UC Santa Cruz

Previous research found that the protein HPG27_526 was downregulated in Helicobacter pylori biofilm, so a HPG27_526 mutant was expected to have increased biofilm formation. Surprisingly, a HPG27_526 mutant was found to have a biofilm defect compared to WT, which was confirmed by our studies. Bioinformatic work was done using the HMMR and PHYRE2 software and the results suggested that the HPG27_526-encoded protein was part of the AI-2 exporter family. For this reason, the AI-2 export capabilities of HPG27_526 were assessed, and HPG27_526 was found to not play a significant role in AI-2 export. To figure out possible reasons for the biofilm defect, a growth curve was done, but there was no difference of growth between WT and the HPG27_526 mutant. Since no growth defect was observed, we used scanning electron microscopy to evaluate physical difference between WT and the mutant, but no differences were observed aside from decreased biofilm formation. These results confirm that HPG27_526 is required for biofilm formation but is not required for growth or AI-2 export.