Evaluation of the new VITEK 2 NH identification card

Abstract number: 1733_1216

Valenza G., Ruoff C., Vogel U., Frosch M., Abele-Horn M.

Objectives: The purpose of this study was to evaluate the ability of the new VITEK 2 NH card (bioMérieux, Nürtingen, Germany) to identify fastidious Gram-negative bacteria in comparison to reference methods.

Methods: A total of 149 strains belonging to the species listed in the data base of the VITEK 2 software were investigated, including Neisseria spp., Haemophilus spp., Campylobacter spp., Capnocytophaga spp., Cardiobacterium hominis, Eikenella corrodens, Gardnerella vaginalis, Kingella denitrificans, and Moraxella catarrhalis. Thirty-one strains were originated from the strain collection of the German National Reference Centre for Meningococci (NRZM), from the American Type Culture Collection (ATCC), and from the German Collection of Microorganisms and Cell Culture (DSM). The remaining 118 strains were own clinical isolates, which previously had been identified by API NH system or other conventional methods. The new VITEK 2 NH cards were used according to the manufacturer's recommendations. The cards were filled with organism suspensions made in 0.45% aqueous NaCl to turbidity equivalent to a McFarland #3 standard. Identification results were generated by a computer-assisted algorithm. In the case of conflicting results, 16S rRNA gene sequencing (16 S) method was used for genetic identification.

Results: The new VITEK 2 NH card was able to identify 142 (95%) strains to the genus level and 138 (92.7%) strains to the species level. Six (4%) strains were misidentified and five (3.3%) strains could not be identified. 19 of 21 pathogenic Neisseria isolates were correctly identified.

Conclusion: The new VITEK 2 NH card appears to be a useful method for the identification of fastidious Gram-negative bacteria and seems to be an improvement over the conventional diagnostic methods of some fastidious microorganisms. More work is needed to finally evaluate the performance of VITEK 2 with regard to pathogenic Neisseria.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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