[Pays de la Loire Pneumococcus Observatory: antimicrobial resistance of Streptococcus pneumoniae in 2007]

Abstract

Objectives: Between 1st January and 31st December 2007, 331 Streptococcus pneumoniae strains were collected from 20 participating laboratories in the Pneumococcus Network Pays de la Loire county to assess their susceptibility to antibiotics and to evaluate serogroups of strains.

Method: The coordinating centre performed MICs of penicillin G, amoxicillin and cefotaxime by the reference agar dilution method. Results were interpreted according to CA-SFM breakpoints. Sensitivity to other antibiotics were studied and serotyping of each strain performed.

Results: Three hundred and thirty one strains were isolated in 2007. They were collected from 30 cerebrospinal fluids, 239 blood samples, 53 middle ear fluids and nine pleural fluids. The percentage of pneumococci with decreased susceptibility to penicillin G (PDSP) was 39% and was higher in children (51%) than in adults (35%). The PDSP were often multidrug resistants especially with a high percentage of resistance to erythromycin (87.6% versus 8.4% for pneumococci sensitive to penicillin G). Finally, the most prevalent serogroup was the serogroup 19 (29.6% of isolates).

Conclusion: A decrease of PDSP was observed since 2001 and high-level resistant strains to beta-lactams remain low. The rate of PDSP in Pays de la Loire is in the national average.