Antimicrobial spectrum of activity of telavancin and comparator agents tested against methicillin-resistant Staphylococcus aureus recovered from United States and European hospitals over a 3year sampling period (20072009)
Abstract number: P932
Objectives: To monitor the activities of telavancin (TLV) and comparators against methicillin-resistant S. aureus (MRSA) collected from the United States (US) and Europe (EU) including Turkey, over a three year period (20072009). TLV was recently approved in the US and Canada for the treatment of adult patients with complicated skin and skin structure infections (cSSSI) caused by susceptible Gram-positive pathogens. This new lipoglycopeptide has shown potent in vitro activity against staphylococci, including multidrug-resistant (MDR) strains.
Methods: A total of 4,077 and 1,334 MRSA isolates were collected respectively from 42 and 29 hospitals in the US and EU (13 different countries). All isolates were submitted to a coordinator laboratory. Species identifications were confirmed by standard algorithms and, when necessary, by Vitek 2. Antimicrobial susceptibility testing was performed by CLSI methods (M07-A8, 2009). Interpretive criteria were those from EUCAST (2009), except for TLV where the susceptibility breakpoint approved by the US-FDA for S. aureus (1 mg/L) was applied.
Results: MRSA were recovered from bacteremia (38.5%), pneumonia (18.0%), SSSI (36.2%) and other infection sites (7.3%). MRSA rates ranged from 56.2% in 2007 to 52.0% in 2009 in the US and from 28.3% in 2007 to 22.7% in 2008 in EU. Among EU countries, the MRSA rates varied considerably, ranging from 0.6% in Sweden to 64.7% in Greece. Overall TLV was consistently active against MRSA over the study period (MIC90, 0.25 mg/L; 100.0% susceptible; see table). Resistance to teicoplanin was noted among isolates from both regions, and resistance rates were highest in Turkey (19.5%) and Italy (4.1%). Daptomycin (DAP; MIC90, 0.5 mg/L), linezolid (LZD; MIC90, 2 mg/L) and trimethoprim/sulfamethoxazole (TMP/SMX; MIC90, 0.5 mg/L) were also active against MRSA. Quinupristin/dalfopristin (Q/D) MIC90 values increased one doubling dilution among US and EU MRSA. Susceptibility rates to gentamicin were higher in the US (95.6%) compared to EU (80.8%-86.9%).
Conclusions: Over a three year surveillance period TLV exhibited sustained potency against MRSA isolates from the US and EU. While vancomycin, DAP, LZD and Q/D were also active against these strains, overall TLV MIC90 values were at least 2-fold lower when compared to these agents. These data emphasize the importance of continued longitudinal surveillance to monitor the activities of marketed antimicrobial agents, mainly against MDR strains.
|Session name:||Abstracts 20th European Congress of Clinical Microbiology and Infectious Diseases|
|Location:||Vienna, Austria, 10 - 13 April 2010|
|Back to top|