Arcobacter butzleri: Underestimated Enteropathogen

Molecular methods applied to 2,855 strains of Campylobacter-like organisms received from a surveillance network of Campylobacter infections in France identified 29 Arcobacter butzleri infections. This species ranks fourth for Campylobacteraceae isolation and appears to have the same pathogenic potential as the other species in the genus

Structure and Magnetism of well-defined cobalt nanoparticles embedded in a niobium matrix

Our recent studies on Co-clusters embedded in various matrices reveal that the co-deposition technique (simultaneous deposition of two beams : one for the pre-formed clusters and one for the matrix atoms) is a powerful tool to prepare magnetic nanostructures with any couple of materials even though they are miscible. We study, both sharply related, structure and magnetism of the Co/Nb system. Because such a heterogeneous system needs to be described at different scales, we used microscopic and macroscopic techniques but also local selective absorption ones. We conclude that our clusters are 3 nm diameter f.c.c truncated octahedrons with a pure cobalt core and a solid solution between Co and Nb located at the interface which could be responsible for the magnetically inactive monolayers we found. The use of a very diluted Co/Nb film, further lithographed, would allow us to achieve a pattern of microsquid devices in view to study the magnetic dynamics of a single-Co cluster.Comment: 7 TeX pages, 9 Postscript figures, detailed heading adde

Campylobacter infections in human : results of threeyears of surveillance 2001 - 2003

The frequency of Campylobacter infections in human, their potential severity, and the existence of preventive measures warrant the creation of a surveillance system. A Campylobacter surveillance system based on private laboratories (PL) was set up in France in 2002 to complement the hospital laboratory-based system(HL). Since 1 January 2001 (for HL), 1 April 2002 (for PL) and 31 December 2003, the Campylobacter National reference Centre analyzed 3 698 strains. Initially thought to be 3.4/100,000, the overall isolation rate was grossly underestimated, as the latest figure is 14/100,000 among children under 5 years old. The strains were mainly C. jejuni (76.9%), followed by C. coli (17.0%) and C. fetus (5.4%). Resistance rates were 41% for ampicillin and 28% for nalidixic acid. Surveillance must be maintained to collect more data on Campylobacter epidemiology in France and to estimate its incidence in the general population.La fréquence des infections humaines à Campylobacter, leur gravité potentielle et l'existence de mesures de prévention justifient une surveillance. En France, un système de surveillance des infections à Campylobacter a été mis en place en avril 2002, à partir des laboratoires de ville (LABM), en complément de celui du réseau des laboratoires hospitaliers (LH) existant depuis 1986. Entre le 1/01/01 (pour les LH), le 1/04/02 (pour les LABM) et le 31/12/03, le Centre National de Référence des Campylobacter a expertisé 3698 souches. Le taux global d'isolement de 3,4/100000 était très largement sous-estimé : il était de 14/100000 pour les enfants âgés de moins S ans. C. jejuni représentait 76,9% des souches, suivi de C. coli (17,0 %) et de C. fetus (5,4%). Le taux de résistance à l'ampicilline était de 41 % et à l'acide nalidixique de 28%. Les efforts pour la surveillance doivent être poursuivis, afin de mieux connaître les caractéristiques épidémiotogiques des infection à Campylobacter en France et de faire des estimations d'incidence en population générale