Comparative activity of ceftobiprole against Gram-positive and Gram-negative isolates from Europe and the Middle East: the CLASS study

• Published in: Journal of antimicrobial chemotherapy 2011, Vol.66 (1), p.151-159
• Main Authors: ROSSOLINI, Gian M, DRYDEN, Matthew S, KOZLOV, Roman S, QUINTANA, Alvaro, FLAMM, Robert K, LÄUFFER, Jörg M, LEE, Emma, MORRISSEY, Ian
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - pharmacology; Bacteriology; Cephalosporins - pharmacology; Comparative studies; Drug resistance; Drug Resistance, Multiple, Bacterial; Europe; Gram-negative bacteria; Gram-Negative Bacteria - drug effects; Gram-Negative Bacteria - isolation & purification; Gram-Negative Bacterial Infections - microbiology; Gram-positive bacteria; Gram-Positive Bacteria - drug effects; Gram-Positive Bacteria - isolation & purification; Gram-Positive Bacterial Infections - microbiology; Humans; Microbial Sensitivity Tests; Middle East; Pseudomonas aeruginosa; Staphylococcus aureus; Staphylococcus infections
• ISSN: 0305-7453; 1460-2091
• DOI: 10.1093/jac/dkq397

to assess the in vitro activity of ceftobiprole and comparators against a recent collection of Gram-positive and Gram-negative pathogens, in order to detect potential changes in susceptibility patterns, and to evaluate the Etest assay for ceftobiprole susceptibility testing. contemporary Gram-positive and Gram-negative isolates (excluding extended-spectrum β-lactamase-producing isolates) from across Europe and the Middle East were collected, and their susceptibility to ceftobiprole, vancomycin, teicoplanin, linezolid, ceftazidime and cefepime was assessed using the Etest method. Quality testing [using Etest and broth microdilution (BMD)] was conducted at a central reference laboratory. some 5041 Gram-positive and 4026 Gram-negative isolates were included. Against Gram-positive isolates overall, ceftobiprole had the lowest MIC50 (0.5 mg/L), compared with 1 mg/L for its comparators (vancomycin, teicoplanin and linezolid). Against methicillin-resistant Staphylococcus aureus, all four agents had a similar MIC90 (2 mg/L), but ceftobiprole had a 4-fold better MIC90 (0.5 mg/L) against methicillin-susceptible strains. Only 38 Gram-positive isolates were confirmed as ceftobiprole resistant. Among Gram-negative strains, 86.9%, 91.7% and 95.2% were susceptible to ceftobiprole, ceftazidime and cefepime, respectively. Pseudomonas aeruginosa was less susceptible to all three antimicrobials than any other Gram-negative pathogen. There was generally good agreement between local Etest results and those obtained at the reference laboratory (for ceftobiprole: 86.8% with Gram-negatives; and 94.7% with Gram-positives), as well as between results obtained by BMD and Etest methods (for ceftobiprole: 98.2% with Gram-negatives; and 98.4% with Gram-positives). ceftobiprole exhibits in vitro activity against a wide range of Gram-positive and Gram-negative pathogens, including multidrug-resistant strains. No changes in its known susceptibility profile were identified.