Antimicrobial susceptibility of Listeria monocytogenes isolates from human cases in northern Italy, 2008-2010: MIC determination according to EUCAST broth microdilution method.
Susceptibility of 96 Listeria monocytogenes human isolates collected in northern Italy between 2008 and 2010, to 15 antimicrobials, was investigated. Minimum inhibitory concentration (MIC) was evaluated by means of the standardized broth microdilution method, according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) international guidelines. All L. monocytogenes human isolates were susceptible to penicillin G (MIC(90)≤0·06 μg/ml), meropenem (MIC(90)≤0·06 μg/ml), and erythromycin (MIC(90) = 0·12 μg/ml). Susceptibility to the other tested antimicrobials could not be interpreted due to the lack of breakpoint values although two (2%) isolates were shown to have tetracycline MICs above EUCAST epidemiological cut-off values (ECOFF). Bactericidal activity for amoxicillin, gentamicin, and levofloxacin was generally observed at concentrations 2-4 times higher than MIC values. Though L. monocytogenes human strains, isolated in the north of Italy, appear to be susceptible to most antimicrobial agents used in human therapy, this study provides new data for epidemiological surveillance and clinical breakpoints definition.
Moira
M
Madeo
Rosario
R
Musumeci
Anna Maria Laura
AM
Careddu
Ettore
E
Amato
Mirella Maria
MM
Pontello
Clementina Elvezia
CE
Cocuzza
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D006801:Humans; D007558:Italy; D008089:Listeria monocytogenes / Q000187:drug effects* / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests / Q000379:methods
D000900:Anti-Bacterial Agents
Antimicrobials susceptibility,; Bactericidal activity,; EUCAST guidelines; Listeria monocytogenes,; Minimum inhibitory concentration,