In vitro time-kill studies of antibacterial agents from putative marine Streptomyces species isolated from the Nahoon beach, South Africa
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Date
2010-12
Journal Title
Journal ISSN
Volume Title
Publisher
African Journal of Pharmacy and Pharmacology Vol. 4(12)
Abstract
We assessed the antibiotic production potentials of ten putative Streptomyces strains isolated from the
Nahoon beach and their antibacterial activities against a wide range of bacteria including reference
strains, environmental strains and clinical isolates. The minimum inhibitory concentrations (MICs) of
the crude ethyl acetate extracts ranged from 0.039 to 10 mg/mL and the least minimum bactericidal
concentration (MBC) demonstrated was 0.625 mg/mL against a reference strain Staphylococcus aureus
ATCC 6538. Time kill kinetics of all extracts revealed bacteriostatic and bactericidal activities. Average
log reductions in viable cell counts for all the extracts ranged from 0.86 log10 and 3.99 log10 cfu/mL after
3 h interaction and 0.01 log10 and 4.86 log10 after 6 h interaction at MIC, 2 × MIC, 3 × MIC and 4 × MIC
concentrations. Most of the extracts were speedily bactericidal at 3 × MIC and 4 × MIC resulting in over
50% elimination of most of the test bacteria within 3 and 6 h interaction. Our findings suggest that the
marine Streptomyces isolated from the Nahoon beach have tremendous potential as sources of new
antibacterial compounds.
Description
African Journal of Pharmacy and Pharmacology, Vol. 4, No 12, p.908-916.
Keywords
Time-kill, antibacterial compounds, Marine streptomyces, Nahoon beach