Quantifying the primary and secondary effects of antimicrobial resistance on surgery patients: Methods and data sources for empirical estimation in England

Antimicrobial Impact of Wood Vinegar Produced Through Co-Pyrolysis of Eucalyptus Wood and Aromatic Herbs

BACKGROUND

The search for substances that can overcome microorganisms' resistance and enhance the antimicrobial activity of given products has attracted the attention of researchers. Eucalyptus wood vinegar (WV) is a promising product for developing alternative antimicrobials.

OBJECTIVES

This study aimed to evaluate whether the production of WV in the co-pyrolysis of eucalyptus wood with aromatic herbs would incorporate compounds from them into WV and if that would enhance its antimicrobial action.

METHODOLOGY

WV was produced alone and through co-pyrolysis with marjoram (Origanum majorana), Peruvian oregano (Origanum vulgare), rosemary (Salvia rosmarinus), thyme (Thymus vulgaris), and Turkish oregano (Origanum onites) at a proportion of 25% of herbs to the bone-dry wood weight. The antimicrobial effects were assessed against strains of gram-negative and -positive bacteria, and Candida glabrata. Microorganisms' colony growth in agar had their absorbances recorded after inoculation and incubation. Chemical characterization of the new products was performed by gas chromatography and mass spectrometry (GC/MS).

RESULTS

After coproduction, there were relevant chemical changes concerning the original WV. Thymol, for instance, was incorporated into the WV through co-pyrolysis with marjoram, Peruvian and Turkish oregano, and thyme. The coproducts were more efficient than the WV produced only with wood, with thyme-incorporated products having the highest efficiency. This can be attributed to the increase and incorporation of the substances after coproduction, and particularly the role of thymol in enhancing the antimicrobial action.

CONCLUSION

Given the results, the co-production of WV with eucalyptus wood and aromatic herbs has the potential to provide alternative antimicrobial products.

Structure-Activity Relationship of Pyrrolidine Pentamine Derivatives as Inhibitors of the Aminoglycoside 6'-N-Acetyltransferase Type Ib

Resistance to amikacin and other major aminoglycosides is commonly due to enzymatic acetylation by the aminoglycoside 6'-N-acetyltransferase type I enzyme, of which type Ib [AAC(6')-Ib] is the most widespread among Gram-negative pathogens. Finding enzymatic inhibitors could be an effective way to overcome resistance and extend the useful life of amikacin. Small molecules possess multiple properties that make them attractive for drug development. Mixture-based combinatorial libraries and positional scanning strategy have led to the identification of a chemical scaffold, pyrrolidine pentamine, that, when substituted with the appropriate functionalities at five locations (R1-R5), inhibits AAC(6')-Ib-mediated inactivation of amikacin. Structure-activity relationship studies have shown that while truncations to the molecule result in loss of inhibitory activity, modifications of functionalities and stereochemistry have different effects on the inhibitory properties. In this study, we show that alterations at position R1 of the two most active compounds, 2700.001 and 2700.003, reduced inhibition levels, demonstrating the essential nature not only of the presence of an S-phenyl moiety at this location but also the distance to the scaffold. On the other hand, modifications on the R3, R4, and R5 positions had varied effects, demonstrating the potential for optimization. A correlation analysis between molecular docking values (ΔG) and the dose required for two-fold potentiation of the compounds described in this and the previous studies showed a significant correlation between ΔG values and inhibitory activity.

Pharmacokinetics, tissue distribution, bioavailability and excretion of the anti-virulence drug Fluorothiazinon in rats and rabbits

Growing antimicrobial resistance has accelerated the development of anti-virulence drugs to suppress bacterial toxicity without affecting cell viability. Fluorothiazinon (FT), an anti-virulence, type three secretion system and flagella motility inhibitor which has shown promise to suppress drug-resistant pathogens having the potential to enhance the efficacy of commonly prescribed antibiotics when used in combination. In this study we characterized the pharmacokinetics, tissue distribution, bioavailability and excretion of FT in rats and rabbits. FT presented a dose-proportional linear increase in the blood of rats. Tissue distribution profiling confirmed that FT distributes to all organs being substantially higher than in the blood of rats. The bioavailability of FT was higher when administered with starch than with water implying FT should be ideally dosed with food. FT was primarily excreted in the feces in rats and rabbits while negligible amounts are recovered from the urine.