[Rapid detection of Mycoplasma pneumoniae in clinical samples by the polymerase chain reaction technique]

The polymerase chain reaction (PCR) technique was used to detect Mycoplasma pneumoniae in clinical samples (bronchoalveolar lavage fluids and throat swabs). A specific DNA sequence for M. pneumoniae was selected from a genomic library. The amplification target region was partial DNA sequence of the 500- bp fragment. The oligonucleotide sequence of two primers (MP5-1 and MP5-2) were complementary with the oligonucleotide sequence in two ends of the amplification target region. PCR with purified DNA fragment as templates yielded an expected 144-bp fragment from M. pneumoniae but not from any of the other Mycoplasma spp. assayed. With this method, the 144-bp product specific for M. pneumoniae could be obtained from a minimum of 10 pg of M. pneumoniae DNA. Subsequently this PCR technique was used for the detection of M. pneumoniae in bronchoalveolar lavage fluids or in throat swab samples. Thirty of 140 samples from the patients with non-bacterial pneumonia gave positive results in the test. Twenty-one indirect hemoagglutination test-negative clinical samples from the same patients of 140 cases gave positive results in the same PCR test. When the amplified products were hybridized with a complementary probe (MP5-4 oligonucleotide probe), thirty PCR-positive samples all gave positive hybridization signals. It suggests that PCR method can be used for the direct detection of M. pneumoniae in clinical samples.