Antimicrobial activity of cefmenoxime (SCE-1365)

Area of Science:

• Microbiology
• Pharmacology
• Infectious Diseases

Background:

• Introduction of cefmenoxime (SCE-1365 or A-50912) as a novel semisynthetic cephalosporin antibiotic.
• Need for comparative analysis of new antibiotics against established agents and a broad spectrum of microorganisms.

Purpose of the Study:

• To evaluate the in vitro antimicrobial activity of cefmenoxime.
• To compare cefmenoxime's efficacy against cefazolin, cefoxitin, cefamandole, and cefotaxime.
• To assess cefmenoxime's activity against aerobic, facultative, and anaerobic bacteria, including specific pathogens.

Main Methods:

• In vitro susceptibility testing of cefmenoxime against 486 bacterial strains (compared with cefazolin, cefoxitin, cefamandole) and 114 strains (compared with cefotaxime).
• Determination of minimum inhibitory concentrations (MICs) and MIC90 values for various bacterial groups.
• Evaluation of cefmenoxime's bactericidal activity, effect of inoculum size, synergy with gentamicin, and resistance development.

Main Results:

• Cefmenoxime exhibited potent activity against Enterobacteriaceae, Streptococcus pneumoniae, Streptococcus pyogenes, Haemophilus influenzae, Neisseria gonorrhoeae, and Neisseria meningitidis.
• Activity was nearly equivalent to cefotaxime against tested organisms and superior to other cephalosporins against most aerobic/facultative bacteria, excluding Staphylococcus aureus.
• Synergistic activity observed with gentamicin against Enterobacteriaceae and Pseudomonas aeruginosa; slow resistance development noted for susceptible strains.

Conclusions:

• Cefmenoxime demonstrates broad-spectrum in vitro activity, positioning it as a potentially valuable cephalosporin antibiotic.
• Its efficacy against key Gram-negative and Gram-positive pathogens warrants further clinical investigation.
• The combination with gentamicin shows promise for enhanced therapeutic outcomes.