Recovery of Bordetella pertussis from PCR-positive nasopharyngeal samples is dependent on bacterial load.

Viable Bordetella pertussis isolates are essential for surveillance purposes. We performed culture of 223 PCR-positive nasopharyngeal samples. B. pertussis was recovered from 45 (20.2%) of the samples. Growth was associated with a high bacterial load, as determined by PCR. Culture from PCR-positive samples is a feasible approach to recover B. pertussis isolates, and culture can be limited to samples with a high bacterial load.