%0 Journal Article %A Pettit, Robin K. %A Fakoury, Bridget R. %A Knight, John C. %A Weber, Christine A. %A Pettit, George R. %A Cage, Gary D. %A Pon, Sandy %T Antibacterial activity of the marine sponge constituent cribrostatin 6 %D 2004 %J Journal of Medical Microbiology, %V 53 %N 1 %P 61-65 %@ 1473-5644 %R https://doi.org/10.1099/jmm.0.05250-0 %I Microbiology Society, %X The antibacterial activity of the nitrogen heterocyclic sponge constituent cribrostatin 6 was examined. Cribrostatin 6 was bacteriostatic for a variety of Gram-positive species and was bactericidal for the majority of clinical isolates of Streptococcus pneumoniae, including penicillin-resistant strains. Minimum bactericidal concentration/MIC ratios were ⩽2 for 75 % of S. pneumoniae clinical isolates. Kill-curve analysis confirmed the bactericidal action of cribrostatin 6. Bactericidal activity was rather slow, beginning at 2, 4 or 8 h, depending on the strain. The frequency of occurrence of bacterial spontaneous mutations to resistance was ⩽10−7. The maximum tolerated dose of cribrostatin 6 in mice was 750–1000 μg kg−1 day−1. Cribrostatin 6 is a promising lead antibiotic for Gram-positive bacteria, particularly S. pneumoniae, a leading cause of infection and mortality worldwide. %U https://www.microbiologyresearch.org/content/journal/jmm/10.1099/jmm.0.05250-0