Detection of Mycobacterium ulcerans by real-time PCR with improved primers.
BACKGROUND
Buruli ulcer is a severe skin disease caused by Mycobacterium ulcerans. Real-time PCR targeting the IS2404 sequence has been used as a reliable and rapid method for the diagnosis of Buruli ulcer and detection of M. ulcerans in the environment. The genome of M. ulcerans contains hundreds of IS2404 copies, which have variability in certain sequences. Therefore, the design of new primers specific to conserved IS2404 regions may potentially improve the sensitivity of M. ulcerans detection and, consequently, the diagnosis of Buruli ulcer, thus ensuring timely treatment of the disease.


RESULTS
In silico analysis indicates that DNA sequences of the IS2404 elements are highly variable within a single strain. As the binding sites of conventional IS2404-specific primers used for M. ulcerans detection contain polymorphic sequences, we designed new primers, which enabled the detection of M. ulcerans by real-time PCR with higher sensitivity and similar specificity with respect to that of conventional primers. However, the increase in sensitivity with the new primers depended on the M. ulcerans strain.


CONCLUSIONS
The results suggest that real-time PCR based on the new primers could improve Buruli ulcer diagnosis and M. ulcerans detection in environmental samples.
Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641 Japan.
Noriko
N
Shinoda
Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association, 3-1-24 Matsuyama, Kiyose, Tokyo 204-8533 Japan.
Hajime
H
Nakamura
Graduate School of Infection Control Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641 Japan ; Kitasato Institute for Life Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641 Japan.
Mineo
0000-0003-4259-3353
M
Watanabe
Buruli ulcer; Diagnosis; Mycobacterium ulcerans; Real-time PCR