title: In vitro activities of RWJ-54428 (MC-02,479) against multiresistant gram-positive bacteria.
abstract: RWJ-54428 (MC-02,479) is a new cephalosporin with a high level of activity against gram-positive bacteria. In a broth microdilution susceptibility test against methicillin-resistant Staphylococcus aureus (MRSA), RWJ-54428 was as active as vancomycin, with an MIC at which 90% of isolates are inhibited (MIC(90)) of 2 microg/ml. For coagulase-negative staphylococci, RWJ-54428 was 32 times more active than imipenem, with an MIC(90) of 2 microg/ml. RWJ-54428 was active against S. aureus, Staphylococcus epidermidis, and Staphylococcus haemolyticus isolates with reduced susceptibility to glycopeptides (RWJ-54428 MIC range, < or = 0.0625 to 1 microg/ml). RWJ-54428 was eight times more potent than methicillin and cefotaxime against methicillin-susceptible S. aureus (MIC(90), 0.5 microg/ml). For ampicillin-susceptible Enterococcus faecalis (including vancomycin-resistant and high-level aminoglycoside-resistant strains), RWJ-54428 had an MIC(90) of 0.125 microg/ml. RWJ-54428 was also active against Enterococcus faecium, including vancomycin-, gentamicin-, and ciprofloxacin-resistant strains. The potency against enterococci correlated with ampicillin susceptibility; RWJ-54428 MICs ranged between < or = 0.0625 and 1 microg/ml for ampicillin-susceptible strains and 0.125 and 8 microg/ml for ampicillin-resistant strains. RWJ-54428 was more active than penicillin G and cefotaxime against penicillin-resistant, -intermediate, and -susceptible strains of Streptococcus pneumoniae (MIC(90)s, 0.25, 0.125, and < or = 0.0625 microg/ml, respectively). RWJ-54428 was only marginally active against most gram-negative bacteria; however, significant activity was observed against Haemophilus influenzae and Moraxella catarrhalis (MIC(90)s, 0.25 and 0.5 microg/ml, respectively). This survey of the susceptibilities of more than 1,000 multidrug-resistant gram-positive isolates to RWJ-54428 indicates that this new cephalosporin has the potential to be useful in the treatment of infections due to gram-positive bacteria, including strains resistant to currently available antimicrobials.
authors: Microcide Pharmaceuticals Inc, Mountain View, California 94043, USA.
authors: S
authors: S
authors: Chamberland
authors: J
authors: J
authors: Blais
authors: M
authors: M
authors: Hoang
authors: C
authors: C
authors: Dinh
authors: D
authors: D
authors: Cotter
authors: E
authors: E
authors: Bond
authors: C
authors: C
authors: Gannon
authors: C
authors: C
authors: Park
authors: F
authors: F
authors: Malouin
authors: M N
authors: MN
authors: Dudley
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002511:Cephalosporins / Q000494:pharmacology*; D018432:Drug Resistance, Multiple / Q000502:physiology*; D016983:Enterococcus / Q000187:drug effects; D006020:Glycopeptides; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D006193:Haemophilus influenzae / Q000187:drug effects; D006801:Humans; D008826:Microbial Sensitivity Tests; D001936:Moraxella catarrhalis / Q000187:drug effects; D013210:Staphylococcus / Q000187:drug effects; D013296:Streptococcus pneumoniae / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D006020:Glycopeptides; C420727:RWJ 54428