Detection of Burkholderia pseudomallei DNA in patients with septicemic melioidosis

Septicemic melioidosis is the most severe form of melioidosis, which is caused by Burkholderia pseudomallei. It is endemic in Southeast Asia and is the leading cause of death from community-acquired septicemia in northeast Thailand. A major factor that contributes to the high mortality is the delay in isolation and identification of the causative organism. More than half of the patients die within the first 2 days after hospital admission, before bacterial cultures become positive. The present study was undertaken to develop a rapid diagnostic method for identification of this organism. A nested PCR system that amplified a part of 16S rRNA gene that was highly specific to B. pseudomallei was developed. This system was able to detect as few as two bacteria present in the PCR. DNAs from all 30 clinical isolates of B. pseudomallei and none of the other bacteria tested were amplified. The described PCR system has been employed for the detection of the organism in clinical specimens, including buffy coat and pus from internal organs. The detection of B. pseudomallei in buffy coat specimens by PCR was shown to be comparable to the detection of bacteria from blood cultures in septicemic melioidosis cases.