Open AccessScanning Electronmicroscopy of Staphylococcus Aureus and Enterococcus Faecalis Exposed to Daptomycin
Author(s) -
Linda J. Wale,
Andrew P. Shelton,
David Greenwood
Publication year - 1989
Publication title -
journal of medical microbiology/journal of medical microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.91
H-Index - 117
eISSN - 1473-5644
pISSN - 0022-2615
DOI - 10.1099/00222615-30-1-45
Subject(s) - daptomycin , enterococcus faecalis , lipopeptide , staphylococcus aureus , microbiology and biotechnology , bacteria , antibiotics , strain (injury) , enterococcus , streptococcaceae , biology , chemistry , vancomycin , anatomy , genetics
The novel lipopeptide antibiotic, daptomycin, at a concentration of 8 mg/L, caused gross morphological changes in both a methicillin-sensitive and a methicillin-resistant strain of Staphylococcus aureus and in a strain of Enterococcus faecalis. The earliest (after 1 h) surface lesion observed was the appearance of boss-like processes randomly distributed on the cell surface. Later, grossly deformed bacteria were seen and in two of the three bacteria prolonged exposure led to degeneration of the cells into an amorphous syncytial mass. Omission of calcium (which is known to potentiate the activity of daptomycin) from the culture medium did not affect the morphological response to an inhibitory concentration of the antibiotic.