Comparative In Vitro Activities of GAR-936 against Aerobic and Anaerobic Animal and Human Bite Wound Pathogens

ABSTRACT

GAR-936 is a new semisynthetic glycylcycline with a broad antibacterial spectrum, including tetracycline-resistant strains. The in vitro activities of GAR-936, minocycline, doxycycline, tetracycline, moxifloxacin, penicillin G, and erythromycin were determined by agar dilution methods against 268 aerobic and 148 anaerobic strains of bacteria (including Pasteurella, Eikenella,Moraxella, Bergeyella, Neisseria, EF-4, Bacteroides, Prevotella,Porphyromonas, Fusobacterium,Staphylococcus, Streptococcus,Enterococcus, Corynebacterium,Propionibacterium, Peptostreptococcus, andActinomyces) isolated from infected human and animal bite wounds in humans, including strains resistant to commonly used antimicrobials. GAR-936 was very active, with an MIC at which 90% of the strains are inhibited (MIC₉₀) of ≤0.25 μg/ml, against all aerobic gram-positive and -negative strains, including tetracycline-resistant strains of Enterococcus,Streptococcus, and coagulase-negative staphylococci, except for Eikenella corrodens (MIC₉₀, ≤4 μg/ml). GAR-936 was also very active against all anaerobic species, including tetracycline-, doxycycline-, and minocycline-resistant strains ofPrevotella spp., Porphyromonas spp.,Bacteroides tectum, and Peptostreptococcusspp., with an MIC₉₀ of ≤0.25 μg/ml. Erythromycin- and moxifloxacin-resistant fusobacteria were susceptible to GAR-936, with an MIC₉₀ of 0.06 μg/ml.