GENETIC SCREENING FOR IDENTIFICATION OF SALMONELLA TYPHIMURIUM TN5 MUTANTS WITH POTENTIAL HYPERSENSITIVITY TO SHORT-CHAIN FATTY ACIDS

This study was conducted to test if transposon footprinting could be used to identify transposon mutants of Salmonella typhimurium with growth defects in a media containing short-chain fatty acids (SCFA) as the test selective condition. High concentrations of SCFA are one of the characteristic conditions in the animal intestine that has been suggested to play a role in inhibiting colonization by nonindigenous bacterial pathogens. When the mutant pools containing 25 Tn5 mutants/pool were analyzed for transposon footprints before and after selection, a polymerase chain reaction (PCR) product could be identified that was present in an input pool, but not in a corresponding output pool. The results indicate that transposon footprinting can be used for negative screening of genes sensitive to SCFA in the S. typhimurium bacterial genome.