A multiplex nested PCR for the simultaneous detection of Salmonella typhi, Mycobacterium tuberculosis, and Burkholderia pseudomallei in patients with pyrexia of unknown origin (PUO) in Vellore, South India.

BACKGROUND AND

OBJECTIVES

Salmonella typhi, Mycobacterium tuberculosis, and Burkholderia pseudomallei are among the most important monocyte-tropic bacterial agents causing pyrexia of unknown origin (PUO), with a significant number of endemic infections in both South and Southeast Asian regions. These infections pose a major risk to travelers to these regions as well.

METHODS

We developed and evaluated a multiplex nested polymerase chain reaction (PCR) for the simultaneous detection of the three pathogens in 305 patients' buffy coat samples.

RESULTS

The assay for S. typhi and B. pseudomallei was able to detect down to 1 colony forming unit/5 μL PCR input and M. tuberculosis was detected down to 20 genome copies/5 μL PCR input. S. typhi was detected in 10 (3.3 %) individuals, B. pseudomallei in 10 individuals (3.3 %), and M. tuberculosis in 18 individuals (5.9 %). Co-infections of M. tuberculosis and B. pseudomallei were detected in three individuals and S. typhi and B. pseudomallei in two individuals.

CONCLUSION

This protocol is efficient for PUO diagnosis especially in Asian countries.