Bifunctional enzyme SpoT is involved in biofilm formation of Helicobacter pylori with multidrug resistance by upregulating efflux pump Hp1174 (gluP)

The drug resistance of Helicobacter pylori (H. pylori) is gradually becoming a serious problem. Biofilm formation is an important factor that leads to multidrug resistance in bacteria. The ability of H. pylori to form biofilms on the gastric mucosa has been known. However, there are few studies on the regulation mechanisms of H. pylori biofilm formation and multidrug resistance. Guanosine 3-diphosphate 5-triphosphate and guanosine 3,5-bispyrophosphate [(p)ppGpp] are global regulatory factors and are synthesized in H. pylori by the bifunctional enzyme SpoT. It has been reported that (p)ppGpp is involved in the biofilm formation and multidrug resistance of various bacteria. In this study, we found that SpoT also plays an important role in H. pylori biofilm formation and multidrug resistance. Therefore, it is necessary to carry out some further studies regarding its regulatory mechanism. Considering that efflux pumps are of great importance in the biofilm formation and multidrug resistance of bacteria, we tried to find if efflux pumps controlled by SpoT participate in these activities. Then, we found that Hp1174 (glucose/galactose transporter, gluP), an efflux pump of the MFS family, is highly expressed in biofilm-forming and multi-drug resistance (MDR) H. pylori and is upregulated by SpoT. Through further research, we determined that gluP involved in H. pylori biofilm formation and multidrug resistance. Furthermore, the average expression level of gluP in clinical MDR strains was considerably higher than that in clinical drug-sensitive strains. Taken together, our results revealed a novel molecular mechanism of H. pylori tolerance to multidrug.