Poster AA12 - Next-Generation Antibiotic: Strain Resistances

Introduction: This study explores the efficacy of new advanced developed antibiotic compounds against P. aeruginosa, focusing on Antibiotic B, an enhanced derivative of Ceftriaxone. The study measured the intracellular uptake of Antibiotic B and introduced a novel adjuvant, Influximax, which augmented its antibacterial activity. Results showed a diminished potential for resistance emergence with Antibiotic B, particularly when used in combination with Influximax. The study suggests that optimizing antibiotic delivery into bacterial cells and leveraging synergistic adjuvant combinations can enhance drug resistance combat.

Materials and

Methods: In our study on Pseudomonas aeruginosa PAO1, we cultured bacteria in Lysogeny Broth at 37˚C, optimizing growth conditions by adjusting sodium chloride concentrations and pH levels to mimic physiological conditions. Next-generation antibiotics with novel mechanisms were employed, solubilized per manufacturer specifications for maximum efficacy. We measured antibiotic accumulation using a fluorescence-based assay, tagging antibiotics with fluorescein isothiocyanate and rhodamine to monitor uptake. Minimum Inhibitory Concentration (MIC) values were determined using the broth dilution method, and antibiotic effectiveness was further assessed through time-kill curve assays. Adjuvants such as efflux pump inhibitors and membrane permeabilizers were tested alongside antibiotics to enhance penetration and combat resistance, evaluated through synergistic effects in fluorescence-based and time-kill assays.

Results, Conclusions, and Discussions: In the study, accumulation assays were conducted to assess the intracellular concentration of next-generation antibiotics in Pseudomonas aeruginosa PAO1 using fluorescence-tagged antibiotics and spectroscopy. The results indicated that Antibiotic A accumulated steadily over 60 minutes, while Antibiotic B showed faster uptake, reaching similar levels in just 30 minutes, suggesting a more efficient penetration into bacterial cells. A One-Way ANOVA confirmed significant differences in the accumulation rates between the two antibiotics, with Antibiotic B showing superior uptake properties. Penetration rate measurements further supported Antibiotic B's faster and more effective intracellular reach, contributing to its heightened bactericidal activity as demonstrated over a 24-hour period in reducing colony-forming units. The data collectively highlight Antibiotic B's potential for enhanced therapeutic efficacy against Pseudomonas aeruginosa, important for informing treatment strategies and managing resistance.

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