Comparative in vitro activity of telavancin (TD-6424), a rapidly bactericidal, concentration-dependent anti-infective with multiple mechanisms of action against Gram-positive bacteria.
OBJECTIVE
We compared the in vitro activity of telavancin with that of vancomycin, teicoplanin, linezolid, quinupristin/dalfopristin, moxifloxacin and ampicillin, penicillin or oxacillin as appropriate, by the NCCLS/EUCAST and BSAC methods.


METHODS
The organisms (n = 401) included in the study were patient isolates from St Thomas' Hospital and were selected to include representatives of the clinically important Gram-positive aerobic species. Susceptibility testing was performed by agar dilution methods on Mueller-Hinton agar according to the NCCLS/EUCAST guidelines, in comparison with Iso-Sensitest agar according to the BSAC guidelines.


RESULTS
Telavancin was active against all the Gram-positive species tested and nearly 90% of isolates included in the study had telavancin MICs </= 1 mg/L. Vancomycin-resistant enterococci and lactobacilli isolates with vancomycin MICs > 64 mg/L had telavancin MIC ranges of 0.5-8 and 2-16 mg/L, respectively. There was no evidence of cross-resistance with other comparator drugs. The results for telavancin for the two susceptibility testing methods were mostly either the same or within one doubling dilution.


CONCLUSIONS
The susceptibility breakpoints for telavancin have yet to be established, but it would appear that telavancin has superior potency to the other tested glycopeptides, and on a weight-for-weight basis displays activity that is comparable to, or better than, that of the other agents tested.
King
Anna
A
Department of Infection, GKT School of Medicine, St Thomas' Hospital Campus, London, UK. anna.king@kcl.ac.uk
Phillips
Ian
I
Kaniga
Koné
K
D000617:Aminoglycosides / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000890:Anti-Infective Agents / Q000494:pharmacology*; D003470:Culture Media; D004305:Dose-Response Relationship, Drug; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology; D006801:Humans; D000077427:Lipoglycopeptides; D008826:Microbial Sensitivity Tests
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D003470:Culture Media; D000077427:Lipoglycopeptides; C487637:telavancin