Abstract

Helicobacter pylori is capable of entering into yeast, but the factors driving this endosymbio-sis remain unknown. This work aimed to determine if temperatures outside the optimal range for H. pylori increase its harboring within Candida. H. pylori strains were co-cultured with Candida strains in Brucella broth supplemented with 5% fetal bovine serum and incubated at 4, 25, 37 or 40◦ C. After co-culturing, yeasts containing bacteria-like bodies (Y-BLBs) were observed by optical microscopy, and the bacterium were identified as H. pylori by FISH. The H. pylori 16S rRNA gene was amplified from the total DNA of Y-BLBs. The viability of intra-yeast H. pylori cells was confirmed using a viability assay. All H. pylori strains were capable of entering into all Candida strains assayed. The higher percentages of Y-BLBs are obtained at 40◦ C with any of the Candida strains. H pylori also increased its harboring within yeast in co-cultures incubated at 25◦ C when compared to those incubated at 37◦ C. In conclusion, although H. pylori grew significantly at 40◦ C, this temperature increased its harboring within Candida. The endosymbiosis between both microorganisms is strain-dependent and permits bacterial cells to remain viable under the stressing environmental conditions assayed.