7432-s and Pneumococcal-Infections

MICs of 21 beta-lactams were determined by agar dilution against 283 penicillin-susceptible (pen-S), 122 intermediate (pen-I) and 23 fully penicillin-resistant (pen-R) pneumococci. MICs of all beta-lactams increased with increasing MICs of penicillin. Clometocillin was the most active penicillin against pen-I or pen-R pneumococci. All oral cephalosporins except cefuroxime and cefpodoxime were less active than penicillin and none was satisfactory against pen-I or pen-R pneumococci. The parenteral third- and fourth-generation cephalosporins (except ceftazidime) were similar in activity to penicillin against pen-S isolates. Cefpirome showed the lowest mean MICs against pen-I and pen-R strains.

Topics: Amoxicillin; Ampicillin; Anti-Bacterial Agents; beta-Lactams; Carbapenems; Cefaclor; Cefadroxil; Cefatrizine; Cefepime; Cefixime; Cefotaxime; Cefpirome; Cefpodoxime; Ceftazidime; Ceftibuten; Ceftizoxime; Ceftriaxone; Cefuroxime; Cephalosporins; Cephradine; Drug Resistance, Microbial; Drug Resistance, Multiple; Humans; Microbial Sensitivity Tests; Penicillin Resistance; Penicillins; Piperacillin; Pneumococcal Infections; Serotyping; Species Specificity; Streptococcus pneumoniae

There is concern that third-generation cephalosporins may not be effective in the treatment of acute otitis media due to Streptococcus pneumoniae. Using the chinchilla animal model, we compared two third-generation cephalosporins, cefixime (Suprax) and ceftibuten (investigational), with ampicillin and saline controls in an investigator-blinded, randomized trial. Whereas the saline controls performed worse than all other groups, no significant differences were detected among the three antibiotics regarding the time required to sterilize the middle ear cleft, or the prevalence of positive cultures after 10 days of therapy. The statistical power of the comparisons of cefixime and ceftibuten with ampicillin were 98% and 67%, respectively. The results of this in vivo animal study fail to support the contention that the two third-generation cephalosporins investigated are not effective in the treatment of pneumococcal acute otitis media. Caution is advised when extrapolating these results to the general clinical setting.

Topics: Acoustic Impedance Tests; Acute Disease; Ampicillin; Animals; Cefixime; Cefotaxime; Ceftibuten; Cephalosporins; Chinchilla; Drug Evaluation, Preclinical; Otitis Media with Effusion; Pneumococcal Infections