Comparison of three commercial test systems for biotyping Haemophilus influenzae and Haemophilus parainfluenzae.

The biotypes of Haemophilus influenzae and Haemophilus parainfluenzae isolates were determined with three commercially available biochemical test kits: the IDS RapID NH system, the Neisseria-Haemophilus identification test (NHI card), and the API NH strip. The API NH strip performed best, correctly classifying the biotypes of 371 of 380 (97.6%) different challenge strains.