Antimicrobial activities of tosufloxacin against Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella branhamella catarrhalis isolated from otolaryngological infectious diseases

In 2003, the Japan Society for Infectious Diseases in Otolaryngology conducted its third nationwide survey of clinical isolates from otolaryngological infectious diseases. We selected three primary causative organisms of otolaryngological infectious diseases, Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella Branhamella catarrhalis, and evaluated their sensitivities to tosufloxacin (TFLX), a new oral quinolone, because the survey revealed a rise in drug-resistant strains, suggesting potential problems with the antibiotics commonly used against these organisms. The minimum inhibitory concentration (MIC)(90) values of TFLX against S. pneumoniae, H. influenzae, and M. catarrhalis were 0.25 microg/ml, <or=0.06 microg/ml, and <or=0.06 microg/ml respectively, and TFLX was shown to be as effective as or superior to other new quinolones. In addition, TFLX showed sufficient antimicrobial effects against frequently detected drug-resistant bacteria such as penicillin-resistant S. pneumoniae (PRSP) and beta-lactamase-negative, ampicillin-resistant strains of H. influenzae (BLNAR). Furthermore, only a few strains of bacteria showed resistance to TFLX.