In vitro antibacterial activities of crude extracts of Garcinia kola seeds against wound sepsis associated Staphylococcus strains

Extracts of Garcinia kola seeds were evaluated for their activity against fourStaphylococcus strains isolated from wound sepsis specimens. Three of the isolates were identified by 16S rDNA sequencing as Staphylococcus aureuswith the GenBank Accession numbers, EU244633, EU244634, EU244636, and another was identified as Staphylococcus sciuri (Accession number EU244635). The aqueous methanol and acetone extracts of Garcinia kola seeds showed activity against all four isolates at 30 mgml-1 (aqueous extract) and 10 mgml-1(acetone and methanol extracts). The MIC values for the aqueous extract were the same (10 mgml-1) for all the isolates. The acetone and methanol extracts had lower MIC values in the ranges of 0.3125 - 0.625 mgml-1. The acetone extract showed strong bactericidal activity against S. aureus strain OKOH3 resulting in a 2.70 Log10 reduction in counts at 1.25 mgml-1 (2 × MIC) within 4 h of exposure and a complete elimination of the organism after 8 h. The same extract was weakly bactericidal against S. aureus strain OKOH1, achieving only a 2.92 Log10 reduction in counts at 1.25 mgml-1 (4 × MIC) in 24 h. The interactions between the acetone extract and antibiotics were largely additive and indifferent with no combinations showing classical synergistic interactions. We conclude that extracts of Garcinia kola seeds can potentially be useful in the treatment of staphylococcal wound infections.