[The ground visual field assessment, using two methods, compared with Goldmann perimetry]. / Évaluation du champ visuel au sol, selon deux méthodes, comparée avec le champ visuel de Goldmann. Validation de l'évaluation du champ visuel au sol.

In visual rehabilitation, ground visual field assessment (GVFA) makes it possible to assess the size of scotomas in connection with locomotion and to restore the width of the patient's visual field (VF). The information obtained by these tests has never been compared with Goldmann testing. The purpose of this study was to assess the reproducibility of VF measurement under different conditions (Goldmann perimetry, manual and automated GVFA). Ten patients (51.4±14.0 years, 4 men and 6 women) with tunnel fields inferior or equal to the central 25°, performed three different versions of a binocular VF assessment: Goldmann perimetry, manual GVFA, and automated GVFA. The two versions of the GVFA were performed at 1m then 5m from the patient on the ground, and finally 5m away from the patient at eye level, facing the patient. The main outcome was the total perceived surface for each test. The reproducibility of the measurement was average or good for the test at 1m (ICC=0.685 to 0.866). Conversely, it was very poor between the tests at 5m, except for the automated and manual GVFA at 5m on the ground (ICC=0.888). This study shows good reproducibility of the GVFA measurements at 1m with less reproducibility at 5m, which can be explained by difficulties in the execution of the GVFA. Among the tests, the automated GVFA appears to be more reliable than the manual GVFA and is preferred by patients.

Distribution of mutation frequencies among Salmonella enterica isolates from animal and human sources and genetic characterization of a Salmonella Heidelberg hypermutator.

Hypermutation is an important mechanism used by different Salmonella enterica subspecies enterica to regulate genetic stability in adaptation to changing environments, including antimicrobial treatments and industrial processes. Strong hypermutator strains generally contain a mutation in genes of the methyl mismatch repair (MMR) system and have mutation frequencies up to 1000-fold higher than wild type strains. The objectives of this study were to determine the distribution of mutation frequencies from a collection of 209 Salmonella strains, to genetically characterize a strong mutator, and to study MMR mutated protein-DNA binding interactions. Only one strain of S. Heidelberg was determined to have a hypermutator phenotype by virtue of its high mutation rate. Sequencing of genes of the MMR system showed a 12bp deletion in the mutS gene was present. The MMR mutated protein-DNA binding interactions were studied by bioanalysis, using the available crystal structure of a similar MutS protein from Escherichia coli. This analysis showed the small deletion in the Salmonella MutS was localized within the core domain. A retardation assay with MutS from hypermutable and wild type strains showed this mutation has no effect on MutS DNA binding. A better understanding of the genetic mechanisms of hypermutation will help to anticipate the behavior of hypermutator strains in various conditions.

[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.

Use of high-performance liquid chromatography (HPLC) to monitor beta-lactam plasma concentrations during the treatment of endocarditis.

Guidelines recommend high doses of beta-lactams for the therapy of endocarditis. This report describes a retrospective study of 15 endocarditis patients (median age 64 years), treated according to guidelines, whose beta-lactam trough plasma concentrations were measured with high-performance liquid chromatography because of tolerance or efficacy concerns. For amoxycillin, the mean level was 86.8 mg/L (range: 30-212 mg/L); five (45%) patients had concentrations > 1000 x MIC. For cloxacillin, the mean level was 47.9 mg/L (range: 16.7-104 mg/L). The consequences of high and unpredicted beta-lactam trough plasma concentrations for a prolonged period have not yet been thoroughly evaluated.

[Human pasteurellosis: diagnosis, treatment and precautions]. / Le diagnostic, le traitement et la prévention des pasteurelloses humaines.

The circumstances of diagnosis of human pasteurellosis are reviewed. The diagnosis is usually suspected for animal bite or scratch wounds. Conversely, in other infections the diagnosis is only based on bacteriological data. Phenotypic misidentification of Pasteurellaceae from clinical material is common. The phenotypic criteria of identification of the six species of human pathogen Pasteurella are presented. We emphasise that bite wound specimens have to be cultured for aerobic and anaerobic bacteria and yield an average of 5 bacterial isolates per culture. Antibiotic therapy relies upon amino-penicillins or cephalosporins, although b-lactamase producing strains are scarce. Fluoroquinolones can be an alternative for systemic infections. Molecular typing unequivocally points out the risk of transmission from pets to humans. Immunocompromised persons have to be made aware of precautions.

[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.

[Comparative study of the bacteriostatic and bactericidal activity of levofloxacin against Pasteurella strains isolated from man]. / Etude comparative de l'activité bactériostatique et bactéricide de la lévofloxacine vis-à-vis des souches de Pasteurella isolées chez l'homme.

The MICs of seven quinolones, nalidixic acid, pefloxacin, ofloxacin, d-ofloxacin, ciprofloxacin, sparfloxacin and levofloxacin, were determined by agar dilution method comparatively to those of amoxycillin, cefpodoxime, doxycyclin and clarithromycin against 75 clinical isolates of Pasteurella multocida, P. dagmatis and P. canis. Time-kill method was performed for three selected P. multocida isolates. Fluoroquinolones were the most active agents. At concentration of 0.016 mg/L of sparfloxacin or levofloxacin the 75 isolates were inhibited. The MICs of levofloxacin and sparfloxacin showed that the activity of these molecules was two to four times higher than that of the other quinolones studied. Time-kill studies showed a complete killing in six hours with the CMI x 2 of pefloxacin, ofloxacin, ciprofloxacin, sparfloxacin and levofloxacin. This result was obtained more rapidly with the quinolones than with amoxicillin or cefpodoxime. Doxycycline and clarithromycin were devoid of bactericidal activity.