Effects of <i>dam</i> and <i>seqA</i> genes on biofilm and pellicle formation in <i>Salmonella</i>

In this study, the effects of <i>dam</i> and <i>seqA</i> genes on the formation of pellicle and biofilm was determined using five different <i>Salmonella</i> serovars <i>S</i>. Group C1 (DMC2 encoded), <i>S</i>. Typhimurium (DMC4 encoded), <i>S</i>. Virchow (DMC11 encoded), <i>S</i>. Enteritidis (DMC22 encoded), and <i>S</i>. Montevideo (DMC89 encoded). <i>dam</i> and <i>seqA</i> mutants in <i>Salmonella</i> serovars were performed by the single step lambda red recombination method. The mutants obtained were examined according to the properties of biofilm on the polystyrene surfaces and the pellicle formation on the liquid medium. As a result of these investigations, it was determined that the biofilm formation properties on polystyrene surfaces decreased significantly (p dam and <i>seqA</i> mutants, while the pellicle formation properties were lost in the liquid medium. When pBAD24 vector, containing the <i>dam</i> and <i>seqA</i> genes cloned behind the inducible arabinose promoter, transduced into <i>dam</i> and <i>seqA</i> mutant strains, it was determined that the biofilm formation properties on the polystyrene surfaces reached to the natural strains’ level in all mutant strains. Also, the pellicle formation ability was regained in the liquid media. All these data demonstrate that <i>dam</i> and <i>seqA</i> genes play an important role in the formation of biofilm and pellicle structures in <i>Salmonella</i> serovars.