Analysis of the detection efficacy of Xpert MTB/RIF, Lowenstein–Jensen medium culture, and fluorescence smear microscopy methods for Mycobacterium tuberculosis diagnosis

Abstract

Objectives: Tuberculosis (TB) remains a major global health threat, necessitating accurate, rapid, and cost-effective diagnostic methods to improve early detection and control of the disease. The traditional methods for detecting Mycobacterium tuberculosis (MTB) in clinical testing are fluorescence smear microscopy (FSM) and Lowenstein–Jensen medium culture (LJMC) methods. With the development of molecular diagnostics, the Xpert MTB/rifampicin assay (Xpert) has become increasingly used. This study compared Xpert with traditional FSM and LJMC using sputum specimens to study the application value in the diagnosis of TB.

Methods: A total of 342 examination reports were included. Sputum samples from all study subjects were tested using FSM, LJMC, and Xpert methods.

Results: The Xpert method showed a significantly higher positive rate than FSM, and a slightly higher rate than LJMC.

Conclusion: Among all sputum samples from suspected or confirmed TB patients, Xpert detected all cases that were positive by FSM, while both Xpert and LJMC missed positives found by each other. FSM also detected a small number of positives not detected by LJMC. Overall, Xpert had the highest positive detection rate, and FSM the lowest. Although FSM is the fastest and least expensive (costing only one-seventh of Xpert), it demonstrated the lowest sensitivity, with its positive rate being roughly half that of Xpert or LJMC.

Keywords

Acid-fast bacilli / Fluorescence smear microscopy / Lowenstein–Jensen medium culture / Mycobacterium tuberculosis / Rifampicin resistance / Xpert Mycobacterium tuberculosis/Rifampicin assay

Acknowledgements

None.

Funding

This work was funded by Hefei Municipal Health Commission of Anhui Province of China (Grant No. Hwk2022zc051), the Yangtze River Delta Science and Technology Innovation Community Joint Basic Research Project of China (Grant No. 2024CSJZN1200), and the National Natural Science Foundation of China (Grant No. 82300261).

Conflict of interest

The authors declare no competing interests.

Author contributions

Conceptualization : Ying Dong, Yu Huang

Formal analysis: Xiaodan Zha, Lunshan Lu, Ying Wang, Yu Huang

Investigation: Ying Dong, Changcheng Zhao, Xiaodan Zha, Chun Liu, Yu Huang

Methodology: Ying Dong, Lunshan Lu, Yu Huang, Frankliu Gao

Writing–original draft: Ying Dong, Chun Liu, Yu Huang, Frankliu Gao

Writing–review & editing: Yu Huang

Ethics approval and consent to participate

This study was approved by the Ethics Committee of the First Affiliated Hospital of University of Science and Technology of China (USTC) (2024KY-384).

Consent for publication

Not applicable.

Availability of data

The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.

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