Molecular detection of Burkholderia pseudomallei in patients with suspected pulmonary and extra pulmonary tuberculosis.

Objectives: Since melioidosis mimics tuberculosis clinically and radiologically, there is a need for a rapid diagnostic method to help the clinician to initiate appropriate antimicrobial treatment in order to prevent mortality. Our objective was to standardize a nested PCR for B. pseudomallei and its detection in pulmonary and extra pulmonary samples from patients with suspected TB. Materials and Methods: Archived pulmonary and extra pulmonary samples which were negative for M. tuberculosis smear microscopy, culture and PCR were included in the study. DNA was extracted (QiAmp Blood DNA kit, Qiagen, Germany) and conventional nested PCR were carried out to detect the presence of 16S-23S spacer region of B. pseudomallei. The DNA was detected by 2% agarose gel electrophoresis and the presence of 251 bp was considered positive. Results: A total of 55 samples were tested, out of which 9 (16.3%) samples tested positive for Burkholderia pseudomallei using nested PCR, which included 5 extra pulmonary and 4 pulmonary samples. These patients belonged to Tamil Nadu 8 (88.8%) and West Bengal 1 (11.1%) both of which are rice growing regions. Among the nine patients who were positive for B. pseudomallei by nested PCR, 2 (22%) were receiving empirical anti-tubercular treatment (ATT). Also, these patients encountered co-morbid condition like renal failure, malignancy, diabetes and co-infection with HIV. Conclusion: We suggest that the patients with symptoms suggestive of both pulmonary and extra pulmonary tuberculosis should be routinely tested for Burkholderia pseudomallei by molecular methods for timely initiation of appropriate therapy and avoid unnecessary exposure to ATT. J Microbiol Infect Dis 2017; 7(1): 21-28