Posted: May 20th, 2010 - 4:47pm
Source: Antimicrob. Agents Chemother. June 2010 V.54 N.6 p.2728-2731

Institut Pasteur, Centre National de Référence des Listeria and World Health Organization Collaborating Centre for Foodborne Listeriosis, Paris, France,1 Institut Pasteur, Centre National de Référence de la Résistance aux Antibiotiques, Paris, France,2 Institut Pasteur, Groupe Microorganismes et Barrières de l'Hôte, Paris, France,3 INSERM avenir U604, Paris, France,4 Université Paris Descartes, Hôpital Necker-Enfants Malades, Assistance Publique-Hôpitaux de Paris, Paris, France,5 Laboratoire de Microbiologie du Centre Hospitalier de Versailles, Le Chesnay, France6
Received 3 November 2009/ Returned for modification 24 January 2010/ Accepted 5 April 2010
Susceptibility to antibiotics of 4,816 clinical L. monocytogenes strains isolated since 1926 was studied, and the temporal evolution of susceptibility to antibiotics was analyzed through several decades. The mechanisms of resistance in each resistant strain were studied. The prevalence of resistant strains was estimated at 1.27% among isolates from humans. Resistance to tetracyclines+ and fluoroquinolones was more common and has recently emerged. Although acquired resistance in clinical L. monocytogenes did not implicate clinically relevant antibiotics, the possibility of resistance gene transfers, the description of the first clinical isolate with high-level resistance to trimethoprim, and the recent increase in penicillin MICs up to 2 µg/ml reinforce the need for microbiological surveillance.