Does bacteriology laboratory automation reduce time to results and increase quality management?

Due to reductions in financial and human resources, many microbiological laboratories have merged to build very large clinical microbiology laboratories, which allow the use of fully automated laboratory instruments. For clinical chemistry and haematology, automation has reduced the time to results and improved the management of laboratory quality. The aim of this review was to examine whether fully automated laboratory instruments for microbiology can reduce time to results and impact quality management. This study focused on solutions that are currently available, including the BD Kiestra™ Work Cell Automation and Total Lab Automation and the Copan WASPLab(®).

[International adoption and child psychological vulnerability]. / Adoption internationale et vulnérabilité psychologique de l'enfant.

Child psychiatry consultations specialised in filiation and international adoption help adopted children with psychological troubles and their adoptive parents. Regardless to this experience and to recent issues in the fields of attachment and narrativity, psychotraumatism and transcultural, some psychological risk factors for internationnally adopted children are described, requiring specialised psychological help.

[Pet-rat bite fever and septic arthritis: molecular identification of Streptobacillus moniliformis]. / Arthrite septique après morsure de rat: identification de Streptobacillus moniliformis par biologie moléculaire.

Pet-rat bite fever is a relatively rare disease consecutive to a rat bite or scratch. The authors report a case of septic arthritis following a pet rat bite. Streptobacillus moniliformis was identified in the knee synovial fluid and identified by 16S rRNA sequencing. This is a rapid and efficient tool for identification of fastidious bacterium. The patient was cured by an amoxicillin treatment.

[Screening for bacteriuria in diabetic patients. Is it possible to stop systematic urine cytobacteriological testing?]. / Dépistage des bactériuries à l'admission chez les patients diabétiques: peut-on abandonner les examens cytobactériologiques urinaires systématiques?

OBJECTIVES AND METHOD: The discordance between test by urine dipstick (nitrites and leucocyte-esterase) and analysis in laboratory, with urinary culture on the same sample was studied in diabetic patients, from October 2000 to May 2002, to eventually stop systematic laboratory test. The dipstick result (Clinitek 20 Bayer) was classified as "possibility of bacteriuria" if one of the two tests was positive. Bacteriuria was considered significant if the laboratory test result gave, at least 10(5) bacteria per mL, (one strain), and at least 10(4) leucocytes. The out point was the dipstick negative predictive value (NPV). RESULTS: The study included 683 patients. The dipstick result was "possibility of bacteriuria" in 153 cases (22.4%). Thirty-nine bacteriuria (5.7%) were reported, including 2 dipstick false negatives. The NPV was 99.6% [IC 95% : 99.1-100]. CONCLUSION: The systematic laboratory tests were stopped.

Nocardia ignorata, a new agent of human nocardiosis isolated from respiratory specimens in Europe and soil samples from Kuwait.

Nocardia ignorata is a recently described species identified on the basis of a single isolate of unknown origin. Here we describe the epidemiological, phenotypic, and phylogenetic characteristics of this new species, based on five new clinical and soil isolates.

A multigene approach to phylogenetic analysis using the genus Mycobacterium as a model.

Advances in DNA sequencing and the increasing number of sequences available in databases have greatly enhanced the bacterial identification process. Several species within the genus Mycobacterium cause serious human and animal diseases. In order to assess their relative positions in the evolutionary process, four gene fragments, from the 16S rRNA (564 bp), hsp65 (420 bp), rpoB (396 bp) and sod (408 bp) genes, were sequenced from 97 strains, including all available type strains of the genus Mycobacterium. The results demonstrate that, in this case, the concatenation of different genes allows significant increases in the power of discrimination and the robustness of the phylogenetic tree. The sequential and/or combined use of sequences of several genes makes it possible to refine the phylogenetic approach and provides a molecular basis for accurate species identification.

Pyrolysis-gas-liquid chromatography with atomic emission detection for the identification of Corynebacterium species.

We report here the application of pyrolysis-gas chromatography followed by atomic emission detection (AED) for the characterisation of microorganisms. AED measured the quantity of carbon, sulfur and nitrogen in the molecules separated chromatographically. Twenty-three strains, representing eight Corynebacterium species, were tested in this preliminary study. Co-ordinate principal analysis grouped 11 strains in their respective species group. Most of the other strains appear randomly distributed, perhaps because these strains require additional nutrients. These preliminary results show that the method could be used as a tool for the taxonomic and perhaps the epidemiologic characterisation of bacteria.

[Renal differential aging processes and ofloxacin pharmacokinetics in the elderly]. / Vieillissement différentiel rénal et pharmacocinétique de population de l'ofloxacine chez le sujet agé.

Ageing generates an important inter- and intra-individual variability in drug pharmacokinetics. The increasing frequency of ofloxacin adverse effects in elderly patients results from increased ofloxacin plasma levels about two or threefold over normal concentrations. A retrospective study of ofloxacin population pharmacokinetics in 17 elderly patients (83.6 +/- 6.8 years) shows the existence of three subgroups according to ofloxacin total clearance [group 1: 1.44 l/h, group 2: 4.37 l/h and group 3: 15.08 l/h] reflecting the important inter-individual variability. No correlation between this clearance and creatinine clearance, nor between this clearance and age, could be established, showing the limits of traditional drug monitoring in the elderly. Ofloxacin pharmacokinetic parameters estimated by the non-parametric software NPEM2 in the 17 elderly patients (absorption rate constant, Ka: 2.668 +/- 1.256 h-1; apparent volume of distribution related to weight, Vs: 1.272 +/- 0.778 l/kg; elimination rate constant, Ks: 0.265 +/- 0.247 10(-3) min/ml/h) are clearly different from those estimated in young adults. These results show the limits of classic drug monitoring in the elderly, and also the interest of adaptive control of a drug regimen.

[Post-antibiotic effect of three aminoglycosides against Klebsiella pneumoniae]. / Effet post-antibiotique de trois aminosides sur Klebsiella pneumoniae.

This paper introduces a new method to quantify post antibiotic effect. This method was applied to the study of the effect of three aminoglycosides antibiotics on seven strains of Klebsiella pneumoniae. The antimicrobial was removed by filtration, washing with peptone broth and neutralization by heparin. Growth curves were monitored by automated measurement of optical density with Urimat-ATB (bioMérieux). The inoculum fluctuation bias was eliminated with the help of a mathematical analysis of results. Absence of carry-over was controlled for each bacteria-antibiotic combination. A significant post antibiotic effect was observed with the three antibiotics after 2 hours exposure to a concentration equivalent to 2 x MIC. There was no significant difference between the 3 aminoglycosides tested.

[Comparative study of two systems for the determination of the sensitivity of yeasts to antifungal agents]. / Etude comparative de deux systèmes de détermination de la sensibilité des levures à quatre antifongiques.

One hundred yeast strains (including 60 Candida albicans) were tested in two laboratories using two different antifungal susceptibility test kits, ATB Fungus and Mycostandard. Tests were carried out under everyday work conditions. Four antifungal agents were compared: amphotericin B, flucytosine, miconazole, and ketoconazole. Results were discrepant in 19.2% (77/400) of cases. Following retesting of discordant cases with both kits, the agreement rate for strain characterization was 95.5%. Few discrepancies were seen with flucytosine. Conflicting results obtained with amphotericin B were due to poor reproducibility of Mycostandard results, especially for species other than C. albicans. In contrast, reproducibility of the ATB Fungus kit was inadequate for miconazole. The rate of discrepant results was greatest for ketoconazole. Intermediate susceptibility was seen more often with ATB Fungus for C. albicans and with Mycostandard for C. glabrata and C. krusei. The lack of reproducibility under routine working conditions should lead gallery manufacturers to strive to achieve clearer readings.

Preparation of a latex reagent for the detection of anti-Staphylococcus aureus ribitol teichoic acid antibodies.

Purified S. aureus ribitol teichoic acid was covalently bound to carboxylated latex particles. The immunological properties of the polysaccharide antigen were preserved. The reagent obtained was used for the quantification of anti-ribitol teichoic acid antibodies by means of a direct and rapid agglutination test carried out on a slide. There was good correlation between the preliminary results of this test and those obtained with counter-immunoelectrophoresis (CIE). The method is faster and more sensitive than CIE.

[Sensitivity to antibiotics of 64 strains of Stomatococcus mucilaginosus isolated in human clinical cases. Demonstration of erythromycin resistance]. / Sensibilité aux antibiotiques de soixante-quatre souches de Stomatococcus mucilaginosus isolées en clinique humaine. Mise en évidence d'une résistance à l'érythromycine.

Susceptibility to fifteen antibiotics of 64 stains of Stomatococcus mucilaginosus isolated from bronchial secretions was tested by susceptibility antibiotics diffusion and MIC method. Sixteen phenotypic profiles were determined by MIC. Some of these profiles and the spontaneous loss of resistance to erythromycin indicate plasmidic origin of this resistance.

[Use of an expert system as a tool to carry out urinary cyto-bacteriologic tests]. / Utilisation d'un système expert d'aide à la réalisation des examens cytobactériologiques urinaires.

An expert system for urine examinations was developed. Its validation was performed in a routine work, by comparison of expert decisions with software conclusions. Results of finished examinations or in progress were taken into account. The agreement was satisfactory. In addition to reliability, advantages constituted by availability, flexibility and adaptability were notified. Repeatability and reproducibility were also emphasized.

Study of Staphylococcus aureus teichoic acid immunodominant site by help of synthetic haptens.

The beta ribitol teichoic acid was extracted and purified from Staphylococcus aureus strain Wood 46 and chemically and immunologically characterised. Rabbit antiserum was prepared against formalin killed Staphylococcus aureus cells. Liquid phase immunoprecipitation of the beta ribitol teichoic acid-anti-Staphylococcus aureus serum system was studied by laser nephelometry. Various mono- and disaccharides (N-acetyl-glucosamine-ribitol with alpha- or beta-linkage and N-acetyl-glucosamine-ribitol-phosphate with beta-linkage) were prepared by organic synthesis, reproducing part of the ribitol teichoic acid molecule. Inhibition by those mono- or disaccharides of the precipitation of the beta-ribitol teichoic acid-Staphylococcus aureus antibodies system was studied quantitatively by determining inhibitory ratio of each inhibitor. Glucose, ribitol and glucosamine were weak inhibitors whereas N-acetyl-glucosamine was a better one, stronger than disaccharide with an alpha-linkage. The beta linked disaccharide and beta-methyl-N-acetyl-glucosamine gave comparable inhibition and both compounds were effective inhibitors. The most potent inhibitor was phosphorylated beta-linked disaccharide which inhibited 25% more than the same disaccharide without phosphorus. Thus, the function of phosphorus in Staphylococcus aureus beta ribitol teichoic acid recognition by antibodies was demonstrated.