[Evolution of antibiotic resistance and serogroups of Streptococcus pneumoniae over the 1997-2003 period in Brittany]. / Evolution de la résistance aux antibiotiques et des sérogroupes de Streptococcus pneumoniae en Bretagne entre 1997 et 2003.

At this time, many antibiotics have decreased activity against Streptococcus pneumoniae, a major agent of infectious disease. In this study, we evaluated antibiotic susceptibility and serogroups of strains isolated from bacteraemia, meningitis and acute otitis media in adults and children over the 1997-2003 period in Brittany, France. In 2003, 62% of the isolates were not susceptible to penicillin and 11% were fully resistant. The prevalence of erythromycin resistance was 63%. Resistance rates were higher among isolates recovered from children than adults. Serogroups 19 and 14 were the most frequently isolated, especially the 19 one among children. The emergence of this serogroup might be a consequence of the use of heptavalent conjugate vaccine introduced in 2001 in France. Future surveillance after vaccination will be needed to detect emerging serogroups and resistance among S. pneumoniae.

Geographic dissemination of methicillin-resistant Staphylococcus aureus strains: a French regional study.

The aim of this study was to compare methicillin-resistant Staphylococcus aureus strains collected in eight hospitals located in the same region of France (Brittany) over a short period (January 1999-July 2000). Ninety-two isolates of methicillin-resistant S. aureus were characterised by their pulsotype and their antibiotype. Pulsotype analysis permitted the definition of three clusters. Two of them comprised 83% of the studied isolates. Phenotypic analysis showed two major antibiotypes, widespread in Brittany but with a heterogeneous geographic distribution and one antibiotype fitting the definition of glycopeptide intermediate S. aureus. These data argue for the high epidemicity of methicillin-resistant S. aureus among the same region.

[Antibiotics resistance of Streptococcus pneumoniae. Results from the Brittany registry for 1999]. / Etat de la résistance aux antibiotiques de Streptococcus pneumoniae dans la région Bretagne. Résultats de l'Observatoire Régional du Pneumocoque pour l'année 1999.

Throughout 1999, clinical microbiology laboratories of 13 hospitals in Brittany have recovered Streptococcus pneumoniae isolates in 832 patients, 312 (37.5%) female and 518 (62.2%) male. Two hundred fifty five of them (30.6%) were children. One hundred eighty eight isolates were recovered from blood cultures (22.6%), 16 from CSF (1.9%), 449 from lungs (54%), and 88 from ear exsudates (10.6%).A 5 microgram oxacillin-disk test was used to detect isolates with reduced susceptibility to penicillin G. Determination of MICs of penicillin G, amoxicillin and cefotaxime were then performed by agar dilution method on 402 strains previously categorized resistant or intermediate. Five hundred forty six isolates were PSDP, 33.5% of them were resistant to penicillin G, 2.2% to amoxicillin and 0.2% to cefotaxime. As expected, a decreased susceptibility to beta-lactamins was frequently associated with resistance to macrolides, cotrimoxazole and tetracycline. Among PSDP, the most prevalent serotypes were 23 (23.7%), 14 (23.5%) and 19 (19.1%). In Brittany, the constant rise of PSDP (1993-1994: 28.5%; 1997: 56.4%; 1999: 65.6 %) could be perhaps explain by analysis of social and demographic data.

[Bactec 9240: seeded volume of bottles of blood culture, impact on the results]. / Bactec 9240: volume d'ensemencement des flacons d'hémoculture, impact sur les resultats.

For 14 months, effects of volume on blood culture with Bactec 9240 are studied. Amongst the 1392 vials sending a signal out, 15.5% are false positive (FP). They stand out as such true positives by that very fact: negative subcultures, higher blood volumes, shorter time for detection, greater number of aerobic vials. Exclusively for FP, blood volume and detection delay are linked. In short, whatever the volume of culture may be, the prevalence of aerobic vial is observed with FP. The best volume of blood for the positive vials is 8 ml. Blood volume for each vial must be distinguished from whole culture volume of blood for each patient. If Bactec 9240 seems to be perfectible, for now, its optimum use should be septic discharge culture of about 30 blood milliliters shared out amongst 2 aerobic vials and 2 anaerobic vials, and incubation time should be kept at 7 days.

[Phenotypes of resistance to antibiotics of Acinetobacter baumannii. Impact on therapeutic orientation]. / Phénotypes de résistance aux antibiotiques des Acinetobacter baumannii. Incidence sur l'orientation thérapeutique.

By studying the sensitivity to antibiotics of 74 Acinetobacter baumannii strains, four phenotype groups were distinguished. The resistance of one of them (11% of the strains) to imipenem, argues against the therapeutic attitudes that now prevail. From studies on the kinetics of bactericidal activity of antibiotics and there association we propose what should be done in the laboratory to provide help to the physician for the antibiotic choice.

[Computer technology in the interpretation of aminoglycoside determinations]. / Apports de l'informatique dans l'interprétation des dosages d'aminosides.

Given the difficulty of interpreting the results of aminoglycoside determinations using current methods, we decided to use data processing in order to help practitioners in their prescriptions of these drugs. Our software has numerous advantages. Results can be interpreted even before obtention of the steady-state and whatever the interval between specimen taking and drug administration, which permit different modalities of blood sampling. Data storage enables the operator to make retroactive studies in order to establish better correlation between blood concentrations and side effects. This method gives practitioners the necessary pharmacological data for rapid adjustments in aminoglycosides dosage.

[Changes in the rheologic properties of various samples of blood preserved at +4 degrees C]. / Evolution des propriétés rhéologiques de différents types de sangs conservés à +4 degr'es C.

Apparent stationary viscosity, viscoelasticity and thixotropy measured with a Couette viscosimeter have been determined on blood samples stored in eight anticoagulant and/or preservative solutions. All the results as well as those obtained in a previous morphological study show clearly the advantages of the SAG or PAGGS storage processes. It is observed that the rheological parameters of RBC stored in protein poor media are, between the 30 th and 35 th days, identical on CPD at the first week and with that measured in CPD concentrates between second and third week (for a same hematocrit value). We want to emphasize that the erythrocytes stored in these new media retain for a long time their ability to circulate in the capillary system.