Hybrid Antibiotics Targeting the Bacterial Ribosome

Area of Science:

• Microbiology
• Structural Biology
• Medicinal Chemistry

Background:

• Antimicrobial resistance (AMR) is a major global health threat, with resistance mechanisms outpacing new antibiotic development.
• Novel strategies are needed to overcome existing resistance and develop new antibacterial agents.
• Hybrid antibiotics targeting multiple sites on the bacterial ribosome offer a promising approach.

Purpose of the Study:

• To design, synthesize, and characterize novel hybrid antibiotics targeting the bacterial ribosome.
• To investigate the molecular mechanisms of action of these hybrid antibiotics using structural biology techniques.
• To identify potent hybrid antibiotics effective against multidrug-resistant bacteria.

Main Methods:

• Rational design and synthesis of hybrid antibiotics combining azithromycin, tedizolid, and chloramphenicol.
• Microbiological evaluation against a panel of multidrug-resistant bacteria.
• Cryo-electron microscopy to determine the structural basis of ribosome-hybrid antibiotic interactions.

Main Results:

• Four novel hybrid antibiotics targeting the peptidyltransferase center (PTC) and nascent peptide exit tunnel (NPET) of the ribosome were synthesized and characterized.
• Cryo-electron microscopy provided detailed structural insights into the binding modes of these hybrids.
• A hybrid of azithromycin and tedizolid demonstrated broad-spectrum activity against multidrug-resistant Gram-positive bacteria and was effective against ribosomal protection (ABC-F) resistance mechanisms.

Conclusions:

• The rational design of hybrid antibiotics targeting adjacent ribosomal sites is a viable strategy to overcome antimicrobial resistance.
• The identified azithromycin-tedizolid hybrid represents a promising new class of dual-action antibiotics with potential clinical applications.
• This work provides a framework for developing bifunctional inhibitors against bacterial targets.