[Comparative activity of sulfamethoxazole-trimethoprim (SMZ-TMP) on bacteria responsible for ORL infections]

The bacteriostatic activity in vitro of co-trimoxazole (SMZ-TMP); ampicillin, tetracycline and oleandomycin was evaluated against 225 bacterial strains. All the strains (49 Pneumococci, 49 Haemophilus, 41 Streptococci and 86 Staphylococcus aureus) were isolated from sinusitis (63 strains) and otitis (162 strains) in monomicrobial samples. The minimal inhibitory concentrations (MICs) of the 4 antibiotics were determined by the agar diffusion method on all strains. Moreover MICs of SMZ-TMP were determined by the broth dilution method on Haemophilus strains. Seventy seven p. cent of the strains were found sensitive to SMZ-TMP, 70.7% to ampicillin, 85.4% to tetracycline and 73% to oleandomycin. SMZ-TMP was the most effective on Staphylococcus aureus (80% of the isolates were sensitive), whereas ampicillin was effective on all Streptococcus, and Pneumococcus strains and tetracycline was the most active on Haemophilus strains (88% of the isolates were sensitive).