In Vitro Activity of Cefditoren against Respiratory Pathogens

초록

Background Cefditoren is a third generation orally administered cephalosporin with excellent activity against respiratory pathogens. This study was performed to determine the comparative antibacterial activity of cefditoren against clinical isolates of respiratory tract infection. Materials and Methods According to the NCCLS guideline, in vitro activities of cefditoren and other antibiotics were tested against respiratory pathogens including 117 isolates of Streptococcus pneumoniae, 60 isolates of Haemophilus influenzae, and 31 isolates of Moraxella catarrhalis. Results The level of cefditoren activity against S. pneumoniae (MIC50/90, 0.5/1 µg/mL) was superior to amoxicillin±clavulanate (MIC50/90, 4/16 µg/mL), clarithromycin (MIC50/90, >32/>32 µg/mL), and most of the marketed cephalosporins (MIC50/90, 8-64/16-128 µg/mL). Although the MIC of cefditoren was relatively higher than those of new fluoroquinolone agents (MIC50/90, 0.03-1/0.06-1 µg/mL), it was comparable to ceftriaxone (MIC50/90, 0.5/1 µg/mL). In addition, cefditoren was active against two quinolone resistant pneumococci strains with MIC of 0.5 µg/mL. In detail, cefditoren was active against pneumococci strains with MIC50 and MIC90 values of 0.015/0.12, 0.12/0.5, and 0.5/1 µg/mL for penicillin-susceptible, -intermediate, and -resistant pneumococci, respectively. Cefditoren was also active against all respiratory isolates of H. influenzae (MIC50/90, 0.03/0.06 µg/mL) and M. catarrhalis (MIC50/90, 0.03/0.05 µg/mL) irrespective of β-lactamase production or ampicillin resistance. Conclusion Cefditoren is considered to be a good option for outpatient treatment of respiratory infections, particulary if there is concern about S. pneumoniae infection with decreased susceptibility to penicillin or β-lactamase producing organisms.

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