Tomatidine acts in synergy with aminoglycoside antibiotics against multiresistant Staphylococcus aureus and prevents virulence gene expression
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
OBJECTIVES: This study characterized the multiple biological activities of the natural compound tomatidine against Staphylococcus aureus. Notably, this work examined the antibacterial activity of tomatidine in combination with other antibiotics and the influence of this compound on the expression of virulence factors in S. aureus. METHODS: The effect of tomatidine on the susceptibility of S. aureus to several antibiotic classes was determined by a broth microdilution procedure and a chequerboard protocol to measure fractional inhibitory concentration indices and to reveal drug interactions. Time-kill experiments for aminoglycoside/tomatidine combinations were also performed. The haemolytic ability of several strains in the presence of tomatidine was measured on blood agar plates and the expression of virulence-associated genes in strain ATCC 29213 treated with tomatidine was monitored by quantitative PCR. RESULTS: Tomatidine specifically potentiated the inhibitory effect of aminoglycosides but not of other classes of drugs. This potentiating effect was observed against strains of different clinical origins (human blood, cystic fibrosis airways, osteomyelitis, skin tissues and bovine mastitis), including aminoglycoside-resistant bacteria possessing the aac(6')-aph(2″), ant(4')-Ia and aph(3')-IIIa genes. The killing kinetics for the combination of aminoglycosides with tomatidine revealed strong bactericidal activity. Although tomatidine did not possess growth-inhibitory activity of its own against prototypical S. aureus, it inhibited the haemolytic activity of several strains and, more specifically, blocked the expression of several genes normally influenced by the agr system. CONCLUSIONS: These results show that tomatidine is an aminoglycoside potentiator that also acts as an anti-virulence agent targeting both antibiotic-susceptible and antibiotic-resistant S. aureus.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it