Comparative activity of telavancin against isolates of community-associated methicillin-resistant Staphylococcus aureus.
OBJECTIVE
This study compared the activity of telavancin, a novel multivalent lipoglycopeptide with rapid bactericidal activity, with those of five standard antibiotics for methicillin-resistant Staphylococcus aureus (MRSA) against isolates of community-associated MRSA (CA-MRSA).


METHODS
Microdilution tests performed according to CLSI guidelines using cation-adjusted Mueller-Hinton broth were used to determine the MIC values of telavancin, quinupristin/dalfopristin, vancomycin, trimethoprim/sulfamethoxazole, linezolid and daptomycin versus 60 CA-MRSA isolates. MBC values of telavancin were determined according to CLSI guidelines and American Society for Microbiology standards. PFGE was performed using the restriction enzyme SmaI. Samples from three predominant pulsed-field types were typed by multilocus sequence typing. Staphylococcal cassette chromosome mec typing was determined by multiplex PCR. The Panton-Valentine leucocidin (PVL) genes (lukS-PV and lukF-PV) were identified by PCR.


RESULTS
The telavancin MIC90 and MBC90 values for this collection of 60 CA-MRSA isolates were 0.5 and 1 mg/L, respectively, with MIC and MBC values both ranging from 0.25 to 1 mg/L. Telavancin was found to be bactericidal in this study, as its MBC was no more than 2-fold higher than its MIC for all CA-MRSA isolates tested except one. (A single isolate yielded an MBC/MIC ratio of 4.) PVL- and non-PVL-producing strains demonstrated similar susceptibility to telavancin and comparator agents.


CONCLUSIONS
Based on in vitro activity, telavancin should be an effective agent against CA-MRSA.
Saravolatz
Louis D
LD
Department of Internal Medicine, St John Hospital and Medical Center, Detroit, MI, USA. louis.saravolatz@stjohn.org
Pawlak
Joan
J
Johnson
Leonard B
LB
D000617:Aminoglycosides / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015373:Bacterial Typing Techniques; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000187:drug effects; D003001:Cloning, Molecular; D017714:Community-Acquired Infections / Q000382:microbiology*; D006801:Humans; D007956:Leukocidins / Q000378:metabolism; D000077427:Lipoglycopeptides; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D013203:Staphylococcal Infections / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D007956:Leukocidins; D000077427:Lipoglycopeptides; D002786:Cholesterol Side-Chain Cleavage Enzyme; C487637:telavancin