Evaluation of the new Vitek 2 GN card for the identification of gram-negative bacilli frequently encountered in clinical laboratories.

The new Vitek 2 GN card (bioMérieux, Marcy-l'Etoile, France) was developed for better identification of fermenting and nonfermenting bacilli. This new card allows the identification of 159 taxa. A total of 426 isolates (331 fermenting and 95 nonfermenting gram-negative bacilli) belonging to 70 taxa covered by the database were evaluated. All isolates were identified in parallel with the ID 32 GN, the API 20E, and the API 20NE methods. The system correctly identified 97.4% (n=415) of the strains. Only 2.1% (n=9) needed additional testing. One strain (0.25%) was misidentified (Klebsiella pneumoniae subsp. pneumoniae), and another one (0.25%) was not identified (Morganella morganii subsp. morganii). The new GN card gives more accurate identifications overall for gram-negative bacilli when compared to the systems described in other similar studies.

[Rhône-Alpes observatory of Streptococcus pneumoniae in 1999: 35 cases of meningitis]. / Observatoire Rhône-Alpes du pneumocoque en 1999: 35 cas de méningites.

In 1999, in Rhône-Alpes region, in a survey of resistance to antibiotics of Streptococcus pneumoniae, 35 cases of meningitis were observed. A retrospectic questionnary was sent to each participant. MICs to Penicillin, Amoxicillin and Cefotaxime were determined with ATB-PNEUMO gallery or E-test and by disk diffusion for the other antibiotics. The results were interpreted according to the recommendations of the CA-SFM. Mean age was 38.1 years (range : 1 month -78 years) and sex-ratio 2/5. Eight patients had previously received antibiotics, 22 patients had risk factors and 23 were transferred in intensive care unit. The patients received C3G + glycopeptide in 15 of 16 children and in 13/19 adults according to the consensus recommendations. Diagnostic was made on the direct examination of CSF in 83%, and blood cultures was positive in 74.3% of cases. The percentage of PRP was 48.6% with 17.1% of intermediate-amoxicilline and 14.3% intermediate-cefotaxime strains. Resistance to trimethoprim-sulfamethoxazole was 45.7%, to chloramphenicol 30% and to fosfomycin 6.9%. All the strains were susceptible to rifampicin and vancomycin. Among the 17 PRP strains, 7 were belonging to serotype 6 (6 in children). The clinical outcome was fatal in 7 male cases (20%), without risk factors in 3 children and 6 of 7 strains were susceptible to penicillin. Six patients (17%) had auditive and/or neurologic sequellaes. This study shows that nearly 50% of strains isolated in meningitis, in Rhône-Alpes region, were not susceptible to penicillin, and confirms the frequency of sequellaes while the mortality is not related with the resistance of strains to the antibiotics.

[Evaluation of the E-test and the ATB-PNEUMo battery for determining the beta-lactam MIC for Streptococcus pneumoniae in daily practice]. / Evaluation du E-test et de la galerie ATB-PNEUMo dans la détermination des CMI aux bêtalactamines de Streptococcus pneumoniae en pratique quotidienne.

In 1999, during the survey of resistance of Streptococcus pneumoniae to antibiotics by 31 clinical laboratories of Rhône-Alpes area, MIC to penicillin (P), amoxicillin (AMX) and cefotaxime (CTX) of 877 PRP strains or with a diameter of inhibition to oxacillin inferior to 26 mm, were determined by each institution by E-test (n = 220 strains) or ATB-PNEUMO (n = 657 strains). MICs of these three antibiotics were determined by dilution in agar medium by the coordinating center. The essential agreement was respectively for ATB-PNEUMO and E-test 89% versus 84% for P (p > 0.05), of 86% vs 79% for AMX (p < 0.01), and of 91% vs 86% for CTX (p = 0.03). When the strains were classified in clinical category, the differences were significant (p < 0.001) for AMX (85% vs 71%) and for CTX (82% vs 75%) but not for P (73% vs 78%). ATB-PNEUMO method was more sensitive than E-test for the detection of strains susceptible to P (90 vs 73%), to AMX (83 vs 78%) and to CTX (80 vs 72%) and for the strains intermediate to AMX (90 vs 78%). On the contrary, E-test is more specific than ATB-PNEUMO for the detection of P-resistant strains (94 vs 86%). Finally, the specificity of both methods is the same for detection of P-S, AMX-R and CTX-I strains.

[Evaluation of enzymuria as a tracer in nephrotoxicity: results of a multicenter study]. / Evaluation de l'enzymurie comme marqueur de néphrotoxicité: résultats d'une expérience multicentrique.

Urinary excretion of three enzymes of different subcellular location in kidney tissue, alanine aminopeptidase (AAP), gammaglutamyltransferase (GGT), N acetyl-beta-D glucosaminidase (NAG), was carried out in 79 healthy adults and 108 healthy children and in 69 adults with various therapies: antibiotics (32 cases), non steroidal anti-inflammatory drugs (NSAIDs) (22 cases), cisplatinum (12 cases) and cyclosporine (3 cases). A circadian rhythm has been shown in children. In patients treated with antibiotics, the importance and duration of the increased enzymes urinary excretion were variable but the excretion of AAP was always higher than that of GGT and NAG. Short term therapies by NSAIDs were without influence on enzymuria but long term therapies produced a moderate increase of NAG excretion. Enzymuria increased immediately after cisplatinum administration and decreased after each daily dose, except in patients with previously high creatininemia. Cyclosporine induced a slight increase in AAP and NAG excretion. Enzymuria, thus, increased early reflecting a toxic effect of the drug at the cellular level whereas creatininemia increase, marker of renal fonctionnal insufficiency, occurs only occasionally and lately.

[Enzymuria]. / Enzymurie.

Study of enzymuria rises more and more interest in human pathology as a diagnosis parameter of renal diseases or as an index of nephrotoxicity. In this two fields, the literature demonstrated the interest of enzymes of the brush border of proximal tubuli (alanine amino peptidase, gamma glutamyl transpeptidase, alkaline phosphatase) and of lysosomal enzymes (beta glucuronidase and N acetyl beta D glucosaminidase). The authors analyse the problems limiting the present use of these methods: incomplete knowledge of enzyme of the different parts of the renal tissue and of the mechanisms of enzymuria (choice of enzymes and time periods for sampling); analytical problems referring to the study of enzymes in a complex medium (treatment and storage of samples, choice of adapted methods for activity measurement); at last the way of expression the results is still to be defined.