Sequence-based identification of gram negative nonfermenters using commercial 16S rDNA databases

This poster presents a study assessing the validity of the databases from two commercial systems were compared for the identification of NF. Background: Identification of gram negative nonfermenters (NF) from cultured human specimens is often difficult using traditional phenotypic methods. Partial 16S rDNA sequencing to identify NF depends on the completeness of the comparative database. Public databases lack quality control, but are routinely updated as sequences are published. Commercial databases are often incomplete and lack routine updates. In this study, the validity of the databases from two commercial systems were compared for the identification of NF. Methods: 100 NF clinical isolates identified by phenotypic methods were included. The 16S rDNA sequence for the first 500 bases was determined for each isolate. Consensus sequences were compared to the MicroSeq500 (Applied Biosystems) and Virodec (Roche Diagnostics) databases.