Antimicrobial Property of Microorganisms Isolated from Soil and Water – Body Samples in Ghana

Introduction: Soil and aquatic microorganisms have been the major sources of novel antimicrobial agents over the past years. The continues use of these agents against pathogenic organisms have resulted in multi-drug resistant pathogens, hence, the need to search for new and potent antimicrobial agents. Methods: In this study, microorganisms were isolated from 24 samples collected from soil, the Kakum River (water and sediments) and the Gulf of Guinea (water and sediments). The microorganisms present in these samples were screened for their antimicrobial producing potentials. Results: A total of 138 microorganisms were isolated out of which thirty-six (36) showed growth–inhibitory activity against at least one of the test organisms used for the screening. The extract of a selected isolate, GKSE1, showed antibacterial activity against B. subtilis, S. aureus, S. epidermidis, S. pyogenes, E. faecalis, E. coli, K. pneumonia, P. aeruginosa, S. typhi, S. typhorium and S. dysentriae with minimum inhibitory concentration ranging from 1.563–6.250 mg/mL. The extract was stable in aqueous solution for more than three months and also had activity after autoclaving at 121oC for 15 minutes. TLC analysis of the crude extract revealed 5 spots with 2 regions of inhibition in a bioautography assay. Conclusion: This study has shown that microorganisms isolated from soil, Kakum River and the sea has the potential to produce antimicrobial agents with the isolate GKSE1, identified as Enterococcus faecalis having excellent activity.