[Antibacterial activity of ceftriaxone]

Area of Science:

• Microbiology
• Pharmacology
• Infectious Diseases

Background:

• Ceftriaxone is a new aminothiazolyl methoxy-iminocephalosporin.
• Understanding its in vitro characteristics is crucial for clinical application.

Purpose of the Study:

• To characterize the in vitro properties of ceftriaxone.
• To compare its antibacterial activity with cefotaxime.
• To assess its stability against beta-lactamases and its spectrum of activity.

Main Methods:

• In vitro susceptibility testing against various bacterial strains.
• Evaluation of stability against plasmid and chromosome-mediated beta-lactamases.
• Identification of penicillin-binding protein (PBP) targets.

Main Results:

• Ceftriaxone exhibits a long elimination half-life (8 hours), contributing to extended antibacterial efficacy.
• It is highly stable against most beta-lactamases.
• The antibiotic shows broad-spectrum activity against Gram-positive cocci and Gram-negative bacilli, including beta-lactamase producers.
• Variable activity against Pseudomonas sp. and Acinetobacter sp. was observed, with synergistic effects noted when combined with aminoglycosides or other beta-lactams.
• Ceftriaxone targets multiple PBPs (PBP1b, 2, and 3), inducing filamentation in bacteria like E. coli, Ps. aeruginosa, and Haemophilus.

Conclusions:

• Ceftriaxone possesses significant in vitro activity against challenging bacterial strains.
• Its stability, broad spectrum, and PBP targeting suggest potential as a valuable cephalosporin for severe infections.