Table 3.
Activity and morphological effect of synthetic compounds on H. pylori.
| Compound | H. pylori Strain(s) | Technic Determining Morphology |
Technic Determining Viability | Main Results Covering the Morphological Transformation of H. pylori | Authors Interpretation | Bibliography |
|---|---|---|---|---|---|---|
| DFMO | SS1 | Light microscopy, TEM | Culture, Luminescence (ATP level) |
- Viability ↓ (<1 log, 24 h, MIC) - Coccoid forms (6 h, MIC) - Reversion from coccoid to spiral forms (6 h after the DFMO removal) - ↑ iATP level (0–12 h, MIC), no difference later (24 h, MIC) |
Inhibitory activity with the reversibility of morphology | [56] |
| Niclosamide | ATCC 49503 | SEM | Culture, Fluorescence (membrane integrity) |
- Viability ↓ (approx. 1.5 log, 24 h, 4× MIC) - Coccoid forms produced in a dose-dependent manner (3 h, MIC to 8× MIC) - No membrane permeabilization (1 h, 64× MIC) |
Inhibitory activity | [57] |
| Polyethyleneimine functionalized zinc oxide | ATCC 700392 | SEM, TEM |
Culture, Luminescence (ATP level), qRT-PCR (RNA degradation), Fluorescence (membrane integrity) |
- Viability ↓ (1 log, 24 h, MIC) - 10% (0.5 h, MIC) and 33% (3 h, MIC) of coccoid forms - Membrane damage (3 h, MIC) - ↓ iATP level (3 h, MIC) - Degradation of rRNA (time-dependent, MIC) |
Inhibitory activity | [58] |
| Polyoxometalates: As4W40 Sb9W21 SiVW11 |
ATCC 43504 | SEM | Culture | - Total viability ↓ for As4W40 and Sb9W21 (10× MIC, 24 h and 12 h, respectively) - Stable viability for SiVW11 (10× MIC, 24 h) - Intensive formation of coccoids for As4W40 and Sb9W21 (36 h, > MICs) - Weak formation of coccoids for SiVW11 (36 h, > MICs) |
Bactericidal (As4W40 and SB9W21) or bacteriostatic (SiVW11) activity |
[59] |
| NE-2001 | ATCC 43504 | TEM | Culture | - Viability ↓ (1 log, 24 h, MIC) - Coccoid forms with an intact membrane (6 h, ½× MIC) - Ghost (degenerative) cells with coccoid-like shape with a loosening of the outer membrane (6 h, MIC) |
Bactericidal activity | [60] |
| TG44 | ATCC 43504 | SEM, TEM |
Culture | - Total viability ↓ (24 h, 8× MIC) - Viability ↓ (<1 log, 24 h, MIC to 4× MIC) - Spiral forms with membrane vesicles around (3 h, ½× MIC to 4× MIC) - Coccoid forms with blebbing and outer membrane detachment (3 h, 64× MIC) |
Bactericidal activity | [61] |
| SQ109 | G27 | TEM | Culture, Fluorescence (membrane integrity) |
- Total viability ↓ (8 h, 2× MBC) - Coccoid forms (98–99%) with disintegration of the inner membrane (8 h, 2× MBC) - Ghost (degenerative) cells (1–2%) (8 h, 2× MBC) - No membrane disruption using fluorescence analysis (10 h, 2× MBC) |
Bactericidal activity | [62] |
| 3-Bromopyruvate | Tx30a J99 |
Light microscopy, SEM |
Culture, Fluorescence (membrane integrity) |
- Total viability ↓ (6 h, 4 h, and 2 h for MIC, 2× MIC, and 4× MIC, respectively) - 33.5% (Tx30a) and 57.5% (J99) of coccoid forms (2 h, 4× MIC) - 97–98% of coccoid forms for both (24 h, 4× MIC) - ↓ green/red fluorescence (time-dependent, MIC to 4× MIC) |
Bactericidal activity | [40] |
| Sertraline | Tx30a J99 |
Light microscopy, SEM |
Culture, Fluorescence (membrane integrity) |
- Total viability ↓ (8 h, 4× MIC for J99 or 24 h, 4× MIC for Tx30a) - Viability ↓ (2–4 log, 24 h, MIC) - > 85% of coccoid forms (8 h, 4× MIC for J99 or 24 h, 4× MIC for Tx30a) - ↓ green/red fluorescence (time-dependent, MIC to 4× MIC) |
Bactericidal activity | [41] |
Symbols: decrease (↓), increase (↑). Abbreviations: difluoromethylornithine (DFMO), intracellular ATP (iATP), ribosomal RNA (rRNA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), quantitative reverse transcription polymerase chain reaction (qRT-PCR), minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC).