[Comparative study of the in vitro activity of 5 new antibiotics on strains isolated from urinary infections]

Area of Science:

• Microbiology
• Pharmacology
• Infectious Diseases

Background:

• Urinary tract infections (UTIs) are commonly caused by Enterobacteriaceae, Pseudomonas, and Enterococcus species.
• Evaluating the in vitro antibiotic susceptibility of these pathogens is crucial for effective treatment.
• Several antibiotics, including cefotaxime, ceftriaxone, ceftazidime, piperacillin, and netilmicin, are used to treat UTIs.

Purpose of the Study:

• To evaluate the in vitro antimicrobial activity of five key antibiotics against common urinary tract pathogens.
• To compare the efficacy of broth dilution and Sensititre methods for determining minimal inhibitory concentrations (MICs).

Main Methods:

• The study assessed 189 urinary isolates of Enterobacteriaceae, Pseudomonas, and Enterococcus.
• Minimal inhibitory concentrations (MICs) were determined using both the broth dilution method and the Sensititre system.
• Antibiotics tested included cefotaxime, ceftriaxone, ceftazidime, piperacillin, and netilmicin.

Main Results:

• Cefotaxime demonstrated the highest in vitro activity against Enterobacteriaceae, with most isolates susceptible to ≤1 µg/ml.
• Ceftazidime was the most effective antibiotic against Pseudomonas isolates.
• Piperacillin exhibited good activity against Enterococcus isolates.
• The broth dilution and Sensititre methods showed comparable results for MIC determination.

Conclusions:

• Cefotaxime, ceftazidime, and piperacillin show significant in vitro activity against specific common urinary pathogens.
• The choice of antibiotic should be guided by the identified pathogen and its susceptibility profile.
• Both broth dilution and Sensititre are reliable methods for assessing antibiotic susceptibility.