Investigating the synergistic antimicrobial effect of carvacrol and zinc oxide nanoparticles against Campylobacter jejuni
Bibliographic record
Abstract
Foodborne illness is a growing concern world-wide, and Campylobacter in particular has been reported to cause approximately 145,000 foodborne illness cases every year in Canada. A recent annual report from the Canadian Integrated Program for Antimicrobial Resistance Surveillance reveals an increasing trend of antibiotic-resistant Campylobacter isolated from poultry sources across Canada. The large number of foodborne illnesses and emergence of the resistant strains of Campylobacter pose a serious threat in the agri-food industry. Hence, there is increasing urgency to find alternatives to conventional antimicrobials to reduce the prevalence of Campylobacter in the food supply chain while reducing the likelihood of resistance. Combining antimicrobials is a potential intervention strategy to reduce the growth of pathogens by expanding the spectrum of antimicrobial activity. In this study, carvacrol and zinc oxide nanoparticles (ZnO NPs) were investigated in regards to their synergistic antimicrobial effect against C. jejuni. The combination of these two agents for treatment is based upon current evidence of their individual antimicrobial activity. The objectives of this thesis project were to (1) determine the synergistic antimicrobial effect of carvacrol and ZnO NPs against C. jejuni, (2) investigate the macromolecular fingerprints and gene expression profile of C. jejuni after the combinational treatment, and (3) explain the potential mechanism of the synergistic antimicrobial effect. In this work, a macrobroth dilution method was used to test the antimicrobial effect of the compounds against C. jejuni. The macromolecular fingerprints of C. jejuni cells treated with carvacrol and ZnO NPs were investigated using confocal micro-Raman spectroscopy, whereas Real-Time Quantitative Polymerase Chain Reaction (RT-qPCR) was employed to study the variation in bacterial gene expression after the antimicrobial treatment. The synergistic antimicrobial effect of carvacrol and ZnO NPs against C. jejuni was clearly demonstrated using the time-kill curve. The macromolecular fingerprints and gene expression profile revealed the role of carvacrol in the synergistic antimicrobial effect against C. jejuni. The results of this study provide fundamental knowledge about bacterial stress in response to the synergistic antimicrobial effects. This antimicrobial combination may be utilized as an intervention strategy to reduce the prevalence of C. jejuni in agri-foods.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 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 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".