistant bacteria after transduction, is the one containing the resistance marker? or other regions could be also transferred and incorporated in the chromosome in the same bacterium?

Thank you very much in advance!