MYCOPLASMA CONTAMINATION OF CHLAMYDIA-PNEUMONIAE ISOLATES

We examined 6 C. pneumonia isolates from The American Type Culture Col lection (ATCC) and 2 Finnish isolates for Mycoplasma contamination. Th ree of the ATCC isolates and both of the Finnish isolates were Mycopla sma-contaminated. The contaminants were characterized by means of grow th in BEa and BEg media, immunoblotting, polymerase chain reaction and pulsed field gel electrophoresis. Tao of the 6 ATCC isolates [ATCC VR 1355 (TWAR strain 2043) and ATCC VR1356 (TWAR strain 2023)] were infec ted with Mycoplasma hominis and 1 isolate [ATCC VR2282 (TWAR strain TW 183)] was contaminated with both Mycoplasma hominis and Mycoplasma ora le, whereas 3 of the ATCC isolates [ATCC VR1310, ATCC VR1360 (TWAR str ain CM-1) and ATCC 53592 (TWAR strain AR39)] were not contaminated. Th e Finnish C. pneumoniae isolates Kajaani 6 and Parola were found to be contaminated with M. hominis and M. orale, respectively. The contamin ation of C, pneumoniae stock cultures, frequently used in the microimm unofluorescence test, with human pathogens, could pose a serious probl em in C. pneumoniae serology.