[A comparative study of antibacterial activity of ceftibuten, ceftazidime, cefuroxime and ampicillin against clinical isolates].

Ceftibuten is an orally active third generation new cephalosporin. Its antibacterial activity in vitro was tested to many clinical isolates and was compared to the activity of ceftazidime, cefuroxime and ampicillin, by twofold serial dilution method in Müller-Hinton agar--detection of minimum inhibitory concentrations (MIC) and by the disc-diffusion method of Kirby-Bauer. The new cephalosporin demonstrated great activity against the different clinical important strains. Many resistant strains to ampicillin were high susceptible to ceftibuten. The majority of Gram-negative organisms, including Enterobacteriaceae, the respiratory pathogens M.(B.) catarrhalis and H. influenzae are highly susceptible to Ceftibuten, however Pseudomonas, Acinetobacter are resistant. The majority of methicillin-susceptible strains of Staphylococcus are resistant too. New cephallosporin was also active against S. pyogenes (Streptococcus gr. A) and penicillin-susceptible pneumococci, but was inactive against S. agalactiae (Streptococcus gr. B), S. pneumoniae penicillin-resistant strains and enterococci, similar to the other cephalosporins. The activity of ceftibuten was higher than that of ampicillin and cefuroxime against beta-lactamases positive strains of H. influenzae and M.(B) catarrhalis, also against tested strains of Enterobacteriaceae. The major priority of the new antibacterial agent over other cephalosporins and ampicillin is its stability to hydrolysis by the main broad-spectrum beta-lactamases producing E. coli and K. pneumoniae sp.