Comparative in vitro activity of gemifloxacin against gram-positive and gram-negative clinical isolates in Argentina

The in vitro activity of gemifloxacin against 1,000 clinical isolates of 14 7 Streptococcus pneumoniae (115, penicilin susceptible: 26, intermediate pe nicillin-resistant and 6, penicillin-resistant), 127 Hemophilus influenzae (109, beta lactamasa non-producer; 18, beta lactamase producers), 95 Strept ococcus pyogenes (6. azytromycin-resistant), 84 Moraxella catarrhalis (79, beta lactamase producers), 110 Staphilococcus aureus (89, methicillin-susce ptible: 21, methicilin-resistant). 98 Eenterococcus faecalis and 339 Entero bacteriacea, (recovered from patients with respiratory tract infection:, sk in and soft tissue infection and urinary tract infection), was compared wit h the activities of four fluorquinolones and five other antimicrobial agent s. Of the quinolones tested, gemifloxacin was the most potent against Strep tococcus pneunioniae, including penicillin intermediate and resistant strai ns. Mic., values obtained for gemifloxacin. ciprofloxacin, ofloxacin, levof loxacin and trvafloxacin were 0.03, 2, 2, 1 and 0.25 mg/L respectively. Gem ifloxacin was 16 fold more potent than ciprofloxacin against methicillin-su sceptible Staphlylococcus aureus and 32 fold more potent than ciprofloxacin against Streptococcus pyogenes. When tested against Hemophilus influenzae. Moraxella catarrhalis and Enterobacteriaceae, all the quinolones showed si milar activity. Our results demonstrate that gemifloxacin has similar activ ity than the other quinolones tested against Gram-negative organisms and is considerably more potent against Gram-positive organisms.