COMPARISON OF NASOPHARYNGEAL ASPIRATES AND THROAT SWAB SPECIMENS IN APOLYMERASE CHAIN REACTION-BASED TEST FOR MYCOPLASMA-PNEUMONIAE

Nasopharyngeal aspirates and throat swab specimens were compared in a polymerase chain reaction (PCR)-based test for Mycoplasma pneumoniae. The pathogen was detected in 50 % and 45 % of throat swab specimens an d aspirates, respectively, However, in specimens negative for Mycoplas ma pneumoniae by PCR, amplification inhibitors were detected in 0 % an d 36 % of throat specimens and aspirates, respectively. Further invest igations confirmed that no throat specimens, but one-quarter of aspira tes, are likely to be rejected for containing inadequate respiratory m aterial or excess amplification inhibitors. Because rejection of most of the unsuitable specimens is possible only after PCR, the use of asp irates is less cost-effective. This, and the reluctance to subject pat ients to aspiration, make the aspirate an inferior specimen for detect ion of Mycoplasma pneumoniae by PCR.