Comparison of Traditional Phenotypic Identification Methods with

Correct identification of nonfermenting Gram-negative bacilli (NFB) is crucial for patient management. We compared phenotypic identifications of 96 clinical NFB isolates with identifications obtained by 5 16S rRNA gene sequencing. Sequencing identified 88 isolates (91.7%) with>99 % similarity to a sequence from the assigned species; 61.5 % of sequencing results were concordant with phenotypic results, indicating the usability of sequencing to identify NFB. Nonfermenting Gram-negative bacilli (NFB) are ubiquitous in the environment and may cause opportunistic infections in immunocompromised patients and individuals with cystic fi-brosis (2, 9). Accurate diagnosis and appropriate treatment require species-specific identification of clinically significant NFB isolates. Conventional phenotypic identification may in-volve a number of methods, including observation of growth and colony morphology on various media, analysis of manual biochemical reactions, and the use of automated and nonau-tomated commercially available biochemical panels. Unfortu