Biphasic Rapid Culture in Differential Diagnosis of Tuberculosis.

Abstract

Context: Early intervention and treatment are key measures for tuberculosis (TB) prevention and control, making early, rapid, and accurate diagnostic methods crucial. The Liquid-solid (Biphasic) rapid cultures is a novel tool for the differential diagnosis of tuberculosis.

Objective: The study intended to evaluate the value of the biphasic cultures by comparing it to the acid-fast staining and liquid cultures, which have been the traditional gold-standard technology, to determine its value in the diagnosis of TB.

Design: The research team conducted an experimental study.

Setting: The study took place at the Affiliated Wuxi Fifth Hospital of Jiangnan University in Wuxi, China.

Participants: Participants were 221 patients with suspected pulmonary tuberculosis who had been admitted to the hospital between July 2020 and December 2021.

Outcome measures: Using three methods-liquid-solid (biphasic) culture, acid-fast staining, and mycobacterial growth indicator tube (MGIT) 960 liquid culture, the research team tested participants' sputum samples: (1) for sensitivity; (2) for time to positive culture results, and (3) for differential diagnosis.

Results: The biphasic culture's sensitivity was significantly higher than that of acid-fast staining, (P = .0003), and no significant difference existed between it and the MGIT 960 liquid cultures. The biphasic cultures's mean time to positivity was significantly shorter than that of the MGIT 960 liquid culture at the intervals 11-20 d (P < .0001) and 21-35 days (P = .0001). Moreover, the biphasic cultures could preliminarily differentiate nontuberculous mycobacteria (NTM) from mycobacterium tuberculosis (MTB), which is a significant advantage in tuberculosis diagnosis.

Conclusions: This study highlights the potential of a biphasic culture as a reliable tool for the rapid differential diagnosis of tuberculosis, with a faster detection cycle and a higher sensitivity than conventional methods. The biphasic cultures is a valuable addition to the tuberculosis diagnostic armamentarium and can help improve patients' outcomes by enabling earlier diagnosis and treatments.