Open AccessTeicoplanin and daptomycin bactericidal activities in the presence of albumin or serum under controlled conditions of pH and ionized calcium
Author(s) -
Kenneth C. Lamp,
Michael J. Rybak
Publication year - 1993
Publication title -
antimicrobial agents and chemotherapy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.07
H-Index - 259
eISSN - 1070-6283
pISSN - 0066-4804
DOI - 10.1128/aac.37.3.605
Subject(s) - daptomycin , teicoplanin , chemistry , staphylococcus aureus , albumin , calcium , microbiology and biotechnology , serum albumin , vancomycin , bacteria , biology , biochemistry , organic chemistry , genetics
Teicoplanin and daptomycin bactericidal rates (BRs) were measured from standard kill curves in supplemented Mueller-Hinton broth (B), B with 3 g of albumin per dl (BA), B with 50% pooled human serum (BS), and in broth to simulate free concentrations (BF) under controlled physiologic conditions of pH (7.4) and ionized calcium (1.15 to 1.17 mM) against two clinical Staphylococcus aureus strains. Total concentrations of teicoplanin and daptomycin, respectively, were 45 and 12.5 micrograms/ml in B, BA, and BS and 4.5 and 1.25 micrograms/ml in BF. All BRs are reported as log10 CFU per milliliter per hour. There was a trend for the teicoplanin BR to be inhibited by serum for strain 67 (BR in B was -0.26 +/- 0.08 versus a BR in BS of -0.19 +/- 0.08 [P > 0.05]). The teicoplanin BRs for strain 135 were unaffected by the type of medium used (range, -0.17 to -0.20). For both strains, daptomycin BRs were adversely affected by lower concentrations, albumin, and serum. The BR of daptomycin was significantly faster in B (-4.53 +/- 1.92) (P 0.05). Against strain 135, daptomycin again produced the highest BR in B; however, the BRs in BF, BA, and BS were almost identical, indicating that only free daptomycin was active. After correcting for the influence of protein binding, pH, and ionized calcium, teicoplanin appeared to be inhibited by serum, and daptomycin demonstrated enhanced BRs against different S. aureus strains in the presence of albumin or serum.