Salmonella is a leading bacterial cause of foodborne illness worldwide. During a previous study investigating the enzymes responsible for regulating cyclic-di-GMP concentrations, a mutant in the cyclic-di-GMP-specific phosphodiesterase STM3615 was identified that displayed a phenotype characterized by decreased survival on agar plates and a shorter bacterium length. I was able to determine that the periplasmic domain of STM3615 was responsible for this phenotype, not the enzymatic phosphodiesterase domain. Based upon a bioinformatic analysis of the protein, I then hypothesized that the periplasmic domain of STM3615 was interacting with a periplasmic protein to give rise to this phenotype. To identify this periplasmic protein partner, a transposon mutagenesis approach was taken to disrupt genes within the STM3615 mutant. Two mutants, rcsD and yrfG, within the STM3615 deletion mutant restored the WT phenotype and require further investigation. RcsD is an important partner of the transcription regulatory protein RcsB that controls expression of FtsZ, a key player in cell division.