Transrenal DNA detection of Mycobacterium tuberculosis in patients with pulmonary tuberculosis

Background: Multiple attempts have been made to use biological samples other than sputum to diagnose tuberculosis (TB). Sputum acid-fast bacillus (AFB) microscopy is the fastest, most straightforward, and most inexpensive method for diagnosing pulmonary TB. However, urine can be used in place of sputum owing to its various advantages, such as a noninvasive method of collection, convenient handling and storage, and minimal risk of infection in health-care workers involved in sample collection. In this study, we aimed to assess the suitability of urine as a sample to obtain transrenal DNA (trDNA) to diagnose TB. This study involved several patients with TB undergoing inpatient treatment, whose AFB microscopy showed negative inversion. Methods: Here, 51 urine samples were collected from 40 patients with TB and examined to confirm the presence of trDNA. First, we compared the efficiency of two trDNA extraction methods: An automated magnetic bead-based method and a more efficient anchoring extraction method. Statistical analyses were performed using Excel software (Microsoft Office Professional Plus 2019). Results: Although molecular diagnosis using GeneXpert yielded negative results, a peculiarity was observed. There was no significant difference between GeneXpert findings and our results nor was there any difference in the sequential trDNA samples obtained. However, even when GeneXpert results were negative, trDNA was detected in seven out of ten samples using the anchor extraction method. Conclusions: Further studies are needed to establish biomarkers for the progression of TB treatment.