pylori strains. CCUG 17874 untreated bacteria (Figure 2A) show homogeneous cytoplasm and rare membrane/cytoplasm detachments (arrow). M/C-R2 untreated bacteria (Figure 2B) show homogeneous cytoplasm, flagella and vesicles (arrow). CCUG 17874 bacteria treated with polysorbate 80 (Figure 2C) are swollen and

morphologically altered; cytoplasm is granular and detached from the inner membrane (arrow head); vesicles (arrow) are present. M/C-R2 bacteria treated with polysorbate 80 (Figure 2D) are swollen and morphologically altered; cytoplasm is not homogeneous and numerous vesicles are present (arrow). CCUG 17874 bacteria Smoothened Agonist treated with clarithromycin (Figure 2E) show altered shape, typical

“holes” in the cytoplasm (arrow head), membrane/cytoplasm detachment (arrows) and fragments of flagella. Some M/C-R2 U0126 organisms treated with clarithromycin (Figure 2F) have a conserved morphology, others Tariquidar show granular cytoplasm and altered membranes. Flagella and vesicles (arrows) are present. CCUG 17874 bacteria incubated with metronidazole (Figure 2G) are severely altered and show detachment of cytoplasm, often fragmented, from inner membrane (arrows). M/C-R2 bacteria treated with metronidazole (Figure 2H) are morphologically similar to control. CCUG 17874 treated with polysorbate 80 and clarithromycin (Figure 2I) displays alterations typical of organisms treated with the two substances used alone: swollen cells and detachment

membrane/cytoplasm (arrow). M/C-R2 bacteria treated with polysorbate 80 and clarithromycin (Figure 2J) are Clostridium perfringens alpha toxin mostly swollen, their cytoplasm is granular and numerous vesicles are present (arrows). CCUG 17874 strain treated with polysorbate 80 and metronidazole (Figure 2K) displays swollen bacteria, granular cytoplasm, presence of vesicles (arrows) and detachment of fragmented cytoplasm from the inner membrane (arrow head). M/C-R2 bacteria treated with polysorbate 80 and metronidazole (Figure 2L) are swollen; cytoplasm is granular and displays the presence of “holes”. Vesicles are present (arrows). Bars 2A-L: 1000 nm. To examine the ultrastructural characteristics of the organisms treated with the studied substances, the bacteria were incubated overnight with the single drugs and with antibiotics associated with polysorbate 80 at concentrations corresponding to the respective MBCs. In both strains treated with polysorbate 80 (Table 3), we observed swollen bacteria and alterations of the outer membrane (Figures 2C, 2D), particularly evident in CCUG 17874 H. pylori strain. The cytoplasm showed a typical granular texture; in both strains, we noted the presence of vesicles, which were more numerous in C/M-R2 strain. The two strains challenged with clarithromycin showed different ultrastructural alterations. CCUG 17874 H.