In vitro activity of linezolid and 12 other antimicrobials against coryneform bacteria.
OBJECTIVE
To compare the in vitro activity of linezolid with 12 other antimicrobials against 190 strains of the coryneform bacteria, including 60 strains of C. amycolatum, 30 of C. striatum, 30 of C. jeikeium, 10 of C. urealyticum, 20 of B. casei, 20 of D. hominis and 20 of T. otitidis.


METHODS
Minimum inhibitory concentrations (MICs) and time-death curves were carried out according to the recommendations of the Clinical and Laboratory Standards Institute (CLSI).


RESULTS
Linezolid was very active against the 130 strains of the Corynebacterium species studied. Only the glycopeptides showed similar efficacy. In contrast, penicillin G, ampicillin, macrolides, lincosamides, fluoroquinolones and aminoglycosides showed generally high MICs. Among the beta-lactams, only imipenem was active against the majority of strains of C. striatum and C. amycolatum, and, approximately half of the C. jeikeium and C. urealyticum isolates. Both Dermabacter hominis and Brevibacterium casei showed marked resistance against most of the antimicrobials tested, while Turicella otitidis only showed high MICs against macrolides and clindamycin. For all of them, linezolid, vancomycin and teicoplanin proved effective. The time-death curves showed linezolid to behave as a bacteriostatic agent (approximately 90% death rate). Such activity was more accentuated for C. amycolatum and C. striatum (reduction of 1.3 and 1.7log(10)CFU/mL, respectively) than for C. jeikeium and C. urealyticum (reduction of 1.0 and 0.8log(10), respectively).


CONCLUSIONS
Our results indicate that linezolid is active against coryneform bacteria. The efficacy of linezolid is equal to or even superior to that of the glycopeptides.
Gómez-Garcés
José-Luis
JL
Servicio de Microbiología, Hospital de Móstoles, Instituto Madrileño de la Salud, c/Rio Jucar s/n, 28935 Móstoles, Madrid, Spain. jlgarces@microb.net
Alos
Juan-Ignacio
JI
Tamayo
Javier
J
D000081:Acetamides / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003352:Corynebacterium / Q000145:classification / Q000187:drug effects*; D024881:Drug Resistance, Bacterial; D024841:Fluoroquinolones / Q000494:pharmacology*; D006020:Glycopeptides / Q000494:pharmacology*; D066298:In Vitro Techniques; D000069349:Linezolid; D018942:Macrolides / Q000145:classification / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D023303:Oxazolidinones / Q000494:pharmacology*; D047090:beta-Lactams / Q000494:pharmacology*
D000081:Acetamides; D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D006020:Glycopeptides; D018942:Macrolides; D023303:Oxazolidinones; D047090:beta-Lactams; D000069349:Linezolid