Detection of Chlamydia pneumoniae in clinical specimens by polymerase chain reaction using nested primers.

A nested primers strategy was used to develop a two-step PCR test for the direct species-specific detection of the 16s rRNA gene of Chlamydia pneumoniae. This test was applied to 58 nasopharyngeal or oropharyngeal swab specimens collected from patients in studies of community-acquired pneumonia and in a local outbreak of respiratory disease. Twelve patients (21%) showed evidence of Chlamydia pneumoniae infection in serological tests (7/56; 13%), culture (8/58; 14%) or PCR (10/58; 17%). Nested PCR but not single-step PCR was found to be as sensitive as culture or serology for detection of infection with this organism. In summary, nested PCR can be useful in direct testing of clinical specimens for Chlamydia pneumoniae, making additional DNA purification steps unnecessary.