Open AccessThe mode of antistaphylococcal action of Eleutherine americana
Author(s) -
Ifesan Beatrice Olawumi Temilade,
Joycharat Nantiya,
Voravuthikunchai Supayang Piyawan
Publication year - 2009
Publication title -
fems immunology & medical microbiology
Language(s) - English
Resource type - Journals
eISSN - 1574-695X
pISSN - 0928-8244
DOI - 10.1111/j.1574-695x.2009.00599.x
Subject(s) - staphylococcus aureus , biology , microbiology and biotechnology , enterotoxin , minimum inhibitory concentration , antibacterial activity , micrococcaceae , mechanism of action , strain (injury) , mode of action , bacteria , food science , traditional medicine , antimicrobial , biochemistry , in vitro , medicine , anatomy , escherichia coli , gene , genetics
The anti‐methicillin‐resistant Staphylococcus aureus (anti‐MRSA) activity and the possible mechanism of action of a crude extract from red bulbs of Eleutherine americana Merr. were investigated. The crude ethanolic extract from E. americana produced minimum inhibitory concentrations (MICs) of 62.5–1000 and 250 μg mL −1 against MRSA isolates and the reference strains, respectively. Treatment of S. aureus ATCC 27664 with a crude extract at 2MIC reduced the inoculum size by 5 log at 24 h compared with the control. The combined effect of the extract and 7.5% NaCl on the enterotoxin‐producing ATCC strain resulted in no detection of organisms within 24 h compared with the control. The release of cell materials after extract treatment was determined by measuring OD 260 nm , the treatment resulted in cytoplasmic leakage. Determination of OD 620 nm showed that the extract did not cause gross cell wall damage. However, observation of S. aureus cells under an electron microscope after treatment with 2MIC and 4MIC of the crude extract revealed that the extract caused damage to membrane morphology. A knowledge of the mechanism of action of the E. americana extract may offer useful hints in the search for novel antibacterial substance.