Comparison of active and dormant Mycobacterium tuberculosis DosR/DevR regulon polymerase chain reaction-restriction fragment length polymorphism patterns.

INTRODUCTION

This retrospective cross-sectional study aimed to evaluate the differences between the restriction fragment length polymorphism (RFLP) patterns of the dormancy survival regulator (DosR) regulon in latent tuberculosis vs active disease.

METHODS

Sputum samples from 90 patients with active Mycobacterium tuberculosis infection were collected. The presence of the devR, devS, and dosT genes in active and induced dormant M tuberculosis infection was evaluated using polymerase chain reaction (PCR). In addition, the differences between the restriction enzyme digestion of these genes were determined using the RFLP method.

RESULTS

The devR gene was much more prevalent in dormant than in active samples, with statistical significance set at P = .033. The PCR-RFLP patterns obtained from the effect of the AciI endonuclease on devR, the EaeI and HincII endonucleases on devS, and the HaeIII and AciI endonucleases on dosT showed a statistically significant difference between the active and dormant groups (P = .001, P = .01, P = .008, P = .001, and P = .001, respectively), and this difference was associated with more diverse patterns in the active group.

DISCUSSION: Results suggested that the DosR regulon may have more nucleotide variations at the active stage. This study is the first to investigate the devR, devS, and dosT genes using PCR-RFLP as a cost-effective and straightforward method.