PCR results of the quorum sensing sdiA gene of local Egyptian Salmonella isolates in comparison with non-Salmonella isolates: Lanes 1-8: Salmonella isolates that were PCR-positive for the sdiA gene, which produces a 274-bp product. Lane M: 100-bp molecular ladder. Lanes 9-12: Negative PCR results for the sdiA gene of four non-Salmonella isolates (E. coli, Klebsiella pneumonia, Proteus vulgaris, and Pseudomonas aeruginosa). 

Maximum likelihood phylogenetic tree based on sdiA gene sequences showing the relationship between our study sequences and 11 representatives of sequences retrieved from GenBank. The percentage of replicate trees in which the associated taxa clustered together in the bootstrap test (500 replicates) is shown next to the branches. Only branches with bootstraps greater than 50 are labelled. The bacterial isolate sequenced in this study is indicated by a red diamond.