In vitro activity of ceftaroline and comparator antimicrobials against European and Middle East isolates from complicated skin and skin-structure infections collected in 2008-2009.
The activities of ceftaroline, the active metabolite of the pro-drug ceftaroline fosamil, a novel anti-meticillin-resistant staphylococcal cephalosporin, and nine comparators were determined against surveillance isolates collected in 2008-2009. Over 3000 isolates associated with complicated skin and skin-structure infections (cSSSIs) were collected from 106 centres in 19 countries. MICs were determined using CLSI broth microdilution methodology. Clonal relatedness of meticillin-resistant Staphylococcus aureus (MRSA) with raised ceftaroline MICs (2 mg/L) was assessed by MLST, PFGE and mec typing. The presence of Panton-Valentine leukocidin in these isolates was also determined. Ceftaroline was active against 500 MRSA and 479 meticillin-susceptible S. aureus, with MIC(50/90) values of 0.5/2 mg/L and 0.25/0.25 mg/L, respectively. For coagulase-negative staphylococci (CoNS), the ceftaroline MIC(50/90) values for meticillin-resistant strains (n=159) were the same as those seen for MRSA. Meticillin-susceptible CoNS (n=113) had the same MIC(90) as that seen with S. aureus, but the MIC(50) was lower at 0.06 mg/L. Ceftaroline was also active against β-haemolytic streptococci (n=526; MIC(50/90)=0.004/0.015 mg/L), other streptococci (n=75; 0.015/0.06 mg/L), common Enterobacteriaceae (n=897; 0.25/≥128 mg/L) and Enterococcus faecalis (n=329; 1/16 mg/L). Those MRSA with ceftaroline MICs of 2mg/L were found to be from four clonal groups associated with the country of origin. These data confirm the broad-spectrum in vitro activity of ceftaroline against cSSSI pathogens. Ceftaroline is unique among clinically available cephalosporins, having good in vitro activity against MRSA and meticillin-resistant CoNS and moderate activity against Gram-negative bacteria.
Quotient Bioresearch Ltd., Fordham, UK. imorrissey@ihmainc.com
Ian
I
Morrissey
Anne
A
Leakey
John Blackman
JB
Northwood
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification*; D002511:Cephalosporins / Q000494:pharmacology*; D004269:DNA, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D005060:Europe; D005838:Genotype; D006801:Humans; D008826:Microbial Sensitivity Tests; D008877:Middle East; D058885:Multilocus Sequence Typing; D017192:Skin Diseases, Bacterial / Q000382:microbiology*; D000097583:Ceftaroline
D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D004269:DNA, Bacterial; D000097583:Ceftaroline