[Microbiological studies with the new penicillin BRL 17421 (temocillin)]

Area of Science:

• Microbiology
• Pharmacology
• Infectious Diseases

Background:

• Emerging antibiotic resistance necessitates the development of new antimicrobial agents.
• The Enterobacteriaceae family represents a significant group of clinically relevant pathogens.
• Understanding the in vitro activity of novel antibiotics is crucial for guiding clinical use.

Purpose of the Study:

• To evaluate the in vitro antibacterial activity of BRL 17421 (temocillin), a new penicillin derivative.
• To compare the efficacy of temocillin against standard antibiotics like mezlocillin, piperacillin, cefazolin, and cefotaxime.
• To determine the sensitivity of mezlocillin-resistant gram-negative rods to temocillin.

Main Methods:

• Quantitative serial broth dilution tests were employed to determine Minimum Inhibitory Concentrations (MICs).
• Antibacterial activity was assessed against 751 clinical isolates of the Enterobacteriaceae family.
• The study included an additional evaluation of 211 mezlocillin-resistant gram-negative rods.

Main Results:

• Temocillin exhibited significant in vitro antibacterial activity across various Enterobacteriaceae species.
• MICs for most tested strains (e.g., Escherichia coli, Klebsiella pneumoniae) ranged from 0.5 mg/l to 16 mg/l.
• Temocillin demonstrated efficacy against mezlocillin-resistant isolates, though some Serratia marcescens strains showed resistance.

Conclusions:

• Temocillin possesses a high level of in vitro antibacterial activity against a broad spectrum of Enterobacteriaceae.
• The compound is effective against gram-negative rods, including those exhibiting resistance to mezlocillin.
• Further investigation into temocillin's clinical utility is warranted based on its in vitro profile.