Comparison of Bordetella species identification among differing rt-PCR assays in the United States

Abstract

When testing specimens collected from patients with suspected pertussis, large-scale commercial laboratories in the United States employ an IS 481 -based assay that cannot differentiate between Bordetella pertussis and Bordetella holmseii . The level of B. holmesii causing pertussis-like illness in the United States is not well-understood given that only B. pertussis is nationally notifiable. After re-testing with a multiplex, species-specific rt-PCR assay, our data show low levels of B. holmesii identified in a sample of IS 481 -positive clinical specimens originally identified by commercial laboratory rt-PCR assays. These results reinforce the validity of large-scale commercial rt-PCR testing as a reliable diagnostic tool for pertussis in the United States.