MYCOPLASMA CONTAMINATION OF CHLAMYDIAE ISOLATED FROM CLINICAL SPECIMENS

Ten Chlamydia pneumoniae strains were screened for Mycoplasma contamin ation using two differently designed Mycoplasma-specific polymerase ch ain reactions (PCR). The primers of the Mycoplasma specific PCR design ed by Spaepen et al. (9) cross-reacted with all of the C. pneumoniae s trains giving false-positive results. When the 10 strains of C. pneumo niae were tested for mycoplasmas with the PCR designed by Harasawa et al. (5), only 3 were positive. Mycoplasmas were cultured from these th ree C. pneumoniae strains confirmning the latter PCR results. The PCR of Harasawa er al. (5) was highly specific for mycoplasmas and did not cross-react with C. pneumoniae. These findings suggest that chlamydia e should be periodically screened for Mycoplasma contamination. Carefu l attention to primer design is important if PCR is chosen as the scre ening method.