Extraction and Characterization of Staphylococcins from S. aureus Isolated from Selected Environments within Akure Metropolis and Evaluation of Their Antibacterial Activity

Abstract

Staphylococcins are bacteriocins produced by Staphylococcus aureus and it has been proven that they have antibacterial potential. The purpose of this study was to compare the staphylococcin producing potential of S. aureus isolated from different environments and the antibacterial potential of the staphylococcins extracted. Using standard microbiological techniques S. aureus was isolated from different environments. The isolated S. aureus from the selected environments were screened for antibacterial potentials against the bacterial species (Pseudomonas aeruginosa, Proteus sp, Bacillus subtilis and Klebsiella pneumoniae) isolated from wound samples using agar well diffusion assay. The staphylococcins extracted were partially purified and molecularly characterized using Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The partially purified staphylococcins (PPS) were then screened for growth inhibitory activity against the isolated bacterial species from different wound samples while the effects of temperature and pH on the antibacterial activity of PPSs were also assessed using standard methods. Partially Purified Staphylococcin (PPSs) extracted from S. aureus isolated from leg wound (SALW), S. aureus from human stool (SAHS) and S. aureus isolated from cow dung (SACD) however displayed better inhibitory activity on most of the multi antibiotic resistant isolated bacteria with SALW. The inhibitory activities of the extracted staphylococcins were maximal at neutral pH and temperature of 27±2ºC while their potency reduced at extreme pH and increased temperatures. The molecular weight of the extracted staphylococcins ranged from 21kDa to 83kDa. From this study, the antibacterial activity of the extracted staphylococcins from S. aureus on bacteria isolated from wounds varied based on the environment from which the S. aureus was isolated. Staphylococcins SALW, SAHS and SACD were observed to show higher antibacterial activity than that of the antibiotics used on most of the bacteria isolates. Therefore, in sourcing for alternative therapy, SALW, SAHS and SACD should be exploited for the treatment of wound infections.