Cefaclor: a contemporary look at susceptibility of key pathogens from around the globe.

The orally administered cephalosporin antibiotic, cefaclor, has been available for clinical use in many countries since 1979. Because widespread antibiotic use is often cited as a factor in the emergence of bacterial resistance to antibiotics, we sought to determine the degrees of resistance to cefaclor expressed by key pathogens recently isolated in 10 countries widely distributed around the world. Using the E-test, minimal inhibitory concentrations (MIC) were determined for cefaclor and several comparator antibiotics against approximately 700 fresh clinical isolates of each of six bacterial species. The results demonstrated that > 90% of Haemophilus influenzae (beta-lactamase producing and non-producing), Haemophilus parainfluenzae (beta-lactamase producing and non-producing), Moraxella catarrhalis (> 90% beta-lactamase producing), and methicillin-susceptible Staphylococcus aureus, and 85% of Escherichia coli were susceptible to cefaclor at the NCCLS interpretive breakpoints. MIC distributions showed that there has been no change in the activity of cefaclor against penicillin-susceptible strains of Streptococcus pneumoniae since 1977.