APPLICATION OF A NESTED, MULTIPLEX PCR TO PSITTACOSIS OUTBREAKS

We developed a nested, multiplex PCR for simultaneous detection of thr ee species of chlamydiae in human and avian specimens, The PCR was des igned to increase sensitivity and to circumvent inhibitors of PCR pres ent in clinical specimens. The target sequence was the 16S rRNA gene, The first-step PCR was genus specific, and the second step PCR was mul tiplexed (i.e., had multiple primer sets in the same tube) and could d iscriminate among Chlamydia pneumoniae, Chlamydia psittaci, and Chlamy dia trachomatis on the basis of the molecular weight of the amplicon. The limit of detection of each of the two PCR steps was 5 inclusion-fo rming units, We used PCR and serologic evidence during outbreaks of ps ittacosis to infer that C. psittaci had been transmitted from birds pu rchased in pet stores to humans, We also used this method to test both live and dead birds from pet stores for infection with C. psittaci. C ompared with culture, the application of PCR to avian specimens increa sed the rate of C. psittaci detection.