Polymerase chain reaction assay for pertussis: simultaneous detection and discrimination of Bordetella pertussis and Bordetella parapertussis.

A polymerase chain reaction (PCR) assay which allows the simultaneous detection and discrimination of the two causative agents of pertussis, Bordetella pertussis and Bordetella parapertussis, was developed. Primer pairs were based on insertion sequence elements IS481 and IS1001. IS481 is specific for B. pertussis and is present in about 80 copies per cell, while IS1001 is specific for B. parapertussis and is found in 20 copies per cell. An internal control was included in the PCR assay to monitor the performance of the PCR and to identify possible inhibitory components in clinical samples. Discrimination of amplified DNA derived from the internal control, B. pertussis, or B. parapertussis was accomplished by differential spacing of the primers. The sensitivity of the combined PCR method was found to be very high and allowed the detection of one cell of either pathogen. The usefulness of the method was investigated by using a limited number of clinical samples derived from patients with serologically proven pertussis.